SEC Info  
    Home      Search      My Interests      Help      Sign In      Please Sign In

Ecovyst Inc. – ‘10-K’ for 12/31/23 – ‘EX-101.SCH’

On:  Thursday, 2/29/24, at 4:02pm ET   ·   For:  12/31/23   ·   Accession #:  1708035-24-70   ·   File #:  1-38221

Previous ‘10-K’:  ‘10-K’ on 2/28/23 for 12/31/22   ·   Latest ‘10-K’:  This Filing   ·   18 References:   

Find Words in Filings emoji
 
  in    Show  and   Hints

  As Of               Filer                 Filing    For·On·As Docs:Size

 2/29/24  Ecovyst Inc.                      10-K       12/31/23  167:20M

Annual Report   —   Form 10-K   —   SEA’34

Filing Table of Contents

Document/Exhibit                   Description                      Pages   Size 

 1: 10-K        Annual Report                                       HTML   3.70M 
 2: EX-21.1     Subsidiaries List                                   HTML     50K 
 3: EX-23.1     Consent of Expert or Counsel                        HTML     42K 
 4: EX-23.2     Consent of Expert or Counsel                        HTML     41K 
 9: EX-97.1     Clawback Policy re: Recovery of Erroneously         HTML     55K 
                Awarded Compensation                                             
 5: EX-31.1     Certification -- §302 - SOA'02                      HTML     47K 
 6: EX-31.2     Certification -- §302 - SOA'02                      HTML     47K 
 7: EX-32.1     Certification -- §906 - SOA'02                      HTML     44K 
 8: EX-32.2     Certification -- §906 - SOA'02                      HTML     44K 
15: R1          Cover                                               HTML    110K 
16: R2          Audit Information                                   HTML     47K 
17: R3          Consolidated Statements of Income                   HTML    175K 
18: R4          Consolidated Statements of Comprehensive Income     HTML     79K 
                (Loss)                                                           
19: R5          Consolidated Balance Sheets                         HTML    154K 
20: R6          Condensed Consolidated Balance Sheets               HTML     64K 
                (Parenthetical)                                                  
21: R7          Consolidated Statements of Stockholders? Equity     HTML    120K 
22: R8          Consolidated Statements of Cash Flows               HTML    174K 
23: R9          Consolidated Statements of Stockholders? Equity     HTML     44K 
                (Parenthetical)                                                  
24: R10         Background and Basis of Presentation                HTML     49K 
25: R11         Summary of Significant Accounting Policies          HTML    106K 
26: R12         New Accounting Standards                            HTML     61K 
27: R13         Divestitures                                        HTML    110K 
28: R14         Revenue from Contracts with Customers               HTML    105K 
29: R15         Fair Value Measurements                             HTML     72K 
30: R16         Stockholders' Equity                                HTML    149K 
31: R17         Other Operating Expense, Net                        HTML     58K 
32: R18         Inventories, Net                                    HTML     56K 
33: R19         Investments in Affiliated Companies                 HTML     79K 
34: R20         Property, Plant and Equipment                       HTML     55K 
35: R21         Leases                                              HTML    146K 
36: R22         Reportable Segments                                 HTML    131K 
37: R23         Goodwill and Other Intangible Assets                HTML    102K 
38: R24         Accrued Liabilities                                 HTML     56K 
39: R25         Long-term Debt                                      HTML     73K 
40: R26         Other Long-term Liabilities                         HTML     54K 
41: R27         Financial Instruments                               HTML     94K 
42: R28         Income Taxes                                        HTML    149K 
43: R29         Benefit Plans                                       HTML    244K 
44: R30         Stock-Based Compensation                            HTML    166K 
45: R31         Earnings per Share                                  HTML     90K 
46: R32         Commitments and Contingent Liabilities              HTML     50K 
47: R33         Related Party Transactions                          HTML     52K 
48: R34         Supplemental Cash Flow Information                  HTML     57K 
49: R35         Subsequent Events                                   HTML     44K 
50: R36         Schedule I - Condensed Financial Information of     HTML    108K 
                Parent                                                           
51: R37         Pay vs Performance Disclosure                       HTML     54K 
52: R38         Insider Trading Arrangements                        HTML     48K 
53: R39         Summary of Significant Accounting Policies          HTML    189K 
                (Policies)                                                       
54: R40         Summary of Significant Accounting Policies          HTML     59K 
                (Tables)                                                         
55: R41         Divestitures (Tables)                               HTML    100K 
56: R42         Revenue from Contracts with Customers Revenue from  HTML     90K 
                Contracts with Customers (Tables)                                
57: R43         Fair Value Measurements (Tables)                    HTML     65K 
58: R44         Stockholders' Equity (Tables)                       HTML    138K 
59: R45         Other Operating Expense, Net (Tables)               HTML     58K 
60: R46         Inventories (Tables)                                HTML     56K 
61: R47         Investments in Affiliated Companies (Tables)        HTML     74K 
62: R48         Property, Plant and Equipment (Tables)              HTML     54K 
63: R49         Leases (Tables)                                     HTML     98K 
64: R50         Reportable Segments (Tables)                        HTML    133K 
65: R51         Goodwill and Other Intangible Assets (Tables)       HTML    138K 
66: R52         Accrued Liabilities Accrued Liabilities (Tables)    HTML     55K 
67: R53         Long-term Debt (Tables)                             HTML     66K 
68: R54         Other Long-term Liabilities Other Long-term         HTML     54K 
                Liabilities (Tables)                                             
69: R55         Financial Instruments (Tables)                      HTML     97K 
70: R56         Income Taxes (Tables)                               HTML    153K 
71: R57         Benefit Plans (Tables)                              HTML    249K 
72: R58         Stock-Based Compensation - (Tables)                 HTML    149K 
73: R59         Earnings per Share (Tables)                         HTML     91K 
74: R60         Supplemental Cash Flow Information (Tables)         HTML     57K 
75: R61         Schedule I - Condensed Financial Information of     HTML    104K 
                Parent (Tables)                                                  
76: R62         Background and Basis of Presentation (Details)      HTML     53K 
77: R63         Summary of Significant Accounting Policies -        HTML     95K 
                Narratives (Details)                                             
78: R64         Summary of Significant Accounting Policies -        HTML     64K 
                Correction of an Error (Details)                                 
79: R65         Divestitures - Narrative (Details)                  HTML    108K 
80: R66         Divestitures - Reconciliation of Loss (Details)     HTML     97K 
81: R67         Divestitures - Income Information (Details)         HTML     88K 
82: R68         Divestitures - Schedule Of Financing Obligation     HTML     53K 
                Assets And Liabilities (Details)                                 
83: R69         Divestitures - Financing Lease Obligation           HTML     61K 
                (Details)                                                        
84: R70         Revenue from Contracts with Customers - Narrative   HTML     53K 
                (Details)                                                        
85: R71         Revenue from Contracts with Customers -             HTML     77K 
                Disaggregated Revenue (Details)                                  
86: R72         Fair Value Measurements - Assets and Liabilities    HTML     70K 
                Measured at Fair Value on a Recurring Basis                      
                (Details)                                                        
87: R73         Stockholders' Equity - Components of AOCI           HTML     70K 
                (Details)                                                        
88: R74         Stockholders' Equity - Pre-tax and After-tax        HTML     72K 
                Components of Other Comprehensive Income (Loss)                  
                (Details)                                                        
89: R75         Stockholders' Equity - Change by Component          HTML     85K 
                (Details)                                                        
90: R76         Stockholders' Equity - Reclassifications out of     HTML     86K 
                AOCI (Details)                                                   
91: R77         Stockholders' Equity - Treasury Stock Repurchases   HTML     74K 
                (Details)                                                        
92: R78         Stockholders' Equity - Dividends Paid (Details)     HTML     44K 
93: R79         Other Operating Expense, Net (Details)              HTML     54K 
94: R80         Inventories (Details)                               HTML     56K 
95: R81         Inventories, Net - Narratives (Details)             HTML     45K 
96: R82         Investments in Affiliated Companies - Narratives    HTML     71K 
                (Details)                                                        
97: R83         Investments in Affiliated Companies - Ownership     HTML     49K 
                Percentage (Details)                                             
98: R84         Investments in Affiliated Companies - Summarized    HTML     77K 
                Balance Sheet (Details)                                          
99: R85         Investments in Affiliated Companies - Summarized    HTML     78K 
                Income Statement (Details)                                       
100: R86         Investments in Affiliated Companies - Rollforward   HTML     54K  
                (Details)                                                        
101: R87         Property, Plant and Equipment (Details)             HTML     59K  
102: R88         Property, Plant and Equipment - Narratives          HTML     44K  
                (Details)                                                        
103: R89         Leases - Narratives (Details)                       HTML     46K  
104: R90         Leases - Right-of-Use Lease Assets and Lease        HTML     66K  
                Liabilities (Details)                                            
105: R91         Leases - Remaining Average Weighted Average Lease   HTML     52K  
                Term and Discount Rates (Details)                                
106: R92         Leases - Lease Maturity Schedule - ASC 842          HTML     78K  
                (Details)                                                        
107: R93         Leases - Other Lease Information (Details)          HTML     53K  
108: R94         Reportable Segments - Narratives (Details)          HTML     46K  
109: R95         Reportable Segments - Summary Financial             HTML     65K  
                Information by Reportable Segment (Details)                      
110: R96         Reportable Segments - Reconciliation of Net Income  HTML     87K  
                to Adjusted EBITDA (Details)                                     
111: R97         Reportable Segments - Capital Expenditures          HTML     53K  
                (Details)                                                        
112: R98         Reportable Segments - Sales by Geography (Details)  HTML     59K  
113: R99         Reportable Segments - Assets by Geography           HTML     48K  
                (Details)                                                        
114: R100        Goodwill and Other Intangible Assets - Goodwill     HTML     57K  
                Rollforward (Details)                                            
115: R101        Goodwill and Other Intangible Assets - Narratives   HTML     74K  
                (Details)                                                        
116: R102        Goodwill and Other Intangible Assets - Schedule of  HTML     96K  
                Intangible Assets (Details)                                      
117: R103        Goodwill and Other Intangible Assets - Future       HTML     58K  
                Amortization (Details)                                           
118: R104        Accrued Liabilities Accrued Liabilities (Details)   HTML     60K  
119: R105        Long-term Debt (Details)                            HTML     69K  
120: R106        Long-term Debt - ABL Facility (Details)             HTML     93K  
121: R107        Long-term Debt - 2021 Term Loan Facility (Details)  HTML     76K  
122: R108        Long-term Debt - Fair Value (Details)               HTML     52K  
123: R109        Long-term Debt - Aggregate Long-term Debt           HTML     59K  
                Maturities (Details)                                             
124: R110        Other Long-term Liabilities Other Long-term         HTML     58K  
                Liabilities (Details)                                            
125: R111        Financial Instruments - Interest Rate Cap           HTML     66K  
                Agreements (Details)                                             
126: R112        Financial Instruments - Fair Value (Details)        HTML     81K  
127: R113        Financial Instruments - Effect on Other             HTML     52K  
                Comprehensive Income (Details)                                   
128: R114        Financial Instruments - Cash Flow Hedge Impact on   HTML     50K  
                Statements of Income (Details)                                   
129: R115        Income Taxes - Income (loss) before Income Taxes    HTML     52K  
                and Noncontrolling interest (Details)                            
130: R116        Income Taxes - Provision for Income Tax (Details)   HTML     70K  
131: R117        Income Taxes - Reconciliation of Statutory Tax      HTML     69K  
                Rate (Details)                                                   
132: R118        Income Taxes - Components of Deferred Tax Asset     HTML     83K  
                (Liability) (Details)                                            
133: R119        Income Taxes - Narratives (Details)                 HTML     74K  
134: R120        Income Taxes - Schedule of Unrecognized Tax         HTML     47K  
                Benefits Roll Forward (Details)                                  
135: R121        Income Taxes - Payment for Taxes (Details)          HTML     51K  
136: R122        Income Taxes - Inflation Reduction Act (Details)    HTML     47K  
137: R123        Benefit Plans - Change in Benefit Obligation and    HTML     92K  
                Plan Assets (Details)                                            
138: R124        Benefit Plans - Recognized on the Balance Sheet     HTML     58K  
                (Details)                                                        
139: R125        Benefit Plans - Accumulated Other Comprehensive     HTML     59K  
                Income (Details)                                                 
140: R126        Benefit Plans - Net Periodic Benefit Cost           HTML     70K  
                (Details)                                                        
141: R127        Benefit Plans - Amounts recognized in NPBC and OCI  HTML     61K  
                (Details)                                                        
142: R128        Benefit Plans - Projected and Accumulated Benefit   HTML     53K  
                Obligation (Details)                                             
143: R129        Benefit Plans - Weighted Average Assumptions for    HTML     48K  
                Pension Obligation (Details)                                     
144: R130        Benefit Plans - Weighted Average Assumptions for    HTML     57K  
                Net Periodic Cost (Details)                                      
145: R131        Benefit Plans - Plan Assets (Details)               HTML     94K  
146: R132        Benefit Plans - Benefit Plan, Future Payments       HTML     62K  
                (Details)                                                        
147: R133        Benefit Plans - Defined Contribution Plan           HTML     46K  
                (Details)                                                        
148: R134        Stock-Based Compensation - Narratives (Details)     HTML    119K  
149: R135        Stock-Based Compensation - Stock Option Activity    HTML     88K  
                (Details)                                                        
150: R136        Stock-Based Compensation - Restricted Stock         HTML    138K  
                Awards, Restricted Stock Units and Performance                   
                Stock Units (Details)                                            
151: R137        Stock-Based Compensation - Total Stock-Based        HTML     75K  
                Compensation Expense (Details)                                   
152: R138        Reconciliation from Basic to Diluted Weighted       HTML     50K  
                Average Shares Outstanding (Details)                             
153: R139        Calculation of Basic and Diluted Earnings per       HTML    103K  
                Shares (Details)                                                 
154: R140        Anti-dilutive Shares (Details)                      HTML     54K  
155: R141        Commitments and Contingent Liabilities -            HTML     57K  
                Narratives (Details)                                             
156: R142        Related Party Transactions (Details)                HTML     77K  
157: R143        Supplemental Cash Flow Information (Details)        HTML     57K  
158: R144        Schedule I - Condensed Statements of Income         HTML     80K  
                (Details)                                                        
159: R145        Schedule I - Condensed Balance Sheet (Details)      HTML     97K  
160: R146        Schedule I - Condensed Balance Sheet Shares Data    HTML     69K  
                (Details)                                                        
161: R147        Schedule I - Condensed Statement of Cash Flow       HTML     92K  
                (Details)                                                        
162: R148        Schedule I - Narrative (Details)                    HTML     48K  
164: XML         IDEA XML File -- Filing Summary                      XML    311K  
167: XML         XBRL Instance -- ecvt-20231231_htm                   XML   4.72M  
163: EXCEL       IDEA Workbook of Financial Report Info              XLSX    337K  
11: EX-101.CAL  XBRL Calculations -- ecvt-20231231_cal               XML    412K 
12: EX-101.DEF  XBRL Definitions -- ecvt-20231231_def                XML   1.39M 
13: EX-101.LAB  XBRL Labels -- ecvt-20231231_lab                     XML   3.35M 
14: EX-101.PRE  XBRL Presentations -- ecvt-20231231_pre              XML   2.26M 
10: EX-101.SCH  XBRL Schema -- ecvt-20231231                         XSD    330K 
165: JSON        XBRL Instance as JSON Data -- MetaLinks              934±  1.40M  
166: ZIP         XBRL Zipped Folder -- 0001708035-24-000070-xbrl      Zip   1.20M  


‘EX-101.SCH’   —   XBRL Schema — ecvt-20231231


This Exhibit is an XBRL File.


                                                                                                                                                                                
<?xml version="1.0" encoding="windows-1252"?>
<!-- XBRL Document Created with the Workiva Platform -->
<!-- Copyright 2024 Workiva -->
<!-- r:26df8be1-3d9f-4442-8ca3-aaa9143545cf,g:ab0f4aa3-43c4-4db9-b9b6-93ca560a6439 -->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:ecvt="http://www.ecovyst.com/20231231" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:dtr-types1="http://www.xbrl.org/dtr/type/2020-01-21" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2022-03-31" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.ecovyst.com/20231231">
<xs:import namespace="http://fasb.org/srt/2023" schemaLocation="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd"/>
<xs:import namespace="http://fasb.org/us-gaap/2023" schemaLocation="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd"/>
<xs:import namespace="http://www.w3.org/1999/xlink" schemaLocation="http://www.xbrl.org/2003/xlink-2003-12-31.xsd"/>
<xs:import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd"/>
<xs:import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd"/>
<xs:import namespace="http://www.xbrl.org/dtr/type/2020-01-21" schemaLocation="https://www.xbrl.org/dtr/type/2020-01-21/types.xsd"/>
<xs:import namespace="http://www.xbrl.org/dtr/type/2022-03-31" schemaLocation="https://www.xbrl.org/dtr/type/2022-03-31/types.xsd"/>
<xs:import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd"/>
<xs:import namespace="http://xbrl.sec.gov/country/2023" schemaLocation="https://xbrl.sec.gov/country/2023/country-2023.xsd"/>
<xs:import namespace="http://xbrl.sec.gov/currency/2023" schemaLocation="https://xbrl.sec.gov/currency/2023/currency-2023.xsd"/>
<xs:import namespace="http://xbrl.sec.gov/dei/2023" schemaLocation="https://xbrl.sec.gov/dei/2023/dei-2023.xsd"/>
<xs:import namespace="http://xbrl.sec.gov/ecd/2023" schemaLocation="https://xbrl.sec.gov/ecd/2023/ecd-2023.xsd"/>
<xs:annotation>
<xs:appinfo>
<link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="ecvt-20231231_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:type="simple"/>
<link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="ecvt-20231231_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:type="simple"/>
<link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="ecvt-20231231_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:type="simple"/>
<link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="ecvt-20231231_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:type="simple"/>
<link:roleType id="Cover" roleURI="http://www.ecovyst.com/role/Cover">
<link:definition> 0000001 - Document - Cover </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="AuditInformation" roleURI="http://www.ecovyst.com/role/AuditInformation">
<link:definition> 0000002 - Document - Audit Information </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="CONSOLIDATEDSTATEMENTSOFINCOME" roleURI="http://www.ecovyst.com/role/CONSOLIDATEDSTATEMENTSOFINCOME">
<link:definition> 0000003 - Statement - CONSOLIDATED STATEMENTS OF INCOME </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="CONSOLIDATEDSTATEMENTSOFINCOME_1" roleURI="http://www.ecovyst.com/role/CONSOLIDATEDSTATEMENTSOFINCOME_1">
<link:definition> 0000003 - Statement - CONSOLIDATED STATEMENTS OF INCOME </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS" roleURI="http://www.ecovyst.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS">
<link:definition> 0000004 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="CONSOLIDATEDBALANCESHEETS" roleURI="http://www.ecovyst.com/role/CONSOLIDATEDBALANCESHEETS">
<link:definition> 0000005 - Statement - CONSOLIDATED BALANCE SHEETS </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="CONDENSEDCONSOLIDATEDBALANCESHEETSParenthetical" roleURI="http://www.ecovyst.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETSParenthetical">
<link:definition> 0000006 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY" roleURI="http://www.ecovyst.com/role/CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY">
<link:definition> 0000007 - Statement - CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="CONSOLIDATEDSTATEMENTSOFCASHFLOWS" roleURI="http://www.ecovyst.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS">
<link:definition> 0000008 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITYParenthetical" roleURI="http://www.ecovyst.com/role/CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITYParenthetical">
<link:definition> 0000009 - Statement - CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (Parenthetical) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="BackgroundandBasisofPresentation" roleURI="http://www.ecovyst.com/role/BackgroundandBasisofPresentation">
<link:definition> 0000010 - Disclosure - Background and Basis of Presentation </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="SummaryofSignificantAccountingPolicies" roleURI="http://www.ecovyst.com/role/SummaryofSignificantAccountingPolicies">
<link:definition> 0000011 - Disclosure - Summary of Significant Accounting Policies </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="NewAccountingStandards" roleURI="http://www.ecovyst.com/role/NewAccountingStandards">
<link:definition> 0000012 - Disclosure - New Accounting Standards </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="Divestitures" roleURI="http://www.ecovyst.com/role/Divestitures">
<link:definition> 0000013 - Disclosure - Divestitures </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="RevenuefromContractswithCustomers" roleURI="http://www.ecovyst.com/role/RevenuefromContractswithCustomers">
<link:definition> 0000014 - Disclosure - Revenue from Contracts with Customers </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="FairValueMeasurements" roleURI="http://www.ecovyst.com/role/FairValueMeasurements">
<link:definition> 0000015 - Disclosure - Fair Value Measurements </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="StockholdersEquity" roleURI="http://www.ecovyst.com/role/StockholdersEquity">
<link:definition> 0000016 - Disclosure - Stockholders' Equity </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="OtherOperatingExpenseNet" roleURI="http://www.ecovyst.com/role/OtherOperatingExpenseNet">
<link:definition> 0000017 - Disclosure - Other Operating Expense, Net </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="InventoriesNet" roleURI="http://www.ecovyst.com/role/InventoriesNet">
<link:definition> 0000018 - Disclosure - Inventories, Net </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="InvestmentsinAffiliatedCompanies" roleURI="http://www.ecovyst.com/role/InvestmentsinAffiliatedCompanies">
<link:definition> 0000019 - Disclosure - Investments in Affiliated Companies </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="PropertyPlantandEquipment" roleURI="http://www.ecovyst.com/role/PropertyPlantandEquipment">
<link:definition> 0000020 - Disclosure - Property, Plant and Equipment </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="Leases" roleURI="http://www.ecovyst.com/role/Leases">
<link:definition> 0000021 - Disclosure - Leases </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ReportableSegments" roleURI="http://www.ecovyst.com/role/ReportableSegments">
<link:definition> 0000022 - Disclosure - Reportable Segments </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="GoodwillandOtherIntangibleAssets" roleURI="http://www.ecovyst.com/role/GoodwillandOtherIntangibleAssets">
<link:definition> 0000023 - Disclosure - Goodwill and Other Intangible Assets </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="AccruedLiabilities" roleURI="http://www.ecovyst.com/role/AccruedLiabilities">
<link:definition> 0000024 - Disclosure - Accrued Liabilities </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="LongtermDebt" roleURI="http://www.ecovyst.com/role/LongtermDebt">
<link:definition> 0000025 - Disclosure - Long-term Debt </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="OtherLongtermLiabilities" roleURI="http://www.ecovyst.com/role/OtherLongtermLiabilities">
<link:definition> 0000026 - Disclosure - Other Long-term Liabilities </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="FinancialInstruments" roleURI="http://www.ecovyst.com/role/FinancialInstruments">
<link:definition> 0000027 - Disclosure - Financial Instruments </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="IncomeTaxes" roleURI="http://www.ecovyst.com/role/IncomeTaxes">
<link:definition> 0000028 - Disclosure - Income Taxes </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="BenefitPlans" roleURI="http://www.ecovyst.com/role/BenefitPlans">
<link:definition> 0000029 - Disclosure - Benefit Plans </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="StockBasedCompensation" roleURI="http://www.ecovyst.com/role/StockBasedCompensation">
<link:definition> 0000030 - Disclosure - Stock-Based Compensation </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="EarningsperShare" roleURI="http://www.ecovyst.com/role/EarningsperShare">
<link:definition> 0000031 - Disclosure - Earnings per Share </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="CommitmentsandContingentLiabilities" roleURI="http://www.ecovyst.com/role/CommitmentsandContingentLiabilities">
<link:definition> 0000032 - Disclosure - Commitments and Contingent Liabilities </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="RelatedPartyTransactions" roleURI="http://www.ecovyst.com/role/RelatedPartyTransactions">
<link:definition> 0000033 - Disclosure - Related Party Transactions </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="SupplementalCashFlowInformation" roleURI="http://www.ecovyst.com/role/SupplementalCashFlowInformation">
<link:definition> 0000034 - Disclosure - Supplemental Cash Flow Information </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="SubsequentEvents" roleURI="http://www.ecovyst.com/role/SubsequentEvents">
<link:definition> 0000035 - Disclosure - Subsequent Events </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ScheduleICondensedFinancialInformationofParent" roleURI="http://www.ecovyst.com/role/ScheduleICondensedFinancialInformationofParent">
<link:definition> 0000036 - Disclosure - Schedule I - Condensed Financial Information of Parent </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="SummaryofSignificantAccountingPoliciesPolicies" roleURI="http://www.ecovyst.com/role/SummaryofSignificantAccountingPoliciesPolicies">
<link:definition> 9954471 - Disclosure - Summary of Significant Accounting Policies (Policies) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="SummaryofSignificantAccountingPoliciesTables" roleURI="http://www.ecovyst.com/role/SummaryofSignificantAccountingPoliciesTables">
<link:definition> 9954472 - Disclosure - Summary of Significant Accounting Policies (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="DivestituresTables" roleURI="http://www.ecovyst.com/role/DivestituresTables">
<link:definition> 9954473 - Disclosure - Divestitures (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="RevenuefromContractswithCustomersRevenuefromContractswithCustomersTables" roleURI="http://www.ecovyst.com/role/RevenuefromContractswithCustomersRevenuefromContractswithCustomersTables">
<link:definition> 9954474 - Disclosure - Revenue from Contracts with Customers Revenue from Contracts with Customers (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="FairValueMeasurementsTables" roleURI="http://www.ecovyst.com/role/FairValueMeasurementsTables">
<link:definition> 9954475 - Disclosure - Fair Value Measurements (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="StockholdersEquityTables" roleURI="http://www.ecovyst.com/role/StockholdersEquityTables">
<link:definition> 9954476 - Disclosure - Stockholders' Equity (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="OtherOperatingExpenseNetTables" roleURI="http://www.ecovyst.com/role/OtherOperatingExpenseNetTables">
<link:definition> 9954477 - Disclosure - Other Operating Expense, Net (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="InventoriesTables" roleURI="http://www.ecovyst.com/role/InventoriesTables">
<link:definition> 9954478 - Disclosure - Inventories (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="InvestmentsinAffiliatedCompaniesTables" roleURI="http://www.ecovyst.com/role/InvestmentsinAffiliatedCompaniesTables">
<link:definition> 9954479 - Disclosure - Investments in Affiliated Companies (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="PropertyPlantandEquipmentTables" roleURI="http://www.ecovyst.com/role/PropertyPlantandEquipmentTables">
<link:definition> 9954480 - Disclosure - Property, Plant and Equipment (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="LeasesTables" roleURI="http://www.ecovyst.com/role/LeasesTables">
<link:definition> 9954481 - Disclosure - Leases (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ReportableSegmentsTables" roleURI="http://www.ecovyst.com/role/ReportableSegmentsTables">
<link:definition> 9954482 - Disclosure - Reportable Segments (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="GoodwillandOtherIntangibleAssetsTables" roleURI="http://www.ecovyst.com/role/GoodwillandOtherIntangibleAssetsTables">
<link:definition> 9954483 - Disclosure - Goodwill and Other Intangible Assets (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="AccruedLiabilitiesAccruedLiabilitiesTables" roleURI="http://www.ecovyst.com/role/AccruedLiabilitiesAccruedLiabilitiesTables">
<link:definition> 9954484 - Disclosure - Accrued Liabilities Accrued Liabilities (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="LongtermDebtTables" roleURI="http://www.ecovyst.com/role/LongtermDebtTables">
<link:definition> 9954485 - Disclosure - Long-term Debt (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="OtherLongtermLiabilitiesOtherLongtermLiabilitiesTables" roleURI="http://www.ecovyst.com/role/OtherLongtermLiabilitiesOtherLongtermLiabilitiesTables">
<link:definition> 9954486 - Disclosure - Other Long-term Liabilities Other Long-term Liabilities (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="FinancialInstrumentsTables" roleURI="http://www.ecovyst.com/role/FinancialInstrumentsTables">
<link:definition> 9954487 - Disclosure - Financial Instruments (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="IncomeTaxesTables" roleURI="http://www.ecovyst.com/role/IncomeTaxesTables">
<link:definition> 9954488 - Disclosure - Income Taxes (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="BenefitPlansTables" roleURI="http://www.ecovyst.com/role/BenefitPlansTables">
<link:definition> 9954489 - Disclosure - Benefit Plans (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="StockBasedCompensationTables" roleURI="http://www.ecovyst.com/role/StockBasedCompensationTables">
<link:definition> 9954490 - Disclosure - Stock-Based Compensation - (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="EarningsperShareTables" roleURI="http://www.ecovyst.com/role/EarningsperShareTables">
<link:definition> 9954491 - Disclosure - Earnings per Share (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="SupplementalCashFlowInformationTables" roleURI="http://www.ecovyst.com/role/SupplementalCashFlowInformationTables">
<link:definition> 9954492 - Disclosure - Supplemental Cash Flow Information (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ScheduleICondensedFinancialInformationofParentTables" roleURI="http://www.ecovyst.com/role/ScheduleICondensedFinancialInformationofParentTables">
<link:definition> 9954493 - Disclosure - Schedule I - Condensed Financial Information of Parent (Tables) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="BackgroundandBasisofPresentationDetails" roleURI="http://www.ecovyst.com/role/BackgroundandBasisofPresentationDetails">
<link:definition> 9954494 - Disclosure - Background and Basis of Presentation (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="SummaryofSignificantAccountingPoliciesNarrativesDetails" roleURI="http://www.ecovyst.com/role/SummaryofSignificantAccountingPoliciesNarrativesDetails">
<link:definition> 9954495 - Disclosure - Summary of Significant Accounting Policies - Narratives (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="SummaryofSignificantAccountingPoliciesCorrectionofanErrorDetails" roleURI="http://www.ecovyst.com/role/SummaryofSignificantAccountingPoliciesCorrectionofanErrorDetails">
<link:definition> 9954496 - Disclosure - Summary of Significant Accounting Policies - Correction of an Error (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="DivestituresNarrativeDetails" roleURI="http://www.ecovyst.com/role/DivestituresNarrativeDetails">
<link:definition> 9954497 - Disclosure - Divestitures - Narrative (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="DivestituresReconciliationofLossDetails" roleURI="http://www.ecovyst.com/role/DivestituresReconciliationofLossDetails">
<link:definition> 9954498 - Disclosure - Divestitures - Reconciliation of Loss (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="DivestituresIncomeInformationDetails" roleURI="http://www.ecovyst.com/role/DivestituresIncomeInformationDetails">
<link:definition> 9954499 - Disclosure - Divestitures - Income Information (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="DivestituresScheduleOfFinancingObligationAssetsAndLiabilitiesDetails" roleURI="http://www.ecovyst.com/role/DivestituresScheduleOfFinancingObligationAssetsAndLiabilitiesDetails">
<link:definition> 9954500 - Disclosure - Divestitures - Schedule Of Financing Obligation Assets And Liabilities (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="DivestituresFinancingLeaseObligationDetails" roleURI="http://www.ecovyst.com/role/DivestituresFinancingLeaseObligationDetails">
<link:definition> 9954501 - Disclosure - Divestitures - Financing Lease Obligation (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="DivestituresFinancingLeaseObligationDetails_1" roleURI="http://www.ecovyst.com/role/DivestituresFinancingLeaseObligationDetails_1">
<link:definition> 9954501 - Disclosure - Divestitures - Financing Lease Obligation (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="RevenuefromContractswithCustomersNarrativeDetails" roleURI="http://www.ecovyst.com/role/RevenuefromContractswithCustomersNarrativeDetails">
<link:definition> 9954502 - Disclosure - Revenue from Contracts with Customers - Narrative (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="RevenuefromContractswithCustomersDisaggregatedRevenueDetails" roleURI="http://www.ecovyst.com/role/RevenuefromContractswithCustomersDisaggregatedRevenueDetails">
<link:definition> 9954503 - Disclosure - Revenue from Contracts with Customers - Disaggregated Revenue (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="FairValueMeasurementsAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails" roleURI="http://www.ecovyst.com/role/FairValueMeasurementsAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails">
<link:definition> 9954504 - Disclosure - Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="StockholdersEquityComponentsofAOCIDetails" roleURI="http://www.ecovyst.com/role/StockholdersEquityComponentsofAOCIDetails">
<link:definition> 9954505 - Disclosure - Stockholders' Equity - Components of AOCI (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="StockholdersEquityPretaxandAftertaxComponentsofOtherComprehensiveIncomeLossDetails" roleURI="http://www.ecovyst.com/role/StockholdersEquityPretaxandAftertaxComponentsofOtherComprehensiveIncomeLossDetails">
<link:definition> 9954506 - Disclosure - Stockholders' Equity - Pre-tax and After-tax Components of Other Comprehensive Income (Loss) (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="StockholdersEquityChangebyComponentDetails" roleURI="http://www.ecovyst.com/role/StockholdersEquityChangebyComponentDetails">
<link:definition> 9954507 - Disclosure - Stockholders' Equity - Change by Component (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="StockholdersEquityReclassificationsoutofAOCIDetails" roleURI="http://www.ecovyst.com/role/StockholdersEquityReclassificationsoutofAOCIDetails">
<link:definition> 9954508 - Disclosure - Stockholders' Equity - Reclassifications out of AOCI (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="StockholdersEquityTreasuryStockRepurchasesDetails" roleURI="http://www.ecovyst.com/role/StockholdersEquityTreasuryStockRepurchasesDetails">
<link:definition> 9954509 - Disclosure - Stockholders' Equity - Treasury Stock Repurchases (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="StockholdersEquityDividendsPaidDetails" roleURI="http://www.ecovyst.com/role/StockholdersEquityDividendsPaidDetails">
<link:definition> 9954510 - Disclosure - Stockholders' Equity - Dividends Paid (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="OtherOperatingExpenseNetDetails" roleURI="http://www.ecovyst.com/role/OtherOperatingExpenseNetDetails">
<link:definition> 9954511 - Disclosure - Other Operating Expense, Net (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="InventoriesDetails" roleURI="http://www.ecovyst.com/role/InventoriesDetails">
<link:definition> 9954512 - Disclosure - Inventories (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="InventoriesDetails_1" roleURI="http://www.ecovyst.com/role/InventoriesDetails_1">
<link:definition> 9954512 - Disclosure - Inventories (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="InventoriesNetNarrativesDetails" roleURI="http://www.ecovyst.com/role/InventoriesNetNarrativesDetails">
<link:definition> 9954513 - Disclosure - Inventories, Net - Narratives (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="InvestmentsinAffiliatedCompaniesNarrativesDetails" roleURI="http://www.ecovyst.com/role/InvestmentsinAffiliatedCompaniesNarrativesDetails">
<link:definition> 9954514 - Disclosure - Investments in Affiliated Companies - Narratives (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="InvestmentsinAffiliatedCompaniesOwnershipPercentageDetails" roleURI="http://www.ecovyst.com/role/InvestmentsinAffiliatedCompaniesOwnershipPercentageDetails">
<link:definition> 9954515 - Disclosure - Investments in Affiliated Companies - Ownership Percentage (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="InvestmentsinAffiliatedCompaniesSummarizedBalanceSheetDetails" roleURI="http://www.ecovyst.com/role/InvestmentsinAffiliatedCompaniesSummarizedBalanceSheetDetails">
<link:definition> 9954516 - Disclosure - Investments in Affiliated Companies - Summarized Balance Sheet (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="InvestmentsinAffiliatedCompaniesSummarizedIncomeStatementDetails" roleURI="http://www.ecovyst.com/role/InvestmentsinAffiliatedCompaniesSummarizedIncomeStatementDetails">
<link:definition> 9954517 - Disclosure - Investments in Affiliated Companies - Summarized Income Statement (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="InvestmentsinAffiliatedCompaniesRollforwardDetails" roleURI="http://www.ecovyst.com/role/InvestmentsinAffiliatedCompaniesRollforwardDetails">
<link:definition> 9954518 - Disclosure - Investments in Affiliated Companies - Rollforward (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="PropertyPlantandEquipmentDetails" roleURI="http://www.ecovyst.com/role/PropertyPlantandEquipmentDetails">
<link:definition> 9954519 - Disclosure - Property, Plant and Equipment (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="PropertyPlantandEquipmentNarrativesDetails" roleURI="http://www.ecovyst.com/role/PropertyPlantandEquipmentNarrativesDetails">
<link:definition> 9954520 - Disclosure - Property, Plant and Equipment - Narratives (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="LeasesNarrativesDetails" roleURI="http://www.ecovyst.com/role/LeasesNarrativesDetails">
<link:definition> 9954521 - Disclosure - Leases - Narratives (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="LeasesRightofUseLeaseAssetsandLeaseLiabilitiesDetails" roleURI="http://www.ecovyst.com/role/LeasesRightofUseLeaseAssetsandLeaseLiabilitiesDetails">
<link:definition> 9954522 - Disclosure - Leases - Right-of-Use Lease Assets and Lease Liabilities (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="LeasesRemainingAverageWeightedAverageLeaseTermandDiscountRatesDetails" roleURI="http://www.ecovyst.com/role/LeasesRemainingAverageWeightedAverageLeaseTermandDiscountRatesDetails">
<link:definition> 9954523 - Disclosure - Leases - Remaining Average Weighted Average Lease Term and Discount Rates (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="LeasesLeaseMaturityScheduleASC842Details" roleURI="http://www.ecovyst.com/role/LeasesLeaseMaturityScheduleASC842Details">
<link:definition> 9954524 - Disclosure - Leases - Lease Maturity Schedule - ASC 842 (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="LeasesLeaseMaturityScheduleASC842Details_1" roleURI="http://www.ecovyst.com/role/LeasesLeaseMaturityScheduleASC842Details_1">
<link:definition> 9954524 - Disclosure - Leases - Lease Maturity Schedule - ASC 842 (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="LeasesOtherLeaseInformationDetails" roleURI="http://www.ecovyst.com/role/LeasesOtherLeaseInformationDetails">
<link:definition> 9954525 - Disclosure - Leases - Other Lease Information (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ReportableSegmentsNarrativesDetails" roleURI="http://www.ecovyst.com/role/ReportableSegmentsNarrativesDetails">
<link:definition> 9954526 - Disclosure - Reportable Segments - Narratives (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ReportableSegmentsSummaryFinancialInformationbyReportableSegmentDetails" roleURI="http://www.ecovyst.com/role/ReportableSegmentsSummaryFinancialInformationbyReportableSegmentDetails">
<link:definition> 9954527 - Disclosure - Reportable Segments - Summary Financial Information by Reportable Segment (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ReportableSegmentsReconciliationofNetIncometoAdjustedEBITDADetails" roleURI="http://www.ecovyst.com/role/ReportableSegmentsReconciliationofNetIncometoAdjustedEBITDADetails">
<link:definition> 9954528 - Disclosure - Reportable Segments - Reconciliation of Net Income to Adjusted EBITDA (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ReportableSegmentsCapitalExpendituresDetails" roleURI="http://www.ecovyst.com/role/ReportableSegmentsCapitalExpendituresDetails">
<link:definition> 9954529 - Disclosure - Reportable Segments - Capital Expenditures (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ReportableSegmentsSalesbyGeographyDetails" roleURI="http://www.ecovyst.com/role/ReportableSegmentsSalesbyGeographyDetails">
<link:definition> 9954530 - Disclosure - Reportable Segments - Sales by Geography (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ReportableSegmentsAssetsbyGeographyDetails" roleURI="http://www.ecovyst.com/role/ReportableSegmentsAssetsbyGeographyDetails">
<link:definition> 9954531 - Disclosure - Reportable Segments - Assets by Geography (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="GoodwillandOtherIntangibleAssetsGoodwillRollforwardDetails" roleURI="http://www.ecovyst.com/role/GoodwillandOtherIntangibleAssetsGoodwillRollforwardDetails">
<link:definition> 9954532 - Disclosure - Goodwill and Other Intangible Assets - Goodwill Rollforward (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="GoodwillandOtherIntangibleAssetsNarrativesDetails" roleURI="http://www.ecovyst.com/role/GoodwillandOtherIntangibleAssetsNarrativesDetails">
<link:definition> 9954533 - Disclosure - Goodwill and Other Intangible Assets - Narratives (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="GoodwillandOtherIntangibleAssetsScheduleofIntangibleAssetsDetails" roleURI="http://www.ecovyst.com/role/GoodwillandOtherIntangibleAssetsScheduleofIntangibleAssetsDetails">
<link:definition> 9954534 - Disclosure - Goodwill and Other Intangible Assets - Schedule of Intangible Assets (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="GoodwillandOtherIntangibleAssetsFutureAmortizationDetails" roleURI="http://www.ecovyst.com/role/GoodwillandOtherIntangibleAssetsFutureAmortizationDetails">
<link:definition> 9954535 - Disclosure - Goodwill and Other Intangible Assets - Future Amortization (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="AccruedLiabilitiesAccruedLiabilitiesDetails" roleURI="http://www.ecovyst.com/role/AccruedLiabilitiesAccruedLiabilitiesDetails">
<link:definition> 9954536 - Disclosure - Accrued Liabilities Accrued Liabilities (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="LongtermDebtDetails" roleURI="http://www.ecovyst.com/role/LongtermDebtDetails">
<link:definition> 9954537 - Disclosure - Long-term Debt (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="LongtermDebtDetails_1" roleURI="http://www.ecovyst.com/role/LongtermDebtDetails_1">
<link:definition> 9954537 - Disclosure - Long-term Debt (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="LongtermDebtABLFacilityDetails" roleURI="http://www.ecovyst.com/role/LongtermDebtABLFacilityDetails">
<link:definition> 9954538 - Disclosure - Long-term Debt - ABL Facility (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="LongtermDebt2021TermLoanFacilityDetails" roleURI="http://www.ecovyst.com/role/LongtermDebt2021TermLoanFacilityDetails">
<link:definition> 9954539 - Disclosure - Long-term Debt - 2021 Term Loan Facility (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="LongtermDebtFairValueDetails" roleURI="http://www.ecovyst.com/role/LongtermDebtFairValueDetails">
<link:definition> 9954540 - Disclosure - Long-term Debt - Fair Value (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="LongtermDebtAggregateLongtermDebtMaturitiesDetails" roleURI="http://www.ecovyst.com/role/LongtermDebtAggregateLongtermDebtMaturitiesDetails">
<link:definition> 9954541 - Disclosure - Long-term Debt - Aggregate Long-term Debt Maturities (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="OtherLongtermLiabilitiesOtherLongtermLiabilitiesDetails" roleURI="http://www.ecovyst.com/role/OtherLongtermLiabilitiesOtherLongtermLiabilitiesDetails">
<link:definition> 9954542 - Disclosure - Other Long-term Liabilities Other Long-term Liabilities (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="FinancialInstrumentsInterestRateCapAgreementsDetails" roleURI="http://www.ecovyst.com/role/FinancialInstrumentsInterestRateCapAgreementsDetails">
<link:definition> 9954543 - Disclosure - Financial Instruments - Interest Rate Cap Agreements (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="FinancialInstrumentsFairValueDetails" roleURI="http://www.ecovyst.com/role/FinancialInstrumentsFairValueDetails">
<link:definition> 9954544 - Disclosure - Financial Instruments - Fair Value (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="FinancialInstrumentsEffectonOtherComprehensiveIncomeDetails" roleURI="http://www.ecovyst.com/role/FinancialInstrumentsEffectonOtherComprehensiveIncomeDetails">
<link:definition> 9954545 - Disclosure - Financial Instruments - Effect on Other Comprehensive Income (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="FinancialInstrumentsCashFlowHedgeImpactonStatementsofIncomeDetails" roleURI="http://www.ecovyst.com/role/FinancialInstrumentsCashFlowHedgeImpactonStatementsofIncomeDetails">
<link:definition> 9954546 - Disclosure - Financial Instruments - Cash Flow Hedge Impact on Statements of Income (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="IncomeTaxesIncomelossbeforeIncomeTaxesandNoncontrollinginterestDetails" roleURI="http://www.ecovyst.com/role/IncomeTaxesIncomelossbeforeIncomeTaxesandNoncontrollinginterestDetails">
<link:definition> 9954547 - Disclosure - Income Taxes - Income (loss) before Income Taxes and Noncontrolling interest (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="IncomeTaxesProvisionforIncomeTaxDetails" roleURI="http://www.ecovyst.com/role/IncomeTaxesProvisionforIncomeTaxDetails">
<link:definition> 9954548 - Disclosure - Income Taxes - Provision for Income Tax (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="IncomeTaxesReconciliationofStatutoryTaxRateDetails" roleURI="http://www.ecovyst.com/role/IncomeTaxesReconciliationofStatutoryTaxRateDetails">
<link:definition> 9954549 - Disclosure - Income Taxes - Reconciliation of Statutory Tax Rate (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="IncomeTaxesComponentsofDeferredTaxAssetLiabilityDetails" roleURI="http://www.ecovyst.com/role/IncomeTaxesComponentsofDeferredTaxAssetLiabilityDetails">
<link:definition> 9954550 - Disclosure - Income Taxes - Components of Deferred Tax Asset (Liability) (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="IncomeTaxesNarrativesDetails" roleURI="http://www.ecovyst.com/role/IncomeTaxesNarrativesDetails">
<link:definition> 9954551 - Disclosure - Income Taxes - Narratives (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="IncomeTaxesScheduleofUnrecognizedTaxBenefitsRollForwardDetails" roleURI="http://www.ecovyst.com/role/IncomeTaxesScheduleofUnrecognizedTaxBenefitsRollForwardDetails">
<link:definition> 9954552 - Disclosure - Income Taxes - Schedule of Unrecognized Tax Benefits Roll Forward (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="IncomeTaxesPaymentforTaxesDetails" roleURI="http://www.ecovyst.com/role/IncomeTaxesPaymentforTaxesDetails">
<link:definition> 9954553 - Disclosure - Income Taxes - Payment for Taxes (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="IncomeTaxesInflationReductionActDetails" roleURI="http://www.ecovyst.com/role/IncomeTaxesInflationReductionActDetails">
<link:definition> 9954554 - Disclosure - Income Taxes - Inflation Reduction Act (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="BenefitPlansChangeinBenefitObligationandPlanAssetsDetails" roleURI="http://www.ecovyst.com/role/BenefitPlansChangeinBenefitObligationandPlanAssetsDetails">
<link:definition> 9954555 - Disclosure - Benefit Plans - Change in Benefit Obligation and Plan Assets (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="BenefitPlansRecognizedontheBalanceSheetDetails" roleURI="http://www.ecovyst.com/role/BenefitPlansRecognizedontheBalanceSheetDetails">
<link:definition> 9954556 - Disclosure - Benefit Plans - Recognized on the Balance Sheet (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="BenefitPlansAccumulatedOtherComprehensiveIncomeDetails" roleURI="http://www.ecovyst.com/role/BenefitPlansAccumulatedOtherComprehensiveIncomeDetails">
<link:definition> 9954557 - Disclosure - Benefit Plans - Accumulated Other Comprehensive Income (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="BenefitPlansNetPeriodicBenefitCostDetails" roleURI="http://www.ecovyst.com/role/BenefitPlansNetPeriodicBenefitCostDetails">
<link:definition> 9954558 - Disclosure - Benefit Plans - Net Periodic Benefit Cost (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="BenefitPlansAmountsrecognizedinNPBCandOCIDetails" roleURI="http://www.ecovyst.com/role/BenefitPlansAmountsrecognizedinNPBCandOCIDetails">
<link:definition> 9954559 - Disclosure - Benefit Plans - Amounts recognized in NPBC and OCI (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="BenefitPlansProjectedandAccumulatedBenefitObligationDetails" roleURI="http://www.ecovyst.com/role/BenefitPlansProjectedandAccumulatedBenefitObligationDetails">
<link:definition> 9954560 - Disclosure - Benefit Plans - Projected and Accumulated Benefit Obligation (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="BenefitPlansWeightedAverageAssumptionsforPensionObligationDetails" roleURI="http://www.ecovyst.com/role/BenefitPlansWeightedAverageAssumptionsforPensionObligationDetails">
<link:definition> 9954561 - Disclosure - Benefit Plans - Weighted Average Assumptions for Pension Obligation (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="BenefitPlansWeightedAverageAssumptionsforNetPeriodicCostDetails" roleURI="http://www.ecovyst.com/role/BenefitPlansWeightedAverageAssumptionsforNetPeriodicCostDetails">
<link:definition> 9954562 - Disclosure - Benefit Plans - Weighted Average Assumptions for Net Periodic Cost (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="BenefitPlansPlanAssetsDetails" roleURI="http://www.ecovyst.com/role/BenefitPlansPlanAssetsDetails">
<link:definition> 9954563 - Disclosure - Benefit Plans - Plan Assets (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="BenefitPlansBenefitPlanFuturePaymentsDetails" roleURI="http://www.ecovyst.com/role/BenefitPlansBenefitPlanFuturePaymentsDetails">
<link:definition> 9954564 - Disclosure - Benefit Plans - Benefit Plan, Future Payments (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="BenefitPlansDefinedContributionPlanDetails" roleURI="http://www.ecovyst.com/role/BenefitPlansDefinedContributionPlanDetails">
<link:definition> 9954565 - Disclosure - Benefit Plans - Defined Contribution Plan (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="StockBasedCompensationNarrativesDetails" roleURI="http://www.ecovyst.com/role/StockBasedCompensationNarrativesDetails">
<link:definition> 9954566 - Disclosure - Stock-Based Compensation - Narratives (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="StockBasedCompensationStockOptionActivityDetails" roleURI="http://www.ecovyst.com/role/StockBasedCompensationStockOptionActivityDetails">
<link:definition> 9954567 - Disclosure - Stock-Based Compensation - Stock Option Activity (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="StockBasedCompensationRestrictedStockAwardsRestrictedStockUnitsandPerformanceStockUnitsDetails" roleURI="http://www.ecovyst.com/role/StockBasedCompensationRestrictedStockAwardsRestrictedStockUnitsandPerformanceStockUnitsDetails">
<link:definition> 9954568 - Disclosure - Stock-Based Compensation - Restricted Stock Awards, Restricted Stock Units and Performance Stock Units (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="StockBasedCompensationTotalStockBasedCompensationExpenseDetails" roleURI="http://www.ecovyst.com/role/StockBasedCompensationTotalStockBasedCompensationExpenseDetails">
<link:definition> 9954569 - Disclosure - Stock-Based Compensation - Total Stock-Based Compensation Expense (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ReconciliationfromBasictoDilutedWeightedAverageSharesOutstandingDetails" roleURI="http://www.ecovyst.com/role/ReconciliationfromBasictoDilutedWeightedAverageSharesOutstandingDetails">
<link:definition> 9954570 - Disclosure - Reconciliation from Basic to Diluted Weighted Average Shares Outstanding (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="CalculationofBasicandDilutedEarningsperSharesDetails" roleURI="http://www.ecovyst.com/role/CalculationofBasicandDilutedEarningsperSharesDetails">
<link:definition> 9954571 - Disclosure - Calculation of Basic and Diluted Earnings per Shares (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="AntidilutiveSharesDetails" roleURI="http://www.ecovyst.com/role/AntidilutiveSharesDetails">
<link:definition> 9954572 - Disclosure - Anti-dilutive Shares (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="CommitmentsandContingentLiabilitiesNarrativesDetails" roleURI="http://www.ecovyst.com/role/CommitmentsandContingentLiabilitiesNarrativesDetails">
<link:definition> 9954573 - Disclosure - Commitments and Contingent Liabilities - Narratives (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="RelatedPartyTransactionsDetails" roleURI="http://www.ecovyst.com/role/RelatedPartyTransactionsDetails">
<link:definition> 9954574 - Disclosure - Related Party Transactions (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="SupplementalCashFlowInformationDetails" roleURI="http://www.ecovyst.com/role/SupplementalCashFlowInformationDetails">
<link:definition> 9954575 - Disclosure - Supplemental Cash Flow Information (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ScheduleICondensedStatementsofIncomeDetails" roleURI="http://www.ecovyst.com/role/ScheduleICondensedStatementsofIncomeDetails">
<link:definition> 9954576 - Disclosure - Schedule I - Condensed Statements of Income (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ScheduleICondensedBalanceSheetDetails" roleURI="http://www.ecovyst.com/role/ScheduleICondensedBalanceSheetDetails">
<link:definition> 9954577 - Disclosure - Schedule I - Condensed Balance Sheet (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ScheduleICondensedBalanceSheetSharesDataDetails" roleURI="http://www.ecovyst.com/role/ScheduleICondensedBalanceSheetSharesDataDetails">
<link:definition> 9954578 - Disclosure - Schedule I - Condensed Balance Sheet Shares Data (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ScheduleICondensedStatementofCashFlowDetails" roleURI="http://www.ecovyst.com/role/ScheduleICondensedStatementofCashFlowDetails">
<link:definition> 9954579 - Disclosure - Schedule I - Condensed Statement of Cash Flow (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
<link:roleType id="ScheduleINarrativeDetails" roleURI="http://www.ecovyst.com/role/ScheduleINarrativeDetails">
<link:definition> 9954580 - Disclosure - Schedule I - Narrative (Details) </link:definition>
<link:usedOn> link:presentationLink </link:usedOn>
<link:usedOn> link:calculationLink </link:usedOn>
<link:usedOn> link:definitionLink </link:usedOn>
</link:roleType>
</xs:appinfo>
</xs:annotation>
<xs:element id="ecvt_DefinedBenefitPlanAmountsforAssetLiabilityandAccumulatedOtherComprehensiveIncomeRecognizedinStatementofFinancialPosition" abstract="false" name="DefinedBenefitPlanAmountsforAssetLiabilityandAccumulatedOtherComprehensiveIncomeRecognizedinStatementofFinancialPosition" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_RegenerationAndTreatmentServicesMember" abstract="true" name="RegenerationAndTreatmentServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_ProductsMember" abstract="true" name="ProductsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_SparePartsPolicyPolicyTextBlock" abstract="false" name="SparePartsPolicyPolicyTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
<xs:element id="ecvt_LesseeRemainingLeaseTerm" abstract="false" name="LesseeRemainingLeaseTerm" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
<xs:element id="ecvt_April2022StockRepurchaseProgramMember" abstract="true" name="April2022StockRepurchaseProgramMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_RealEstateTaxAbatementPercent" abstract="false" name="RealEstateTaxAbatementPercent" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
<xs:element id="ecvt_EcoServicesPensionEquityPlanMember" abstract="true" name="EcoServicesPensionEquityPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_FinanceLeaseAndFinancingObligationToBePaidYearFive" abstract="false" name="FinanceLeaseAndFinancingObligationToBePaidYearFive" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_FIFOOrWeightedAverageInventoryAmount" abstract="false" name="FIFOOrWeightedAverageInventoryAmount" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_UnallocatedCorporateExpenses" abstract="false" name="UnallocatedCorporateExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_RepaymentOfFinancingObligation" abstract="false" name="RepaymentOfFinancingObligation" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_DefinedBenefitPlanBenefitObligationPremiumsPaid" abstract="false" name="DefinedBenefitPlanBenefitObligationPremiumsPaid" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_PackagingAndEngineeringPlasticsMember" abstract="true" name="PackagingAndEngineeringPlasticsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_ZeolystInternationalMember" abstract="true" name="ZeolystInternationalMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_FinanceLeasesAndFinancingObligationWeightedAverageRemainingLeaseTerm" abstract="false" name="FinanceLeasesAndFinancingObligationWeightedAverageRemainingLeaseTerm" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
<xs:element id="ecvt_DebtExtinguishmentCosts" abstract="false" name="DebtExtinguishmentCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_CompanyPerformanceMeasureMember" abstract="true" name="CompanyPerformanceMeasureMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_FinancingLeaseAndFinancingObligationLiabilityUndiscountedExcessAmount" abstract="false" name="FinancingLeaseAndFinancingObligationLiabilityUndiscountedExcessAmount" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_InflationReductionActAverageAnnualAdjustedIncomeExcess" abstract="false" name="InflationReductionActAverageAnnualAdjustedIncomeExcess" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_MandatoryPaymentsExcessCashFlow" abstract="false" name="MandatoryPaymentsExcessCashFlow" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
<xs:element id="ecvt_ScheduleofTaxPaymentsTableTextBlock" abstract="false" name="ScheduleofTaxPaymentsTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
<xs:element id="ecvt_PaymentsUnderFinancingArrangement" abstract="false" name="PaymentsUnderFinancingArrangement" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_EquityMethodInvestmentsRollForward" abstract="true" name="EquityMethodInvestmentsRollForward" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
<xs:element id="ecvt_INEOSCapitalPartnersMember" abstract="true" name="INEOSCapitalPartnersMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_FinanceLeaseAndFinancingObligationToBePaidYearThree" abstract="false" name="FinanceLeaseAndFinancingObligationToBePaidYearThree" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_ExciseTaxOnTreasuryStockRepurchased" abstract="false" name="ExciseTaxOnTreasuryStockRepurchased" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_RevenueAndCostShippingAndHandlingPolicyPolicyTextBlock" abstract="false" name="RevenueAndCostShippingAndHandlingPolicyPolicyTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
<xs:element id="ecvt_FinanceLeaseAndFinancingObligationLiabilitiesNoncurrent" abstract="false" name="FinanceLeaseAndFinancingObligationLiabilitiesNoncurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_DebtInstrumentCovenantFixedChargeCoverageRatioMinimum" abstract="false" name="DebtInstrumentCovenantFixedChargeCoverageRatioMinimum" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
<xs:element id="ecvt_IndefiniteLivedIntangibleAssetsExcludingGoodwillNet" abstract="false" name="IndefiniteLivedIntangibleAssetsExcludingGoodwillNet" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_NonCashInvestingActivityAbstract" abstract="true" name="NonCashInvestingActivityAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
<xs:element id="ecvt_OperatingAndFinanceRightOfUseLeaseAssetsTotal" abstract="false" name="OperatingAndFinanceRightOfUseLeaseAssetsTotal" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_PerformanceMeasureAxis" abstract="true" name="PerformanceMeasureAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
<xs:element id="ecvt_ValuedatLowerofCostandNetRealizableValueAbstract" abstract="true" name="ValuedatLowerofCostandNetRealizableValueAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
<xs:element id="ecvt_FinancingObligationLiability" abstract="false" name="FinancingObligationLiability" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_DerivativeNumberOfInstrumentsInEffect" abstract="false" name="DerivativeNumberOfInstrumentsInEffect" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
<xs:element id="ecvt_DisposalGroupIncludingDiscontinuedOperationPricePerDefinitiveAgreement" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationPricePerDefinitiveAgreement" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_TotalShareholderReturnTSRMember" abstract="true" name="TotalShareholderReturnTSRMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_OtherForeignCountriesMember" abstract="true" name="OtherForeignCountriesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_DebtInstrumentFirstLienLeverageRatio" abstract="false" name="DebtInstrumentFirstLienLeverageRatio" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
<xs:element id="ecvt_A2021GrantsMember" abstract="true" name="A2021GrantsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_PerformanceStockUnitFairValueAssumptionsRiskFreeInterestRate" abstract="false" name="PerformanceStockUnitFairValueAssumptionsRiskFreeInterestRate" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
<xs:element id="ecvt_PerformanceStockUnitFairValueAssumptionsExpectedVolatilityRate" abstract="false" name="PerformanceStockUnitFairValueAssumptionsExpectedVolatilityRate" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
<xs:element id="ecvt_March2020StockRepurchaseProgramMember" abstract="true" name="March2020StockRepurchaseProgramMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_FinanceLeaseAndFinancingObligationLiabilityToBePaid" abstract="false" name="FinanceLeaseAndFinancingObligationLiabilityToBePaid" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_ServicesMember" abstract="true" name="ServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_ZeolystJointVentureMember" abstract="true" name="ZeolystJointVentureMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_PerformanceStockUnitsGrantsInPeriodWeightedAverageGrantDateFairValue" abstract="false" name="PerformanceStockUnitsGrantsInPeriodWeightedAverageGrantDateFairValue" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType"/>
<xs:element id="ecvt_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPlanTax" abstract="false" name="AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPlanTax" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_ProductDemonstrationCostsMember" abstract="true" name="ProductDemonstrationCostsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_EcoServicesHourlyPensionPlanMember" abstract="true" name="EcoServicesHourlyPensionPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_IncomeLossfromEquityMethodInvestmentsExcludingPurchaseAccountingAdjustments" abstract="false" name="IncomeLossfromEquityMethodInvestmentsExcludingPurchaseAccountingAdjustments" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_EstimateDisposalLoss" abstract="false" name="EstimateDisposalLoss" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_PerformanceMeasureDomain" abstract="true" name="PerformanceMeasureDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
<xs:element id="ecvt_IndustrialMiningAutomotiveMember" abstract="true" name="IndustrialMiningAutomotiveMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_EquityMethodInvestmentAmortizationExpense" abstract="false" name="EquityMethodInvestmentAmortizationExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_A2023GrantsMember" abstract="true" name="A2023GrantsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
<xs:element id="ecvt_DisposalGroupIncludingDiscontinuedOperationTransactionCostsForDisposal" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationTransactionCostsForDisposal" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_November2022InterestRateCapAugust2024ToJuly2026Member" abstract="true" name="November2022InterestRateCapAugust2024ToJuly2026Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
<xs:element id="ecvt_FinanceLeasesAndFinancingObligationWeightedAverageDiscountRatePercent" abstract="false" name="FinanceLeasesAndFinancingObligationWeightedAverageDiscountRatePercent" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
<xs:element id="ecvt_ProvisionToReturnAdjustmentRecognized" abstract="false" name="ProvisionToReturnAdjustmentRecognized" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_CashpaidforamountsincludedinthemeasurementofleaseliabilitiesAbstract" abstract="true" name="CashpaidforamountsincludedinthemeasurementofleaseliabilitiesAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
<xs:element id="ecvt_BusinessOptimizationIntegrationRestructuringAndOtherRelatedCosts" abstract="false" name="BusinessOptimizationIntegrationRestructuringAndOtherRelatedCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_AdjustmentForAmortizationExpense" abstract="false" name="AdjustmentForAmortizationExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_RealEstateTaxAbatementTerm" abstract="false" name="RealEstateTaxAbatementTerm" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
<xs:element id="ecvt_FinanceLeaseAndFinancingObligationLiabilitiesCurrent" abstract="false" name="FinanceLeaseAndFinancingObligationLiabilitiesCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_PrincipalPaymentsUnderFinanceLeasesAndFinancingObligationsIncludedInFinancingCashFlows" abstract="false" name="PrincipalPaymentsUnderFinanceLeasesAndFinancingObligationsIncludedInFinancingCashFlows" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_EmployeeMember" abstract="true" name="EmployeeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_LineofCreditFacilityPotentialCommitmentFeePercentage" abstract="false" name="LineofCreditFacilityPotentialCommitmentFeePercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
<xs:element id="ecvt_PerformanceStockUnitsMember" abstract="true" name="PerformanceStockUnitsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_RightofUseAssetsObtainedinExchangeforNewLeaseLiabilitiesNonCashAbstract" abstract="true" name="RightofUseAssetsObtainedinExchangeforNewLeaseLiabilitiesNonCashAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
<xs:element id="ecvt_PQHoldingsEcoServicesMember" abstract="true" name="PQHoldingsEcoServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_PerformanceMaterialsMember" abstract="true" name="PerformanceMaterialsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_OtherIncomeExpenseNet" abstract="false" name="OtherIncomeExpenseNet" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_FinancingObligationsAssetsAndLiabilitiesLineItems" abstract="true" name="FinancingObligationsAssetsAndLiabilitiesLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
<xs:element id="ecvt_ExciseTaxesPayable" abstract="false" name="ExciseTaxesPayable" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_FinanceLeaseAndFinancingObligationAccruedLiabilities" abstract="false" name="FinanceLeaseAndFinancingObligationAccruedLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_FinanceLeaseAndFinancingObligationLiability" abstract="false" name="FinanceLeaseAndFinancingObligationLiability" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_IncomeTaxBenefitOnTransactionCostsAndStockBasedCompensationExpenseOnly" abstract="false" name="IncomeTaxBenefitOnTransactionCostsAndStockBasedCompensationExpenseOnly" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_CleanFuelsEmissionControlsOtherMember" abstract="true" name="CleanFuelsEmissionControlsOtherMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_January2022InterestRateCapExpiringOctober2025Member" abstract="true" name="January2022InterestRateCapExpiringOctober2025Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_SubsurfaceRemediationAndWetlandsManagementMember" abstract="true" name="SubsurfaceRemediationAndWetlandsManagementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_January2022InterestRateCapExpiringOctober2024Member" abstract="true" name="January2022InterestRateCapExpiringOctober2024Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_SharebasedCompensationAwardTrancheFourMember" abstract="true" name="SharebasedCompensationAwardTrancheFourMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_OperatingandFinanceLeaseLiabilitiesTotal" abstract="false" name="OperatingandFinanceLeaseLiabilitiesTotal" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_SummaryOfSignificantAccountingPoliciesLineItems" abstract="true" name="SummaryOfSignificantAccountingPoliciesLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
<xs:element id="ecvt_SupplierPaymentTimingPeriod" abstract="false" name="SupplierPaymentTimingPeriod" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
<xs:element id="ecvt_FinanceLeaseAndFinancingObligationToBePaidYearFour" abstract="false" name="FinanceLeaseAndFinancingObligationToBePaidYearFour" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_BusinessCombinationsMember" abstract="true" name="BusinessCombinationsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_WeightedAverageDiscountRateAbstract" abstract="true" name="WeightedAverageDiscountRateAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
<xs:element id="ecvt_FinancingObligationsAssetsAndLiabilitiesTable" abstract="true" name="FinancingObligationsAssetsAndLiabilitiesTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
<xs:element id="ecvt_A2021TermLoanFacilityMember" abstract="true" name="A2021TermLoanFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_DebtInstrumentOriginalIssueDiscount" abstract="false" name="DebtInstrumentOriginalIssueDiscount" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
<xs:element id="ecvt_WeightedAverageRemainingLeaseTermAbstract" abstract="true" name="WeightedAverageRemainingLeaseTermAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
<xs:element id="ecvt_FinanceLeaseAndFinancingObligationToBePaidYearTwo" abstract="false" name="FinanceLeaseAndFinancingObligationToBePaidYearTwo" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_TransitionServicesAgreementTerm" abstract="false" name="TransitionServicesAgreementTerm" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
<xs:element id="ecvt_DisposalGroupIncludingDiscontinuedOperationNetAssetsDerecognizedOnDisposal" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationNetAssetsDerecognizedOnDisposal" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_PerformanceStockUnitFairValueAssumptionsExpectedTerm" abstract="false" name="PerformanceStockUnitFairValueAssumptionsExpectedTerm" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
<xs:element id="ecvt_FinanceLeaseAndFinancingObligationAssets" abstract="false" name="FinanceLeaseAndFinancingObligationAssets" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_DebtInstrumentVariableRateFloor" abstract="false" name="DebtInstrumentVariableRateFloor" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
<xs:element id="ecvt_TransactionAndOtherRelatedCosts" abstract="false" name="TransactionAndOtherRelatedCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_DeferredTaxAssetsTaxCreditWithholdingsForeign" abstract="false" name="DeferredTaxAssetsTaxCreditWithholdingsForeign" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_DefinedBenefitPlanPlanAssetsPremiumsPaid" abstract="false" name="DefinedBenefitPlanPlanAssetsPremiumsPaid" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_IndefiniteLivedIntangibleAssetsExcludingGoodwillGross" abstract="false" name="IndefiniteLivedIntangibleAssetsExcludingGoodwillGross" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_TwoThousandSeventeenOmnibusPlanMemberMember" abstract="true" name="TwoThousandSeventeenOmnibusPlanMemberMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_PaymentsForBusinessDivestiture" abstract="false" name="PaymentsForBusinessDivestiture" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_DebtInstrumentScheduledRepaymentPercentageOfPrincipal" abstract="false" name="DebtInstrumentScheduledRepaymentPercentageOfPrincipal" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
<xs:element id="ecvt_DebtInstrumentBasisSpreadOnVariableRateSpreadAdjustment" abstract="false" name="DebtInstrumentBasisSpreadOnVariableRateSpreadAdjustment" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
<xs:element id="ecvt_OpenMarketMember" abstract="true" name="OpenMarketMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_FinanceLeaseAndFinancingObligationToBePaidAfterYearFive" abstract="false" name="FinanceLeaseAndFinancingObligationToBePaidAfterYearFive" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_EnvironmentalLossContingencyStatementOfFinancialPositionExtensibleEnumerationNotDisclosedFlag" abstract="false" name="EnvironmentalLossContingencyStatementOfFinancialPositionExtensibleEnumerationNotDisclosedFlag" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
<xs:element id="ecvt_DeferredTaxLiabilitiesOperatingLeaseRightofuseAssets" abstract="false" name="DeferredTaxLiabilitiesOperatingLeaseRightofuseAssets" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_A2022GrantsMember" abstract="true" name="A2022GrantsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_RepaymentOfInterestOnFinancingObligation" abstract="false" name="RepaymentOfInterestOnFinancingObligation" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_TransitionServiceAgreementIncome" abstract="false" name="TransitionServiceAgreementIncome" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_PerformanceStockUnitFairValueAssumptionsExpectedDividendRate" abstract="false" name="PerformanceStockUnitFairValueAssumptionsExpectedDividendRate" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
<xs:element id="ecvt_ZeolystC.V.Member" abstract="true" name="ZeolystC.V.Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_SalesfromPartnershiptoCompanyMember" abstract="true" name="SalesfromPartnershiptoCompanyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_FinanceLeaseAndObligationCost" abstract="false" name="FinanceLeaseAndObligationCost" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_ShareRepurchaseMethodDomain" abstract="true" name="ShareRepurchaseMethodDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_EquityMethodInvestmentsChargesRelatedtoPurchaseAccounting" abstract="false" name="EquityMethodInvestmentsChargesRelatedtoPurchaseAccounting" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_AdvancedMaterialsAndCatalystsMember" abstract="true" name="AdvancedMaterialsAndCatalystsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_InflationReductionActExciseTaxOnNetStockRepurchases" abstract="false" name="InflationReductionActExciseTaxOnNetStockRepurchases" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
<xs:element id="ecvt_DeferredTaxAssetsOperatingLeaseLiability" abstract="false" name="DeferredTaxAssetsOperatingLeaseLiability" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_OperatingLeaseRentalPaymentsMember" abstract="true" name="OperatingLeaseRentalPaymentsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_FinanceLeaseAndFinancingObligationOtherLongTermLiabilities" abstract="false" name="FinanceLeaseAndFinancingObligationOtherLongTermLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_RestrictedStockRestrictedStockUnitsRSUsandPerformanceStockUnitsPSUsMember" abstract="true" name="RestrictedStockRestrictedStockUnitsRSUsandPerformanceStockUnitsPSUsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_SummaryofSignificantAccountingPoliciesTableLineItems" abstract="true" name="SummaryofSignificantAccountingPoliciesTableLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
<xs:element id="ecvt_SalesRebateReserve" abstract="false" name="SalesRebateReserve" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_ScheduleofRightofUseLeaseAssetsandLeaseLiabilitiesTableTextBlock" abstract="false" name="ScheduleofRightofUseLeaseAssetsandLeaseLiabilitiesTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
<xs:element id="ecvt_InflationReductionActCorporateAlternativeMinimumTax" abstract="false" name="InflationReductionActCorporateAlternativeMinimumTax" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
<xs:element id="ecvt_AuditInformationAbstract" abstract="true" name="AuditInformationAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
<xs:element id="ecvt_AccruedCompensationandBonusCurrent" abstract="false" name="AccruedCompensationandBonusCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_SubsurfaceRemediationAndSoilVaporExtractionMember" abstract="true" name="SubsurfaceRemediationAndSoilVaporExtractionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_ForeignCurrencyAdjustmentsRelatedtoEquityMethodInvestments" abstract="false" name="ForeignCurrencyAdjustmentsRelatedtoEquityMethodInvestments" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_SummaryofSignificantAccountingPoliciesTable" abstract="true" name="SummaryofSignificantAccountingPoliciesTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
<xs:element id="ecvt_EcoservicesMember" abstract="true" name="EcoservicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_SecuredOvernightFinancingRateMember" abstract="true" name="SecuredOvernightFinancingRateMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_CashFlowInformationRelatedtoLeasesTableTextBlock" abstract="false" name="CashFlowInformationRelatedtoLeasesTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
<xs:element id="ecvt_FinanceLeaseAndFinancingObligationToBePaidYearOne" abstract="false" name="FinanceLeaseAndFinancingObligationToBePaidYearOne" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_NumberOfDefinedBenefitPensionPlans" abstract="false" name="NumberOfDefinedBenefitPensionPlans" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
<xs:element id="ecvt_DisposalGroupsIncludingDiscontinuedOperationsDisclosureOfPerformanceChemicalsTextBlock" abstract="false" name="DisposalGroupsIncludingDiscontinuedOperationsDisclosureOfPerformanceChemicalsTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
<xs:element id="ecvt_InventoryValuationInFIFOLowerThanLIFO" abstract="false" name="InventoryValuationInFIFOLowerThanLIFO" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_ActuarialGainLossChangesduetoDiscountRates" abstract="false" name="ActuarialGainLossChangesduetoDiscountRates" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_ScheduleOfFinancingObligationAssetsAndLiabilitiesTableTextBlock" abstract="false" name="ScheduleOfFinancingObligationAssetsAndLiabilitiesTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
<xs:element id="ecvt_ProceedsFromFailedSaleLeaseback" abstract="false" name="ProceedsFromFailedSaleLeaseback" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_PerformanceChemicalsMember" abstract="true" name="PerformanceChemicalsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_ShareRepurchaseMethodAxis" abstract="true" name="ShareRepurchaseMethodAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
<xs:element id="ecvt_ManufacturingCostsMember" abstract="true" name="ManufacturingCostsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_FinanceLeasAndFinancingObligationInterestPaymentOnLiability" abstract="false" name="FinanceLeasAndFinancingObligationInterestPaymentOnLiability" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_AdjustedEarningsBeforeInterestTaxesDepreciationAndAmortization" abstract="false" name="AdjustedEarningsBeforeInterestTaxesDepreciationAndAmortization" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_A2020GrantsMember" abstract="true" name="A2020GrantsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_SecondaryOfferingMember" abstract="true" name="SecondaryOfferingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
<xs:element id="ecvt_ActuarialGainLossGeneralExperience" abstract="false" name="ActuarialGainLossGeneralExperience" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
<xs:element id="ecvt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodPercentage" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodPercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
<xs:element id="ecvt_November2022InterestRateCapJuly2023ToJuly2024Member" abstract="true" name="November2022InterestRateCapJuly2023ToJuly2024Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
</xs:schema>


18 Previous Filings that this Filing References

  As Of               Filer                 Filing    For·On·As Docs:Size             Issuer                      Filing Agent

 2/28/23  Ecovyst Inc.                      10-K       12/31/22  185:28M
12/22/22  Ecovyst Inc.                      8-K:5,9    12/16/22   13:568K                                   Donnelley … Solutions/FA
 3/01/22  Ecovyst Inc.                      10-K       12/31/21  181:24M
 1/14/22  Ecovyst Inc.                      S-8         1/14/22    5:168K                                   Donnelley … Solutions/FA
11/09/21  Ecovyst Inc.                      10-Q        9/30/21  106:12M
 8/09/21  Ecovyst Inc.                      10-Q        6/30/21  104:12M
 8/03/21  Ecovyst Inc.                      8-K:1,2,5,8 8/01/21   12:265K                                   Donnelley … Solutions/FA
 7/15/21  Ecovyst Inc.                      8-K:1,9     7/12/21   11:212K                                   Donnelley … Solutions/FA
 6/30/21  Ecovyst Inc.                      8-K:1,9     6/24/21   11:149K                                   Donnelley … Solutions/FA
 6/11/21  Ecovyst Inc.                      8-K:1,2,9   6/09/21   12:5.8M                                   Donnelley … Solutions/FA
 3/04/21  Ecovyst Inc.                      8-K:1,7,8,9 2/28/21   12:978K                                   Donnelley … Solutions/FA
10/16/20  Ecovyst Inc.                      8-K:1,8,9  10/15/20   12:911K                                   Donnelley … Solutions/FA
 2/27/20  Ecovyst Inc.                      10-K       12/31/19  182:30M
12/13/17  Ecovyst Inc.                      8-K:1,2,9  12/11/17    2:929K                                   Donnelley … Solutions/FA
11/14/17  Ecovyst Inc.                      10-Q        9/30/17   92:9.3M
 9/01/17  Ecovyst Inc.                      S-1/A¶                15:9M                                     Donnelley … Solutions/FA
 8/14/17  Ecovyst Inc.                      S-1/A¶                12:9.2M                                   Donnelley … Solutions/FA
 6/09/17  Ecovyst Inc.                      S-1                   16:14M                                    Donnelley … Solutions/FA
Top
Filing Submission 0001708035-24-000070   –   Alternative Formats (Word / Rich Text, HTML, Plain Text, et al.)

Copyright © 2024 Fran Finnegan & Company LLC – All Rights Reserved.
AboutPrivacyRedactionsHelp — Sun., May 12, 12:03:16.1pm ET