FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
CCMP Capital, LP
  2. Issuer Name and Ticker or Trading Symbol
Ecovyst Inc. [ECVT]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O CCMP CAPITAL ADVISORS, LP, 200 PARK AVENUE, SUITE 1700
3. Date of Earliest Transaction (Month/Day/Year)
11/23/2021
(Street)

NEW YORK, NY 10166
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 11/23/2021   S   2,476,680 D $ 9.12 22,443,932 I By CCMP Capital Investors III, L.P. (1) (3)
Common Stock 11/23/2021   S   251,036 D $ 9.12 2,274,919 I By CCMP Capital Investors III (Employee), L.P. (1) (3)
Common Stock 11/23/2021   S   755,087 D $ 9.12 6,842,680 I CCMP Capital Investors III (AV-7), L.P. (1) (3)
Common Stock 11/23/2021   S   42,720 D $ 9.12 387,129 I CCMP Capital Investors III (AV-8), L.P. (1) (3)
Common Stock 11/23/2021   S   854,026 D $ 9.12 7,739,276 I CCMP Capital Investors III (AV-9), L.P. (1) (3)
Common Stock 11/23/2021   S   55,958 D $ 9.12 507,093 I CCMP Capital Investors III (AV-10), L.P. (1) (3)
Common Stock 11/23/2021   S   789,459 D $ 9.12 7,154,160 I Quartz Co-Invest L.P. (2) (3)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
CCMP Capital, LP
C/O CCMP CAPITAL ADVISORS, LP
200 PARK AVENUE, SUITE 1700
NEW YORK, NY 10166
    X    
Quartz Co-Invest, L.P.
C/O CCMP CAPITAL ADVISORS, LP
200 PARK AVENUE, SUITE 1700
NEW YORK, NY 10166
    X    
CCMP Co-Invest III A GP, LLC
C/O CCMP CAPITAL ADVISORS, LP
200 PARK AVENUE, SUITE 1700
NEW YORK, NY 10166
    X    

Signatures

 QUARTZ CO-INVEST L.P., By: CCMP Co-Invest III A GP, LLC, its general partner, By: /s/ Richard G. Jansen, Title: Managing Director and General Counsel   11/23/2021
**Signature of Reporting Person Date

 CCMP CO-INVEST III A GP, LLC, By: /s/ Richard G. Jansen, Title: Managing Director and General Counsel   11/23/2021
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) CCMP Capital Associates III, L.P. ("CCMP Capital Associates") is the general partner of each of CCMP Capital Investors III, L.P. ("CCMP Capital Investors"), CCMP Capital Investors III (Employee), L.P. ("CCMP Employee"), CCMP Capital Investors III (AV-7), L.P. ("CCMP AV-7"), CCMP Capital Investors III (AV-8), L.P. ("CCMP AV-8"), CCMP Capital Investors III (AV-9), L.P. ("CCMP AV-9") and CCMP Capital Investors III (AV-10), L.P. ("CCMP AV-10" and, together with CCMP Capital Investors, CCMP Employee, CCMP AV-7, CCMP AV-8 and CCMP AV-9, the "CCMP Capital Funds"). The general partner of CCMP Capital Associates is CCMP Capital Associates III GP, LLC ("CCMP Capital Associates GP").
(2) CCMP Co-Invest III A GP, LLC ("CCMP Co-Invest GP") is the general partner of Quartz Co-Invest, L.P. ("Quartz" and, together with the CCMP Capital Funds, the "CCMP Investors").
(3) CCMP Capital Associates GP and CCMP Co-Invest GP are each wholly owned by CCMP Capital, LP. The general partner of CCMP Capital, LP is CCMP Capital GP, LLC. CCMP Capital GP, LLC ultimately exercises voting and dispositive power over the shares of common stock of Ecovyst Inc. held by the CCMP Investors. As a result, each of CCMP Capital Associates, CCMP Capital Associates GP, CCMP Co-Invest GP, CCMP Capital, LP and CCMP Capital GP, LLC may be deemed to share beneficial ownership with respect to certain of the shares of common stock of Ecovyst Inc. held by the CCMP Investors. Each of the reporting persons disclaims beneficial ownership of these securities except to the extent of its pecuniary interest therein, and the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.
 
Remarks:
Form 2 of 2.

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