<SEC-DOCUMENT>0000899243-22-009079.txt : 20220303
<SEC-HEADER>0000899243-22-009079.hdr.sgml : 20220303
<ACCEPTANCE-DATETIME>20220303163047
ACCESSION NUMBER:		0000899243-22-009079
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20220301
FILED AS OF DATE:		20220303
DATE AS OF CHANGE:		20220303

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Sichko William J. Jr.
		CENTRAL INDEX KEY:			0001717989

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38221
		FILM NUMBER:		22709387

	MAIL ADDRESS:	
		STREET 1:		C/O PQ GROUP HOLDINGS INC.
		STREET 2:		300 LINDENWOOD DRIVE
		CITY:			MALVERN
		STATE:			PA
		ZIP:			19355

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Ecovyst Inc.
		CENTRAL INDEX KEY:			0001708035
		STANDARD INDUSTRIAL CLASSIFICATION:	CHEMICALS & ALLIED PRODUCTS [2800]
		IRS NUMBER:				813406833
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		300 LINDENWOOD DRIVE
		CITY:			MALVERN
		STATE:			PA
		ZIP:			19355
		BUSINESS PHONE:		610-651-4400

	MAIL ADDRESS:	
		STREET 1:		300 LINDENWOOD DRIVE
		CITY:			MALVERN
		STATE:			PA
		ZIP:			19355

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	PQ Group Holdings Inc.
		DATE OF NAME CHANGE:	20170531
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2022-03-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001708035</issuerCik>
        <issuerName>Ecovyst Inc.</issuerName>
        <issuerTradingSymbol>ECVT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001717989</rptOwnerCik>
            <rptOwnerName>Sichko William J. Jr.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ECOVYST INC.</rptOwnerStreet1>
            <rptOwnerStreet2>300 LINDENWOOD DRIVE</rptOwnerStreet2>
            <rptOwnerCity>MALVERN</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>19355</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>See Remarks</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2022-03-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>32447</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>485879</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>585042</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By family trust</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares of common stock held by a family trust. Mr. Sichko disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein, and the filing of this report is not an admission that Mr. Sichko is the beneficial owner of such securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.</footnote>
    </footnotes>

    <remarks>Vice President and Chief Administrative Officer</remarks>

    <ownerSignature>
        <signatureName>/s/ Joseph S. Koscinski, as attorney-in-fact for William J. Sichko Jr.</signatureName>
        <signatureDate>2022-03-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
