POWER OF ATTORNEY

       The  undersigned  hereby  constitutes  and  appoints Angelo Chaclas, Erik
 Johnson,  Loretta  DiLucido,  and  Patricia  E.  Halberstadt with full power of
 substitution, as the undersigned's true and lawful attorney-in-fact to:

       (1)    prepare,   execute   in   the   undersigned's   name  and  on  the
              undersigned's  behalf,  and  submit  to  the  U.S.  Securities and
              Exchange  Commission  (the  "SEC") a Form ID, including amendments
              thereto,  and  any  other  documents  necessary  or appropriate to
              obtain  codes  and  passwords  enabling  the  undersigned  to make
              electronic  filings  with  the  SEC of reports required by Section
              16(a)  of  the  Securities  Exchange  Act  of  1934 or any rule or
              regulation of the SEC;

       (2)    execute for and on behalf of the undersigned, in the undersigned's
              capacity   as   officer  and/or  director  of  Trinseo  S.A.  (the
              "Company"),  Forms 3, 4, and 5 in accordance with Section 16(a) of
              the Securities Exchange Act of 1934 and the rules thereunder;


       (3)    do  and  perform  any  and  all  acts  for  and  on  behalf of the
              undersigned  that  may  be  necessary or desirable to complete and
              execute  any  such  Form  3,  4,  or  5,  complete and execute any
              amendment  or  amendments  thereto, and timely file such form with
              the SEC and any stock exchange or similar authority; and

       (4)    take  any  other  action of any type whatsoever in connection with
              the  foregoing  that, in the opinion of such attorney-in-fact, may
              be of benefit to, in the best interest of, or legally required by,
              the  undersigned,  it being understood that the documents executed
              by  such attorney-in-fact on behalf of the undersigned pursuant to
              this  Power  of  Attorney  shall be in such form and shall contain
              such  terms and conditions as such attorney-in-fact may approve in
              such attorney-in-fact's discretion.

       The  undersigned  hereby  grants  to such attorney-in-fact full power and
 authority  to  do and perform any and every act and thing whatsoever requisite,
 necessary, or proper to be done in the exercise of any of the rights and powers
 herein  granted,  as fully to all intents and purposes as the undersigned might
 or  could  do  if  personally  present,  with  full  power  of  substitution or
 revocation,  hereby ratifying and confirming all that such attorney-in-fact, or
 such  attorney-in-fact's  substitute or substitutes, shall lawfully do or cause
 to be done by virtue of this power of attorney and the rights and powers herein
 granted.  The undersigned acknowledges that the foregoing attorneys-in-fact, in
 serving  in  such capacity at the request of the undersigned, are not assuming,
 nor  is  the  Company  assuming,  any  of the undersigned's responsibilities to
 comply with Section 16 of the Securities Exchange Act of 1934.

       This  Power  of  Attorney shall remain in full force and effect until the
 undersigned is no longer required to file Forms 3, 4, and 5 with respect to the
 undersigned's holdings of and transactions in securities issued by the Company,
 unless  earlier revoked by the undersigned in a signed writing delivered to the
 foregoing attorney-in-fact.

       IN  WITNESS WHEREOF, the undersigned has caused this Power of Attorney to
 be executed as of July 31, 2020.

/s/ James Mingyu Ni
-------------------
Name: James Mingyu Ni