Exhibit 10.2

SECOND AMENDMENT

TO

STOCKHOLDER AGREEMENT

This SECOND AMENDMENT, dated as of July 15, 2011 (this “Amendment”), to the
Stockholder Agreement, dated as of February 26, 2010 and amended by the First
Amendment to Stockholder Agreement effective June 29, 2010 (the “Stockholder
Agreement”), is by and among (i) Renewable Energy Group, Inc. (formerly REG
Newco, Inc.), a Delaware corporation (the “Company”), (ii) the undersigned
holders of the Company’s Series A Preferred Stock, and (iii) the undersigned
holders of the Company’s Common Stock.

RECITALS

WHEREAS, the Company and the undersigned parties to the Stockholder Agreement
who collectively hold the requisite number of shares of Common Stock and
Preferred Stock necessary to amend and supplement the Stockholder Agreement
pursuant to Section 8(k) thereof, desire to amend and supplement certain terms
of the Stockholder Agreement as described herein; and

WHEREAS, all capitalized terms not defined herein shall have the meaning
ascribed to such terms in the Stockholder Agreement.

NOW, THEREFORE, in consideration of the premises, and of the representations,
warranties, covenants and agreements contained herein, the parties hereto agree
as follows:

1. Definitions. The preamble of the Stockholder Agreement is amended to delete
the definition of “Common Stock” and Section 1 of the Stockholder Agreement is
amended to add the following defined terms:

“Common Stock” means the Common Stock, par value $0.0001 per share, of the
Company and any class of common stock of the Company issued upon conversion or
in exchange for such common stock, including without limitation (whether or not
authorized on the date hereof), the Class A Common Stock into which such Common
Stock may be changed as contemplated by the Second Restated Certificate and the
Common Stock into which such Class A Common Stock may be converted as further
contemplated by the Second Restated Certificate.

“Investment Agreement” means that certain Investment Agreement, dated as of
July 15, 2011, by and among the Company and the Stockholders named therein.

“Planned IPO” means the first sale by the Company of Common Stock in a firm
commitment underwritten public offering pursuant to an effective registration
statement on Form S-1 (or any successor form) under the Securities Act, which
sale of shares is completed on or prior to June 30, 2012.

“Second Restated Certificate” means the Second Amended and Restated Certificate
of Incorporation approved by the Board of Directors of the Company on July 15,
2011.

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“Third Restated Certificate” means the Third Amended and Restated Certificate of
Incorporation approved by the Board of Directors of the Company on July 15,
2011.

2. Election of Directors: Other Voting Matters.

(a) Section 2(a)(i) of the Stockholder Agreement is amended and restated in its
entirety as follows: “(i) the authorized number of the Company’s Board of
Directors (the “Board”) to be maintained at not less than ten (10) nor more than
fourteen (14) directors, provided that this Section 2(a) shall not prohibit a
Stockholder from voting in favor of the Third Restated Certificate so long as
the Third Restated Certificate does not become effective prior to the
termination of this Agreement.”

(b) Section 2(a)(v) of the Stockholder Agreement is amended and restated in its
entirety as follows:

“(v) the removal from the Board (with or without cause) of any representatives
designated hereunder at the written request of the parties possessing the right
to designate such representatives (but only upon such written request and under
no other circumstances), provided, however, that each party entitled to
designate a representative to the Board shall, upon the written request of the
Company, use its best efforts to cause such representative director to submit
his resignation from the Board, such resignation to take effect no later than
immediately prior to the closing of the initial sale of shares of Common Stock
by the Company in the Planned IPO and, in the event such a resignation is not
obtained promptly following the Company’s written request, to provide a written
request for, and to vote in favor of, the removal of such representative
director, effective no later than immediately prior to such closing.”

3. Transfer Restrictions.

(a) Section 3(b) of the Stockholder Agreement is amended and restated in its
entirety as follows:

“(b) Lockup.

(i) In the event the Company shall undertake its first sale to the public
pursuant to a registration statement of the Company filed under the Securities
Act other than the Planned IPO, each Stockholder shall agree in writing, in form
and substance customary for similar transactions, if requested by the managing
underwriter or underwriters thereof, not to lend, offer, pledge, sell, contract
to sell (including, without limitation, any short sale), sell any option or
contract to purchase, purchase any option or contract to sell, grant any option,
right or warrant to purchase, or otherwise transfer or dispose of, directly or
indirectly, any shares of Common Stock or other securities of the Company
convertible into or exercisable or exchangeable for Common Stock held by such
Stockholder immediately before the effective date of the registration statement
for such offering, or enter into any swap or other arrangement that transfers to
another, in whole or in part, any of the economic consequences of ownership of
Common Stock (whether any such transaction is described in this subsection is to
be settled by delivery of Common Stock or such other securities, in cash or
otherwise, except for securities to be sold to such underwriter pursuant to such
registration statement; provided, however that:

(A) such period shall not exceed one hundred eighty (180) days after the
effective date of the registration statement, except that such 180-day period
may be extended for not more than eighteen (18) days if such extension is
reasonably necessary to allow the Company’s underwriters to comply with NASD
Conduct Rule 2711 (or any similar successor rule); and

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(B) the Company’s directors, officers and stockholders individually owning more
than one percent (1%) of the Company’s outstanding Common Stock (after giving
effect to conversion into Common Stock of all outstanding Preferred Stock) also
agree to such limitations.”

(ii) In the event that the Company advises a Stockholder that it intends to file
or has filed a registration statement with respect to the Planned IPO, each
Stockholder shall enter into a lock-up agreement with the representatives of the
underwriters identified by the Company in substantially the form attached as
Exhibit A within ten days of the Company’s request.”

(iii) The Company may impose stop-transfer instructions with respect to the
shares of Common Stock or other securities of the Company convertible into or
exercisable or exchangeable for Common Stock subject to the foregoing
restriction until the end of such one hundred eighty (180) day period (or the
extended period set forth above).”

(b) Clause (ii) of Section 3(e) of the Stockholder Agreement is amended and
restated as follows: “any redemption or conversion of the Series A Preferred
Stock pursuant to the terms of such Series A Preferred Stock as set forth in the
certificate of incorporation”

4. Miscellaneous. Section 8 of the Stockholder Agreement is amended to add the
following new subparagraph (l):

“(l) For the avoidance of doubt, the Stockholders and the Company acknowledge
and agree that (i) (x) the registration and offering and sale of Common Stock by
the Company in the Planned IPO and, if applicable, the registration and offering
and sale of Common Stock by any Stockholder pursuant to the same registration
statement that covers the Planned IPO, (y) the conversion and redemption of the
Series A Preferred Stock and the issuance of Series B Preferred Stock and Common
Stock upon such conversion as contemplated by the Second Restated Certificate
and (z) the agreements and transactions contemplated by the Investment
Agreement, would not and will not violate or involve a breach of or default
under, or require any party hereto to provide any notice, take any action or
obtain any approval under, and the Stockholders shall not have any rights with
respect thereto under, any of the provisions of Sections 2(a), 3(a), 3(c) or
3(d), Section 4 or Section 6 of this Agreement, and (ii) this Stockholder
Agreement shall terminate in accordance with its terms and be of no further
force or effect upon the closing of the Planned IPO, provided that such
termination shall not limit any obligation of any Stockholder to be bound by the
lockup agreement and the Company’s ability to impose stop transfer instructions
as contemplated by Section 3(b) hereof.”

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5. Waivers.

(a) The Company and the Stockholders hereby waive the provisions of Sections 3,
4 and 6 of the Stockholder Agreement with respect to the transactions
contemplated by that certain Letter Agreement, dated as of July 15, 2011, by and
among the Company and the Stockholders named therein, and agree that such
transactions would not and will not violate or involve a breach of or default
under, or require any party to provide any notice, take any action or obtain any
approval under, and the Company and the Stockholders shall not have any rights
with respect thereto under, any of the provisions of such Sections of the
Stockholder Agreement.

(b) The Company and the Stockholders hereby waive the provisions of Section 6 of
the Stockholder with respect to the Company’s issuance of 500,000 shares of
Class A Common Stock pursuant to that certain Termination Agreement and Mutual
Release, dated as of July 15, 2011, by and between the Company, REG Services,
LLC and USRG Holdco IX, LLC, and agree that such issuance would not and will not
violate or involve a breach of or default under, or require any party to provide
any notice, take any action or obtain any approval under, and the Company and
the Stockholders shall not have any rights with respect thereto under, any of
the provisions of such Section 6 of the Stockholder Agreement.

6. Representations and Warranties. Each party hereto represents and warrants to
each of the other parties hereto that:

(a) Such party is duly organized, validly existing and in good standing under
the laws of the jurisdiction in which it is organized.

(b) Such party has the requisite power and authority to execute and deliver this
Amendment and to consummate the transactions contemplated hereby and such
execution, delivery and consummation have been duly authorized by all necessary
action. This Amendment has been duly executed and delivered by such party and
constitutes the valid and binding obligation of such party, enforceable against
it in accordance with its terms.

(c) Neither the execution and delivery of this Amendment nor the consummation of
the transactions contemplated hereby will (i) conflict with, or result in a
breach or violation of, any provision of its organizational documents,
(ii) constitute, with or without notice or the passage of time or both, a breach
violation or default under any law, rule, regulation, permit, license, agreement
or other instrument of such party or to which such party or such party’s
property is subject, or (iii) require any consent, approval or authorization of,
or notification to, or filing with, any federal, state, local or foreign court,
governmental agency or regulatory or administrative authority on the part of
such party.

(d) Such party (other than the Company) is the owner of the number of shares of
Common Stock and/or Preferred Stock set forth opposite such party’s name on the
signature pages hereto for purposes of approving this Amendment to the
Stockholder Agreement.

7. Other.

(a) Except as expressly set forth herein, this Amendment shall not by
implication or otherwise alter, modify, amend or in any way affect any of the
terms, conditions, obligations, covenants or agreements contained in the
Stockholder Agreement, all of which shall continue to be in full force and
effect.

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(b) This Amendment may be executed in any number of counterparts, each of which
shall for all purposes be deemed to be an original, and all such counterparts
shall together constitute but one and the same instrument.

IN WITNESS WHEREOF, this Amendment has been duly executed and delivered by the
duly authorized officers of the parties hereto as of the date first written
above.

 

RENEWABLE ENERGY GROUP, INC. By: /s/ Jeffrey Stroburg Name: Jeffrey Stroburg
Title: Chairman and CEO

 

    SHARES OF COMMON     AND/OR PREFERRED STOCK WEST CENTRAL COOPERATIVE    
Series A Preferred Stock: 563,635 By: /s/ Jeffrey Stroburg     Common Stock:
10,909,053 Name: Jeffrey Stroburg     Title: President and CEO     BUNGE NORTH
AMERICA, INC.     Series A Preferred Stock: 1,361,723 By: /s/ Eric Hakmiller    
Common Stock: 702,780 Name: Eric Hakmiller     Title: Vice President Bunge
Biofuels     NATURAL GAS PARTNERS VIII, L.P.     Series A Preferred Stock:
2,559,808 By: G.F.W. Energy VIII, L.P., general partner     Common Stock: 1,096
      By: GFW VIII, L.L.C., general partner                 By: /s/ William J.
Quinn     Name: William J. Quinn     Title: Authorized Member    

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E D & F MAN HOLDINGS BV     Series A Preferred Stock: 2,222,152 By: /s/ Paul
Chatterton     Common Stock: 342,850 Name: Paul Chatterton     Title: Appointed
Representative     USRG HOLDCO V, LLC     Series A Preferred Stock: 3,388,635
By: USRG Management Company, LLC, its manager     Common Stock: 2,563,268
      By: /s/ Jonathan Koch     Name: Jonathan Koch     Title: Managing Director
    NGP ENERGY TECHNOLOGY PARTNERS, L.P.     Series A Preferred Stock: 2,559,808
By: /s/ Christopher Sorrells     Common Stock: 1,096 Name: Christopher Sorrells
    Title: Managing Director