August 28, 1997

Alabama Synfuel #1, Ltd.
c/o Covol Technologies, Inc.
3280 North Frontage Road
Lehi, Utah 84043

Covol Technologies, Inc.
3280 North Frontage Road
Lehi, Utah 84043

         Re:  Letter Amendment

Gentlemen:

         Reference is made to the Alabama Project Purchase  Agreement,  dated as
of March 20, 1997, by and among Alabama Synfuel #1 Ltd. and Covol  Technologies,
Inc., as sellers and  Birmingham Syn Fuel,  LLC, as buyer,  as amended by letter
agreements  dated as of June 27, July 7, and August 28, 1997,  respectively,  as
the same may be further amended, supplemented or otherwise modified from time to
time (the "Purchase  Agreement").  Capitalized  terms used herein shall have the
meanings ascribed thereto in the Purchase Agreement.

         The parties hereto hereby amend the Purchase Agreement by:

         a.       Inserting  the language  "and each other Transaction Document"
                  immediately  following the word  "Agreement" in the third line
                  of Section 7.1(c) thereof;

         b.       Deleting the  following  language in clause (i) of Section 8.1
                  thereof  "satisfaction or waiver of the condition set forth in
                  Section  7.1(i)  hereto",  and  inserting  in  its  place  the
                  following  language  "'Date  of  Substantial   Completion'  as
                  defined in the Construction Contract"; and

         c.       Deleting Sections 8.2(d) and (e) thereof in their entirety.



         This letter agreement may be executed in one or more counterparts,  all
of which shall be considered one and the same letter agreement.

                                      COVOL TECHNOLOGIES, INC.

                                      By:/s/ Stanley M. Kimball
                                         -----------------------
                                      Name: Stanley M. Kimball
                                      Title: CEO


                                      ALABAMA SYN FUEL #1 LTD.

                                      By:/s/ Stanley M. Kimball
                                         ---------------------------------
                                      Name: Stanley M. Kimball
                                      Title: CEO of Covol, General Partner


                                      BIRMINGHAM SYN FUEL, L.L.C.

                                      By: /s/ Reynold Roeder
                                         ---------------------
                                      Name: Reynold Roeder
                                      Title: Vice President

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