Document:

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                                                                   EXHIBIT 10(g)

                                    AGREEMENT

                                     Between

                            CHEVRON RESEARCH COMPANY

                                       and

                         SOUTH HAMPTON REFINING COMPANY

                                   Relating to

                             CHEVRON AROMAX PROCESS

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                  THIS AGREEMENT, is effective as of the Tenth day of March,
1988, between Chevron Research Company, a Delaware corporation, hereinafter
referred to as "Chevron Research", and South Hampton Refining Company, a Texas
corporation, hereinafter referred to as "South Hampton";

                  W I T N E S S E T H:

                  WHEREAS, Chevron Research has developed a new catalytic
process for converting petroleum naphtha and desires to have that new process
demonstrated in commercial operation by a licensee other than an Affiliate of
Chevron Research; and

                  WHEREAS, the process heretofore has only been demonstrated on
a bench and pilot plant scale and Chevron Research and South Hampton both
acknowledge that the process may not work as hoped in a refinery; and

                  WHEREAS South Hampton is willing to test and demonstrate the
process in an existing unit that will be converted from use as a catalytic
reforming unit and that is located at South Hampton's Silsbee, Texas, refinery
("Refinery"); and

                  WHEREAS, as Chevron Research's first non-affiliated licensee
and demonstrator of the new process in the United States of America, South
Hampton wishes to agree with Chevron Research on the terms and conditions for
conducting the demonstration and for licenses relating to the use of the process
in the converted unit;

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                  NOW, THEREFORE, for and in consideration of the premises and
the mutual covenants contained in this Agreement, the parties agree as follows:

                            ARTICLE 1-0 - DEFINITIONS

                  1.1. Whenever used in this Agreement, the following terms
shall have the meanings prescribed in Schedule "A" attached hereto and made a
part hereof: "AROMAX Process"; "AROMAX Catalyst"; "Type L zeolite"; "Patent
Rights"; "Catalyst Patent Rights"; "Technical Information"; "Subsidiary";
"Affiliate"; "Licensed Unit"; "Stock Charge"; "Barrel"; "United States";
"Procedures Manual"; and Demonstration Run".

           ARTICLE 2-0 - LICENSES - Chevron Research to South Hampton

                  2.1. Subject to the terms and conditions of this Agreement,
Chevron Research grants to South Hampton a nonexclusive, nontransferable,
fully-paid license under Chevron Research's Patent Rights and Catalyst Patent
Rights to practice the AROMAX Process in the Licensed Unit. This license
includes the right under Chevron Research's Patent Rights to make or have made
any apparatus for South Hampton's use in practicing the AROMAX Process in the
Licensed Unit, and the right to export to,

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sell, or use in any country the products produced in the Licensed Unit when
practicing the AROMAX Process.

                  2.2. Nothing contained in this Agreement shall be construed as
granting any rights, express or implied, under any of Chevron Research's patents
or Patent Rights or Catalyst Patent Rights or as estopping Chevron Research from
claiming infringement of any of its patents or Patent Rights or Catalyst Patent
Rights in connection with any operation of South Hampton not conducted in the
Licensed Unit.

           ARTICLE 3-0 - LICENSES - South Hampton to Chevron Research

                  3.1. South Hampton grants to Chevron Research and its
Subsidiaries a nonexclusive, nontransferable, royalty-free license under South
Hampton's Patent Rights and Catalyst Patent Rights to practice the AROMAX
Process in the United States and elsewhere. This license includes the right
under South Hampton's Patent Rights to make or have made any apparatus for
Chevron Research's use and/or sale to its AROMAX Process licensees for their use
in practicing the AROMAX Process; and the right to export to, sell, or use in
any country the products of such process.

                  3.2. South Hampton grants to Chevron Research, without
obligation to account, the nonexclusive right to grant (either directly or
indirectly through others) nonexclusive licenses

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under South Hampton's Patent Rights and Catalyst Patent Rights to Chevron
Research's other AROMAX Process licensees to use South Hampton Technical
Information, if those licensees grant back, without obligation to account, a
license under their Patent Rights and Catalyst Patent Rights inuring to South
Hampton's benefit under this Agreement.

                        ARTICLE 4-0 TECHNICAL INFORMATION

                  4.1. Upon South Hampton's request, Chevron Research's
Technical Information shall be available to South Hampton for use in the
operations of the Licensed Unit. South Hampton shall not use any Technical
Information furnished by Chevron Research in any additional processing unit
without first entering into an appropriate licensing arrangement with Chevron
Research covering such use. Except as provided by Section 5.1(7) below, such
licensing arrangement shall be under the terms and conditions then being offered
to other licensees by Chevron Research.

                  4.2. All Technical Information, including all data, plans,
specifications, flow sheets and drawings, furnished directly or indirectly, in
writing or otherwise, to South Hampton by Chevron Research, whether pursuant to
Article 5-0 of this Agreement or otherwise, are and shall remain Chevron
Research's property and shall be used only for the construction, erection,
alteration, maintenance, repair and operation of the Licensed

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Unit. South Hampton shall use all reasonable efforts to prevent duplication or
disclosure of all Technical Information furnished directly or indirectly, in
writing or otherwise, by Chevron Research which is confidential in nature and
has been so designated. South Hampton may furnish portions of Chevron Research's
Technical Information, to the extent necessary for South Hampton's operation of
Licensed Unit, to others who have entered into an appropriate agreement with
Chevron Research. Chevron Research shall not be unreasonable with respect to
the terms and conditions of any such agreement or with respect to the approval
or selection of any party to such agreement and Chevron Research shall not
require payment of a fee as a condition to entering into such an appropriate
agreement. South Hampton shall exercise all reasonable efforts to prevent others
from acquiring information concerning, and/or samples of, AROMAX Catalyst
acquired from Chevron Research or its nominee.

                  4.3. Notwithstanding any other provision in this Agreement,
South Hampton shall not, except as permitted in writing by Chevron Research,
perform or have performed any analyses or tests of any nature to determine the
structure or composition or physical-chemical characteristics of AROMAX
Catalyst whether such catalyst is new, used, or spent. However, upon request,
Chevron Research will assist South Hampton in arranging

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such analyses or tests as necessary for the purposes of metals recovery and
catalyst disposal.

                  4.4. Chevron Research's obligation pursuant to Section 4-1
above shall not include any obligation on the part of Chevron Research under
this Agreement to furnish or make available to South Hampton detailed
information with respect to the specific design, construction, and/or operation
of any commercial AROMAX Process plants. Any furnishing by Chevron Research to
South Hampton of such specific information for, or other services in connection
with, a commercial AROMAX Process plant shall be done pursuant to Article 5-0
of this Agreement or pursuant to agreements separate and apart from this
Agreement on terms and conditions mutually satisfactory to Chevron
Research and South Hampton.

                  4.5. All data, plans, specifications, flow sheets and
drawings, furnished directly or indirectly, in writing or otherwise, to South
Hampton by Chevron Research pursuant to Article 5-0 of this Agreement shall be
used by South Hampton only for the construction, erection, alteration,
maintenance, repair and operation of the Licensed Unit. Subject to Section 4.2,
South Hampton may furnish such portions of such data, plans, specifications,
flow sheets and drawings to others to the extent necessary for the construction,
erection, alteration, maintenance, repair and operation of the Licensed Unit.

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                  4.6. Upon Chevron Research's request, South Hampton's
Technical Information shall be available to Chevron Research. Chevron Research
agrees that it will use all reasonable efforts to prevent duplication or
disclosure to third parties, except entities having obligations of secrecy to
Chevron Research that are equivalent to the obligations of secrecy used by
Chevron Research to protect its own Technical Information, of all Technical
Information furnished, directly or indirectly, in writing or otherwise, by South
Hampton that is confidential in nature and has been so designated.

                  4.7. No obligation shall be imposed by this Article 4-0 upon
the recipient party with respect to the protection and use of any portion of
proprietary information which corresponds in substance to information (i) that
was developed by and in the recipient party's possession prior to receipt
hereunder of the corresponding information, (ii) that at the time of disclosure
is, or thereafter becomes through no act or failure to act by the recipient
party, published information generally known in the petroleum refining industry,
or (iii) that is furnished to the recipient party by another as a matter or
right without restriction on disclosure; provided, however, that the occurrence
of either (i) or (ii) or (iii), above, shall not be construed as granting any
rights, express or implied, under patents licensable by Chevron Research or by
South Hampton as the case may be. Such

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information shall not be deemed to be within one of the foregoing exceptions if
it is merely embraced by more general information available on a nonconfidential
basis or in the recipient party's possession. In addition, any combination of
features shall not be deemed to be within the foregoing exceptions unless the
combination itself and its principle of operation are embraced by corresponding
information which is within one of the foregoing exceptions.

             ARTICLE 5-0 - TECHNICAL COOPERATION AND DEMONSTRATION

                  5.1. Because the Licensed Unit is the first demonstration unit
for the AROMAX Process, Chevron Research will make available to South Hampton
different services than it normally makes available to licensees of its fully
commercialized technology. Chevron Research and South Hampton agree that certain
obligations and responsibilities relating to the conversion, preparation,
startup, and operation of the Licensed Unit shall be as follows:

           1.     Laboratory Work

                  a. Chevron Research will conduct or have conducted, at its
expense, all standard laboratory tests and analyses appropriate to support the
Demonstration Run. In order to perform

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such analyses, Chevron Research may set up its own gas chromatographic
equipment at the Refinery. Test results shall be Chevron Research Technical
Information.

                  b. To the extent pilot plant work is necessary or appropriate,
in Chevron Research's opinion, to support the Demonstration Run, Chevron
Research will perform pilot plant tests or have them performed, at its expense.
Pilot plant results shall be Chevron Research Technical Information.

           2.     Engineering Support

                  a. Process Engineering--Chevron Research will provide, at
its expense, process engineering services required to prepare the Licensed Unit
for start-up. Those process engineering services include preparing sulfur
sorber and sulfur control catalyst reactor specifications, reviewing and
evaluating existing Refinery equipment for suitability for the Demonstration Run
and determining modifications that are necessary, preparing flow schemes for
feed and product streams of the Licensed Unit, defining the plant configuration
for the Demonstration Run, and preparing performance estimates. Chevron
Research, upon request and upon reasonable notice from South Hampton, will
prepare and furnish for South Hampton's use a Procedures Manual for the Licensed
Unit. South Hampton shall be responsible for process

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engineering evaluations relating to the operation of the debutanizer column on
the product streams from the Licensed Unit.

                  b. Plant Cleanup for Sulfur Removal--Chevron Research will
specify the procedures appropriate for cleaning the Licensed Unit and associated
equipment and pipes before catalyst may be loaded and the unit started up. South
Hampton will perform or have performed those cleanup procedures at its expense
and under the supervision or guidance of Chevron Research.

                  c. Plant operation--South Hampton will provide plant operators
at its expense. Chevron Research will station or have stationed, at its expense,
at least one engineer at the refinery during the first six weeks of the
Demonstration Run covering plant cleanup, startup, and the initial phases of
operation of the Licensed Unit. The Chevron engineer(s) will provide full shift
assistance during the two week period following startup of the Licensed Unit.
Full shift assistance will also be provided during the first regeneration of the
first charge of AROMAX Process Catalyst to the Licensed Unit. Chevron Research
will instruct South Hampton's employees at the Refinery in the operation of
Licensed Units, including reasonable training, at times mutually agreeable to
South Hampton and Chevron Research.

                  d. Routine operation--Chevron Research will make available
engineering assistance for normal operations and for

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emergencies from the San Francisco area or from the Port Arthur Refinery of
Chevron U.S.A. Inc., as appropriate, for the Licensed Unit during the
Demonstration Run.

          3.     Equipment

                  a. Chevron Research will provide online sulfur measurement
apparatus or equipment appropriate to monitor the sulfur content of the feed
stream to the Licensed Unit during the Demonstration Run. At the end of the
Demonstration Run, South Hampton may buy that online sulfur measurement
equipment from Chevron Research at a price to be mutually agreed, taking into
account depreciation of the equipment.

                  b. Except for the online sulfur measurement equipment provided
for by Section 5.1(3)(a), South Hampton will provide, at its expense, all
equipment, including but not limited to reactor vessels, sulfur sorber and
sulfur control vessels, sampling and monitoring equipment and associated piping,
sampling ports and valves, and all process control equipment, appropriate to
conduct the AROMAX Process in the Licensed Unit. South Hampton will bear the
costs of installing any equipment, including online sulfur measurement
apparatus, in the Licensed Unit.

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          4.     Catalysts and Sorbents

                  a. Sulfur Sorbent--Chevron Research will provide the first
charge of sulfur sorbent for use in the Demonstration Run. Chevron Research will
retain ownership of that first charge and upon its deactivation will be
responsible for proper disposal of it. South Hampton will provide all further
sulfur sorbent charges necessary for the operation of the Licensed Unit at its
expense.

                  b. Sulfur Control Catalysts--Chevron Research will provide the
first charge of each of the sulfur control catalysts to be installed for both
the cleanup phase and the Demonstration Run in the Licensed Unit. Chevron
Research shall retain all ownership rights in the catalysts, including catalyst
bases and platinum and other metals deposited on the catalyst bases, and upon
deactivation of the sulfur control catalysts will be responsible for proper
disposal of them. South Hampton will provide all further sulfur control catalyst
charges necessary for the operation of the Licensed Unit at its expense.

                  c. AROMAX Catalyst--Chevron Research will provide the first
charge of AROMAX Catalyst to be installed in the Licensed Unit ("First Charge").
Chevron Research shall retain all ownership rights in the First Charge,
including catalyst base and platinum and other metals deposited on the catalyst
base.

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Chevron Research expects that the First Charge will achieve a total service
life in excess of nine months from startup through use of multiple
regenerations.

                  From time to time during the Demonstration Run, Chevron
Research will estimate the length of the then current run of the First Charge
and the length of the run immediately following the next regeneration of the
First Charge. The total service life of the First Charge will end with the then
current run when the estimated length for the run immediately following the next
regeneration is one and one-half months or less, unless South Hampton elects to
continue to use the First Charge. In the event South Hampton elects to continue
to use the First Charge for a run that Chevron Research has estimated will be
one and one-half months or less, the total service life of the First Charge
shall end when South Hampton ceases using the First Charge.

                  In the event the total service life of the First Charge is
less than nine months from startup, a replacement charge of AROMAX Catalyst is
recommended, and South Hampton elects to place a replacement charge of AROMAX
Catalyst in the Licensed Unit, Chevron Research will provide one replacement
charge at no cost to South Hampton. Chevron Research shall retain all ownership
rights in the replacement charge of AROMAX Catalyst, including catalyst base and
platinum and other metals deposited on the catalyst base.

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                  d. Except as provided in Section 5.1(4)(c), Chevron Research
will make AROMAX Catalyst, sulfur control catalysts or sulfur sorbents available
to South Hampton pursuant to catalyst supply contracts containing Chevron
Research's standard commercial terms and conditions if South Hampton wishes to
continue practicing the AROMAX Process in the Licensed Unit or South Hampton
wishes to continue using sulfur sorbent or sulfur control catalysts after
removal of the first charge of each. Except as provided in Section 5.l(4)(c),
all costs relating to all catalyst charges after the first, including metals
recovery and disposal, will be for South Hampton's account. Upon request,
Chevron Research will assist South Hampton in locating a source of metals for
such further charges.

         5.      Refinery integration

                  a. Feeds and Utilities--South Hampton will provide all feeds
and utilities, including nitrogen gas and electrolytic hydrogen for the cleanup,
startup, and regeneration phases of the demonstration, at its expense.

                  b. Hydrogen--The unit being converted produces hydrogen gas
that is supplied to other units at the Refinery. During the plant cleanup and
startup phases of the demonstration, South Hampton will arrange for a hydrogen
source to supply all hydrogen requirements of its other units at the Refinery
at its expense.

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In the event of either a process failure of the AROMAX Process after startup of
the Licensed Unit so that the Licensed Unit does not produce hydrogen (a need to
regenerate AROMAX Catalyst is not a process failure) or a delay in startup
beyond two weeks after commencement of plant cleanup, such delay being caused in
Chevron Research's opinion by inadequate plant cleanup even though Chevron
Research plant cleanup instructions are followed, Chevron Research shall arrange
for hydrogen to be provided to the Refinery until the unit resumes hydrogen
production. Notwithstanding the foregoing, Chevron Research's total liability in
the event of such a process failure (a need to regenerate AROMAX Catalyst is not
a process failure) or delay, including the cost of hydrogen provided, shall not
exceed the greater of either Thirty-five Thousand Dollars ($35,000) or an amount
agreed to in writing by an officer of Chevron Research. Chevron Research shall
keep South Hampton informed of the amounts of costs applied against said total
liability of Chevron Research.

           6.    Visitation rights

                  a. At any time following execution of this Agreement, Chevron
Research may, at its election, announce to the trade that South Hampton is an
AROMAX Process licensee. South Hampton grants to Chevron Research and its
representatives, visitors, customers, and nominees the right of access to the
Licensed Unit during normal business hours for a period ending either five

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years after startup of the Licensed Unit or upon conversion of the unit to a
process other than the AROMAX Process, whichever occurs first. South Hampton may
limit such visits to a maximum of two per calendar month, may require Chevron
Research personnel to accompany any such visitors, and may require any such
visitors to enter into a secrecy agreement appropriate to protect South
Hampton's proprietary information used at the Refinery.

         7.   Second unit license

         During the term of this Agreement, Chevron Research agrees that upon
written request by South Hampton, Chevron Research shall grant South Hampton an
AROMAX Process license so that South Hampton's 4,000 BPOD catalytic reforming
unit located at the Refinery may be a licensed AROMAX Process unit. Chevron
Research and South Hampton agree that AROMAX Process royalty rates charged to
South Hampton for that unit, whether running or fully paid royalty rates, shall
be based on Chevron Research's then current AROMAX Process royalty rates as
follows:

<TABLE>
<CAPTION>
                                               Royalty rate: % of then
          Barrels/Calendar Day                current AROMAX Process rate
          --------------------                ---------------------------
<S>                                           <C>
                 0 - 1,000                                  0%
             1,001 - 20000                                 50
             2,001 - 3,000                                 75
                over 3,000                                100
</TABLE>

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                       ARTICLE 6-0 - CHARGES AND PAYMENTS

                  6.1 Except as provided by Article 5-0 above, South Hampton
shall pay Chevron Research for all work and services, including pilot plant
tests (if any), performed for South Hampton pursuant to this Agreement or as
otherwise mutually agreed. South Hampton shall, within thirty (30) days after
submission of Chevron Research's invoices therefor, pay to Chevron Research
a sum equal to the cost of all work and services performed by Chevron Research
during each calendar month plus an amount to equal twenty percent (20%) of the
cost invoiced to allow Chevron Research to recover costs incurred but not
billed. Included in the determination of such cost, but not by way of
limitation, shall be: all direct expenses such as blueprints, computer usage,
engineering and drafting supplies, analytical services, postage and shipping,
telegraph, telephone, transportation and living expenses of Chevron Research's
employees while engaged in services rendered at points other than at Chevron
Research's home office or laboratories, and all similar expenses directly
incurred in connection with such work and services; the salaries or wages
allocated for the actual time of Chevron Research's employees engaged in such
work and services; and an amount in respect of Chevron Research's overhead and
indirect expenses that shall be determined as a percentage of such salaries and
wages, such percentage to be the same as that applied by Chevron

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Research for similar services being performed at the time in question by Chevron
Research for others under similar conditions and on substantially the same terms
as this agreement. All charges and payments specified herein refer to lawful
money of the United States and all payments to be made by South Hampton
hereunder shall be paid to Chevron Research at the office of Chevron Research or
by wire transfer in immediately available funds to Chevron Research's bank, each
as designated in Article 8-0 hereof.

                   ARTICLE 7-0 - RESPONSIBILITY AND LIABILITY

                  7.1 Neither party shall be liable for failures and delays in
performance due to any cause or circumstance beyond its reasonable control,
including, without thereby limiting the generality of the foregoing, any
failures or delays in performance caused by differences with workmen, lockouts,
fires, acts of God or the public enemy, riots, incendiaries, interference by
civil or military authorities, compliance with the laws of the United States or
with the orders of any governmental authority, compliance with public policy,
delays in transit or delivery on the part of transportation companies or
communication facilities, or any failure of sources of material.

                  7.2. Although Chevron Research represents that the work and
services performed by it under this Agreement shall be

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performed in accordance with accepted engineering standards, South Hampton
acknowledges that the AROMAX Process is not yet commercialized and that the
Licensed Unit is a scale-up demonstration and test unit. Chevron Research's
only liability, if any, respecting the Licensed Unit and/or the operation of it
and/or the Demonstration Run, including but not limited to any breach of the
foregoing representation or for any losses, damages, claims or demands of any
nature arising out of work and services provided under this Agreement, to South
Hampton and/or South Hampton's contractors and/or third parties shall be that
set forth in Section 5.l(5)(b) above. In no event shall Chevron Research be
liable for or obligated in any manner to pay any consequential or indirect
damages.

                  7.3. Except as provided in Article 5-0, South Hampton shall
have complete control of the construction, erection, alteration, maintenance,
repair and operation of Licensed Unit at all times.

                       ARTICLE 8-0 - TERM AND TERMINATION

                  8.1. Chevron Research's obligations to South Hampton pursuant
to Article 5-0 to perform services, make payments, or incur costs for its own
account with respect to the Demonstration Run or the Licensed Unit shall
terminate upon completion of the Demonstration Run.

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                  8.2. In the event of a breach of any provision of or default
in any obligation under this Agreement, including a failure or refusal by South
Hampton to make payments to Chevron Research as required by Article 6-0, unless
the breaching party fully remedies such breach with reasonable promptness under
the circumstances after the breach is called to its attention in writing by the
other party, then such other party may terminate this Agreement by giving the
breaching party written notice of termination. No such termination for breach
shall relieve the breaching party of any liability for breach incurred prior to
the effective date of said termination or from the obligation to fulfill any
payment obligation based on operations prior to said effective date of
termination. No express or implied waiver of any breach of any of the provisions
of this Agreement shall constitute a waiver of any subsequent breach of the same
or different provisions hereof. The right of termination provided in this
section is in addition to any other rights available by law, including the right
to sue for breach without terminating.

                  8.3. South Hampton may terminate this Agreement at any time
after the expiration of seven (7) years from the date on which the Licensed Unit
first goes on stream, by giving sixty (60) days' prior written notice to Chevron
Research. The date on which the Licensed Unit first goes on stream shall be the
startup

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date for the Demonstration Run unless otherwise agreed by Chevron Research and
South Hampton.

                  8.4 If there is either a process failure of the AROMAX Process
after startup of the Licensed Unit so that the Licensed Unit does not produce
hydrogen (a need to regenerate AROMAX Catalyst is not a process failure) or a
delay in startup beyond two weeks after commencement of plant cleanup, as
provided in Section 5.l(5)(b), and if Chevron Research's total liability in the
event of such a process failure or delay pursuant to Section 5.1(5)(b) is or
will be exceeded, South Hampton may, at its election, terminate either the
Demonstration Run (if started) or this Agreement by written notice to Chevron
Research.

                  8.5. Upon any termination of this Agreement South Hampton
shall retain its right to use Chevron Research's Technical Information in the
Licensed Unit and its rights under Chevron Research's Patent Rights and Catalyst
Patent Rights but only to the extent to which, had this Agreement not been
terminated, South Hampton would have been entitled to process Stock Charge
without payment to Chevron Research. Termination of this Agreement shall not
terminate Chevron Research's right to use and to disclose South Hampton's
Technical Information provided in Article 4-0 or Chevron Research's rights under
South Hampton's Patent Rights and Catalyst Patent Rights as provided in Article
3-0. However, the rights retained by South Hampton and

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Chevron Research after termination shall not extend to any Patent Rights or
Catalyst Patent Rights based on inventions made after the effective date of
termination or to any information developed or acquired after the effective date
of such termination.

                  8.6. In the event of termination, South Hampton shall not be
entitled to refunds of any amounts paid hereunder and if South Hampton has
authorized Chevron Research to perform work for South Hampton for which payment
would be due to Chevron Research, South Hampton shall pay Chevron Research an
amount for reasonable costs incurred as preparation for work authorized but not
yet performed and incurred in shutting down services then being performed.

                  8.7. Termination of this Agreement shall not affect either
party's right to enforce any obligation or liability accruing under this
Agreement prior to the effective date of termination. Termination of this
Agreement shall not relieve South Hampton or Chevron Research with respect to
protection and use of confidential Technical Information as provided in Article
4-0.

                  8.8. Unless sooner terminated as hereinabove provided, this
Agreement shall continue in full force and effect for a period of fifteen (15)
years from the effective date, on which date this Agreement shall automatically
terminate.

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                        ARTICLE 9-0 - GENERAL PROVISIONS

                  9.1 The addresses of the parties hereto are as follows:

             Chevron Research:       Chevron Research Company
                                     Licensing and Catalyst Division
                                     P.O. Box 1627
                                     Richmond, CA   94802-0627

             Copy to:                Chevron Corporation
                                     Law Department, Contracts Division
                                     P.O. Box 7141
                                     San Francisco, CA 94120-7141

             Chevron Research's
               Bank Account:         Wells Fargo Bank
                                     3900 MacDonald Avenue
                                     Richmond, CA 94804
                                     Account No. 4335-028510

             South Hampton:          South Hampton Refining Company
                                     P.O. Box 1636
                                     Farm Road 418
                                     Silsbee, TX 77656

Any notice required or permitted under this Agreement, shall be personally
delivered, sent by registered mail, sent by Telex, or sent by ordinary mail.

                  9.2 "AROMAX Process" and "AROMAX Catalyst" are proprietary
names, and South Hampton shall not contest Chevron Research's claim of ownership
of or claim any rights or interests in the words "AROMAX Process" or AROMAX
Catalyst" and South Hampton shall make no commercial use of the words "AROMAX
Process" or "AROMAX Catalyst" as trademarks, or otherwise, unless

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such commercial use and the manner thereof have first been approved in writing
by Chevron Research.

                  9.3 This Agreement shall not be assignable by either party
without the prior written consent of the other party hereto, except that it may
be assigned without such consent to the successor of either party or to a
person, firm, or corporation acquiring all or substantially all of the business
and assets of such party. Nothing herein contained, however, shall be deemed to
prevent Chevron Research from assigning this Agreement to any corporation which
shall acquire all or substantially all of Chevron Research's technical
information and unexpired patents in the petroleum refining field. No assignment
of this Agreement shall be valid until and unless this Agreement shall have been
assumed by the assignee. When duly assigned in accordance with the foregoing,
this Agreement shall be binding upon and shall inure to the benefit of the
assignee.

                  Any assignment of this Agreement shall provide that neither
South Hampton nor Chevron Research shall be relieved of their respective
obligations with respect to the use, duplication or disclosure of data or other
information of a confidential nature as provided in Article 4-0.

                  No sale, lease or other disposition by South Hampton of the
Licensed Unit shall relieve South Hampton of its obligation

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with respect to the use, duplication, or disclosure of data or other information
of a confidential nature as provided in Article 4-0 above.

                  9.4 Except as otherwise expressly provided herein, neither
Refiner nor any director, employee or agent of Refiner or of Refiner's
subcontractors or vendors, shall give to or receive from any director, employee
or agent of Chevron or any Affiliate any gift or entertainment of significant
value or any commission, fee or rebate in connection with this Agreement. In
addition, neither Refiner nor any director, employee or agent of Refiner or of
Refiner's subcontractors or vendors, shall enter into any business arrangement
with any director, employee or agent of Chevron or any Affiliate who is not
acting as a representative of Chevron or its Affiliate without prior written
notification thereof to Chevron. Any representative authorized by Chevron may
audit any and all records of Refiner or Refiner's subcontractors or vendors for
the sole purpose of determining whether there has been compliance with this
Section 9.4.

                  9.5 This Agreement is executed and delivered with the
understanding that it embodies the entire agreement between the parties and that
there are no prior representations, warranties, or agreements relating thereto.

                                      -25-
<PAGE>   27

                  9.6 This Agreement shall be construed and the legal relations
of the parties determined in accordance with the laws of state of California.

                  9.7 This Agreement shall become effective on the date first
written above upon execution by South Hampton and by Chevron Research in
California, U.S.A. No change in, addition to, or waiver of the terms and
provisions hereof shall be binding upon Chevron Research or South Hampton
unless approved in writing by their respective authorized representatives, and
no modification shall be effected by the acknowledgment or acceptance of
purchase order forms containing other or different terms and conditions.

                  IN WITNESS WHEREOF, the parties hereto have caused their
respective corporate names to be hereto subscribed by their respective officers
and agents thereunto duly authorized.

                                       CHEVRON RESEARCH COMPANY

                                       By
                                         ---------------------------------
                                       Title
                                            ------------------------------
                                       Date
                                           -------------------------------

SOUTH HAMPTON REFINING COMPANY

By
  ----------------------------------
Title
     -------------------------------
Date
    --------------------------------

Attachments:  Schedule A"

                                      -26-
<PAGE>   28

                                  SCHEDULE "A"

                                   DEFINITIONS

                  1. "AROMAX Process" shall mean a catalytic process for
converting normally liquid hydrocarbons in a Charge Stock to a normally liquid
hydrocarbon product or products, having a higher aromatic hydrocarbon content
than the Charge Stock wherein the conversion is conducted at a temperature above
555(degrees)F, and at a total pressure below 800 psi, in the presence of
hydrogen and a solid catalyst containing a Type L zeolite and at least the metal
platinum, or compounds thereof.

                  2. "AROMAX Catalyst" shall mean a solid catalyst containing
at least a Type L zeolite and at least the metal platinum, or compounds thereof,
for use in the practice of the AROMAX Process.

                  3. Type L zeolite" shall mean a crystalline alumino-silicate
as disclosed in U.S. Patent 3,216,789, Breck, et al., issued November 9, 1965.

                  4. Patent Rights shall mean all claims, or the equivalent of
claims (hereinafter referred to as "claims"), of all patents and published
patent applications of all countries to the extent and only to the extent that
said claims are directed primarily to the AROMAX Process (including, without
limitation, claims to apparatus for carrying out the AROMAX Process and

                                      -1-
<PAGE>   29

product of the AROMAX Process, but excluding claims to catalyst compositions,
methods of catalyst loading, and methods of catalyst manufacture), based on
inventions conceived prior to five (5) years after the effective date of this
Agreement, and transferable interests in or rights with respect thereto; in each
case to the extent that, and subject to the terms and conditions (including the
obligation to account to and/or make payments to others) under which, the
person, firm, or company in question now has or hereafter shall have the right
to grant licenses, immunities, or licensing rights thereunder.

                   5. "Catalyst Patent Rights" shall mean all claims, or the
equivalent of claims (hereinafter referred to as "claims"), of all patents and
published patent applications of all countries to the extent and only to the
extent that said claims cover the composition of the AROMAX Process Catalyst
(excluding claims directed to methods of manufacture of AROMAX Process Catalyst)
based on inventions conceived prior to five (5) years after the effective date
of this Agreement, and transferable interests in or rights with respect thereto;
in each case to the extent that, and subject to the terms and conditions
(including the obligation to account to and/or make payments to others) under
which, said person, firm, or company in question now has or hereafter shall have
the right to grant licenses, immunities, or licensing rights thereunder.

                                      -2-
<PAGE>   30

                  6. "Technical Information" shall mean improvements and
developments relating to and operating techniques necessary for the operation of
the AROMAX Process, in a stage of development suitable for commercial use,
developed prior to five (5) years after the effective date of this Agreement, to
the extent that, and subject to the terms and conditions (including the
obligation to account to and/or make payments to others) under which, the
person, firm, or company in question has the right to disclose such information
to others. Technical Information" shall not include information relating to (i)
catalyst manufacture, (ii) catalyst loading, or (iii) catalytic reforming or
similar processes other than the AROMAX Process.

                  7. "Subsidiary" shall mean any company in which the company in
question, directly or indirectly, shall, at the time in question, own or have
the power to exercise control of a majority of the stock having the right to
vote for the election of directors. For purposes of this Agreement, Chevron
Corporation, incorporated in the State of Delaware, U.S.A., and its
Subsidiaries, as defined above, shall be deemed to be Subsidiaries of Chevron
Research.

                  8. "Affiliate" shall mean any company of which the designated
company now or hereafter owns or controls, directly or indirectly, fifty percent
(50%) or more of the stock having the right to vote for the election of
directors thereof. For the purpose of this definition, the stock owned or
controlled by a

                                      -3-
<PAGE>   31

particular company shall be deemed to include all stock owned or controlled,
directly or indirectly, by any other company of which the particular company
owns or controls, directly or indirectly, fifty percent (50%) or more of the
stock having the right to vote for the election of directors thereof. Further,
as used in connection with Chevron Research the term "Affiliate" shall include
Chevron Corporation, a Delaware corporation, and its Affiliates, as defined
above; and Irving Oil Limited, incorporated in New Brunswick, and its one
hundred percent (100%) owned Subsidiaries.

                  9. "Licensed Unit" shall mean South Hampton's AROMAX Process
unit having a design capacity of 131,400 Barrels of Charge Stock per calendar
year (400 Barrels per operating day at an operating factor of 0.9) located at
South Hampton's Silsbee Texas, refinery.

                  10. Stock Charge" shall mean all normally liquid hydrocarbons
charged or recycled to the Licensed Unit.

                  11. "Barrel" shall mean forty-two (42) gallons of two hundred
thirty-one (231) cubic inches each, measured at sixty degrees Fahrenheit (60
degrees F).

                  12. "United States" shall mean all territory to which patents
of the United States of America apply.

                                      -4-
<PAGE>   32

                  13. "Procedures Manual" shall mean, as applicable to the
Licensed Unit: recommended start-up, shutdown, and regeneration procedures and
recommended procedures for catalyst handling.

                  14. "Demonstration Run" shall mean that period of time during
which the AROMAX Process is being demonstrated in the Licensed Unit, beginning
on startup of the Licensed Unit with the first charge of AROMAX Catalyst after
plant cleanup and ending either (a) on the latter to occur of nine months after
startup or completion of regeneration(s) of the first charge of AROMAX Catalyst
to the Licensed Unit or (b) as mutually agreed.

                                      -5-
<PAGE>   33

                                    Revisions

First introductory paragraph: effective date inserted--March 10, 1988

Section 4.3: sentence added at the end, per 3/4/88 fax--"However upon request,
       Chevron Research will assist South Hampton in arranging such analyses or
       tests as necessary for the purposes of metals recovery and catalyst
       disposal."

Section 5.l(4)(b), sulfur control catalysts, line 3: phrase inserted per 3/4/88
       fax--"both the cleanup phase and"

Section 5.1(4)(c): entire section revised per N.N. Carter/D.V. Law telephone
       discussion

Section 5.1(7), line 1: introductory phrase added for consistency with revised
       5.l(4)(c) and new 8.4--"During the term of this Agreement,"

Section 6.1, line 5, "twenty (20)" changed to "thirty (30)" per 3/4/88 fax

Article 8-0, a new Section 8.4 inserted per N.N. Carter/D.V. Law telephone
       discussion, remaining sections in the article renumbered

Section 9.1, in South Hampton address, "Attn:" deleted, "Farm Road 418" inserted

Schedule A, paragraph 9, design capacity inserted

<PAGE>   34

                      [CHEVRON RESEARCH COMPANY LETTERHEAD]

                                           March 8, 1988

          Mr. David B. Carpenter
          South Hampton Refining
             Company
          P.O. Box 1636
          Farm Road 418
          Silsbee, Texas 77659

          Dear Mr. Carpenter:

          Duplicate execution copies of the contract between South Hampton and
          Chevron Research for the Chevron AROMAX Process demonstration are
          attached. Please have both copies executed for South Hampton and
          return them to me. I will arrange for execution for Chevron Research
          and return a fully executed copy to you for your files.

          The contract has been revised to make the changes of the March 4
          facsimile message from David Law to you and to respond to concerns
          expressed by Mr. N. N. Carter in a telephone conversation with Mr.
          Law. The revisions are outlined on the attached sheet entitled
          "Revisions."

          We are looking forward to beginning the demonstration.

                                              Very truly yours,

                                              /s/ W. J. ROSSI

          Enclosure

<PAGE>   35

                           FACSIMILE TRANSMITTAL SHEET

                      [CHEVRON RESEARCH COMPANY LETTERHEAD]

TO: Mr. N. N. Carter
    South Hampton Refining Company                   DATE   April 27, 1989
    Silsbee, Texas                                       -------------------
                                                     Page   1   of   18
                                                          ------   ---------
    Fax: (409) 385-2453

================================================================================

    Subject: Continuation of AROMAX Demonstration

    Attached is a draft of our proposed agreement covering continuation of the
    AROMAX demonstration at your refinery. It takes the form of an Addendum to
    the first agreement, "Agreement Relating to AROMAX Process," dated March 10,
    1988.

    Exhibits to the Addendum will be:

           o  Security Agreement: covering the equipment purchased with monies
              loaned by Chevron.

           o  Financing Statements: for State and Hardin County.

           o  Contract of Sale: covering conditional offtake of AROMAX product
              by Chevron Chemical.

    These exhibits  are still under preparation, and will be forwarded as soon
    as possible.

    Please review the Draft Addendum and give us your comments. Note that we
    have updated the costs for the modifications of the AROMAX and RHENIFORMING
    units following a more detailed analysis of the requirements. The amounts
    are now $297,000 and $135,000, respectively.

                                                     Regards,

                                                     /s/ W.J. ROSSI/DAVID V. LAW

   End. - Draft Addendum

   DVLaw:

   NNCarter-1                            JCWatson/BEReynolds-1
   WWSmith-1                             PMSpindler-1
   WLStumpf-1                            WEBrown-1
   WKTurner-1      No Encl.              CMDetz-1
   WJRossi-2                             DVLaw-1
                                         LCfile-1

<PAGE>   36

                            ADDENDUM TO THE AGREEMENT
                           RELATING TO AROMAX PROCESS

                         SECOND COMMERCIAL DEMONSTRATION

       THIS ADDENDUM, effective as of the __ day of __________, 1989, is between
       Chevron Research Company, a Delaware corporation, hereinafter referred to
       as "CHEVRON RESEARCH", and South Hampton Refining Company, a Texas
       corporation, hereinafter referred to as "SOUTH HAMPTON";

       W I T N E S S E T H:

       WHEREAS, CHEVRON RESEARCH and SOUTH HAMPTON have entered into an
       "Agreement Relating to AROMAX Process" effective March 10, 1988
       ("Agreement"), pursuant to which SOUTH HAMPTON carried out a
       demonstration of the AROMAX Process using an existing unit converted to
       reforming operations located at SOUTH HAMPTON's Silsbee, Texas, refinery
       ("Refinery") and which shall have a design capacity of 420 Barrels of
       Demonstration Feed per operating day at an operating factor of 0.9 for
       purposes of the Long-Term Demonstration contemplated by this ADDENDUM
       ("Licensed Unit"); and

       WHEREAS, CHEVRON RESEARCH is interested in supporting a long-term second
       commercial demonstration of the AROMAX process in Licensed

       4-21-89

<PAGE>   37

       Unit processing only Demonstration Feed in a multi-reactor system with
       at least one full catalyst regeneration; and

       WHEREAS, SOUTH HAMPTON as CHEVRON RESEARCH's first non-affiliated
       licensee is willing to carry out a long-term commercial demonstration
       meeting CHEVRON RESEARCH's objectives on the terms and conditions set
       forth in this ADDENDUM;

       NOW, THEREFORE, in consideration of the premises and covenants herein,
       CHEVRON RESEARCH and SOUTH HAMPTON agree as follows:

                             ARTICLE 1-0 DEFINITIONS

      1.1  Whenever used in this ADDENDUM, any term which has been defined in
           the AGREEMENT shall have the same definition. In addition, the
           following terms shall have the definitions prescribed in Schedule I
           attached hereto and a part hereof: "Rheniforming Unit", "AROMAX
           Equipment", "Rheniforming Equipment", "Long-Term Demonstration",
           "Demonstration Feed", "Rheniforming Catalyst", "AROMAX Product",
           "Support Price", and "Received Price".

                                           Rheniforming Unit = Large Reformer
                                               Licensed Unit = Small Reformer

                                      -2-
<PAGE>   38

                        ARTICLE 2-0 TECHNICAL ASSISTANCE

      2.1  In order to support the Long-Term Demonstration of the AROMAX
           Process in Licensed Unit, Licensed Unit must be modified by the
           addition of AROMAX Equipment and new AROMAX Catalyst must be
           installed in Licensed Unit. In addition, since Licensed Unit will not
           provide the estimated hydrogen requirements for SOUTH HAMPTON's
           hydrotreating operations at the Refinery, based upon SOUTH HAMPTON's
           planned expansion of such operations, it will be necessary to return
           the Rheniforming Unit to service. Accordingly, as part of the
           Long-Term Demonstration contemplated by this ADDENDUM, the
           Rheniforming Unit must be modified by the addition of Rheniforming
           Equipment and new Rheniforming F Catalyst must be installed in the
           Rheniforming Unit. CHEVRON RESEARCH and SOUTH HAMPTON agree that the
           relative responsibilities and obligations of the parties during the
           Long-Term Demonstration relating to assistance during pre-startup,
           startup, and normal operations for Licensed Unit and for the
           Rheniforming Unit shall be as follows:

           2.1.1  (Pre-Startup) CHEVRON RESEARCH will specify the equipment
                  modifications required for the Long-Term Demonstration, and
                  will assist SOUTH HAMPTON to locate, inspect, and install
                  AROMAX Equipment and

                                      -3-
<PAGE>   39

                  Rheniforming Equipment. Following installation and inspection
                  of the AROMAX Equipment and Rheniforming Equipment, CHEVRON
                  RESEARCH will specify cleanup and dryout procedures to ready
                  Licensed Unit and the Rheniforming Unit for catalyst loading,
                  and will advise and assist SOUTH HAMPTON during cleanup and
                  dryout. CHEVRON RESEARCH will specify and supply the initial
                  charges of new AROMAX Catalyst, Rheniforming Catalyst, and
                  sorbents required for the Long-Term Demonstration and will
                  assist SOUTH HAMPTON during loading of such Catalysts and
                  sorbents. The extent of pre-startup assistance for Licensed
                  Unit and the Rheniforming Unit to be provided by CHEVRON
                  RESEARCH will be determined by CHEVRON RESEARCH as required to
                  carry out the Long-Term Demonstration after consultation with
                  SOUTH HAMPTON. SOUTH HAMPTON will be responsible for and will
                  carry out pre-startup of Licensed Unit and the Rheniforming
                  Unit. CHEVRON RESEARCH and SOUTH HAMPTON will each bear their
                  own expenses incurred during pre-startup of Licensed Unit and
                  the Rheniforming Unit. CHEVRON RESEARCH will also bear the
                  expense of the initial charge of AROMAX Catalyst,
                  Rheniforming Catalyst, and sorbents. CHEVRON RESEARCH will
                  perform of have performed at its expense cleanup and dryout of
                  Licensed Unit.

                                      -4-
<PAGE>   40

                  when requested by CHEVRON RESEARCH, SOUTH HAMPTON will at its
                  expense provide reasonable assistance during cleanup and
                  dryout of Licensed Unit.

           2.1.2  (Startup) The Rheniforming Unit will be returned to service
                  before starting up Licensed Unit. CHEVRON RESEARCH has
                  previously provided startup procedures for the Rheniforming
                  Unit and will advise and assist SOUTH HAMPTON during startup
                  of the Rheniforming Unit. However, SOUTH HAMPTON will be
                  responsible for carrying out the startup, including the supply
                  of required feed and all chemicals. Following startup of the
                  Rheniforming Unit, SOUTH HAMPTON will startup Licensed Unit
                  with the advice and assistance of CHEVRON RESEARCH. Startup
                  procedures for Licensed Unit will be those previously
                  specified by CHEVRON RESEARCH for the first Demonstration Run
                  conducted pursuant to the Agreement unless otherwise specified
                  or approved by CHEVRON RESEARCH. CHEVRON RESEARCH will specify
                  the Demonstration Feed, the feed rate(s), and operating
                  conditions for Licensed Unit during startup and at all times
                  during the Long-Term Demonstration. The extent of startup
                  assistance for Licensed Unit and the Rheniforming Unit to be
                  provided by CHEVRON RESEARCH will be determined by

                                      -5-
<PAGE>   41

                  CHEVRON RESEARCH an required to carry out the Long-Term
                  Demonstration after consultation with SOUTH HAMPTON, and will
                  include full shift coverage during startup of Licensed Unit.
                  CHEVRON RESEARCH and SOUTH HAMPTON will each bear their own
                  expenses incurred during startup of Licensed Unit and the
                  Rheniforming Unit.

           2.1.3  (Operation) Operations of the Rheniforming Unit will be
                  controlled by and will be the sole responsibility of SOUTH
                  HAMPTON. Rheniforming Process operations will be carried out
                  by SOUTH HAMPTON pursuant to the terms and conditions of the
                  "Agreement Relating to Rheniforming Process" dated May 16,
                  1978, as supplemented and amended by subsequent written
                  agreements entered into by CHEVRON RESEARCH and SOUTH HAMPTON.
                  Operations of Licensed Unit during the Long-Term Demonstration
                  will be controlled by and will be the sole responsibility of
                  SOUTH HAMPTON. SOUTH HAMPTON will operate Licensed Unit during
                  the Long-Term Demonstration to process only Demonstration
                  Feed at a feed rate(s) and under operating conditions to be
                  specified by CHEVRON RESEARCH.

                                      -6-
<PAGE>   42

                       ARTICLE 3-0 CATALYSTS AND SORBENTS

      3.1  The initial charge of AROMAX Catalyst and sorbents for use in
           Licensed Unit for the Long-Term Demonstration will be supplied by
           and delivered to the Refinery by CHEVRON RESEARCH. CHEVRON RESEARCH
           will retain ownership and risk of loss at all times. At the
           conclusion of the Long-Term Demonstration CHEVRON RESEARCH will
           assist SOUTH HAMPTON to unload AROMAX Catalyst and Sorbents and
           CHEVRON RESEARCH may then use and/or dispose of the AROMAX Catalyst
           and sorbents in any manner without accounting to SOUTH HAMPTON.

      3.2  The initial charge of Rheniforming Catalyst, for the Rheniforming
           Unit will be supplied by and delivered to the Refinery by CHEVRON
           RESEARCH. Title and risk of loss will pass to SOUTH HAMPTON upon
           delivery to the Refinery gate. Rheniforming Catalyst supplied
           hereunder, upon transfer of title to SOUTH HAMPTON, will be deemed
           subject to the terms and conditions of the "Rheniforming Catalyst
           Supply Contract", dated May 6, 1978 entered into by CHEVRON RESEARCH
           and SOUTH HAMPTON. Accordingly, SOUTH HAMPTON will not resell or
           otherwise transfer ownership, possession, or control of any portion
           of Rheniforming Catalyst without CHEVRON RESEARCH'S prior written
           approval.

                                      -7-
<PAGE>   43

      3.3  Licensed Unit presently contains Rheniforming Catalyst which will be
           removed during pre-startup in order to convert to the practice of
           the AROMAX Process for the Long-Term Demonstration. SOUTH HAMPTON
           owns such Rheniforming Catalyst and will deliver same to CHEVRON
           RESEARCH at the Refinery gate immediately upon removal. Title and
           risk of loss will pass to CHEVRON RESEARCH upon such delivery.
           CHEVRON RESEARCH may use and/or dispose of the Rheniforming Catalyst
           acquired hereunder in any manner without accounting to SOUTH HAMPTON.

                     ARTICLE 4-0 LOAN AND SECURITY INTEREST

      4.1  CHEVRON RESEARCH will loan to SOUTH HAMPTON up to One Hundred
           Thirty-five Thousand Dollars ($135,000.00) for the sole purpose of
           purchasing Rheniforming Equipment and covering the expenses of SOUTH
           HAMPTON related to Rheniforming Unit cleanup as per the following
           terms and conditions:

           4.1.1  SOUTH HAMPTON will purchase only such Rheniforming Equipment
                  as has been previously approved by CHEVRON RESEARCH, which
                  approval will not be unreasonably withheld.

                                      -8-
<PAGE>   44

           4.1.2  CHEVRON RESEARCH will loan to SOUTH HAMPTON the purchase price
                  of Rheniforming Equipment delivered to the Refinery and funds
                  necessary to cover SOUTH HAMPTON's actual out-of-pocket
                  expenses related to Rheniforming Unit cleanup. However, in no
                  event will CHEVRON RESEARCH'S loan obligation hereunder exceed
                  $135,000.00.

           4.1.3  CHEVRON RESEARCH will lend the purchase price as stated above
                  and SOUTH HAMPTON will execute and record a Security
                  Agreement(s) in the form attached hereto at the time of sale
                  to SOUTH HAMPTON of any equipment within Rheniforming
                  Equipment.

           4.1.4  SOUTH HAMPTON will pay to CHEVRON RESEARCH the full amount
                  loaned to SOUTH HAMPTON hereunder by CHEVRON RESEARCH without
                  interest or penalty in three equal consecutive monthly
                  payments due on the first day of each of the first three
                  calendar months following the calendar month during which the
                  average feed rate of penhex fed to the Refinery over thirty
                  (30) consecutive operating days equals or exceeds 2000 Barrels
                  per day. The foregoing payment obligation will apply during
                  and/or after completion of the Long-Term Demonstration.

                                      -9-
<PAGE>   45

      4.2  CHEVRON RESEARCH will loan to SOUTH HAMPTON up to Two Hundred
           Ninety-seven Thousand Dollars ($297,000) for the sole purpose of
           purchasing AROMAX Equipment as per the following terms and
           conditions:

           4.2.1  SOUTH HAMPTON will purchase only such AROMAX Equipment as has
                  been previously approved by CHEVRON RESEARCH, which approval
                  will not be unreasonably withheld.

           4.2.2  CHEVRON RESEARCH will loan to SOUTH HAMPTON the purchase price
                  of AROMAX Equipment delivered to the Refinery. However, in no
                  event will CHEVRON RESEARCH's loan obligation hereunder exceed
                  the aggregate price F.O.B. the Refinery for all AROMAX
                  Equipment purchased by SOUTH HAMPTON or $297,000.00 whichever
                  is the lesser amount.

           4.2.3  CHEVRON RESEARCH will lend the purchase price as stated above
                  and SOUTH HAMPTON will execute and record a Security
                  Agreement(s) in the form attached hereto at the time of sale
                  to SOUTH HAMPTON of any equipment within AROMAX Equipment.

                                      -10-
<PAGE>   46

           4.2.4  SOUTH HAMPTON will pay to CHEVRON RESEARCH the full amount
                  loaned to SOUTH HAMPTON hereunder by CHEVRON RESEARCH without
                  interest or penalty in nine (9) equal consecutive monthly
                  payments due on the first day of each calendar month following
                  the first seventy-five (75) days of operations of Licensed
                  Unit after startup of the Long-Term Demonstration.

                 ARTICLE 5-0  AROMAX PRODUCT AND CONTRACT OF SALE

      5.1  All AROMAX Product will be sold by SOUTH HAMPTON at the highest
           available price on a monthly basis.

      5.2  CHEVRON RESEARCH will arrange with its affiliated company, Chevron
           Chemical Company ("CHEVRON CHEMICAL), to enter into a Contract of
           Sale with SOUTH HAMPTON for AROMAX Product which SOUTH HAMPTON cannot
           within a reasonable time sell to a third party purchaser. Such
           Contract of Sale acceptable to CHEVRON CHEMICAL and SOUTH HAMPTON is
           attached hereto.

                 ARTICLE 6-0 PRICE SUPPORT, CREDIT, AND REFUND

      6.1  In the event that the Received Price for AROMAX Product sold during
           any calendar month in which SOUTH HAMPTON has a payment obligation to
           CHEVRON RESEARCH pursuant to

                                      -11-
<PAGE>   47

           Section 4.2.4 is less than the Support Price for the same calendar
           month, CHEVRON RESEARCH will grant to SOUTH HAMPTON a credit which
           will be applied against SOUTH HAMPTON'S next monthly payments due
           pursuant to Sections 4.1.4 and 4.2.4. The amount of such credit will
           be the lesser of either the amount of the payments due to CHEVRON
           RESEARCH or the arithmetic product obtained by multiplying the
           number of gallons of AROMAX Product sold by SOUTH HAMPTON during the
           month in question times the arithmetic difference obtained by
           subtracting the Received Price from the Support Price.

      6.2  Following completion of the Long-Term Demonstration or at the end
           of the twelfth month of the Long-Term Demonstration, whichever
           occurs first, if the Received Price averaged over such period is
           equal to or greater than the Support Price averaged over such period,
           within thirty (30) days of the completion of the Long-Term
           Demonstration or the end of the twelfth month of the Long-Term
           Demonstration as the case may be SOUTH HAMPTON will pay to CHEVRON
           RESEARCH a refund in the amount of the total of all the credits taken
           by SOUTH HAMPTON pursuant to Section 6.1 above.

      6.3  SOUTH HAMPTON will keep, and on request provide to CHEVRON RESEARCH,
           verified copies of all books and records required

                                      -12-
<PAGE>   48

           to establish the amount of and the schedule of, any credit(s) or
           payment(s) due hereunder.

                            ARTICLE 7-0 MISCELLANEOUS

      7.1  The provisions of this ADDENDUM are in addition to the provisions in
           the Agreement. This ADDENDUM is not intended to amend, modify, or
           delete any right or obligation of either CHEVRON RESEARCH or SOUTH
           HAMPTON under the Agreement.

      7.2  This ADDENDUM upon full execution will be deemed appended to the
           Agreement and will be deemed a part thereof. Any provision of the
           Agreement which by reasonable interpretation relates to the conduct
           of the Long-Term Demonstration will be so applied. In particular, the
           provisions of Article 4-0, Article 7-0, and Article 9-0 will apply
           to this ADDENDUM and the Long-Term Demonstration hereunder.

      7.3  The Long-Term Demonstration will terminate when one of the following
           events occurs: (1) the initial charge of AROMAX Catalyst provided
           hereunder is spent and no longer regenerable, or, (2) the initial
           charge of AROMAX Catalyst has produced AROMAX Product for twelve (12)
           calendar months, or, (3) CHEVRON RESEARCH terminates the Long-Term
           Demonstration, which it may do at its sole discretion; provided,
           however,

                                      -13-
<PAGE>   49

           that by mutual agreement of the parties the Long-Term Demonstration
           may continue for an additional period(s). During any such additional
           period(s) the terms of Article 5-0 of this ADDENDUM shall not apply.

      7.4  Upon completion of the Long-Term Demonstration, CHEVRON RESEARCH
           shall remove its AROMAX Catalyst from Licensed Unit at the earliest
           reasonable opportunity.

      7.5  At no time prior to, during, or after the Long-Term Demonstration
           will CHEVRON RESEARCH have any responsibility or liability to supply
           or compensate SOUTH HAMPTON for purchased hydrogen supplied for use
           in the Refinery.

                                      -14-
<PAGE>   50

        IN WITNESS WHEREOF, the parties hereto have caused their respective
        corporate names to be subscribed hereto by the respective officers or
        agents thereunto duly authorized.

                                      CHEVRON RESEARCH COMPANY

                                      By
                                        -------------------------------------
                                      Title
                                           ----------------------------------
                                      Date
                                          -----------------------------------

       SOUTH HAMPTON REFINING COMPANY

By
  ------------------------------------
Title
     ---------------------------------
Date
    ----------------------------------

Attachments:  Schedule I
              Security Agreement
              Contract of Sale

                                      -15-
<PAGE>   51

                                   SCHEDULE I

      1.   "Rheniforming Unit" means SOUTH HAMPTON's existing 4,000-Barrel
           per operating day reforming unit located at its Silsbee, Texas,
           refinery. The Rheniforming Unit is presently out of service but has
           operated under license from CHEVRON RESEARCH using Rheniforming F
           Catalyst.

      2.   "AROMAX Equipment" means new and/or used equipment specified by
           CHEVRON RESEARCH as additional equipment for AROMAX Process
           operations in Licensed Unit necessary for the Long-Term
           Demonstration.

      3.   "Rheniforming Equipment" means new and/or used equipment specified by
           CHEVRON RESEARCH as additional equipment necessary for Rheniforming
           Process operations in the Rheniforming Unit.

      4.   "Long-Term Demonstration" means SOUTH HAMPTON's commercial
           demonstration of AROMAX Process operations in Licensed Unit on feeds
           and at feed rates and under operating conditions specified by CHEVRON
           RESEARCH carried out under this ADDENDUM.

                                      I-1
<PAGE>   52

      5.   "Demonstration Feed" means such feed(s) to Licensed Unit as are
           specified by CHEVRON RESEARCH as feed(s) to be processed during the
           Long-Term Demonstration.

      6.   "Rheniforming Catalyst" means Rheniforming F Catalyst supplied by
           CHEVRON RESEARCH.

      7.   "AROMAX Product" means the liquid reformate product from Licensed
           Unit produced during the Long-Term Demonstration.

      8.   "Support Price" means the average of high and low values of the daily
           estimated U.S. Gulf Coast pipeline price in cents per gallon of
           regular unleaded gasoline as reported in Platts Oilgram Price Report
           plus nineteen and one-half cents (19.5 cents) per gallon averaged
           over a calendar month.

      9.   "Received Price" means the price in cents per gallon of AROMAX
           Product sold by SOUTH HAMPTON and averaged over a calendar month.

                                       I-2
<PAGE>   53

                                CONTRACT OF SALE

         This Contract of Sale is entered into as of ________________, 1989, by
and between Chevron Chemical Company, 1301 McKinney, Houston, Texas 77253
("Buyer") and South Hampton Refining Company, P. O. Box 1636, Farm Road 418,
Silsbee, Texas 77656 ("Seller").

         Seller agrees to sell and deliver and Buyer agrees to purchase and
receive the product described below in the quantities and during the period set
forth in this Contract of Sale.

         1. The product to be sold and delivered hereunder is AROMAX test
debutanized reformate having the typical composition shown on Exhibit "A"
attached hereto ("AROMAX Product"). The AROMAX Product shall be produced in
Seller's AROMAX Process Unit when processing feed(s) selected by Chevron
Research Company during the long-term, second commercial demonstration of the
AROMAX Process conducted in the AROMAX Process Unit pursuant to the "Addendum to
the Agreement Relating to AROMAX Process Second Commercial Demonstration"
between Chevron Research Company and South Hampton Refining Company dated
_______________________. The typical feed composition is shown in Exhibit B,
attached hereto.

         2. The quantity of AROMAX Product to be sold hereunder shall be the
total AROMAX Product output from the AROMAX Process Unit during the test run,
less any quantities sold by Seller TO others.

<PAGE>   54

          3. As AROMAX Product is manufactured, Seller shall transport the
AROMAX Product that is to be sold to Buyer under this Contract by tanktruck from
Seller's refinery in Silsbee, Texas, to Seller's storage facilities in Beaumont,
Texas. Seller shall invoice Buyer for each tanktruck load delivered to said
storage facilities for purchase by Buyer and Buyer shall pay Seller for the
amount of such delivered load within thirty (30) days after the date of invoice.
AROMAX Product purchased by Buyer pursuant to this Contract shall be purchased
at the F.O.B. Beaumont price set forth below. Title to the AROMAX Product shall
pass from Seller to Buyer upon delivery of the AROMAX Product into Seller's
storage facilities at Beaumont. Said AROMAX Product shall be stored in
segregated tanks for Buyer and shall not be commingled with materials belonging
to Seller or others. No storage costs or fees shall be assessed against or
payable by Buyer.

          4. The F.O.B. Beaumont price for the AROMAX Product shall be
determined as follows:

Price in cents/gallon = .99 (X(BZ)) + .95 (X(TOL))(P(TOL))

                        +  X(R)(P(NG)) - .13 (1 - X(R))

Where:   X(BZ) = Volume fraction of Benzene
         X(TOL) = Volume fraction of Toluene
         X(R) = Volume fraction of Raffinate =

                1 - .99 (X(BZ)) - .95 (X(TOL))

         P(BZ) =  Average FOB Gulf Coast Contract Benzene Price published in the
                  Benzene & Derivatives Newsletter published by DeWitt & Company
                  Incorporated for the date of the tanktruck delivery.

                                      -2-
<PAGE>   55

              P(TOL) =  Average FOB Gulf Coast Spot Commercial grade Toluene
                        price published in the Toluene/Xylene Newsletter
                        published by Dewitt & Company Incorporated for the date
                        of the tanktruck delivery.

              P(NG)  =  Average Hi-Low Spot Gas Liquid Natural Gasoline price at
                        Mont Belvieu published in Platts' Oilgram for the date
                        of the tanktruck delivery.

              Where the date of tanktruck delivery is a Saturday, Sunday, or
Holiday for which any of the foregoing publications does not publish the
specified price, the specified price published by the publication for the last
business day before such Holiday or Saturday/Sunday shall be used in the
calculation.

         5. Seller shall deliver AROMAX Product to Buyer in Beaumont from
Seller's storage facilities in bargeload quantities unless otherwise agreed by
Buyer.

         6. Notwithstanding the foregoing and despite the fact that, Seller may
have invoiced Buyer for AROMAX Product and that Buyer may have paid Seller
therefor, Seller shall have the risk of loss, including but not limited to
contamination, for all AROMAX Product invoiced to Buyer until such AROMAX
Product is delivered out of Seller's storage facilities to Buyers barge upon
Sellers downguage.

         7. Each tanktruck load of AROMAX Product shall be analyzed by
acceptable gas chromatography techniques to determine the Benzene and Toluene
contents as mass fractions. The amount of such AROMAX Product transported by
tanktruck to storage shall be determined by difference (full versus empty) by
weighing on

                                      -3-
<PAGE>   56

certified scales. The Benzene and Toluene contents of the tanktruck load shall
be determined by multiplying the weight of AROMAX Product delivered into storage
by the appropriate chromatographically determined mass fraction. Weights shall
be converted to volumes for price calculations using densities from ASTM Data
Series Publication DS4A (benzene = 7.3653 lb/gal., toluene = 7.2601 lb./gal.).

         8. Buyer's obligation to purchase and Seller's right to sell pursuant
to this Contract of Sale shall apply only to AROMAX Product produced during the
long-term second commercial demonstration referred to in Paragraph 1 above. In
no event shall this Contract of Sale apply to any AROMAX Product produced more
than one year after the date of the AROMAX Process Unit startup for said
demonstration.

         9. Buyer shall pay Seller, in addition to the price provided herein, an
amount equal to any tax, duty or other charge (including Superfund levies or the
like) assessed on Seller related to sales made pursuant to this Contract unless
such tax, duty, or charge is related to the storage of AROMAX Product, as
provided for above, or is measured by net income.

         10. Seller warrants that at the time of delivery of AROMAX Product out
of Seller's storage facilities to Buyer Seller shall have good title thereto,
said AROMAX Product shall have been produced in Seller's AROMAX Process Unit
from feeds specified by Chevron Research Company, and said AROMAX Product shall
not have been comingled or mixed with any other materials and shall not have
been contaminated with any materials not named in Exhibit A.

                                      -4-
<PAGE>   57

         SELLER DOES NOT MAKE, AND EXPRESSLY DISCLAIMS, AND BUYER EXPRESSLY
WAIVES ANY OTHER WARRANTIES WHATSOEVER, INCLUDING (WITHOUT LIMITATION) ANY
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, REGARDLESS OF
WHETHER ORAL OR WRITTEN, EXPRESSED OR IMPLIED, OR ALLEGEDLY ARISING FROM ANY
USAGE OF ANY TRADE OR ANY COURSE OF DEALING.

         11. Seller's total liability for any claim of any nature made by Buyer
or Buyer's customers after delivery of AROMAX Product out of storage to Buyer's
barges shall not exceed the purchase price of the AROMAX Product sold hereunder.
This shall also constitute Seller's maximum liability even if Buyer or Buyer's
customers mix AROMAX Product with other materials or use AROMAX Product in
specialized equipment. In no event shall Seller be liable for any lost profits
or any indirect, consequential, special, incidental, contingent or punitive
damages incurred by Buyer.

         12. a. Neither party shall be in breach of its obligations hereunder
to the extent that performance is prevented, delayed or (in the sole but
reasonable judgment of the party concerned) made substantially more expensive as
a result of any of the following contingencies: (i) any cause beyond the
reasonable control of the party concerned; (ii) labor disturbance, whether or
not involving the employees of the party concerned or otherwise, and whether or
not the disturbance could be settled by acceding to the demands of a labor
group; (iii) compliance with a request or order of a person purporting to act on
behalf of any government or governmental department or

                                      -5-
<PAGE>   58

agency (including but not limited to EPA, OSHA, etc.); or (iv) shortage in raw
material, transportation, or power.

         b. performance will be excused as provided above even though the
occurrence of the contingency in question may have been foreseen or foreseeable
at the time of contracting or subsequently become foreseeable, so long as such
occurrence is not definite or specific at the time of contracting.

         c. Quantities not purchased or sold due to the provisions of this
Section need not be made up later.

         d. Nothing in this Section shall excuse Buyer from its obligations to
make payments when due.

         13. a. This Contract, integrates the entire understanding between the
parties with respect to the subject matter covered. It supersedes all prior
understandings, drafts, discussions or statements, whether oral or in writing,
expressed or implied, dealing with the same subject matter. It may not be
amended or modified in any manner except by a written agreement signed by both
parties which expressly amends this Contract.

         b. No rights or obligations under this Contract may be assigned without
the prior written consent of the other party.

         c. Any questions concerning the interpretation and enforcement of this
Contract shall be governed by the internal laws of the State of Texas.

         d. Neither party shall give any director, employee or representative of
the other party any commission, fee, rebate, gift or entertainment of
significant cost or value in connection with this Contract, or enter into any
other business arrangement with any director, employee or representative of the
other,

                                      -6-
<PAGE>   59

without prior written notification to the other party. Any representative(s)
authorized by either party may cause an audit of any and all records of the
other party as necessary and proper to verify that there has been compliance
with this paragraph.

         e. Notices given hereunder are effective when sent by telex or received
by mail.

The agreement of the parties is shown by the signatures of their authorized
representatives below.

                                       CHEVRON CHEMICAL COMPANY

                                       By:
                                          -------------------------------------
                                       Title:
                                             ----------------------------------
                                       Date:
                                            -----------------------------------

                                       SOUTH HAMPTON REFINING COMPANY

                                       By:
                                          -------------------------------------
                                       Title:
                                             ----------------------------------
                                       Date:
                                            -----------------------------------

                                      -7-
<PAGE>   60

                                    EXHIBIT A

                   EXPECTED C5+ RECOVERED PRODUCT COMPOSITION
                                 ISOHEXANE FEED
                              SOUTH HAMPTON AROMAX

<TABLE>
<CAPTION>
               Composition, LV %
<S>                                           <C>
               iC5                             9.0

               nC5                            10.1

               CP                              0.1

               Benzene                        44.2 (41.0 -- 46.0)

               2-2 DMB                         2.3

               2-3 DMB                         9.1

               2-MP                           10.6

               3-MP                            7.4

               N-C6                            5.3

               MCP                             1.9
</TABLE>

<PAGE>   61

                                    EXHIBIT B

                           ISOHEXANE FEED COMPOSITION
                              SOUTH HAMPTON AROMAX

<TABLE>
<CAPTION>
               Composition, LV %
<S>                                  <C>
               iC5                   1.0

               nC5                    2.2

               CP                    10.5 (Max.)

               2-2 DMB                2.3

               2-3 DMB               12.1

               2-MP                  54.0 (Min.)

               3-MP                  16.1 (Min.)

               N-C6                   1.5

               MCP                    0.1

               C7+                    0.2
</TABLE>

<PAGE>   62

                                                                   (CONOCO LOGO)

                              [CONOCO LETTERHEAD]

October 7, 1988

Dr. Richard Crain
South Hampton Refining Company
P.O. Box 1636
Silsbee, TX 77656

Dear Dick:

Attached is two copies of the Processing Agreement. Please fill in the date and
the state in which South Hampton is incorporated on the front page of the
agreement and sign. Forward one copy back to me at Conoco.

With this agreement in place and Conoco Treasury's approval of the Letter of
Credit, we will wire you the 85,000 dollars to begin construction of the unit.

I am optimistic for the mutual success of this processing deal and look forward
to working with you and South Hampton Refining. If you have any questions,
please let me know.

Sincerely,

/s/ MICHAEL R. MITCHAEL
-------------------------------
Michael R. Mitchael
/ng

Attachments

10
<PAGE>   63

                           SOUTH HAMPTON REFINING CO.

                              PROCESSING AGREEMENT

THIS AGREEMENT is entered into this 11 day of October 1988, by and between
CONOCO INC., a Delaware corporation (hereinafter referred to as "Conoco"), whose
address is P.O. Box 2197, Houston, Texas 77252, and SOUTH HAMPTON REFINING CO.,
a Texas corporation (hereinafter referred to as "South Hampton"), whose address
is P.O. Box 1636, Silsbee, Texas 77656.

                                   WITNESSETH:

WHEREAS, South Hampton has the ability to process LVT(R) oil for Conoco at South
Hampton's Silsbee, Texas plant ("Plant"); and

WHEREAS, Conoco desires to have its LVT(R) oil ("Feedstock") processed through
processing equipment constructed by South Hampton at its Plant;

NOW, THEREFORE, for and in consideration of the mutual covenants and promises
set forth herein, the parties hereto agree as follows:

<PAGE>   64

1.       TERM OF AGREEMENT

         This Agreement shall have a primary term of one year beginning on
         October 10, 1988, or on the date that the Letter of Credit described in
         Section 3.2 is issued, whichever is later ("Commencement Date"), and
         continuing from month to month thereafter unless cancelled by either
         party by giving the other party sixty (60) days prior written notice.

2.       FEEDSTOCK

         2.1      The Feedstock to be processed by South Hampton shall be LVT(R)
                  oil, having the typical specifications set forth in Exhibit A,
                  attached hereto and made a part hereof.

         2.2      Conoco, at its sole expense, shall supply and deliver
                  Feedstock to South Hampton's Plant from Conoco's Lake Charles
                  Refinery by tank truck.

         2.3      Over the term of this Agreement, Conoco agrees to deliver to
                  South Hampton a minimum of 72,000 barrels of Feedstock for
                  processing the first six (6) months, and 55,000 barrels the
                  second six (6) months. Any light stream material which is
                  rerun for saturation shall be counted in these amounts.

         2.4      South Hampton shall provide a clean 10,000-barrel tank
                  dedicated to Conoco's exclusive use for bulk storage of the
                  Feedstock prior to processing.

                                        2

<PAGE>   65

         2.5      South Hampton will sample and test the Feedstock in tankage at
                  its Plant once every twenty-four (24) hours while receiving
                  Feedstock to determine that its sulfur and ASTM D-86 End Point
                  meet the specifications described in Exhibit A. South Hampton
                  must notify Conoco within two (2) working days after delivery
                  of any off specification Feedstock. If Conoco receives no
                  notice during the two (2) working day period, then the
                  Feedstock will be deemed to meet the specifications on Exhibit
                  A. A laboratory analytical report will be forwarded to Conoco
                  on all Feedstock each week. An independent laboratory analysis
                  shall be used to resolve any discrepancies between Conoco and
                  South Hampton concerning the specifications of the Feedstock.

         2.6      The amount of Feedstock received shall be determined by South
                  Hampton scale tickets showing the difference between the
                  certified full weight and the certified empty weight of the
                  tank trucks.

3.       PROCESSING FACILITY

         3.1      South Hampton shall construct a process facility for the
                  processing of Conoco's Feedstock ("Facility") at South
                  Hampton's Plant. In consideration for the

                                        3
<PAGE>   66

                 Construction Funding ($85,000) supplied by Conoco as set forth
                 in Section 3.2 below, South Hampton will not use the Facility
                 for any purpose which will interfere with the processing of
                 Conoco's Feedstock nor will it sell, dismantle, relocate or in
                 any other manner decommission the Facility, during the term of
                 this Agreement.

         3.2     Conoco agrees to pay to South Hampton on the Commencement Date
                 of this Agreement Construction Funding ($85,000) to be used by
                 South Hampton to finance the construction of the Facility.
                 South Hampton agrees to refund this amount to Conoco from the
                 fees for the first 30,000 barrels of Feedstock that are
                 processed, by subtracting the maximum Construction Funding
                 ($85,000) from the invoices associated with the first 30,000
                 barrels of Feed-stock processed. South Hampton agrees to issue
                 an Irrevocable Standby Letter of Credit covering the
                 Construction Funding ($85,000) until the obligation to Conoco
                 is paid in full. Conoco agrees to maintain the U.S. dollar
                 value of the Letter of Credit in an amount equal to the
                 unrefunded portion of the Construction Funding. The Letter of
                 Credit must be issued by a bank acceptable to Conoco.

                                        4

<PAGE>   67

         3.3     South Hampton agrees to make best efforts to have the Facility
                 operational and capable of processing Feedstock into two (2)
                 streams as described in Section 4 below (collectively
                 "Operational") within five (5) weeks from the Commencement Date
                 of this Agreement. If the Facility is not Operational within
                 eight (8) weeks after the Commencement Date, or ceases to be
                 Operational at any time for longer than thirty (30) days
                 despite repair efforts by South Hampton, Conoco, at its sole
                 option, may terminate this Agreement with no further liability
                 hereunder or may extend the time for the Facility to be
                 Operational to a date acceptable to both parties. If Conoco
                 elects to terminate the Agreement prior to the Construction
                 Funding being totally refunded, South Hampton shall immediately
                 refund to Conoco the unrefunded portion of the Construction
                 Funding provided by Conoco to South Hampton under this
                 Agreement.

         3.4     South Hampton agrees to manufacture under and keep records of
                 statistical process control. South Hampton shall make all such
                 records available to Conoco upon request.

                                        5

<PAGE>   68

4.       FINISHED PRODUCTS

         4.1      South Hampton shall process Feedstock into two separate
                  streams: a light stream and a heavy stream (LVT200(R) oil)
                  (collectively "Products"). The LVT200(R) oil shall meet the
                  specifications set forth in Exhibit B, which is attached
                  hereto and made a part hereof. For every gallon of Feedstock
                  received by South Hampton, South Hampton shall return
                  ninety-nine (99) liquid volume percent Products.

         4.2     South Hampton can control the following items of Exhibit B of
                 the Agreement: (a) IBP, (b) Wt. % Aromatics, (c) P-M Flash,
                 Deg. F. Minimum, and (d) ppm Sulfur. All other items, i.e., (a)
                 EP, (b) API Gravity, and (c) nitrogen content, are functions of
                 the Feedstock and cannot be controlled by South Hampton.

5.       SAMPLING AND ANALYSIS

         5.1     South Hampton will sample and conduct laboratory analysis in
                 its own laboratory for each batch of the Products manufactured
                 hereunder to determine if they meet the specifications set
                 forth in Exhibit B.

         5.2     Once each month, South Hampton, at its sole expense, shall
                 arrange for verification of its analysis of a random sample of
                 the Products by an independent laboratory.

                                       6
<PAGE>   69

         5.3     South Hampton shall provide Conoco with a weekly laboratory
                 analytical report on all Products manufactured.

         5.4     All off specification Products shall be rerun through the
                 process at South Hampton's expense.

6.       STORAGE/DELIVERY

         6.1     South Hampton shall store the Products in clean segregated
                 tankage, not commingled with any product not owned by Conoco,
                 until release to Conoco customers as scheduled by Conoco. Such
                 storage shall be appropriate for loading of Products into rail
                 cars or tank trucks.

         6.2     Each week South Hampton shall forward to Conoco's Sales
                 Manager, Wax and Specialty Products, North American Marketing,
                 a report of inventory of Products in storage.

         6.3     South Hampton agrees to keep confidential any Conoco customer
                 information which it receives from Conoco because of the direct
                 shipment of Products from South Hampton's Plant to Conoco
                 customers.

                                       7
<PAGE>   70

7.       FEES

         7.1     Conoco shall pay South Hampton a fee for all of the services
                 performed hereunder on a cents-per-gallon of Feedstock
                 processed basis, according to the following schedule:

<TABLE>
<CAPTION>
          Gallons of Feedstock Processed            Fee per Gallon Processed
          ------------------------------            ------------------------
<S>                                                 <C>
                  0-50,000 Barrels*                        $0.18
                  50,001+ Barrels*                         $0.16
</TABLE>

          *One Barrel Equals 42 U.S. Standard Gallons.
                  The aforesaid fees are based on Feedstock containing eighteen
                  (18) volume percent aromatics. For each volume percent of
                  aromatics over eighteen (18) percent in the LVT200 stream
                  prior to entering the hydrogen treater (raw LVT200), Conoco
                  shall pay an additional fee of $0.004375 per gallon. For each
                  volume percent of aromatics below eighteen (18) in the raw
                  LVT200, the fee paid by Conoco shall be less by $0.004375 per
                  gallon. Such fee adjustment will be calculated at the end of
                  each month, based upon the average of recorded tests made
                  twice each day by South Hampton on the raw LVT200.

         7.2      In addition to the fees stated in Section 7.1 above, for each
                  volume percent yield of LVT200(R) comprising over fifty (50)
                  percent of the Feedstock, an additional $0.0015 per gallon
                  shall be

                                        8

<PAGE>   71

                 added to the fee on volumes of Feedstock yielding over fifty
                 (50) percent LVT200(R). Likewise, for each volume percent
                 yield of LVT200(R) under fifty (50) percent of the Feedstock,
                 $0.0015 per gallon shall be subtracted from the fee on volumes
                 of Feedstock yielding under fifty (50) percent LVT200(R). Such
                 fee adjustment shall be calculated at the end of each month
                 based on the actual yield results.

         7.3     The process fee for 0-50,000 barrels of Feedstock processed
                 shall never be lower than $0.15 per gallon of Feedstock
                 processed; and for 50,001+ barrels of Feedstock processed,
                 never lower than $0.13 per gallon of Feedstock processed.

         7.4     Included in this fee is South Hampton's profit and other costs
                 including, without limitation, insurance, storage space, labor
                 and overhead, all Federal, State, and local excise taxes, and
                 any other charges assessed by or to South Hampton in the
                 performance of this Agreement.

8.       PAYMENT

         8.1     South Hampton shall invoice Conoco semi-monthly (first and
                 fifteenth) at the appropriate rate based on past volume of
                 Feedstock processed as of the

                                        9

<PAGE>   72

                 invoice date. Conoco shall pay each invoice by check upon
                 receipt.

         8.2     On the date of this Agreement, there is in effect between
                 Conoco and South Hampton a Promissory Note dated September 23,
                 1988 covering the repayment of a debt owed to Conoco by South
                 Hampton. In the event of South Hampton's default under said
                 Promissory Note, South Hampton agrees that Conoco may offset
                 against the fees due to South Hampton under this Agreement, any
                 amounts which are or become due and payable under said
                 Promissory Note, until said Promissory Note is fully paid.

9.       TITLE

         9.1     Title to all Feedstock delivered to South Hampton and all
                 Products manufactured therefrom shall remain in Conoco. South
                 Hampton shall at all times be responsible for Conoco's property
                 in its care, custody, and control, and shall reimburse Conoco
                 for any unaccounted for loss of property (excluding loss
                 allowance if applicable), contamination or damage thereto.

         9.2     At Conoco's request, South Hampton will execute any document
                 which shows title as referenced herein to be in Conoco,
                 including, but not limited to a UCC-1 form.

                                       10

<PAGE>   73

10.      LOSS AND DAMAGE

         10.1    South Hampton shall be responsible for any loss of, or damage
                 to Conoco property, as set forth in Section 9 hereof, within
                 its possession. South Hampton will take title to and be
                 responsible for legally disposing of any contaminated Feedstock
                 or Products or any off specification Products which cannot be
                 rerun pursuant to Section 5.4 above, which occurred while the
                 Feedstock or Products were in South Hampton's care.

         10.2    Reimbursement for loss or contamination of Feedstock shall
                 be at Conoco's Gulf Coast jet fuel price posted in Platt's
                 Oilgram, plus freight from Lake Charles to South Hampton's
                 Plant. Reimbursement for loss or contamination of Products or
                 for any off specification Product which cannot be rerun shall
                 be at Conoco's cost as stated in the previous sentence, plus
                 any fees paid to South Hampton pursuant to Section 7 hereof.
                 Conoco will invoice South Hampton for any losses within sixty
                 (60) days after determination of the loss or contamination.

                                       11
<PAGE>   74

11.      INDEMNITY

         11.1     South Hampton hereby agrees to indemnify, defend, and save
                  Conoco, and its officers, directors, and employees, harmless
                  from any and all loss or liability, including legal expenses,
                  arising out of any claim or cause of action for loss, loss of
                  use of or damage to property or natural resources, personal
                  injuries, violation of any governmental laws, or patent or
                  trademark infringement caused by or arising in any manner from
                  South Hampton's operations or ownership of its Plant and the
                  Facility and performance of the services under this Agreement.

         11.2     Conoco hereby agrees to indemnify, defend, and save South
                  Hampton, and its officers, directors, and employees, harmless
                  from any and all loss or liability including legal expense
                  arising out of any claim or cause of action for loss, loss of
                  use of, or damage to property or natural resources, personal
                  injuries, violation of any governmental laws, or patent or
                  trademark infringement caused by or arising in any manner from
                  Conoco's sale or use of the Products produced under this
                  Agreement, except to the extent caused by South Hampton's sole
                  negligence.

                                       12
<PAGE>   75

12.      INSURANCE

         South Hampton shall maintain in full force and effect the following
         forms and amounts of insurance and shall furnish to Conoco current
         certificates evidencing the insurance maintained. Such certificates
         must provide for not less than ten (10) days' prior written notice to
         Conoco in the event of cancellation or material change affecting
         Conoco's interests. The insurance requirements below are Conoco's
         minimum requirements and shall not be considered indicative of the
         ultimate amounts and types of insurance needed by South Hampton.
         Neither failure to comply nor full compliance with the insurance
         provisions of this Agreement shall limit or relieve South Hampton from
         indemnifying and holding Conoco harmless in compliance with the
         provisions of this Agreement.

         a.  Worker's Compensation Insurance covering all employees in
             accordance with the statutory requirements of the state in which
             the services hereunder are rendered.

         b.  Employer's Liability Insurance in an amount not less than
             $1,000,000 per occurrence.

         c.  Comprehensive General Liability insurance, including Product
             Liability, completed operations, blanket contractual, contractors
             protection, with a

                                       13
<PAGE>   76

             combined single limit for bodily injury and property damage of not
             less than $1,000,000 per occurrence.

         d.  Named Peril Property Insurance of not less than $1,000,000 per
             occurrence to cover the loss of Conoco's Feedstock and Products in
             South Hampton's care, custody, and control. Such coverage shall
             name Conoco as an additional named insured and loss payee with
             respect to Conoco's interest.

13.     FORCE MAJEURE

        Neither party hereto shall be responsible or liable for failure to
        perform its obligations under this Agreement or losses resulting from
        any such failure to perform, or failure to make delivery, if prevented
        from doing so by acts of God, floods, fires, explosions, storms,
        vandalism, transportation difficulties, inability to obtain the
        necessary supplies or other required raw materials, strikes, lockouts,
        or other industrial disturbances, wars, or any law, rule, or action of
        any court or instrumentality of the federal, state or local government,
        or any other cause or causes beyond its reasonable control whether
        similar or dissimilar to those above stated, provided only that the same
        is not willfully done or brought about for the purpose of excusing
        failure or omission to perform under this Agreement. In

                                       14
<PAGE>   77

        the event either party hereto is rendered unable to perform in whole or
        in part, such party shall give notice in writing to the other party of
        the full particulars of such force majeure as soon as possible after
        the occurrence of such cause relied on, and the obligation of such
        party to perform under this Agreement shall be suspended during the
        continuance of any inability so caused, but no longer period, and such
        cause shall insofar as possible be remedied with all reasonable
        dispatch. If any of the events specified in this paragraph shall have
        occurred, South Hampton shall allocate its available services to the
        extent it is capable in a fair and equitable manner among its own needs
        and its customers.

14.      INSPECTION AND AUDIT

         Conoco reserves the right to inspect South Hampton's Facility, Plant
         and operations or audit South Hampton's business records pertaining to
         South Hampton's performance of the terms and conditions of this
         Agreement, at any time during South Hampton's operating hours, by
         giving reasonable notice of its intent to do so and by doing so in a
         manner which will not interfere with South Hampton's normal business
         routine.

                                       15
<PAGE>   78

 15.     TERMINATION

         15.1     If any provision of this Agreement is or becomes violate of
                  any law, or any rule, order, or regulation issued thereunder,
                  either party shall have the right, upon notice to the other to
                  terminate such provision, without affecting other provisions
                  of the Agreement, or to terminate the Agreement in its
                  entirety.

         15.2    In the event of the failure of South Hampton to perform any of
                 its obligations hereunder, and the continuance of such failure
                 after fifteen (15) days' written notice from Conoco, Conoco may
                 terminate this Agreement upon written notice to South Hampton.
                 In the event of insolvency, assignment for the benefit of
                 creditors, or impending bankruptcy proceedings by or against
                 South Hampton, Conoco may, at its option, terminate this
                 Agreement upon written notice to South Hampton. South Hampton
                 hereby agrees to give Conoco prompt written notice of the
                 occurrence of the aforesaid events. Termination of this
                 Agreement in accordance with this Paragraph shall not affect
                 any obligations accruing hereunder prior to such termination,
                 including, but not limited to, South Hampton's obligations
                 under Section 11 (Indemnity). Addi-

                                       16
<PAGE>   79

         tionally, should Conoco terminate this Agreement due to South Hampton's
         failure to perform any of its obligations hereunder, South Hampton
         shall immediately refund to Conoco the unrefunded portion of the
         Construction Funding provided by Conoco to South Hampton under Section
         3.2 of this Agreement.

15.3     In the event of the failure of Conoco to perform any of its obligations
         hereunder, and the continuance of such failure after fifteen (15) days'
         written notice from South Hampton, South Hampton may terminate this
         Agreement upon written notice to Conoco. In the event of insolvency,
         assignment for the benefit of creditors, or impending bankruptcy
         proceedings by or against Conoco, South Hampton may, at its option,
         terminate this Agreement by written notice to Conoco. Conoco hereby
         agrees to give South Hampton prompt written notice of the occurrence of
         the aforesaid events. Termination of this Agreement in accordance with
         this Paragraph shall not affect any obligations accruing hereunder
         prior to such termination, including, but not limited to, Conoco's
         obligations under Paragraph 11 (Indemnity). Additionally, should South
         Hampton terminate this Agreement due to Conoco's failure to perform any
         of its obligations hereunder, the unrefunded

                                       17
<PAGE>   80

         portion of the Construction Funding provided by Conoco under Section
         3.2 will be forfeited to South Hampton.

16.      ASSIGNMENT

         This Agreement shall be binding upon and inure to the benefit of the
         parties hereto and their respective successors and assigns; provided,
         however, neither party may assign this Agreement without the prior
         written consent of the other party.

17.     NOTICES

        All notices required to be given hereunder shall be in writing, by
        telegram, air express service or by certified mail; and shall be
        addressed as follows:

        CONOCO:                Conoco Inc.
                               P.O. Box 2197, TA 2108
                               Houston, Texas 77252
                               Attention: Michael R. Mitchael

       SOUTH HAMPTON:          South Hampton Refining Co.
                               P.O. Box 1636
                               Silsbee, Texas 77656
                               Attention: Richard N. Cram

 18.     WAIVER

         The failure of either South Hampton or Conoco to enforce at any time
         any provisions of this Agreement shall not be construed to be a waiver
         of those provisions or the right thereafter to enforce any such
         provisions.

                                       18
<PAGE>   81

19.      SAFETY AND HEALTH INFORMATION

         Conoco has furnished to South Hampton information (including Material
         Safety Data Sheet(s)) concerning the safety and health aspects of the
         Feedstock and Products handled by South Hampton hereunder, including
         safety and health warnings. South Hampton acknowledges receipt of such
         information and agrees to communicate such warnings and information to
         South Hampton's employees, agents and contractors.

20.      RELATIONSHIP OF THE PARTIES

         20.1    Conoco and South Hampton are completely separate entities. They
                 are not partners, general partners, limited partners, joint
                 venturers, nor agents of each other in any sense whatsoever and
                 neither has the power to obligate or bind the other.

         20.2    South Hampton is an independent contractor and shall be solely
                 responsible at all times for the safe and prudent operation and
                 maintenance of its Plant and the Facility. South Hampton shall
                 always be, and Conoco shall never be, in charge of all
                 equipment, including the Facility owned by South Hampton,
                 direction of all employees and other persons who may be on
                 South Hampton's premises at any time. Conoco, its employees,
                 and agents shall

                                       19
<PAGE>   82

         always abide by instruction and direction of South Hampton while on
         South Hampton's premises. South Hampton shall take all necessary
         precautions including adoption of and compliance with all reasonable
         and customary fire prevention and safety measures to avoid property
         damage and bodily injury.

 20.3    If for United States tax purposes operations hereunder are regarded as
         a partnership, each of the parties elects to be excluded from the
         application of all of the provisions of Subchapter K, Chapter 1,
         Subtitle A, of the Internal Revenue Code of 1986 as amended, as
         permitted and authorized by Section 761 of the Code and regulations
         thereunder. Each party will provide such evidence of this election as
         may be required by law.

         Should there by any requirement that each party further evidence such
         election, such party shall execute such documents and furnish such
         other evidence as may be required to evidence such election. Each party
         shall not give any notices or take any other action inconsistent with
         the election made hereby. If any present or future income tax laws of
         the state or states which are applicable to the transactions of this
         Agreement, or any

                                       20

<PAGE>   83

         future income tax law of the United States, shall contain a provision
         similar to that in Section 761 of the Internal Revenue Code of 1986, as
         amended, each party shall make such election as may be permitted or
         required by such law.

         In making such election, each party states that income or loss derived
         by such party from operations under this Agreement can be adequately
         determined without the computation of partnership taxable income or
         loss.

21.      GOVERNING LAW

         This Agreement shall be governed by and interpreted according to the
         laws of the State of Texas.

22.      ENTIRE AGREEMENT

         This Agreement constitutes and embodies the entire agreement and
         understanding between South Hampton and Conoco. There are no
         agreements, understandings or conditions, oral or written, express or
         implied, that are not included herein. No alteration or amendment of
         this Agreement shall be effective unless it is in writing and signed by
         South Hampton and Conoco.

                                       21
<PAGE>   84

IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be duly
executed as of the date first above written.

CONOCO INC.                        SOUTH HAMPTON REFINING CO.

By: /s/  [ILLEGIBLE]               By: /s/ [ILLEGIBLE]
   -----------------------------      -----------------------------
Title: Sales Manager - WAX         Title:
      --------------------------         --------------------------
       and Specialties - NAM
      --------------------------

                                       22
<PAGE>   85

                                    EXHIBIT A

                           TYPICAL FEED SPECIFICATIONS

                                D-86, (degrees)F

<TABLE>
<S>                                       <C>
          IBP                                  374
           5%                                  384
          50%                                  419
          95%                                  495
           EP                                  523

          API Gravity                          41.6
          WT% Aromatics                    17.8    20 Max
          ppm Sulfur                       1 ppm or less
          P-M Flash, (degrees)F Min            --
          Nitrogen, Total ppm                  3
          Viscosity @ 40(degrees)              2.1
</TABLE>

                                       23
<PAGE>   86

                                    EXHIBIT B

                             PRODUCT SPECIFICATIONS

                                HEAVY (LVT200(R)

                                D-86, (degrees)F

<TABLE>
<S>                                               <C>
                 IBP                                      427*
                  5%                                      440
                 50%                                      459
                 95%                                      525
                  EP                                      545

                 API Gravity                              41.2*
                 WT% Aromatics                    Less than 1
                 ppm Sulfur                       1 ppm or less
                 P-M Flash, (degrees)F Min        200 to 210
                 Nitrogen, Total ppm              Less than .5

</TABLE>

                   *Reported only, not a final specification.

                                       24
<PAGE>   87

                Conoco Inc.                         REQUEST FOR FACSIMILE
[CONOCO LOGO]                                       TRANSMISSION

-------------------------
Date
       5-12-89
-------------------------

FROM
--------------------------------------------------------------------------------
Employee                                                           Ext.

Mike R. Mitchell                                                   1542
--------------------------------------------------------------------------------
City, State, Country                                               Room No.

Houston, Texas                                                     2108
--------------------------------------------------------------------------------
Acct No.

--------------------------------------------------------------------------------

TO
--------------------------------------------------------------------------------
Name                                                               Phone No.

Dick Croin
--------------------------------------------------------------------------------
Department                                                         Room No.

SHR
--------------------------------------------------------------------------------
City, State, Country

--------------------------------------------------------------------------------

-------------------------
No. of Pages

         21 + cover
-------------------------

  NOTE
  1. Your originals must have good contrast (dark detail on light background).
  2. Legible
  3. 1/2-inch margin on all sides of sheet
  4. Number all pages

SPECIAL INSTRUCTIONS
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
11-11 PB. 10-86

<PAGE>   88

                           SOUTH HAMPTON REFINING CO.

                              PROCESSING AGREEMENT

THIS AGREEMENT is entered into this __ day of __________, 1989, by and between
CONOCO INC., a DELAWARE corporation (hereinafter referred to as "Conoco"), whose
address is P.O. Box 4784, Houston, Texas 77210-4784, and SOUTH HAMPTON REFINING
CO., a Texas corporation (hereinafter referred to as "South Hampton"), whose
address is P.O. Box 1636, Silsbee, Texas 77656.

                                   WITNESSETH:

WHEREAS, South Hampton has the ability to process Catalytic Polymerization
Gasoline ("Feedstock") for Conoco at South Hampton's Silsbee, Texas plant
("Plant"); and

WHEREAS, Conoco desires to have its Feedstock processed through processing
equipment constructed by South Hampton at its Plant;

NOW, THEREFORE, for and in consideration of the mutual covenants and promises
set forth herein, the parties hereto agree as follows:

<PAGE>   89

1.       TERM OF AGREEMENT

         This Agreement shall be for a primary term of one (1) year, commencing
         on _____________, 1989 ("Commencement Date"), and shall automatically
         continue thereafter until cancelled by either party by giving the other
         party six (6) months written notice after the end of the primary term
         or at any time thereafter.

 2.      FEEDSTOCK

          2.1     The Feedstock to be processed by South Hampton shall be
                  Catalytic Polymerization Gasoline, having the typical
                  specifications set forth in Exhibit A, attached hereto and
                  made a part hereof.

          2.2     Conoco, at its sole expense, shall supply and deliver
                  Feedstock to South Hampton's Plant from Conoco's Refinery at
                  an average minimum rate of 500 barrels per day for the first
                  six (6) months of this Agreement, and at an average minimum
                  rate of 250 barrels per day for the remainder of the Agreement
                  term.

          2.3     South Hampton shall provide a clean 25,000-barrel tank and a
                  clean 10,000-barrel tank dedicated to Conoco's exclusive use
                  for bulk storage of the Feedstock prior to processing.

                                        2

<PAGE>   90

          2.4     South Hampton will, sample and test the Feedstock in tankage
                  at its Plant once every twenty-four (24) hours while receiving
                  Feedstock to determine its sulfur and distillation
                  characteristics and to verify that it meets the specifications
                  described in Exhibit A. South Hampton must notify Conoco
                  within two (2) working days after delivery of any off
                  specification Feedstock. If Conoco receives no notice during
                  the two (2) working day period, then the Feedstock will be
                  deemed to meet the specifications on Exhibit A. A laboratory
                  analytical report will be forwarded to Conoco on all
                  Feedstock each week. An independent laboratory analysis shall
                  be used to resolve any discrepancies between Conoco and South
                  Hampton concerning the specifications of the Feedstock.

          2.5     The amount of Feedstock received shall be determined by South
                  Hampton scale tickets showing the difference between the
                  certified full weight and the certified empty weight of tank
                  trucks.

 3.       PROCESSING FACILITY

          3.l     South Hampton shall construct a process facility for the
                  processing of Conoco's Feedstock ("Facility") at South
                  Hampton's Plant. In consideration for the

                                       3
<PAGE>   91

                  Construction Funding ($150,000) supplied by Conoco as set
                  forth in Section 3.2 below, South Hampton will not use the
                  Facility for any purpose which will interfere with the
                  processing of Conoco's Feedstock nor will it sell, dismantle,
                  relocate or in any other manner decommission the Facility,
                  during the term of this Agreement.

          3.2     Conoco agrees to pay to South Hampton on the Commencement Date
                  of this Agreement Construction Funding ($150,000) to be used
                  by South Hampton to finance the construction of the Facility.
                  South Hampton agrees to refund this amount to Conoco from the
                  fees for the first 50,000 barrels of Feedstock that are
                  processed, by subtracting the maximum Construction Funding
                  ($150,000) from the invoices associated with the first 50,000
                  barrels of Feedstock processed. South Hampton agrees to issue
                  an Irrevocable Standby Letter of Credit covering the
                  Construction Funding ($150,000) until the obligation to Conoco
                  is paid in full. Conoco agrees to maintain the U.S. dollar
                  value of the Letter of Credit in an amount equal to the
                  unrefunded portion of the Construction Funding. The Letter of
                  Credit must be issued by a bank acceptable to Conoco.

                                       4
<PAGE>   92

          3.3     South Hampton agrees to make best efforts to have the Facility
                  operational and capable of processing Feedstock into the
                  streams described in Section 4 below (collectively
                  "Operational") within three (3) months from the Commencement
                  Date of this Agreement. If the Facility is not Operational
                  within three (3) months after the Commencement Date, or ceases
                  to be Operational at any time for longer than thirty (30) days
                  despite repair efforts by South Hampton, Conoco, at its sole
                  option, may terminate this Agreement with no further
                  liability hereunder or may extend the time for the Facility
                  to be Operational to a date acceptable to both parties. If
                  Conoco elects to terminate the Agreement prior to the
                  Construction Fundind being totally refunded, South Hampton
                  shall immediately refund to Conoco the unrefunded portion of
                  the Construction Funding provided by Conoco to South Hampton
                  under this Agreement.

          3.4     South Hampton agrees to manufacture under and keep records
                  of statistical process control. South Hampton shall make all
                  such records. available to Conoco upon request.

          3.5     In the event that Conoco elects not to have South Hampton
                  produce nonene and tetramer, the tanks and

                                        5

<PAGE>   93

                  equipment designated for those Products will be dedicated to
                  other processing for Conoco.

4.        FINISHED PRODUCTS

          4.1     South Hampton shall process Feedstock into streams
                  in accordance with the following fractionation plan:

                  1) First pass: a) Initial Boiling Point ("IBP") - 275 Deg. F.,
                  b) 275-295 Deg. F. (nonene), and c) 295 + Deg. F.; and

                  2) Second pass using 1c: a) 295-350 Deg. F., b) 350-400 Deg.
                  F. (tetramer), and c) 400 + Deg. F. (collectively "Products").
                  The nonene (lb above) and tetrainer (2b above) shall meet the
                  specifications set forth in Exhibit B, which is attached
                  hereto and made a part hereof. For every gallon of Feedstook
                  received by South Hampton, South Hampton shall return
                  ninety-nine (99) liquid volume percent Products.

5.        SAMPLING AND ANALYSIS

          5.1     South Hampton will sample and conduct laboratory analysis in
                  its own laboratory for each batch of the nonene and tetramer
                  manufactured hereunder to

                                       6
<PAGE>   94

                  determine if they meet the specifications set forth in
                  Exhibit B.

          5.2     South Hampton shall provide Conoco with a weekly laboratory
                  analytical report on all Products manufactured.

          5.3     All off specification Product caused by South Hampton shall
                  be rerun through the process at South Hampton's expense.

6.       STORAGE/DELIVERY

          6.1     South Hampton shall store the Products in clean segregated
                  tankage, not commingled with any product not owned by Conoco,
                  until release to Conoco customers as scheduled by Conoco. Such
                  storage shall be appropriate for loading of Products into rail
                  cars or tank trucks.

          6.2     Each week South Hampton shall forward to Conoco's Sales
                  Manager, Wax and Specialty Products, North American Marketing,
                  a report of inventory of Products in storage.

          6.3     South Hampton agrees to keep confidential any Conoco customer
                  information which it receives from Conoco because of the
                  direct shipment of Products from South Hampton's Plant to
                  Conoco customers.

                                        7
<PAGE>   95

7.      FEES

          7.1     Conoco shall pay South Hampton a fee for all of the services
                  performed hereunder at the rate of twelve cents (12 cents) per
                  gallon of Feedstock processed.

          7.2     Included in this fee is South Hampton's profit and other costs
                  including, without limitation, insurance, storage space, labor
                  and overhead, all Federal, State, and local excise taxes, and
                  any other charges assessed by or to South Hampton in the
                  performance of this Agreement.

          7.3     If during the term of this Agreement there should be a change
                  in the cost of fuel gas (natural gas) to South Hampton,
                  Conoco agrees to adjust the fee set forth in Section 7.1
                  above by an appropriate amount to cover such cost changes.
                  South Hampton shall provide documentation to substantiate
                  these cost changes.

          7.4     The two Feedstock tanks and the tankage containing nonene and
                  tetramer shall be blanketed with nitrogen for the flat fee
                  of $2,000 per month for the first eighteen (18) months of
                  this Agreement, and at no cost to Conoco for any subsequent
                  months that this Agreement is in effect.

                                        8

<PAGE>   96

8.        PAYMENT

          8.1     South Hampton shall invoice Conoco semi-monthly (first and
                  fifteenth) at the appropriate rate based on past volume of
                  Feedstock processed as of the invoice date. South Hampton
                  shall provide to Conoco, along with each invoice, a Plant
                  Operation Report, in a mutually agreed upon form, showing
                  semi-monthly activity under this Agreement. Conoco shall pay
                  each invoice by check upon receipt.

          8.2     On the date of this Agreement, there is in effect between
                  Conoco and South Hampton a Promissory Note dated September 23,
                  1988 covering the repayment of a debt owed to Conoco by South
                  Hampton. In the event of South Hampton's default under said
                  Promissory Note, South Hampton agrees that Conoco may offset
                  against the fees due to South Hampton under this Agreement,
                  any amounts which are or become due and payable under said
                  Promissory Note, until said Promissory Note is fully paid.

9.        PRODUCT TRANSFERS

          When jointly agreed to, Conoco will transfer to South Hampton from
          time to time volumes of the streams designated (1a), (2a), and (2c)
          in Section 4.1 above and manufactured under this Agreement at an
          agreed value to

                                       9

<PAGE>   97

          be negotiated. The agreed value for these streams will be credited
          against the fee charged pursuant to Section 7.1 above at the time of
          transfer.

 10.      TITLE

          10.1    Title to all Feedstock delivered to South Hampton and all
                  Products manufactured therefrom shall remain in Conoco. South
                  Hampton shall at all times be responsible for Conoco's
                  property in its care, custody, and control, and shall
                  reimburse Conoco for any unaccounted for loss of property
                  (excluding loss allowance if applicable), contamination or
                  damage thereto.

          10.2    At Conoco's request, South Hampton will execute any document
                  which shows title as referenced herein to be in Conoco,
                  including, but not limited to a UCC-1 form.

11.       LOSS AND DAMAGE

          11.1    South Hampton shall be responsible for any loss of, or damage
                  to Conoco property, as set forth in Section 10 hereof, within
                  its possession. South Hampton will take title to and be
                  responsible for legally disposing of any contaminated
                  Feedstock or Products or any off specification Products which

                                       10

<PAGE>   98

                  cannot be rerun pursuant to Section 5.3 above, which occurred
                  while the Feedstock or Products were in South Hampton's care.

          11.2    Reimbursement for loss or contamination of Feedstock
                  shall be at the Gulf Coast unleaded gasoline (waterborne)
                  price posted in Platt's Oilgram, plus freight from Conoco's
                  Refinery to South Hampton's Plant. Reimbursement for loss or
                  contamination of Products or for any off specification
                  Products which cannot be rerun shall be at Conoco's cost as
                  stated in the previous sentence, plus any fees paid to South
                  Hampton pursuant to Section 7 hereof. Conoco will invoice
                  South Hampton for any losses within sixty (60) days after
                  determination of the loss or contamination.

 12.      INDEMNITY

          12.1    South Hampton hereby agrees to indemnify, defend, and save
                  Conoco, and its officers, directors, and employees, harmless
                  from any and all loss or liability, including legal expenses,
                  arising out of any claim or cause of action for loss, loss of
                  use of or damage to property or natural resources, personal
                  injuries, violation of any governmental laws, or patent or
                  trademark infringement caused by

                                       11
<PAGE>   99

                  or arising in any manner from South Hampton's operations or
                  ownership of its Plant and the Facility and performance of the
                  services under this Agreement.

          12.2    Conoco hereby agrees to indemnify, defend, and save South
                  Hampton, and its officers, directors, and employees, harmless
                  from any and all loss or liability including legal expense
                  arising out of any claim or cause of action for loss, loss of
                  use of, or damage to property or natural resources, personal
                  injuries, violation of any governmental laws, or patent or
                  trademark infringement caused by or arising in any manner from
                  Conoco's sale or use of the Products produced under this
                  Agreement, except to the extent caused by South Hampton's sole
                  negligence.

13.       INSURANCE

          South Hampton shall maintain in full force and effect the following
          forms and amounts of insurance and shall furnish to Conoco current
          certificates evidencing the insurance maintained. Such certificates
          must provide for not less than ten (10) days' prior written notice to
          Conoco in the event of cancellation or material change affecting
          Conoco's interests. The insurance requirements

                                       12
<PAGE>   100

          below are Conoco's minimum requirements and shall not be considered
          indicative of the ultimate amounts and types of insurance needed by
          South Hampton. Neither failure to comply nor full compliance with the
          insurance provisions of this Agreement shall limit or relieve South
          Hampton from indemnifying and holding Conoco harmless in compliance
          with the provisions of this Agreement.

          a.      Worker's Compensation Insurance covering all employees in
                  accordance with the statutory requirements of the state in
                  which the services hereunder are rendered.

          b.      Employer's Liability Insurance in an amount not less than
                  $1,000,000 per occurrence.

          c.      Comprehensive General Liability insurance, including Product
                  Liability, completed operations, blanket contractual,
                  contractors protection, with a combined single limit for
                  bodily injury and property damage of not less than $1,000,000
                  per occurrence.

          d.      Named Peril Property Insurance of not less than $1,000,000 per
                  occurrence to cover the loss of Conoco's Feedstock and
                  Products in South Hampton's care, custody, and control. Such
                  coverage shall name Conoco as an additional named insured and
                  loss payee with respect to Conoco's interest.

                                       13
<PAGE>   101

14.       FORCE MAJEURE

          Neither party hereto shall be responsible or liable for failure to
          perform its obligations under this Agreement or losses resulting from
          any such failure to perform, or failure to make delivery, if
          prevented from doing so by acts of God, floods, fires, explosions,
          storms, vandalism, transportation difficulties, inability to obtain
          the necessary supplies or other required raw materials, strikes,
          lockouts, or other industrial disturbances, wars, or any law, rule, or
          action of any court or instrumentality of the federal, state or local
          government, or any other cause or causes beyond its reasonable control
          whether similar or dissimilar to those above stated, provided only
          that the same is not willfully done or brought about for the purpose
          of excusing failure or omission to perform under this Agreement. In
          the event either party hereto is rendered unable to perform in whole
          or in part, such party shall give notice in writing to the other
          party of the full particulars of such force majeure as soon as
          possible after the occurrence of such cause relied on, and the
          obligation of such party to perform under this Agreement shall be
          suspended during the continuance of any inability so caused, but no
          longer period, and such cause shall insofar as possible be remedied
          with all reasonable

                                       14
<PAGE>   102

          dispatch. If any of the events specified in this paragraph shall have
          occurred, South Hampton shall allocate its available services to the
          extent it is capable in a fair and equitable manner among its own
          needs and its customers.

15.       INSPECTION AND AUDIT

          Conoco reserves the right to inspect South Hampton's Facility, Plant
          and operations, inventory Conoco Feedstock and Products therein, or
          audit South Hampton's business records pertaining to South Hampton's
          performance of the terms and conditions of this Agreement, at any time
          during South Hampton's operating hours, by giving reasonable notice of
          its intent to do so and by doing so in a manner which will not
          interfere with South Hampton's normal business routine.

16.       TERMINATION

          16.1    If any provision of this Agreement is or becomes violate of
                  any law, or any rule, order, or regulation issued thereunder,
                  either party shall have the right, upon notice to the other to
                  terminate such provision, without affecting other provisions
                  of the Agreement, or to terminate the Agreement in its
                  entirety.

                                       15
<PAGE>   103

          16.2    In the event of the failure of South Hampton to perform any of
                  its obligations hereunder, and the continuance of such failure
                  after fifteen (15) days' written notice from Conoco, Conoco
                  may terminate this Agreement upon written notice to South
                  Hampton. In the event of insolvency, assignment for the
                  benefit of creditors, or impending bankruptcy proceedings by
                  or against South Hampton, Conoco may, at its option, terminate
                  this Agreement upon written notice to South Hampton. South
                  Hampton hereby agrees to give Conoco prompt written notice of
                  the occurrence of the aforesaid events. Termination of this
                  Agreement in accordance with this Paragraph shall not affect
                  any obligations accruing hereunder prior to such termination,
                  including, but not limited to, South Hampton's obligations
                  under Section 12 (Indemnity). Additionally, should Conoco
                  terminate this Agreement due to South Hampton's failure to
                  perform any of its obligations hereunder, South Hampton
                  shall immediately refund to Conoco the unrefunded portion
                  of the Construction Funding provided by Conoco to South
                  Hampton under Section 3.2 of this Agreement.

          16.3    In the event of the failure of Conoco to perform any of its
                  obligations hereunder, and the continuance

                                       16
<PAGE>   104

                  of such failure after fifteen (15) days' written notice from
                  South Hampton, South Hampton may terminate this Agreement upon
                  written notice to Conoco. In the event of insolvency,
                  assignment for the benefit of creditors, or impending
                  bankruptcy proceedings by or against Conoco, South Hampton
                  may, at its option, terminate this Agreement by written notice
                  to Conoco. Conoco hereby agrees to give South Hampton prompt
                  written notice of the occurrence of the aforesaid events.
                  Termination of this Agreement in accordance with this
                  Paragraph shall not affect any obligations accruing hereunder
                  prior to such termination, including, but not limited to,
                  Conoco's obligations under Paragraph 12 (Indemnity).
                  Additionally, should South Hampton terminate this Agreement
                  due to Conoco's failure to perform any of its obligations
                  hereunder, the unrefunded portion of the Construction Funding
                  provided by Conoco under Section 3.2 will be forfeited to
                  South Hampton.

17.       ASSIGNMENT

          This Agreement shall be binding upon and inure to the benefit of the
          parties hereto and their respective successors and assigns; provided,
          however, neither party

                                       17

<PAGE>   105

          may assign this Agreement without the prior written consent of the
          other party.

18.       NOTICES

          All notices required to be given hereunder shall be in writing, by
          telegram, air express service or by certified mail; and shall be
          addressed as follows:

          CONOCO:            Conoco Inc.
                             P.O. Box 4784, TA 2108
                             Houston, Texas 77210-4784
                             Attention: Michael R. Mitchael

          SOUTH HAMPTON:     South Hampton Refining Co.
                             P.O. Box 1636
                             Silsbee, Texas 77656
                             Attention:  Richard N. Crain

 29.      WAIVER

          The failure of either South Hampton or Conoco to enforce at any time
          any provisions of this Agreement shall not be construed to be a waiver
          of those provisions or the right thereafter to enforce any such
          provisions.

20.       SAFETY AND HEALTH INFORMATION

          Conoco has furnished to South Hampton information (including Material
          Safety Data Sheet(s)) concerning the safety and health aspects of the
          feedstock and Products handled by South Hampton hereunder, including
          safety and health warnings. South Hampton acknowledges receipt of

                                       18

<PAGE>   106

          such information and agrees to communicate such warnings and
          information to South Hampton's employees, agents and contractors.

21.       RELATIONSHIP OF THE PARTIES

          21.1    Conoco and South Hampton are completely separate entities.
                  They are not partners, general partners, limited partners,
                  joint venturers, nor agents of each other in any sense
                  whatsoever and neither has the power to obligate or bind the
                  other.

          21.2    South Hampton is an independent contractor and shall be solely
                  responsible at all times for the safe and prudent operation
                  and maintenance of its Plant and the Facility. South Hampton
                  shall always be, and Conoco shall never be, in charge of all
                  equipment, including the Facility owned by South Hampton,
                  direction of all employees and other persons who may be on
                  South Hampton's premises at any time. Conoco, its employees,
                  and agents shall always abide by instruction and direction of
                  South Hampton while on South Hampton's premises. South Hampton
                  shall take all necessary precautions including adoption of and
                  compliance with all reasonable and customary fire prevention
                  and safety measures to avoid property damage and bodily
                  injury.

                                       19

<PAGE>   107

          21.3    If for United States tax purposes operations hereunder are
                  regarded as a partnership, each of the parties elects to be
                  excluded from the application of all of the provisions of
                  Subchapter K, Chapter 1, Subtitle A, of the Internal Revenue
                  Code of 1986 as amended, as permitted and authorized by
                  Section 761 of the Code and regulations thereunder. Each party
                  will provide such evidence of this election as may be required
                  by law.
                       Should there by any requirement that each party further
                  evidence such election, such party shall execute such
                  documents and furnish such other evidence as may be required
                  to evidence such election. Each party shall not give any
                  notices or take any other action inconsistent with the
                  election made hereby. If any present or future income tax laws
                  of the state or states which are applicable to the
                  transactions of this Agreement, or any future income tax law
                  of the United States, shall contain a provision similar to
                  that in Section 761 of the Internal Revenue Code of 1986, as
                  amended, each party shall make such election as may be
                  permitted or required by such law.

                                       20
<PAGE>   108

                  In making such election, each party states that income or loss
                  derived by such party from operations under this Agreement can
                  be adequately determined without the computation of
                  partnership taxable income or loss.

 22.      GOVERNING LAW

          This Agreement shall be governed by and interpreted according to the
          laws of the State of Texas.

 23.      ENTIRE AGREEMENT

          This Agreement constitutes and embodies the entire agreement and
          understanding between South Hampton and Conoco. There are no
          agreements, understandings or conditions, oral or written, or implied,
          that are not included herein. No alteration or amendment of this
          Agreement shall be effective unless it is in writing and signed by
          South Hampton and Conoco.

IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be duly
executed as of the date first above written.

CONOCO INC.                         SOUTH HAMPTON REFINING CO.

By:                                 By:
   ------------------------------      -----------------------------
Title:                              Title:
      ---------------------------         --------------------------

                                       21

<PAGE>   109

                                    EXHIBIT A

                        TYPICAL FEEDSTOCK SPECIFICATIONS

                        CATALYTIC POLYMERIZATION GASOLINE

<TABLE>
<CAPTION>
         TEST                        SPECIFICATION
         ----                        -------------
<S>                                  <C>
Distillation,  (degree)F
         10%                                226
         50%                                288
         90%                                391

Gravity (degree)API                          63
Sulfur, ppm                                2000
Reid Vapor PresBure, psi                    6-9
</TABLE>

<PAGE>   110

                                                                     Page 1 of 2

                                    EXHIBIT B

                             NONENE SPECIFICATIONS

<TABLE>
<CAPTION>
TEST                       ASTM TEST METHOD      SPECIFICATION
----                       ----------------      -------------
<S>                        <C>                   <C>
Appearance                 Visual                Clear and free
                                                 of suspended
                                                 matter

Specific Gravity           D-1298                0.738-0.743

Distillation, (degree)F    D-86
    IBP                                          275 min.
    EP                                           295 max.

Olefins, Vol%              D-1319                98 min.

Color, (Pt-Co)             D-1209                15 max.

Sulfer, ppm                D-3120                10 max.

Water, Vol%               D-1744                0.1 max.

Inhibitor, ppm (BHT)                             15 min.

Peroxides, Active
 Oxygen, ppm               D-1563                10 max.
</TABLE>

<PAGE>   111

                                                                     Page 2 of 2

                                    EXHIBIT B

                             TETRAMER SPECIFICATIONS

<TABLE>
<CAPTION>
TEST                       ASTM TEST METHOD      SPECIFICATION
----                       ----------------      -------------
<S>                        <C>                   <C>
Appearance                 Visual                Clear and free
                                                 of suspended
                                                 matter.

Specific Gravity           D-1298                0.770-0.785

Distillation, (degree)F    D-86
    IBP                                          350 min.
    EP                                           400 max.

Olefins, Vol%              D-1319                98 min.

Color Pt-Co                D-1209                45 max.

Sulfer, ppm                D-3120                10 max.

Water, Vol%                D-1744                0.1 max.

Peroxides, Active
 Oxygen, ppm               D-1563                10 max.
</TABLE><PAGE>   1

                                                                   EXHIBIT 10(h)

                           ADDENDUM TO THE AGREEMENT
                           RELATING TO AROMAX PROCESS

                         SECOND COMMERCIAL DEMONSTRATION

THIS ADDENDUM, effective as of the 13th day of June, 1989, is between Chevron
Research Company, a Delaware corporation, hereinafter referred to as "CHEVRON
RESEARCH", and South Hampton Refining Company, a Texas corporation, hereinafter
referred to as "SOUTH HAMPTON";

W I T N E S S E T H:

WHEREAS, CHEVRON RESEARCH and SOUTH HAMPTON have entered into an "Agreement
Relating to AROMAX Process" effective March 10, 1988 ("Agreement"), pursuant to
which SOUTH HAMPTON carried out a demonstration of the AROMAX Process using an
existing unit converted to reforming operations located at SOUTH HAMPTON's
Silsbee, Texas, refinery ("Refinery") and which shall have a design capacity of
420 Barrels of Demonstration Feed per operating day ("BPOD") at an operating
factor of 0.9 for purposes of the Long-Term Demonstration contemplated by this
ADDENDUM ("Licensed Unit"); and

WHEREAS, CHEVRON RESEARCH is interested in supporting a long-term second
commercial demonstration of the AROMAX process in Licensed

<PAGE>   2

Unit processing only Demonstration Feed in a multi-reactor system with at least
one full catalyst regeneration; and

WHEREAS, SOUTH HAMPTON as CHEVRON RESEARCH's first non-affiliated licensee is
willing to carry out a long-term commercial demonstration meeting CHEVRON
RESEARCH's objectives on the terms and conditions set forth in this ADDENDUM;

NOW, THEREFORE, in consideration of the premises and covenants herein, CHEVRON
RESEARCH and SOUTH HAMPTON agree as follows:

                             ARTICLE 1-0 DEFINITIONS

1.1  Whenever used in this ADDENDUM, any term which has been defined in the
     AGREEMENT shall have the same definition. In addition, the following terms
     shall have the definitions prescribed in Schedule I attached hereto and a
     part hereof: "Rheniforming Unit", "AROMAX Equipment", "Rheniforming
     Equipment", "Long-Term Demonstration", "Demonstration Feed", "Rheniforming
     Catalyst", "AROMAX Product", "Support Price and "Received Price".

                                       -2-
<PAGE>   3

                        ARTICLE 2-0 TECHNICAL ASSISTANCE

2.1  In order to support the Long-Term Demonstration of the AROMAX Process in
     Licensed Unit, Licensed Unit must be modified by the addition of AROMAX
     Equipment and new AROMAX Catalyst must be installed in Licensed Unit. In
     addition, since Licensed Unit will not provide the estimated hydrogen
     requirements for SOUTH HAMPTON's hydrotreating operations at the Refinery,
     based upon SOUTH HAMPTON's planned expansion of such operations, it will be
     necessary to return the Rheniforming Unit to service. Accordingly, as part
     of the Long-Term Demonstration contemplated by this ADDENDUM, the
     Rheniforming Unit must be modified by the addition of Rheniforming
     Equipment and new Rheniforming F Catalyst must be installed in the
     Rheniforming Unit. CHEVRON RESEARCH and SOUTH HAMPTON agree that the
     relative responsibilities and obligations of the parties during the
     Long-Term Demonstration relating to assistance during pre-startup, startup,
     normal, and regeneration operations for Licensed Unit and for the
     Rheniforming Unit shall be as follows:

     2.1.1 (Pre-Startup) CHEVRON RESEARCH will specify the equipment
           modifications required for the Long-Term Demonstration, and will
           assist SOUTH HAMPTON to

                                      -3-
<PAGE>   4

          locate, inspect, and install AROMAX Equipment and Rheniforming
          Equipment. Following installation and inspection of the AROMAX
          Equipment and Rheniforming Equipment, CHEVRON RESEARCH will specify
          cleanup and dryout procedures to ready Licensed Unit and the
          Rheniforming Unit for catalyst loading, and will advise and assist
          SOUTH HAMPTON during cleanup and dryout. CHEVRON RESEARCH will specify
          and supply the initial charges of new AROMAX Catalyst, Rheniforming
          Catalyst, and sorbents required for the Long-Term Demonstration and
          will assist SOUTH HAMPTON during loading of such Catalysts and
          sorbents. The extent of pre-startup assistance for Licensed Unit and
          the Rheniforming Unit to be provided by CHEVRON RESEARCH will be
          determined by CHEVRON RESEARCH as required to carry out the Long-Term
          Demonstration after consultation with SOUTH HAMPTON. SOUTH HAMPTON
          will be responsible for and will carry out pre-startup of Licensed
          Unit and the Rheniforming Unit. CHEVRON RESEARCH will perform or have
          performed cleanup of Licensed Unit for sulfur removal. When requested
          by CHEVRON RESEARCH, SOUTH HAMPTON will provide reasonable assistance
          during cleanup and dryout of Licensed Unit. CHEVRON RESEARCH will
          reimburse SOUTH HAMPTON for the agreed actual out-of-pocket expenses

                                      -4-
<PAGE>   5

          incurred if SOUTH HAMPTON contracts with a third party approved by
          CHEVRON RESEARCH for assistance during the cleanup, and will reimburse
          SOUTH HAMPTON for the actual cost of any nitrogen purchased at CHEVRON
          RESEARCH'S request during the initial dryout of Licensed Unit.

2.1.2     (Startup) The Rheniforming Unit will be returned to service before
          starting up Licensed Unit. CHEVRON RESEARCH has previously provided
          startup procedures for the Rheniforming Unit and will advise and
          assist SOUTH HAMPTON during startup of the Rheniforming Unit. However,
          SOUTH HAMPTON will be responsible for carrying out the startup,
          including the supply of required feed and all chemicals. Following
          startup of the Rheniforming Unit, SOUTH HAMPTON will startup Licensed
          Unit with the advice and assistance of CHEVRON RESEARCH. Startup
          procedures for Licensed Unit will be specified by CHEVRON RESEARCH.
          CHEVRON RESEARCH will also specify the Demonstration Feed, the feed
          rate(s), and operating conditions for Licensed Unit during startup.
          The extent of startup assistance for Licensed Unit and the
          Rheniforming Unit to be provided by CHEVRON RESEARCH will be
          determined by CHEVRON RESEARCH as required to carry

                                      -5-
<PAGE>   6

        out the Long-Term Demonstration after consultation with SOUTH HAMPTON,
        and will include full shift coverage during startup of Licensed Unit.
        CHEVRON RESEARCH will reimburse SOUTH HAMPTON for the actual cost of any
        nitrogen or electrolytic hydrogen purchased at CHEVRON RESEARCH's
        request during startup of Licensed Unit.

2.1.3   (Operation) Operations of the Rheniforming Unit will be controlled by
        and will be the sole responsibility of SOUTH HAMPTON. Rheniforming
        Process operations will be carried out by SOUTH HAMPTON pursuant to the
        terms and conditions of the "Agreement Relating to Rheniforming Process"
        dated May 16, 1978, as supplemented and amended by subsequent written
        agreements entered into by CHEVRON RESEARCH and SOUTH HAMPTON.
        Operations of Licensed Unit during the Long-Term Demonstration will be
        controlled by and will be the sole responsibility of SOUTH HAMPTON.
        SOUTH HAMPTON will operate Licensed Unit during the Long-Term
        Demonstration to process only Demonstration Feed under operating
        conditions to be specified by CHEVRON RESEARCH. Feed rate(s) to Licensed
        Unit will be specified by CHEVRON RESEARCH in consultation with SOUTH
        HAMPTON. However, once established, feed rate

                                      -6-
<PAGE>   7

        will be held relatively constant for at least seven (7) days, and
        subsequent changes will be limited to twenty-five percent (25%) of the
        rate of the previous period, unless otherwise agreed to by CHEVRON
        RESEARCH. At no time will the feed rate to Licensed Unit exceed 420
        BPOD.

2.1.4   (Regeneration) At times specified by CHEVRON RESEARCH, SOUTH HAMPTON
        will regenerate AROMAX Catalyst in Licensed Unit with the advice and
        assistance of CHEVRON RESEARCH. AROMAX Catalyst regeneration procedures
        will be specified by CHEVRON RESEARCH. CHEVRON RESEARCH will reimburse
        SOUTH HAMPTON for the actual cost of any nitrogen or electrolytic
        hydrogen purchased at CHEVRON RESEARCH's request during regeneration of
        AROMAX Catalyst.

2.2     Neither CHEVRON RESEARCH nor SOUTH HAMPTON will be obligated to
        compensate or reimburse the other for services performed or expenses
        incurred as a result of the Long-Term Demonstration except as expressly
        provided for in this Addendum.

                                      -7-
<PAGE>   8

                       ARTICLE 3-0 CATALYSTS AND SORBENTS

3.1  The initial charge of AROMAX Catalyst and sorbents for use in Licensed Unit
     for the Long-Term Demonstration will be supplied by and delivered to the
     Refinery by CHEVRON RESEARCH. CHEVRON RESEARCH will retain ownership and
     risk of loss at all times. At the conclusion of the Long-Term Demonstration
     CHEVRON RESEARCH will assist SOUTH HAMPTON to unload AROMAX Catalyst and
     Sorbents and CHEVRON RESEARCH may then use and/or dispose of the AROMAX
     Catalyst and sorbents in any manner without accounting to SOUTH HAMPTON.

3.2  The initial charge of Rheniforming Catalyst, not to exceed Two Thousand
     (2,000) pounds, for the Rheniforming Unit will be supplied by and delivered
     to the Refinery by CHEVRON RESEARCH. Title and risk of loss will pass to
     SOUTH HAMPTON upon delivery to the Refinery gate. Rheniforming Catalyst
     supplied hereunder, upon transfer of title to SOUTH HAMPTON, will be deemed
     subject to the terms and conditions of the "Rheniforming Catalyst Supply
     Contract", dated May 6, 1978 entered into by CHEVRON RESEARCH and SOUTH
     HAMPTON. Accordingly, SOUTH HAMPTON will not resell or otherwise transfer
     ownership, possession, or control of any portion of Rheniforming Catalyst
     without CHEVRON RESEARCH's prior written approval.

                                      -8-
<PAGE>   9

3.3  Licensed Unit presently contains Rheniforming Catalyst which will be
     removed during pre-startup in order to convert to the practice of the
     AROMAX Process for the Long-Term Demonstration. SOUTH HAMPTON owns such
     Rheniforming Catalyst and will deliver same to CHEVRON RESEARCH at the
     Refinery gate immediately upon removal. Title and risk of loss will pass to
     CHEVRON RESEARCH upon such delivery. CHEVRON RESEARCH may use and/or
     dispose of the Rheniforming Catalyst acquired hereunder in any manner
     without accounting to SOUTH HAMPTON.

                     ARTICLE 4-0 LOAN AND SECURITY INTEREST

4.1  CHEVRON RESEARCH will loan to SOUTH HAMPTON up to One Hundred Thirty-five
     Thousand Dollars ($135,000.00) for the sole purpose of purchasing
     Rheniforming Equipment and covering the expenses of SOUTH HAMPTON related
     to Rheniforming Unit cleanup and startup as per the following terms and
     conditions:

     4.1.1 SOUTH HAMPTON will purchase only such Rheniforming Equipment as has
           been previously approved by CHEVRON RESEARCH, which approval will not
           be unreasonably withheld.

                                      -9-
<PAGE>   10

     4.1.2 CHEVRON RESEARCH will loan to SOUTH HAMPTON the purchase price of
           Rheniforming Equipment delivered to the Refinery and funds necessary
           to cover SOUTH HAMPTON's actual out-of-pocket expenses related to
           Rheniforming Unit cleanup and nitrogen and electrolytic hydrogen
           requirements for startup. However, in no event will CHEVRON
           RESEARCH's loan obligation hereunder exceed $135,000.00.

     4.1.3 CHEVRON RESEARCH will lend the purchase price as stated above and
           SOUTH HAMPTON will execute and record a Security Agreement(s) in the
           form attached hereto at the time of sale to SOUTH HAMPTON of any
           equipment within Rheniforming Equipment.

     4.1.4 SOUTH HAMPTON will pay to CHEVRON RESEARCH the full amount loaned to
           SOUTH HAMPTON hereunder by CHEVRON RESEARCH without interest or
           penalty in three equal consecutive monthly payments due on the first
           day of each of the first three calendar months following the calendar
           month during which the average feed rate of penhex fed to the
           Refinery over thirty (30) consecutive operating days equals or
           exceeds 2000 Barrels

                                      -10-
<PAGE>   11

          per day. The foregoing payment obligation will apply during and/or
          after completion of the Long-Term Demonstration.

     4.2  CHEVRON RESEARCH will loan to SOUTH HAMPTON up to Two Hundred
          Ninety-seven Thousand Dollars ($297,000) for the sole purpose of
          purchasing AROMAX Equipment as per the following terms and
          conditions:

          4.2.1 SOUTH HAMPTON will purchase only such AROMAX Equipment as has
                been previously approved by CHEVRON RESEARCH, which approval
                will not be unreasonably withheld.

          4.2.2 CHEVRON RESEARCH will loan to SOUTH HAMPTON the purchase price
                of AROMAX Equipment delivered to the Refinery. However, in no
                event will CHEVRON RESEARCH'S loan obligation hereunder exceed
                the aggregate price F.O.B. the Refinery for all AROMAX Equipment
                purchased by SOUTH HAMPTON or $297,000.00 whichever is the
                lesser amount.

          4.2.3 CHEVRON RESEARCH will lend the purchase price as stated above
                and SOUTH HAMPTON will execute and record a Security
                Agreement(s) in the form attached

                                      -11-
<PAGE>   12

                hereto at the time of sale to SOUTH HAMPTON of any equipment
                within AROMAX Equipment.

          4.2.4 SOUTH HAMPTON will pay to CHEVRON RESEARCH the full amount
                loaned to SOUTH HAMPTON hereunder by CHEVRON RESEARCH without
                interest or penalty in nine (9) equal consecutive monthly
                payments due on the first day of each calendar month starting on
                the first day of the calendar month following the first seventy-
                five (75) days of operations of Licensed Unit after startup of
                the Long-Term Demonstration. If the Long-Term Demonstration
                terminates before or during the nine (9) month payment period,
                SOUTH HAMPTON'S obligation to make money payments ceases with
                the first payment due following such termination.

                 ARTICLE 5-0 AROMAX PRODUCT AND CONTRACT OF SALE

5.1  All AROMAX product will be sold by SOUTH HAMPTON at the highest available
     price on a monthly basis.

5.2  CHEVRON RESEARCH will arrange with its affiliated company, Chevron Chemical
     Company ("CHEVRON CHEMICAL), to enter into a Contract of Sale with SOUTH
     HAMPTON for AROMAX product

                                      -12-
<PAGE>   13

     which SOUTH HAMPTON cannot within a reasonable time sell to a third party
     purchaser. Such Contract of Sale acceptable to CHEVRON CHEMICAL and SOUTH
     HAMPTON is attached hereto.

                  ARTICLE 6-0 PRICE SUPPORT, CREDIT, AND REFUND

6.1  In the event that the Received Price for AROMAX Product sold during any
     calendar month in which SOUTH HAMPTON has a payment obligation to CHEVRON
     RESEARCH pursuant to Section 4.2.4 is less than the Support Price for the
     same calendar month, CHEVRON RESEARCH will grant to SOUTH HAMPTON a credit
     which will be applied against SOUTH HAMPTON's next monthly payments due
     pursuant to Sections 4.1.4 and 4.2.4. The amount of such credit will be the
     lesser of either the amount of the payments due to CHEVRON RESEARCH or the
     arithmetic product obtained by multiplying the number of gallons of AROMAX
     Product sold by SOUTH HAMPTON during the month in question times the
     arithmetic difference obtained by subtracting the Received Price from the
     Support Price.

6.2  Following completion of the Long-Term Demonstration or at the end of the
     twelfth month of the Long-Term Demonstration, whichever occurs first, if
     the Received Price averaged over such period is equal to or greater than
     the Support Price averaged over such period, within thirty (30) days of the

                                      -13-
<PAGE>   14

     completion of the Long-Term Demonstration or the end of the twelfth month
     of the Long-Term Demonstration as the case may be SOUTH HAMPTON will pay
     to CHEVRON RESEARCH a refund in the amount of the total of all the credits
     taken by SOUTH HAMPTON pursuant to Section 6.1 above.

6.3  SOUTH HAMPTON will keep, and on request provide to CHEVRON RESEARCH,
     verified copies of all books and records required to establish the amount
     of and the schedule of, any credit(s) or payment(s) due hereunder.

                            ARTICLE 7-0 MISCELLANEOUS

7.1  The provisions of this ADDENDUM are in addition to the provisions in the
     Agreement. This ADDENDUM is not intended to amend, modify, or delete any
     right or obligation of either CHEVRON RESEARCH or SOUTH HAMPTON under the
     Agreement.

7.2  This ADDENDUM upon full execution will be deemed appended to the Agreement
     and will be deemed a part thereof. Any provision of the Agreement which by
     reasonable interpretation relates to the conduct of the Long-Term
     Demonstration will be so applied. In particular, the provisions of Article
     4-0, Article 7-0, and Article 9-0 will apply to this ADDENDUM and the
     Long-Term Demonstration hereunder.

                                      -14-
<PAGE>   15

7.3  The Long-Term Demonstration will terminate when one of the following events
     occurs: (1) the initial charge of AROMAX Catalyst provided hereunder is
     spent and no longer regenerable, or, (2) the initial charge of AROMAX
     Catalyst has produced AROMAX Product for twelve (12) calendar months, or,
     (3) CHEVRON RESEARCH terminates the Long-Term Demonstration, which it may
     do at its sole discretion; provided, however, that by mutual agreement of
     the parties the Long-Term Demonstration may continue for an additional
     period(s). During any such additional period(s) the terms of Article 5-0
     of this ADDENDUM shall not apply.

7.4  Upon completion of the Long-Term Demonstration, CHEVRON RESEARCH shall
     remove its AROMAX Catalyst from Licensed Unit at the earliest reasonable
     opportunity.

7.5  At no time prior to, during, or after the Long-Term Demonstration will
     CHEVRON RESEARCH have any responsibility or liability to supply or
     compensate SOUTH HAMPTON for purchased hydrogen supplied for use in the
     Refinery.

                                      -15-
<PAGE>   16

IN WITNESS WHEREOF, the parties hereto have caused their respective corporate
names to be subscribed hereto by the respective officers or agents thereunto
duly authorized.

                                       CHEVRON RESEARCH COMPANY

                                       By /s/ [ILLEGIBLE]
                                          --------------------------------------
                                       Title  President
                                            ------------------------------------

                                       Date 6/13/89
                                            ------------------------------------

SOUTH HAMPTON REFINING COMPANY

By /s/ [ILLEGIBLE]
   ----------------------------------

Title President
      -------------------------------

Date  6/7/89
      -------------------------------

Attachments              Schedule I and Exhibit A
                         Security Agreement
                         Financing Statements
                         Contract of Sale

                                      -16-
<PAGE>   17

                                   SCHEDULE I

1.   "Rheniforming Unit" means SOUTH HAMPTON'S existing 4,000-Barrel per
     operating day reforming unit located at its Silsbee, Texas, refinery. The
     Rheniforming Unit is presently out of service but has operated under
     license from CHEVRON RESEARCH using Rheniforming F Catalyst.

2.   "AROMAX Equipment" means new and/or used equipment specified by CHEVRON
     RESEARCH as additional equipment for AROMAX Process operations in Licensed
     Unit necessary for the Long-Term Demonstration.

3.   "Rheniforming Equipment" means new and/or used equipment specified by
     CHEVRON RESEARCH as additional equipment necessary for Rheniforming Process
     operations in the Rheniforming Unit.

4.   "Long-Term Demonstration" means SOUTH HAMPTON'S commercial demonstration
     of AROMAX Process operations in Licensed Unit on feeds and at feed rates
     and under operating conditions specified by CHEVRON RESEARCH carried out
     under this ADDENDUM.

                                      I-1
<PAGE>   18

5.   "Demonstration Feed" means a feed to Licensed Unit which is a refinery
     produced isohexane stream having typical inspections as set forth in
     Exhibit A attached hereto and a part hereof, or such other feed(s) as may
     be specified by CHEVRON RESEARCH from time-to-time to be processed during
     the Long-Term Demonstration.

6.   "Rheniforming Catalyst" means Rheniforming F Catalyst supplied by CHEVRON
     RESEARCH.

7.   "AROMAX Product" means the liquid reformate product from Licensed Unit
     produced during the Long-Term Demonstration.

8.   "Support Price" means the average of high and low values of the daily
     estimated U.S. Gulf Coast pipeline price in cents per gallon of regular
     unleaded gasoline as reported in Platts Oilgram Price Report plus cents ( )
     per gallon averaged over a calendar month.

9.   "Received Price" means the price in cents per gallon of AROMAX Product sold
     by SOUTH HAMPTON and averaged over a calendar month.

                                      I-2
<PAGE>   19

                                    EXHIBIT A

                           ISOHEXANE FEED COMPOSITION

        Composition, LV %

        iC5                           1.0

        nC5                           2.2

        CP                            10.5      (max.)

        2-2 DMB                       2.3

        2-3 DMB                       12.1

        2-MP                          54.0      (min.)

        3-MP                          16.1      (min.)

        N-C6                          1.5

        MCP                           0.1

        C7+                           0.2       (min.)

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00006-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00006-of-00352.parquet"}]]