Exhibit
4.29




PATENT,
TRADEMARK




AND COPYRIGHT SECURITY
AGREEMENT





THIS
PATENT, TRADEMARK AND COPYRIGHT SECURITY AGREEMENT (this "Agreement") is entered
into as of this 16th day of
July 2008, by and among Valcent Products, Inc., corporation organized under the
laws of Alberta, Canada, Valcent USA Inc., a Nevada corporation, Valcent
Manufacturing, Ltd., a Texas limited partnership, Valcent Management LLC, a
Nevada limited liability company, Vertigo Algae Technologies LLC, a Texas
limited liability company, and Valcent Products EU Limited, a corporation
organized under the laws of the United Kingdom, each with an address of 828
Harbourside Drive, Suite 208, North Vancouver, BC V7P 3R9, (jointly and
severally, the "Borrower"), and Platinum Long Term Growth VI, LLC, as collateral
agent (the "Agent") for the investors identified in the below referenced
Purchase Agreement (collectively, together with their successors and assigns,
the "Lenders").




WHEREAS,
Borrower and the Lenders are parties to a certain Note and Warrant Purchase
Agreement, dated as of July 16, 2008 (as amended, restated, supplemented or
extended from time to time, the "Purchase Agreement"), and a Security Agreement,
dated as of July 16, 2008 (the "Security Agreement"), which provide for, among
other things: (i) the Lenders to extend certain loans to or for the account of
the Borrower; (ii) the grant by the Borrower to the Lenders of a security
interest in all of the Borrower's assets, including, without limitation, its
patents, patent applications, trademarks, trademark applications, goodwill,
service marks, trade names, trade styles, copyrights, copyright applications,
mask works, trade-secrets information, and other proprietary rights, together
with all additions, accessions, accessories, amendments, attachments,
modifications, substitutions, and replacements, proceeds and products of any of
the foregoing, as set forth in the Purchase Agreement and the other Transaction
Documents (capitalized terms used herein and not otherwise defined have the
respective meanings given in the Purchase Agreement); and (iii) the appointment
of the Agent as collateral agent, for the benefit of the Lenders, for purpose of
this Agreement, the Security Agreement and the Mortgage (as defined in the
Purchase Agreement).





NOW,
THEREFORE, in consideration of the foregoing premises and the mutual covenants
and agreements contained, and for other good and valuable consideration (the
receipt and sufficiency of which are hereby acknowledged), the Borrower and the
Agent, for the benefit of the Lenders, agree as follows:





1.              Security Interest in
Patents, Trademarks and Copyrights. To secure the complete and timely
satisfaction of all of Borrower's "Obligations" (as that term is defined in the
Security Agreement) to the Lenders, the Borrower hereby grants and conveys to
the Agent, for the benefit of the Lenders, a security interest (having priority
over all other security interests) with power of sale, to the extent permitted
by law, in all of its now owned or existing, and hereafter acquired or
arising:





(a)
            patents,
      patent applications, including, without limitation, any invention and
      improvement to a patent or patent application, including without
      limitation those patents and patent applications listed on Schedule A
      (being sometimes referred to individually and/or collectively, the
      "Patents");




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(b)
            trademarks,
      registered trademarks and trademark applications, trade names, trade
      styles, service marks, registered service marks and service mark
      applications including, without limitation, the registered trademarks,
      trademark applications, registered service marks and service mark
      applications listed on Schedule B and
      (i) all renewals thereof, (ii) all accounts receivable, income, royalties,
      damages and payments now and hereafter due and/or payable with respect
      thereto, including, without limitation, payments under all licenses
      entered into in connection therewith and damages and payments for past,
      present or future infringements and dilutions thereof, and (iii) the right
      to sue for past, present and future infringements and dilutions thereof,
      and (iv) all of the Borrower's rights corresponding thereto throughout the
      world (all of the foregoing registered trademarks, trademark applications,
      trade names, trade styles, registered service marks and service mark
      applications, together with the items described in clauses (i)-(iv) in
      this Section 1(b), being sometimes hereinafter individually and/or
      collectively referred to as the
"Trademarks");





(c)
            the
      goodwill of Borrower's business connected with and symbolized by the
      Trademarks; and





(d)
            copyrights,
      and copyright applications, including without limitation, those copyrights
      listed in Schedule C
      (being sometimes referred to individually and/or collectively as the
      "Copyrights");





together
with all additions, accessions, accessories, amendments, attachments,
modifications, substitutions, and replacements, proceeds and products of the
foregoing.





2.        
    Recording of Patents and
Trademarks. Borrower represents and warrants that
(1) the patents and patent applications listed in Schedule A, and (2) the
trademark and trademark applications described in Schedule B, have each been
duly recorded in the U.S. Patent and Trademark Office (the "PTO"); and that no
other patents, patent applications, trademarks, or trademark applications have
been filed or recorded with the PTO in which the Borrower has an
interest.





3.         
   Recording
of Copyrights. Borrower represents and warrants that the copyright and
copyright applications described in Schedule C have been duly recorded in the
U.S. Copyright Office, and that no other copyright, and copyright applications
have been recorded in the U.S. Copyright Office, in which the Borrower has an
interest.




4.            
Restrictions on Future
Agreements. Borrower will not, without the Agent's prior written consent,
enter into any agreement, including, without limitation, any license agreement,
that is inconsistent with this Agreement, and Borrower further agrees that it
will not take any action, and will use reasonable efforts not to knowingly
permit any action to be taken by others subject to its control, including
licensees, or knowingly fail to take any action, which would affect the validity
or enforcement of the rights transferred to the Agent, for the benefit of the
Lenders, under this Agreement or the rights associated with those Patents,
Trademarks and/or Copyrights which are in Borrower's reasonable business
judgment, necessary or desirable in the operation of Borrower's
business.




5.            
New Patents,
Trademarks and Copyrights. Borrower represents and warrants that the
Patents, Trademarks, and Copyrights listed on Schedules A, B, and C, include all
of the patents, patent applications, trademark registrations, trademark
applications, service marks registrations, service mark applications, registered
copyrights and copyright applications, now owned or held by Borrower. If, prior
to the termination of this Agreement, Borrower shall (i) create or obtain rights
to any new patents, trademarks, trademark registrations, trademark applications,
trade names, trade styles, service marks, service marks registrations, or
service mark applications, or (ii) become entitled to the benefit of any patent,
trademark, trademark registration, trademark application, trade name, trade
style, service mark, service mark registration, service mark application, the
provisions of Section 1 above shall automatically apply thereto and Borrower
shall give the Agent prompt written notice thereof. Borrower hereby authorizes
the Agent to modify this Agreement by (a) amending Schedules A, B, and/or C, as
the case may be, to include any future patents, trademark registrations,
trademark applications, service mark registrations, service mark applications,
registered copyrights and copyright applications that are Patents, Trademarks or
Copyrights under Section 1 above, or under this Section 5 (whether or not any
such notice from Borrower has been sent or received), and (b) filing, in
addition to and not in substitution for this Agreement, a supplement or addendum
to this Agreement containing on Schedule B therein, as the case may be, such
registered trademarks, trademark applications, service marks, registered service
marks and service mark applications that are Trademarks under Section 1 above or
this Section 5 and to take any action the Agent otherwise deems appropriate to
perfect or maintain the rights and interest of the Agent, for the benefit of the
Lender, under this Agreement with respect to such Patents, Trademarks and
Copyrights.


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6.            
Nature and
Continuation of Security Interest; Notice to Third Parties. This
Agreement has the effect of giving third parties notice of the Agent's Security
Interest in Borrower's Patents, Trademarks and Copyrights. This Agreement is
made for collateral security purposes only. This Agreement shall create a
continuing security interest in the Patents, Trademarks and Copyrights and shall
remain in full force and effect until the liabilities and Obligations of the
Borrower to the Lenders have been paid in full, including all obligations under
the Purchase Agreement and the Transaction Documents (as defined in the Purchase
Agreement).




7.            
Right to Inspect;
Assignments and Security Interests. The Agent shall have the right, at
any reasonable time upon prior written request and from time to time, to inspect
Borrower's premises and to examine Borrower's books, records and operations
relating to the Patents and the Trademarks, including, without limitation,
Borrower's quality control processes; provided, that in conducting such
inspections and examinations, the Agent shall use reasonable efforts not to
disturb unnecessarily the conduct of Borrower's ordinary business operations.
From and after the occurrence of an event of default, under the Purchase
Agreement, or any other Transaction Documents ("Event of Default"), Borrower
agrees that the Agent, or a conservator appointed by the Agent, shall have the
right to take any action to renew or to apply for registration of any Trademarks
as the Agent or said conservator, on its sole judgment, may deem necessary or
desirable in connection with the enforcement of the Agent's rights hereunder.
Borrower agrees (i) except in accordance with Borrower's reasonable business
judgment, not to sell or assign its respective interests in the Patents,
Trademarks and/or Copyrights without the prior written consent of the Agent and
the holders of a majority in principal the amount of the Notes (as defined in
the Purchase Agreement) and (ii) to maintain the quality of any and all products
in connection with which the Trademarks are used, consistent with the quality of
said products as of the date hereof.




8.            
Duties of
Borrower. Borrower shall have the duty to (i) prosecute diligently any
patent application, or trademark application or service mark application that is
part of the Trademarks pending as of the date hereof or thereafter until the
termination of this Agreement, and (ii) preserve and maintain all of Borrower's
rights in the patents, patent applications, trademark applications, service mark
applications and trademark and service mark registrations that are part of the
Patents and Trademarks. Any expenses incurred in connection with the foregoing
shall be borne by Borrower. Borrower shall not, without thirty (30) days prior
written notice to the Agent, abandon any trademark or service mark that is the
subject of a registered trademark, service mark or application therefor and
which, is or shall be necessary or economically desirable in the operation of
the Borrower's business. The Agent shall not have any duty with respect to the
Patents, Trademarks and/or Copyrights. Without limiting the generality of the
foregoing, the Agent shall not be under any obligation to take any steps
necessary to preserve rights in the Patents, Trademarks and/or Copyrights
against any other parties, but may do so at its option during the continuance of
an Event of Default, and all expenses incurred in connection therewith shall be
for the sole account of Borrower and added to the Obligations and liabilities
secured hereby, and by the Transaction Documents.





9.            
Agent's Right to
Sue. Upon the occurrence and during the continuance of any Event of
Default, the Agent shall have the right, for the benefit of the Lenders, to
exercise all rights and remedies available at law or in equity. From and after
the occurrence and during the continuance of an Event of Default, the Agent
shall have the right, but shall not be obligated, to bring suit or take any
other action to enforce the Patents, Trademarks and Copyrights and, if the Agent
shall commence any such suit or take any such action, Borrower shall, at the
request of the Agent, do any and all reasonable lawful acts and execute any and
all proper documents reasonably required by the Agent in aid of such
enforcement. Borrower shall, upon demand, promptly reimburse and indemnify the
Agent for all reasonable out-of-pocket costs and expenses incurred by the Agent
in the exercise of its rights under this Section 9 (including, without
limitation, all attorneys' fees). If, for any reason whatsoever, the Agent is
not reimbursed with respect to the costs and expenses referred to in the
preceding sentence, such costs and expenses shall be added to the Obligations
secured hereby.




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10.      
     Waivers. The Borrower
waives to the extent permitted by applicable law presentment, demand, notice,
protest, notice of acceptance of this Agreement, notice of any loans made,
credit or other extensions granted, collateral received or delivered or any
other action taken in reliance hereon and all other demands and notices of any
description, except for such demands and notices as are expressly required to be
provided to the Borrower under this Agreement or any other document evidencing
the Obligations or the liabilities under the Transaction Documents. With respect
to both the Obligations and the Collateral, the Borrower assents to any
extension or postponement of the time of payment or any other forgiveness or
indulgence, to any substitution, exchange or release of Collateral, to the
addition or release of any party or person primarily or secondarily liable, to
the acceptance of partial payment thereon and the settlement, compromise or
adjustment of any thereof, all in such manner and at such time or times as the
Agent may deem advisable. The Agent may exercise its rights with respect to the
Collateral without resorting, or regard, to other collateral or sources of
reimbursement for Obligations. The Agent shall not be deemed to have waived any
of its rights with respect to the Obligations or the Collateral unless such
waiver is in writing and signed by the Agent. No delay or omission on the part
of the Agent in exercising any right shall operate as a waiver of such right or
any other right. A waiver on any one occasion shall not bar or waive the
exercise of any right on any future occasion. All rights and remedies of the
Agent in the Obligations or the Collateral, whether evidenced hereby or by any
other instrument or papers, are cumulative and not exclusive of any remedies
provided by law or any other agreement, and may be exercised separately or
concurrently.




11.       
    Successors and
Assigns. This Agreement shall be binding upon the Borrower, its
respective successors and permitted assigns, and shall inure to the benefit of
and be enforceable by the Agent and its successors and assigns. Without limiting
the generality of the foregoing sentence, the Agent may assign or otherwise
transfer any agreement or any note held by it evidencing, securing or otherwise
executed in connection with the Obligations, or sell participations in any
interest therein, to any other person or entity.




12.     
      General;
Term.




(a)            This
Agreement may not be amended or modified except by a writing signed by the
Borrower and the Agent, nor may the Borrower assign any of its rights hereunder.
This Agreement and the terms, covenants and conditions hereof shall be construed
in accordance with, and governed by, the laws of the State of New York (without
giving effect to any conflicts of law provisions contained therein). In the
event that any Collateral stands in the name of the Borrower and another or
others jointly, as between the Agent and the Borrower, the Agent may deal with
the same for all purposes as if it belonged to or stood in the name of the
Borrower alone.




(b)            This
Agreement and the security interests granted herein shall terminate on the date
on which all payments under the Notes (as defined in the Purchase Agreement)
have been indefeasibly paid or satisfied in full (including as a result of the
conversion in full of the Notes) and all other obligations have been paid or
discharged (other than contingent indemnification obligations).




13.            WAIVER OF JURY TRIAL
VENUE.





THE
BORROWER HEREBY WAIVES TRIAL BY JURY IN ANY LITIGATION IN ANY COURT WITH RESPECT
TO, IN CONNECTION WITH OR, ARISING OUT OF: (A) THIS AGREEMENT OR ANY OTHER
INSTRUMENT OR DOCUMENT DELIVERED IN CONNECTION HEREWITH; (B) THE VALIDITY,
INTERPRETATION, COLLECTION OR ENFORCEMENT THEREOF; OR (C) ANY OTHER CLAIM OR
DISPUTE HOWEVER ARISING BETWEEN THE BORROWER AND THE LENDERS OR THE AGENT IN
RESPECT OF THIS AGREEMENT.





THE
BORROWER AGREES THAT ANY SUIT FOR THE ENFORCEMENT OF THE OBLIGATIONS, ARISING
OUT OF OR IN ANY MANNER RELATING TO THIS AGREEMENT OR ANY TRANSACTION RELATING
TO ANY TRANSACTION DOCUMENT MAY BE BROUGHT IN THE COURTS OF THE STATE OF NEW
YORK IN THE CITY OF NEW YORK OR ANY FEDERAL COURT SITTING THEREIN AND CONSENTS
TO THE NON-EXCLUSIVE JURISDICTION OF SUCH COURT AND TO SERVICE OF PROCESS IN ANY
SUCH SUIT BEING MADE UPON THE BORROWER BY MAIL AT THE ADDRESS SPECIFIED IN THE
PURCHASE AGREEMENT. THE BORROWER HEREBY WAIVES ANY OBJECTION THAT IT MAY NOW OR
HEREAFTER HAVE TO THE VENUE OF ANY SUCH SUIT OR ANY SUCH COURT OR THAT SUCH SUIT
WAS BROUGHT IN AN INCONVENIENT COURT. THE BORROWER SHALL NOT BE ENTITLED IN ANY
SUCH ACTION OR PROCEEDING TO ASSERT ANY DEFENSE GIVEN OR ALLOWED UNDER THE LAWS
OF ANY STATE OTHER THAN THE STATE OF NEW YORK UNLESS SUCH DEFENSE IS ALSO GIVEN
OR ALLOWED BY THE LAWS OF THE STATE OF NEW YORK. NOTHING IN THIS SECTION SHALL
AFFECT OR IMPAIR IN ANY MANNER OR TO ANY EXTENT THE RIGHT OF THE AGENT TO
COMMENCE LEGAL PROCEEDINGS OR OTHERWISE PROCEED AGAINST THE BORROWER IN ANY
JURISDICTION IN WHICH ANY COLLATERAL IS LOCATED, THE BORROWER CONDUCTS
ACTIVITIES OR WHERE LEGAL PROCEEDINGS MAY BE NECESSARY IN ORDER TO COLLECT OR
ENFORCE THE OBLIGATIONS OR TO SERVE PROCESS IN ANY MANNER PERMITTED BY
LAW.








[Signature
Page Follows]




4


IN WITNESS WHEREOF, the
parties have executed this Agreement as of the date first written
above.






BORROWER:In
      the Presence of:
              
              VALCENT PRODUCTS
      INC./s/  
      witness
              
              By:
              /s/  
      Gerry Jardine /s/  
      George OrrWitness
              
              Name:
              Gerry
      Jardine; George OrrTitle:
              Director;
      CFO/DirectorIn
      the Presence of:
              
              VALCENT USA
    INC./s/  
      witness
              
              By:
              /s/  
      Perry MartinWitness
              
              Name:
              Perry
      A. MartinTitle:
              PresidentIn
      the Presence of:
              
              VALCENT MANUFACTURING,
      LTD.BY:
      Valcent Management, L.L.C.,ITS:
      General Partner/s/  
      witness
              
              By:
              /s/  
      Perry MartinWitness
              
              Name:
              Perry
      A. MartinTitle:
              PresidentIn
      the Presence of:
              
              VALCENT MANAGEMENT
      LLC/s/  
      witness
              
              By:
              /s/  
      Perry MartinWitness
              
              Name:
              Perry
      A. MartinTitle:
              PresidentIn
      the Presence of:
              
              VERTIGRO ALGAE TECHNOLOGIES
      LLC/s/  
      witness
              
              By:
              /s/  
      Eldon SchornWitness
              
              Name:
              Eldon
      SchornTitle:
              DirectorIn
      the Presence of:
              
              VALCENT PRODUCTS EU
      LIMITED/s/  
      witness
              
              By:
              /s/  
      M. Glen KertzWitness
              
              Name:
              M.
      Glen KertzTitle:
              DirectorAgent:In
      the Presence of:
              
              PLATINUM LONG TERM GROWTH VI
      LLC/s/  
      witness
              
              By:
              /s/  
      Mark MordlichtWitness
              
              Name:
              Mark
      MordlichtTitle:
              Managing
      Member




5
  STATE OF
TEXAS                                                        )


)
SS.:


COUNTY OF
EL
PASO                                                 )





On the
15th day of
July, in the year 2008, before me, the undersigned, a notary public in and for
said state, personally appeared Perry A. Martin, President of Valcent USA, Inc.,
personally known to me or proved to me on the basis of satisfactory evidence to
be the individual(s) whose name(s) is (are) subscribed to the within instrument
and acknowledged to me that he/she/they executed the same in his/her/their
capacity(ies), and that by his/her/their signature(s) on the instrument, the
individual(s), or the person upon behalf of which the individual(s) acted,
executed the instrument.








/s/IonaRosenthal


Notary Public


STATE OF
TEXAS                                                        )


)
SS.:


COUNTY OF
EL
PASO                                                 )





On
the 15th
day of July, in the year 2008, before me, the undersigned, a notary public in
and for said state, personally appeared Perry A. Martin, President of Valcent
Management, L.L.C., the General Partner of Valcent Manufacturing, Ltd.
personally known to me or proved to me on the basis of satisfactory evidence to
be the individual(s) whose name(s) is (are) subscribed to the within instrument
and acknowledged to me that he/she/they executed the same in his/her/their
capacity(ies), and that by his/her/their signature(s) on the instrument, the
individual(s), or the person upon behalf of which the individual(s) acted,
executed the instrument.








/s/IonaRosenthal


Notary
Public








STATE OF
TEXAS                                                        )


)
SS.:


COUNTY OF
EL
PASO                                                 )





On
the 15th
day of July, in the year 2008, before me, the undersigned, a notary public in
and for said state, personally appeared Perry A. Martin, President of Valcent
Management, L.L.C., , personally known to me or proved to me on the basis of
satisfactory evidence to be the individual(s) whose name(s) is (are) subscribed
to the within instrument and acknowledged to me that he/she/they executed the
same in his/her/their capacity(ies), and that by his/her/their signature(s) on
the instrument, the individual(s), or the person upon behalf of which the
individual(s) acted, executed the instrument.








/s/IonaRosenthal


Notary Public





PROVINCE
OF BRITISH
COLUMBIA                     
 )


)
SS.:  Valcent Products Inc.


COUNTY OF
CANADA                                              )


6





On the
16th
day of July, in the year 2008, before me, the undersigned, a notary public in
and for said state, personally appeared George Orr, personally known to me or
proved to me on the basis of satisfactory evidence to be the individual(s) whose
name(s) is (are) subscribed to the within instrument and acknowledged to me that
he/she/they executed the same in his/her/their capacity(ies), and that by
his/her/their signature(s) on the instrument, the individual(s), or the person
upon behalf of which the individual(s) acted, executed the
instrument.








/s/ Virgil Z.
Hlus


Notary Public











Schedule
A


Patents
and Patent Applications





Schedule
B


Trademarks
and Trademark Applications




Schedule
C


Copyrights
and Copyright Applications












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