Exhibit 10.2

ALLONGE TO PROMISSORY NOTE

This Allonge to Promissory Note (“Allonge”) is dated as of this 27th day of
April, 2007. Reference is hereby made to that certain Promissory Note dated
December 31, 2004, delivered by SulphCo, Inc., as Maker (“Maker”) to Rudolf
Gunnerman, as lender, as assigned in part to ______________ (“Holder”), pursuant
to that certain Assignment of Promissory Note, dated April 24, 2007
(“Assignment”), and as amended and restated by that certain Promissory Note,
dated April 24, 2007, delivered by Maker to Holder (“Note”).

WHEREAS, Maker has requested that Holder extend the Maturity Date of the Note
for one year, and Holder has agreed to such extension subject to the other terms
set forth herein.

Except as expressly amended by the terms of this Allonge, the terms of the Note
remain in full force and effect. All capitalized terms used and not defined
herein are used as defined in the Note. As the context requires, all references
herein to “Note” refer to the Note as amended by this Allonge.

The following terms of the Note are hereby amended by this Allonge:

I. Maturity Date and Additional Interest Payment Date. The Maturity Date shall
mean December 31, 2008, and in the fourth paragraph of the Note, in the second
line, the words “and December 31, 2006” shall be deleted and replaced with
“December 31, 2006 and December 31, 2007” so as to add an interest payment due
on December 31, 2007

II. The following is hereby added in its entirety:

“Conversion.

1. Conversion Privileges. Subject to Section II. B.3. below, the Conversion
Privileges set forth in paragraph 2 below shall remain in full force and effect
immediately from the date hereof and until the Note is paid in full regardless
of the occurrence of an Event of Default. The Note shall be payable in full on
the Maturity Date, unless previously converted into Common Stock in accordance
with paragraph 2 below; provided, that if an Event of Default has occurred, the
Holder may extend the Maturity Date up to an amount of time equal to the
pendency of the Event of Default. Such extension must be on notice in writing.

2. Conversion Rights. The Holder shall have the right to convert the principal
due under this Note into shares (“Shares”) of the Maker's Common Stock, $.001
par value per share (“Common Stock”) as set forth below.

2.1. Conversion into the Maker's Common Stock.

(a) Subject to Section II. 3. below, the Holder shall have the right from and
after the date of the issuance of this Note and then at any time until this Note
is fully paid, to convert any outstanding and unpaid principal portion of this
Note, at the election of the Holder (the date of giving of such notice of
conversion being a "Conversion Date") into fully paid and nonassessable shares
of Common Stock as such stock exists on the date of issuance of this Note, or
any shares of capital stock of Maker into which such Common Stock shall
hereafter be changed or reclassified, at the conversion price as defined in
paragraph 2.1(b) hereof (the "Conversion Price"), determined as provided herein.
Upon delivery to the Maker of a completed Notice of Conversion, a form of which
is annexed hereto, Maker shall issue and deliver to the Holder within three (3)
business days after the Conversion Date (such third day being the “Delivery
Date”) that number of shares of Common Stock for the portion of the Note
converted in accordance with the foregoing. At the election of the Holder, the
Maker will deliver accrued but unpaid interest on the Note, if any, through the
Conversion Date directly to the Holder on or before the Delivery Date. The
number of shares of Common Stock to be issued upon each conversion of this Note
shall be determined by dividing that portion of the principal of the Note to be
converted by the Conversion Price.

 
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(b) Subject to adjustment as provided in paragraph 2.1(c) hereof, the Conversion
Price per share shall be $3.80, subject to adjustment as described herein.

(c)  The Conversion Price and number and kind of shares or other securities to
be issued upon conversion determined pursuant to Section 2.1(a), shall be
subject to adjustment from time to time upon the happening of certain events
while this conversion right remains outstanding, as follows:

A. Merger, Sale of Assets, etc. If the Maker at any time shall consolidate with
or merge into or sell or convey all or substantially all its assets to any other
corporation, this Note, as to the unpaid principal portion thereof and accrued
interest thereon, shall thereafter be deemed to evidence the right to purchase
such number and kind of shares or other securities and property as would have
been issuable or distributable on account of such consolidation, merger, sale or
conveyance, upon or with respect to the securities subject to the conversion or
purchase right immediately prior to such consolidation, merger, sale or
conveyance. The foregoing provision shall similarly apply to successive
transactions of a similar nature by any such successor or purchaser. Without
limiting the generality of the foregoing, the anti-dilution provisions of this
Section shall apply to such securities of such successor or purchaser after any
such consolidation, merger, sale or conveyance.

B. Reclassification, etc. If the Maker at any time shall, by reclassification or
otherwise, change the Common Stock into the same or a different number of
securities of any class or classes that may be issued or outstanding, this Note,
as to the unpaid principal portion thereof and accrued interest thereon, shall
thereafter be deemed to evidence the right to purchase an adjusted number of
such securities and kind of securities as would have been issuable as the result
of such change with respect to the Common Stock immediately prior to such
reclassification or other change.

C. Stock Splits, Combinations and Dividends. If the shares of Common Stock are
subdivided or combined into a greater or smaller number of shares of Common
Stock, or if a dividend is paid on the Common Stock in shares of Common Stock,
the Conversion Price shall be proportionately reduced in case of subdivision of
shares or stock dividend or proportionately increased in the case of combination
of shares, in each such case by the ratio which the total number of shares of
Common Stock outstanding immediately after such event bears to the total number
of shares of Common Stock outstanding immediately prior to such event.
 
(d) Whenever the Conversion Price is adjusted pursuant to paragraph 2.1(c)
above, the Maker shall promptly mail to the Holder a notice setting forth the
Conversion Price after such adjustment and setting forth a statement of the
facts requiring such adjustment.

(e) During the period the conversion right exists, Maker will reserve from its
authorized and unissued Common Stock a sufficient number of shares to provide
for the issuance of Common Stock issuable upon the full conversion of this Note
and as described herein below. Maker represents that upon issuance, such shares
will be duly and validly issued, fully paid and non-assessable. Maker agrees
that its issuance of this Note shall constitute full authority to its officers,
agents, and transfer agents who are charged with the duty of executing and
issuing stock certificates to execute and issue the necessary certificates for
shares of Common Stock upon the conversion of this Note.

2.2. Method of Conversion. This Note may be converted by the Holder in whole or
in part as described in Section 2.1(a) hereof. Upon partial conversion of this
Note, a new Note containing the same date and provisions of this Note shall, at
the request of the Holder, be issued by the Maker to the Holder for the
principal balance of this Note and interest which shall not have been paid, and
in any case, the unconverted amount of principal and all unpaid interest shall
be duly noted in the books and records of Maker.

2.3. Maximum Conversion. The Holder shall not be entitled to convert on a
Conversion Date that amount of the Note in connection with that number of shares
of Common Stock which would be in excess of the sum of (i) the number of shares
of Common Stock beneficially owned by the Holder and its affiliates on a
Conversion Date, (ii) any Common Stock issuable in connection with the
unconverted portion of the Note, and (iii) the number of shares of Common Stock
issuable upon the conversion of the Note with respect to which the determination
of this provision is being made on a Conversion Date, which would result in
beneficial ownership by the Holder and its affiliates of more than 4.99% of the
outstanding shares of Common Stock of the Maker on such Conversion Date. For the
purposes of the provision to the immediately preceding sentence, beneficial
ownership shall be determined in accordance with Section 13(d) of the Securities
Exchange Act of 1934, as amended, and Regulation 13d-3 thereunder. Subject to
the foregoing, the Holder shall not be limited to aggregate conversions of only
4.99% and aggregate conversion by the Holder may exceed 4.99%. The Holder shall
have the authority and obligation to determine whether the restriction contained
in this Section 2.3 will limit any conversion hereunder and to the extent that
the Holder determines that the limitation contained in this Section applies, the
determination of which portion of the Notes are convertible shall be the
responsibility and obligation of the Holder. The Holder may waive the conversion
limitation described in this Section 2.3, in whole or in part, upon and
effective after 61 days prior written notice to the Maker to increase such
percentage to up to 9.99%. The Holder may allocate which of the equity of the
Maker deemed beneficially owned by the Holder shall be included in the 4.99%
amount or up to 9.99% amount as described above.

 
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3. Reservation. Maker will reserve on behalf of all of Holder from its
authorized but unissued Common Stock a number of common shares equal to 100% of
the amount of Common Stock necessary to allow each holder of a Note to be able
to convert all such outstanding principal balance of holder’s Note.

III. Legend. The Note bears the following legend: THIS NOTE AND THE COMMON
SHARES ISSUABLE UPON CONVERSION OF THIS NOTE HAVE NOT BEEN REGISTERED UNDER THE
SECURITIES ACT OF 1933, AS AMENDED. THIS NOTE AND THE COMMON SHARES ISSUABLE
UPON CONVERSION OF THIS NOTE MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR
HYPOTHECATED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT AS TO THIS
NOTE UNDER SAID ACT OR AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO SULPHCO,
INC. THAT SUCH REGISTRATION IS NOT REQUIRED.

IV. The following is hereby added in its entirety:

“Registration.

4.1. Registration Rights. The Maker hereby grants the following registration
rights to holders of the Notes and certain Stock Option Agreements being
executed and delivered on or about April 26, 2006 and certain shares of stock
purchased in connection therewith. The Maker shall file with the Commission a
Form S-3 registration statement (the “Registration Statement”) (or such other
form that it is eligible to use) in order to register (i) all shares issuable
upon Conversion of this Note, (ii) shares issuable upon exercise by Holder of
the Stock Option Agreement, executed and delivered in connection with the
Assignment, (iii) 125,000 shares of Maker Common Stock purchased by certain Note
holders on or about April 26, 2007 from Gunnerman (“Stock Purchase”), and (iv)
125,000 shares issuable upon exercise by Holder of the Stock Option Agreement,
executed and delivered in connection with the Stock Purchase for resale and
distribution under the 1933 Act by June 8, 2007 (the “Filing Date”), and shall
use commercially reasonable efforts to cause such Registration Statement to be
declared effective as soon as possible thereafter . The Maker will register not
less than a number of shares of common stock in the aforedescribed registration
statement that is equal to 100% of the Shares described in the second sentence
of this paragraph 4.1 and as more fully set forth on Schedule 4.1 hereto
(collectively the “Registrable Securities”). The Registrable Securities shall be
reserved and set aside exclusively for the benefit of each holder listed on
Schedule 4.1, pro rata, and not issued, employed or reserved for anyone other
than each such holder listed on Schedule 4.1. The Registration Statement will
immediately be amended or additional registration statements will be immediately
filed by the Maker as necessary to register additional shares of Common Stock to
allow the public resale of all Common Stock included in and issuable by virtue
of the Registrable Securities

4.2. Registration Procedures. If and whenever the Maker is required by the
provisions of Section 4.1 to effect the registration of any Registrable
Securities under the 1933 Act, the Maker will, as expeditiously as possible:
 
(a) subject to the timelines provided in this Agreement, prepare and file with
the Commission a registration statement required by Section 4, with respect to
such securities and use its best efforts to cause such registration statement to
become and remain effective for the period of the distribution contemplated
thereby (determined as herein provided but not less than 2 years), promptly
provide to the holders of the Registrable Securities copies of all filings and
Commission letters of comment and notify Holders (by telecopier and by e-mail
addresses provided by Holders) and Grushko & Mittman, P.C. (by telecopier and by
email to Counslers@aol.com) on or before the first business day thereafter that
the Maker receives notice that (i) the Commission has no comments or no further
comments on the Registration Statement, and (ii) the registration statement has
been declared effective;
 
 
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(b) prepare and file with the Commission such amendments and supplements to such
registration statement and the prospectus used in connection therewith as may be
necessary to keep such registration statement effective until such registration
statement has been effective for a period of two (2) years, and comply with the
provisions of the 1933 Act with respect to the disposition of all of the
Registrable Securities covered by such registration statement in accordance with
the Sellers’ intended method of disposition set forth in such registration
statement for such period;
 
(c) furnish to the Sellers, at the Maker’s expense, such number of copies of the
registration statement and the prospectus included therein (including each
preliminary prospectus) as such persons reasonably may request in order to
facilitate the public sale or their disposition of the securities covered by
such registration statement or make them electronically available;
 
(d) use its commercially reasonable best efforts to register or qualify the
Registrable Securities covered by such registration statement under the
securities or “blue sky” laws of New York and such jurisdictions as the Sellers
shall request in writing, provided, however, that the Maker shall not for any
such purpose be required to qualify generally to transact business as a foreign
corporation in any jurisdiction where it is not so qualified or to consent to
general service of process in any such jurisdiction;
 
(e) if applicable, list the Registrable Securities covered by such registration
statement with any securities exchange on which the Common Stock of the Maker is
then listed;
 
(f) notify the Holders within 24 hours of the Maker’s becoming aware that a
prospectus relating thereto is required to be delivered under the 1933 Act, of
the happening of any event of which the Maker has knowledge as a result of which
the prospectus contained in such registration statement, as then in effect,
includes an untrue statement of a material fact or omits to state a material
fact required to be stated therein or necessary to make the statements therein
not misleading in light of the circumstances then existing or which becomes
subject to a Commission, state or other governmental order suspending the
effectiveness of the registration statement covering any of the Registrable
Securities;
 
(g) provided same would not be in violation of the provision of Regulation FD
under the 1934 Act, make available for inspection by the Sellers, and any
attorney, accountant or other agent retained by the Seller or underwriter, all
publicly available, non-confidential financial and other records, pertinent
corporate documents and properties of the Maker, and cause the Maker's officers,
directors and employees to supply all publicly available, non-confidential
information reasonably requested by the seller, attorney, accountant or agent in
connection with such registration statement; and
 
(h) provide to the Sellers copies of the Registration Statement and amendments
thereto five business days prior to the filing thereof with the Commission.
 
4.3. Provision of Documents. In connection with each registration described in
this Section 4, each Seller will furnish to the Maker in writing such
information and representation letters with respect to itself and the proposed
distribution by it as reasonably shall be necessary in order to assure
compliance with federal and applicable state securities laws.
 
 
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4.4. Non-Registration Events. The Maker and the holders listed on Schedule 4.1
hereto agree that the Sellers will suffer damages if any registration statement
described in Section 4 is not filed by the Filing Date (the “Non-Registration
Event”). If the Non-Registration Event occurs, then the Maker shall deliver to
the holder of Registrable Securities, as Liquidated Damages, an amount equal to
one percent (1%) for each thirty (30) days (or such lesser pro-rata amount for
any period of less than thirty (30) days) of the Principal Amount of the
outstanding Notes and purchase price of Shares issued upon conversion of the
Notes owned of record by such holder which are subject to the Non-Registration
Event. The Maker may pay the Liquidated Damages in cash. The maximum amount of
Liquidated Damages payable in connection with Non-Registration Event may not
exceed twelve percent (12%). The Liquidated Damages must be paid within ten (10)
days after the end of each thirty (30) day period or shorter part thereof for
which Liquidated Damages are payable. Notwithstanding the foregoing, the Maker
shall not be liable to the Holder under this Section 4.4 for any events or
delays occurring as a consequence of the acts or omissions of the Holders
contrary to the obligations undertaken by Holders in this Agreement. Liquidated
Damages will not accrue nor be payable pursuant to this Section 4.4 nor will the
Non-Registration Event be deemed to have occurred for times during which
Registrable Securities are transferable by the holder of Registrable Securities
pursuant to Rule 144(k) under the 1933 Act.
 
4.5. Expenses. All expenses incurred by the Maker in complying with Section 4,
including, without limitation, all registration and filing fees, printing
expenses (if required), fees and disbursements of counsel and independent public
accountants for the Maker, fees and expenses (including reasonable counsel fees)
incurred in connection with complying with state securities or “blue sky” laws,
fees of the National Association of Securities Dealers, Inc., transfer taxes,
and fees of transfer agents and registrars, are called “Registration Expenses.”
All underwriting discounts and selling commissions applicable to the sale of
Registrable Securities are called "Selling Expenses." The Maker will pay all
Registration Expenses in connection with the registration statement under
Section 4. Selling Expenses in connection with each registration statement under
Section 4 shall be borne by the Seller and may be apportioned among the Sellers
in proportion to the number of shares sold by the Seller relative to the number
of shares sold under such registration statement or as all Sellers thereunder
may agree.
 
4.6. Indemnification and Contribution.
 
(a) In the event of a registration of any Registrable Securities under the 1933
Act pursuant to Section 4, the Maker will, to the extent permitted by law,
indemnify and hold harmless the Seller, each officer of the Seller, each
director of the Seller, each underwriter of such Registrable Securities
thereunder and each other person, if any, who controls such Seller or
underwriter within the meaning of the 1933 Act, against any losses, claims,
damages or liabilities, joint or several, to which the Seller, or such
underwriter or controlling person may become subject under the 1933 Act or
otherwise, insofar as such losses, claims, damages or liabilities (or actions in
respect thereof) arise out of or are based upon any untrue statement or alleged
untrue statement of any material fact contained in any registration statement
under which such Registrable Securities was registered under the 1933 Act
pursuant to Section 4, any preliminary prospectus or final prospectus contained
therein, or any amendment or supplement thereof, or arise out of or are based
upon the omission or alleged omission to state therein a material fact required
to be stated therein or necessary to make the statements therein not misleading
in light of the circumstances when made, and will subject to the provisions of
Section 4.6(c) reimburse the Seller, each such underwriter and each such
controlling person for any legal or other expenses reasonably incurred by them
in connection with investigating or defending any such loss, claim, damage,
liability or action; provided, however, that the Maker shall not be liable to
the Seller to the extent that any such damages arise out of or are based upon an
untrue statement or omission made in any preliminary prospectus if (i) the
Seller failed to send or deliver a copy of the final prospectus delivered by the
Maker to the Seller with or prior to the delivery of written confirmation of the
sale by the Seller to the person asserting the claim from which such damages
arise, (ii) the final prospectus would have corrected such untrue statement or
alleged untrue statement or such omission or alleged omission, or (iii) to the
extent that any such loss, claim, damage or liability arises out of or is based
upon an untrue statement or alleged untrue statement or omission or alleged
omission so made in conformity with information furnished by any such Seller, or
any such controlling person in writing specifically for use in such registration
statement or prospectus.
 
 
 
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(b) In the event of a registration of any of the Registrable Securities under
the 1933 Act pursuant to Section 4, each Seller severally, but not jointly,
will, to the extent permitted by law, indemnify and hold harmless the Maker, and
each person, if any, who controls the Maker within the meaning of the 1933 Act,
each officer of the Maker who signs the registration statement, each director of
the Maker, each underwriter and each person who controls any underwriter within
the meaning of the 1933 Act, against all losses, claims, damages or liabilities,
joint or several, to which the Maker or such officer, director, underwriter or
controlling person may become subject under the 1933 Act or otherwise, insofar
as such losses, claims, damages or liabilities (or actions in respect thereof)
arise out of or are based upon any untrue statement or alleged untrue statement
of any material fact contained in the registration statement under which such
Registrable Securities were registered under the 1933 Act pursuant to Section 4,
any preliminary prospectus or final prospectus contained therein, or any
amendment or supplement thereof, or arise out of or are based upon the omission
or alleged omission to state therein a material fact required to be stated
therein or necessary to make the statements therein not misleading, and will
reimburse the Maker and each such officer, director, underwriter and controlling
person for any legal or other expenses reasonably incurred by them in connection
with investigating or defending any such loss, claim, damage, liability or
action, provided, however, that the Seller will be liable hereunder in any such
case if and only to the extent that any such loss, claim, damage or liability
arises out of or is based upon an untrue statement or alleged untrue statement
or omission or alleged omission made in reliance upon and in conformity with
information pertaining to such Seller, as such, furnished in writing to the
Maker by such Seller specifically for use in such registration statement or
prospectus, and provided, further, however, that the liability of the Seller
hereunder shall be limited to the net proceeds actually received by the Seller
from the sale of Registrable Securities covered by such registration statement.
 
(c) Promptly after receipt by an indemnified party hereunder of notice of the
commencement of any action, such indemnified party shall, if a claim in respect
thereof is to be made against the indemnifying party hereunder, notify the
indemnifying party in writing thereof, but the omission so to notify the
indemnifying party shall not relieve it from any liability which it may have to
such indemnified party other than under this Section 4.6(c) and shall only
relieve it from any liability which it may have to such indemnified party under
this Section 4.6(c), except and only if and to the extent the indemnifying party
is prejudiced by such omission. In case any such action shall be brought against
any indemnified party and it shall notify the indemnifying party of the
commencement thereof, the indemnifying party shall be entitled to participate in
and, to the extent it shall wish, to assume and undertake the defense thereof
with counsel satisfactory to such indemnified party, and, after notice from the
indemnifying party to such indemnified party of its election so to assume and
undertake the defense thereof, the indemnifying party shall not be liable to
such indemnified party under this Section 4.6(c) for any legal expenses
subsequently incurred by such indemnified party in connection with the defense
thereof other than reasonable costs of investigation and of liaison with counsel
so selected, provided, however, that, if the defendants in any such action
include both the indemnified party and the indemnifying party and the
indemnified party shall have reasonably concluded that there may be reasonable
defenses available to it which are different from or additional to those
available to the indemnifying party or if the interests of the indemnified party
reasonably may be deemed to conflict with the interests of the indemnifying
party, the indemnified parties, as a group, shall have the right to select one
separate counsel and to assume such legal defenses and otherwise to participate
in the defense of such action, with the reasonable expenses and fees of such
separate counsel and other expenses related to such participation to be
reimbursed by the indemnifying party as incurred.
 
(d) In order to provide for just and equitable contribution in the event of
joint liability under the 1933 Act in any case in which either (i) a Seller, or
any controlling person of a Seller, makes a claim for indemnification pursuant
to this Section 4.6 but it is judicially determined (by the entry of a final
judgment or decree by a court of competent jurisdiction and the expiration of
time to appeal or the denial of the last right of appeal) that such
indemnification may not be enforced in such case notwithstanding the fact that
this Section 4.6 provides for indemnification in such case, or (ii) contribution
under the 1933 Act may be required on the part of the Seller or controlling
person of the Seller in circumstances for which indemnification is not provided
under this Section 4.6; then, and in each such case, the Maker and the Seller
will contribute to the aggregate losses, claims, damages or liabilities to which
they may be subject (after contribution from others) in such proportion so that
the Seller is responsible only for the portion represented by the percentage
that the public offering price of its securities offered by the registration
statement bears to the public offering price of all securities offered by such
registration statement, provided, however, that, in any such case, (y) the
Seller will not be required to contribute any amount in excess of the public
offering price of all such securities sold by it pursuant to such registration
statement; and (z) no person or entity guilty of fraudulent misrepresentation
(within the meaning of Section 11(f) of the 1933 Act) will be entitled to
contribution from any person or entity who was not guilty of such fraudulent
misrepresentation.
 
 
 
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4.7. Delivery of Unlegended Shares.
 
(a) Within FIVE (5) business days (such third business day being the “Unlegended
Shares Delivery Date”) after the business day on which the Maker has received
(i) a notice that shares of stock issued upon a conversion of the Note or any
other Common Stock deemed Registrable Securities have been sold pursuant to the
Registration Statement or Rule 144 under the 1933 Act, (ii) a representation
that the prospectus delivery requirements, or the requirements of Rule 144, as
applicable and if required, have been satisfied, (iii) the original share
certificates representing the shares of Common Stock that have been sold, and
(iv) in the case of sales under Rule 144, customary representation letters of
the Holder and/or Holder’s broker regarding compliance with the requirements of
Rule 144, the Maker at its expense, (y) shall deliver, and shall cause legal
counsel selected by the Maker to deliver to its transfer agent (with copies to
Holder) an appropriate instruction and opinion of such counsel, directing the
delivery of shares of Common Stock without any legends including the legend set
forth in Section 4(i) above, reissuable pursuant to any effective and current
Registration Statement described in Section 4 of this Agreement or pursuant to
Rule 144 under the 1933 Act (the “Unlegended Shares”); and (z) cause the
transmission of the certificates representing the Unlegended Shares together
with a legended certificate representing the balance of the submitted Shares
certificate, if any, to the Holder at the address specified in the notice of
sale, via express courier, by electronic transfer or otherwise on or before the
Unlegended Shares Delivery Date.
 
(b) In lieu of delivering physical certificates representing the Unlegended
Shares, if the Maker’s transfer agent is participating in the Depository Trust
Company (“DTC”) Fast Automated Securities Transfer program, upon request of a
Holder, so long as the certificates therefor do not bear a legend and the Holder
is not obligated to return such certificate for the placement of a legend
thereon, the Maker shall cause its transfer agent to electronically transmit the
Unlegended Shares by crediting the account of Holder’s prime Broker with DTC
through its Deposit Withdrawal Agent Commission system. Such delivery must be
made on or before the Unlegended Shares Delivery Date.

V. The following is hereby added in its entirety:

Negative Covenants. So long as at least $2 million of the principal amount of
the Notes is outstanding, without the written consent of the holders of a
majority of the aggregate principal amount of the Notes outstanding as of the
date of the request , the Maker will not and will not permit any of its
subsidiaries to directly or indirectly:

(i) create, incur, assume or suffer to exist any pledge, hypothecation,
assignment, deposit arrangement, lien, charge, claim, security interest,
security title, mortgage, security deed or deed of trust, easement or
encumbrance, or preference, priority or other security agreement or preferential
arrangement of any kind or nature whatsoever (including, without limitation, any
lease or title retention agreement, any financing lease having substantially the
same economic effect as any of the foregoing, and the filing of, or agreement to
give, any financing statement perfecting a security interest under the Uniform
Commercial Code or comparable law of any jurisdiction) which is senior to the
obligations owed to the Holders under the Note and Allonge (each, a “Lien”) upon
any of its property, whether now owned or hereafter acquired, except for: (i)
(a) Liens imposed by law for taxes that are not yet due or are being contested
in good faith and for which adequate reserves have been established in
accordance with generally accepted accounting principles; (b) carriers’,
warehousemen’s, mechanics’, material men’s, repairmen’s and other like Liens
imposed by law, arising in the ordinary course of business and securing
obligations that are not overdue by more than 30 days or that are being
contested in good faith and by appropriate proceedings; (c) pledges and deposits
made in the ordinary course of business in compliance with workers’
compensation, unemployment insurance and other social security laws or
regulations; (d) deposits to secure the performance of bids, trade contracts,
leases, statutory obligations, surety and appeal bonds, performance bonds and
other obligations of a like nature, in each case in the ordinary course of
business; (e) Liens created with respect to the financing of the purchase of
property or lease of equipment in the ordinary course of the Maker’s business up
to the amount of the purchase price of such property; and (f) easements, zoning
restrictions, rights-of-way and similar encumbrances on real property imposed by
law or arising in the ordinary course of business that do not secure any
monetary obligations and do not materially detract from the value of the
affected property (each of (a) through (f), a “Permitted Lien”) and (ii)
indebtedness for borrowed money which is not senior or pari passu in right of
payment to the payment of the Notes or distribution of the Maker’s assets, and
for which an appropriate subordination agreement has been executed and delivered
which is acceptable to the Holder in its sole discretion;

 
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(ii) amend its certificate of incorporation, by-laws or its charter documents so
as to adversely affect any rights of the Holder;

(iii) repay, repurchase or offer to repay, repurchase or otherwise acquire or
make any dividend or distribution in respect of any of its Common Stock,
preferred stock, or other equity securities

(iv) prepay or redeem any financing related debt or past due obligations
outstanding as of the Closing Date, unless such financing otherwise provides for
prepayment or redemption by its terms;
 
or

(v) the Maker agrees to provide Holder not less than ten days notice prior to
becoming obligated to or effectuating a Permitted Lien.”

For avoidance of doubt, the Maker may create, incur, assume or suffer to exist
any Lien that is junior or pari passu to the Notes.

VI. The following are hereby added as “Events of Default” under the Note:

1. Breach of Material Covenant. The Maker breaches any material covenant or
other term or condition of this Note (unless any such covenant, etc. contains a
shorter notice or cure period) in any material respect and such breach, if
subject to cure, continues for a period of ten (10) business days after written
notice to the Maker from the Holder.

2. Delisting of the Maker’s Common Stock from any principal market on which it
is listed (i.e.: Over the Counter Bulletin Board or American Stock Exchange,
etc. (“Principal Market”); failure to comply with the requirements for continued
listing on a Principal Market for a period of fifteen consecutive trading days;
or notification from a Principal Market that the Maker is not in compliance with
the conditions for such continued listing on such Principal Market.

3. Stop Trade. An SEC or judicial stop trade order or Principal Market trading
suspension with respect to Maker’s Common Stock that lasts for fifteen or more
consecutive trading days.4 Failure to Deliver Common Stock or Replacement Note.
Maker's failure to timely deliver Common Stock to the Holder pursuant to and in
the form required by this Note and, if requested by Holder, a replacement Note.

4. Cross Default. A default by the Maker of a material term, covenant, warranty
or undertaking of any agreement executed in connection with the Assignment or
the Stock Purchase agreement to which the Maker and Holder are parties, or the
occurrence of a material event of default under such agreements which is not
cured after any required notice and/or cure period.

VII. The governing law for the Note shall be the State of New York and the Note
shall be deemed to be executed and delivered in the State of New York. The
following governing law provision shall apply:

“This Note shall be governed by and construed in accordance with the laws of the
State of New York. Any action brought by either party against the other
concerning the transactions contemplated by this Agreement shall be brought only
in the state courts of New York or in the federal courts located in the state of
New York. Both parties and the individual signing this Agreement on behalf of
the Maker agree to submit to the jurisdiction of such courts. The prevailing
party shall be entitled to recover from the other party its reasonable
attorney's fees and costs. This Note shall be deemed an unconditional obligation
of Maker for the payment of money and, without limitation to any other remedies
of Holder, may be enforced against Maker by summary proceeding pursuant to New
York Civil Procedure Law and rules Section 3213 or any similar rule or statute
in the jurisdiction where enforcement is sought.”
 
Miscellaneous. This Allonge must be delivered by original signature for Maker,
but the Holder may execute and deliver by facsimile copy.

 
-8-

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

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

SULPHCO, INC.

By:__________________
Name:
Title:
 

[NAME OF HOLDER]

By:__________________
Name:
Title:
 
 
 
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NOTICE OF CONVERSION

(To be executed by the Registered Holder in order to convert the Note)

The undersigned hereby elects to convert $_________ of the principal and
$_________ of the interest due on the Note issued by SulphCo Inc. on April __,
2007 into Shares of Common Stock of SulphCo Inc. (the "Maker") according to the
conditions set forth in such Note, as of the date written below.

Date of
Conversion:____________________________________________________________________

Conversion
Price:______________________________________________________________________

Shares To Be
Delivered:_________________________________________________________________

Signature:______________________________________________________________________

Print
Name:_________________________________________________________________________

Address:________________________________________________________________________

_______________________________________________________________________________
 
 
 
-10-

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Schedule 4.1 to Allonge to Promissory Note, dated April 27, 2007
                         
Name
 
Note
Conversion
Shares
 
Option Shares from Note Assignment Option
 
Stock Purchase Shares
 
Option Shares from Stock Purchase Option
 
Total
                         
Ellis Capital LLC
   
305,281
   
348,020
               
653,301
 
Mayflower Oak LLC
   
348,939
   
397,790
   
62,500
   
62,500
   
871,729
 
Iroquois Master Fund Ltd.
   
218,087
   
248,619
   
62,500
   
62,500
   
591,705
 
Scott Cohen
   
114,819
   
130,893
               
245,712
 
Scott Jason Cohen Foundatation Inc.
   
23,263
   
26,519
               
49,782
 
Merav Abbe Irrevocable Trust
   
138,081
   
157,412
               
295,494
 
Ed Rosenblum
   
43,617
   
49,724
               
93,341
 
Devidas Budrani
   
94,464
   
107,689
               
202,153
 
Joshua Silverman
   
14,620
   
16,667
               
31,287
 
Phil Mirabelli
   
14,620
   
16,667
               
31,287
                                   
TOTALS
   
1,315,789
   
1,500,000
   
125,000
   
125,000
   
3,065,789
 

-11-