DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1, 3-14, 16-18, 35, and 37 in the reply filed on 01/16/2026 is acknowledged.
Claims 19, 21-22, 26-27, 34, 36, and 38 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 01/16/2026.
Claim Objections
Claim 4 is objected to because of the following informalities:
In order to ensure the proper language for a list, it is suggested to amend “of” to “or” in claim 4, line 2.
Appropriate correction is required.
Claim 35 is objected to under 37 CFR 1.75 as being a substantial duplicate of claim 17. When two claims in an application are duplicates or else are so close in content that they both cover the same thing, despite a slight difference in wording, it is proper after allowing one claim to object to the other as being a substantial duplicate of the allowed claim. See MPEP § 608.01(m).
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claims 8 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
Claim 8 recites “wherein injecting the oxidizing agent formulation solution into the reactor while maintaining the reactor vessel at the first operating temperature”. However, claim 1, on which claim 8 depends, does not require the operating temperature to be maintained at the first operating temperature for step (c). Clarification is requested.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1, 3-14, 16-18, 35, and 37 are rejected under 35 U.S.C. 103 as being unpatentable over Lovell (US 3,838,066 A) in view of Sears (US 2015/0273533 A1).
Regarding claims 1, 6, and 10-13, Lovell teaches a method for stabilizing pyrophoric materials in a catalyst bed including pyrophoric iron sulfide (i.e., claim 10; the metal sulfides comprise iron sulfides) which accumulates throughout the catalyst bed during the use of the catalyst to promote one or more chemical reactions (Lovell, Col. 2, lines 40-45) (i.e., a method of removal of metal sulfides from a spent catalyst located within a reactor vessel). Lovell teaches the method comprises:
purging the reactor with hydrogen-containing gas and inert gas (Lovell, Col. 3, lines 30-35) (i.e., purging the reactor vessel containing spent catalyst);
cooling the reactor to a temperature of about 300°F (Lovell, Col. 3, lines 36-38) (i.e., bringing the reactor vessel to a first operating temperature);
introducing air into the inert gas stream (Lovell, Col. 3, lines 40-41) (i.e., injecting an oxidizing agent formulation into the reactor vessel);
continuing the introduction of air to slowly obtain a maximum oxygen concentration (Lovell, Col. 3, lines 40-47), which corresponds to a dry gas purge as air is a dry gas (i.e., subjecting the reactor vessel to a dry gas purge);
continuing the appropriate oxygen concentration until the flame-front temperatures in the top of the catalyst bed fall below 325°F (Lovell, Col. 3, lines 45-48) (i.e., bringing the reactor vessel temperature to a second operating temperature); and
increasing the oxygen concentration slowly and maintaining for 4 hours, followed by stopping the air and inert gas addition to indicate if the percentage of oxygen in the circulating gas drops which would indicate that burning is still present (Lovell, Col. 3, lines 50-58) (i.e., isolating the reactor vessel from external contaminant sources and introducing air into the reactor vessel).
However, Lovell does not explicitly teach the oxidizing agent formulation is a solution.
With respect to the difference, Sears teaches a process to treat pyrophoric materials, including iron sulfides, found in refinery equipment by oxidizing iron sulfide using a sodium nitrite solution injected into a gaseous carrier stream (Sears, Abstract) (i.e., oxidizing agent formulation solution; claim 11, the oxidizing agent formulation solution comprises sodium nitrite). Sears further specifically teaches the sodium nitrite solution must be prepared and used at slightly alkaline pH which is accomplished by buffering the stock solution with disodium phosphate (Sears, [0028]) (i.e., claim 6, the oxidizing agent formulation solution comprises a pH buffer), and additionally comprises a chemical additive lauryl dimethylamine oxide in water to provide a quantitative measure of reaction completion (Sears, [0029]) (i.e., claims 12 and 13; the oxidizing agent formulation solution further comprises lauryldimethylamine oxide).
As Sears expressly teaches combining the sodium nitrite solution with steam or nitrogen to oxidize iron sulfide solves the problems of iron sulfide treatment such as rapid exothermic oxidation of pyrophoric materials (Sears, [0009]; [0024]).
Sears is analogous art as it is drawn to the oxidation of iron sulfides remaining in refinery equipment (Sears, Abstract).
In light of the motivation of injecting a sodium nitrite solution into the inert gas and air stream of step (c) as disclosed by Sears, it therefore would have been obvious to one of ordinary skill in the art to modify the method of Lovell by injecting a sodium nitrite solution into the inert gas and air stream of step (c) in order to decrease the intensity of the exothermic reaction between the oxidizing agent and the iron sulfide, and thereby arrive at the claimed invention.
Regarding claim 3, Lovell, in view of Sears, teaches the method of claim 1, wherein the oxygen concentration is monitored during oxidization (Lovell, Col. 3, lines 40-50). While Lovell does not explicitly teach the oxygen content of off-gases expelled from the reactor vessel during the first dry gas purge, it would be obvious to one of ordinary skill in the art to monitor the oxygen content during the first purge in order to know when oxygen was removed in order for heating the reaction vessel without pyrolysis occurring.
Regarding claim 4, Lovell, in view of Sears, teaches the method of claim 1, wherein air is introduced into the inert gas stream slowly and slowly increased every 30 minutes (Lovell, Col. 3, lines 40-41; lines 50-53) with a sodium nitrite solution (Sears, Abstract) (i.e., the oxidizing agent formulation is injected into the reactor vessel continuously, incrementally, or variably over a predetermined period of time).
Regarding claim 5, Lovell, in view of Sears, teaches the method of claim 1, wherein the oxidizing agent comprises air (Lovell, Lovell, Col. 3, lines 40-41) (i.e., the oxidizing agent formulation solution comprises one or more oxidizing agents).
Regarding claim 7, Lovell, in view of Sears, teaches the method of claim 1, wherein disodium phosphate (Sears, [0028]) is a part of the oxidizing agent, and wherein suitable water-soluble surfactants include ionic surfactants comprising an anionic head group such as a phosphate in the instant disclosure (Specification, [0089]). Therefore, the disodium phosphate which is an ionic compound and comprises an anionic head group corresponds to the claimed water-soluble surfactant.
Regarding claim 8, Lovell, in view of Sears, teaches the method of claim 1, wherein iron sulfide typically forms in environments where iron oxide is exposed to hydrogen sulfide, and these conditions commonly exist in closed oil processing equipment made from carbon and steel and used to refine high sulfur feedstock (Sears, [0007]; [0008]). When the iron sulfide crystal is subsequently exposed to air, it oxidizes back to iron oxide and either free sulfur or sulfur dioxide gas is formed. This reaction is accompanied by a considerable amount of heat, and is known as a pyrophoric reaction (Sears, [0009]). To combat the effects of pyrophoric reactions, the industry has employed several standard procedures including acid cleaning with a corrosion inhibitor and hydrogen sulfide suppressant which dissolves iron sulfide scales and releases hydrogen sulfide gas but the disposal of hydrogen sulfide gas can be problematic (Sears, [0011]-[0014]).
Further, sodium nitrite is used to oxidize iron sulfides to elemental sulfur and iron oxide (i.e., avoids the formation of sulfur dioxide) (Sears, [0024]; [0025]).
Therefore, while it is not explicitly taught that the off-gases expelled from the reactor vessel are monitored for H2S and SO2, it would be obvious to one of ordinary skill in the art to be monitoring for hydrogen sulfide, which would be present to form the iron sulfide, as the disposal of hydrogen sulfide is known to be problematic; as well as, monitoring for sulfur dioxide as the formation of sulfur dioxide should not be occurring in the reaction between iron sulfide and sodium nitrite, and would therefore indicate an issue within the reactor, such as an excess of air, to be causing the formation of sulfur dioxide.
Regarding claim 9, Lovell, in view of Sears, teaches the method of claim 1, wherein the oxygen content is increased in the reactor and the temperature increases to no more than 375°F in the reactor indicating the pyrophoric material is burning and the oxygen concentration is continued until the temperature drops to below 325°C to indicate burning has been completed (Lovell, Col. 3, lines 40-50).
While Lovell, in view of Sears, does not explicitly teach the gas purge comprises removing liquid from the reactor vessel and drying the contents of the reactor vessel, it is clear that at between 325 and 375°F, the water from the aqueous solution of sodium nitrite, would evaporate and thereby be removed from the reactor vessel which would mean the contents of the reactor vessel are dry.
Regarding claim 14, Lovell, in view of Sears, teaches the method of claim 1, wherein the sodium nitrite solution must be prepared and used at slightly alkaline pH, such as pH = 8.75 (Sears, [0028]), which falls within the claimed range.
Regarding claim 16, Lovell, in view of Sears, teaches the method of claim 1, wherein the oxidizing agent is injected into the reactor when the reactor is at the first operating temperature (Lovell, Col. 3, lines 35-42) (i.e., wherein c) injecting the oxidizing agent formulation solution into the reactor vessel is performed while maintaining the reactor vessel at the first operating temperature).
Regarding claims 17 and 35, Lovell, in view of Sears, teaches the method of claim 1, wherein the reaction vessel is purged using a hydrogen-containing gas and an inert gas (Lovell, Col. 3, lines 30-34) (i.e., dry gas).
Regarding claim 18, Lovell, in view of Sears, teaches the method of claim 1, wherein in blending a stock concentration, the phosphate buffering chemical may be first blended with water and then the sodium nitrite may be added at the end (Sears, [0028]), which may also be interpreted as the phosphate buffering solution being added the sodium nitrite at the end. Therefore, the phosphate buffering solution may be introduced into the oxidizing agent after the oxidizing agent enters the reactor vessel, i.e., between steps c) and d).
Regarding claim 37, Lovell, in view of Sears, teaches the method of claim 1, wherein while Lovell, in view of Sears, does not explicitly teach eliminating formation of polythionic and thionic acids, and/or eliminating formation of halide acids in piping and/or components of a reactor system comprising the reactor vessel, Lovell, in view of Sears, does not teach the formation of either of these compounds and therefore one of ordinary skill in the art would not expect the formation of these compounds using the method of Lovell, in view of Sears.
Conclusion
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/C.M.C./Examiner, Art Unit 1732
/CORIS FUNG/Supervisory Patent Examiner, Art Unit 1732