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 .
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.
Status of Claims
Claims 1-4 and 8-9 are currently under examination. Claims 5-7 have been cancelled. Claims 1 and 3-4 are amended. Claims 8-9 are newly added.
Previous Grounds of Rejection
In the light of the cancellation, the objection with respect to claim 7 is withdrawn.
In the light of the amendments, the rejection under 35 U.S.C. 103(a) as being unpatentable over Khurram et al. (US 2016/0107963 A1, applicants submitted in IDS) with respect to claims 1-4 is amended as set forth below.
In the light of the cancellation, the rejection under 35 U.S.C. 112(a), with respect to claim 7 is withdrawn.
In the light of the amendments, the rejection under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, with respect to claims 1-4 and 7 is withdrawn. Among them, claim 7 has been cancelled.
New ground of rejection is set forth below.
Amended & New Grounds of Rejections
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-4 and 8-9 is rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
In this case, claim 1 contains subject matter “the flow of fresh natural gas feed maintains a sulfur concentration at an inlet to the hydrogenator sufficient to maintain a hydrogenator catalyst of the hydrogenator in a sulfurized state during start-up, thereby avoiding desulfurization of the hydrogenator catalyst.” which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
All other claims depend directly or indirectly from the rejected claims and are, therefore, also rejected under 35 USC § 112(a) for the reasons set forth above.
Claim 9 contains subject matter “wherein no sulfur is added to the hydrogenator from an external sulfur source separate from the fresh natural gas feed” which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-4 and 8-9 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
The limitation of “the flow of fresh natural gas feed maintains a sulfur concentration at an inlet to the hydrogenator sufficient to maintain a hydrogenator catalyst of the hydrogenator in a sulfurized state during start-up, thereby avoiding desulfurization of the hydrogenator catalyst” recited in claim 1 are unclear and confused because the terms "sufficient" and “sulfurized state” are not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. Appropriated corrections are required.
All other claims depend directly or indirectly from the rejected claims and are, therefore, also rejected under 35 USC § 112(b) for the reasons set forth above.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action:
(a) A patent may not be obtained through the invention is not identically disclosed or described as set forth in section 102 of this title, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains. Patentability shall not be negatived by the manner in which the invention was made.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103(a) 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.
This application currently names joint inventors. In considering patentability of the claims under 35 U.S.C. 103(a), the examiner presumes that the subject matter of the various claims was commonly owned at the time any inventions covered therein were made absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and invention dates of each claim that was not commonly owned at the time a later invention was made in order for the examiner to consider the applicability of 35 U.S.C. 103(c) and potential 35 U.S.C. 102(e), (f) or (g) prior art under 35 U.S.C. 103(a).
Claims 1-4 and 8 are rejected under 35 U.S.C. 103(a) as being unpatentable over Khurram et al. (US 2016/0107963 A1, applicants submitted in IDS).
Regarding claim 1, Khurram et al. discloses a method for recycling natural gas during a steam reformer startup in a methanol plant is provided. The method
comprises suctioning natural gas by a suction drum, boosting natural gas by a natural gas booster downstream of the suction drum, heating a steam reformer (i.e., a waste heat section in the claimed sense) to heat a reformer feed gas downstream of the natural gas booster, heating a hydrogenator downstream of the steam reformer, heating a sulfur adsorber downstream of the hydrogenator, recycling natural gas by a recirculation line downstream of the sulfur adsorber and upstream of the reformer, cooling the recycled natural gas by a heat exchanger downstream of the sulfur adsorber, and suctioning the cooled recycled natural gas into the suction drum downstream of the heat exchanger where the natural gas is recycled until the reformer feed gas reaches a desired temperature. In some aspects, the desired temperature of
the natural gas ranges from 350° C. to 380° C. In further aspects, the temperature can
be in a range derived from any two exemplary values. For example, the desired
temperature of the natural gas ranges from 355° C. to 380° C. After the desired
temperature is reached and the HDS catalyst is activated, the natural gas can feed into
the HDS reactor to remove the sulfur by preheating from the reformer to produce a clean natural gas. The clean natural gas can feed into the reforming section to be converted to syn gas, also called synthesis gas ([0031]-[0053]).
As illustrated in FIG.1, Natural gas then passes through hydrogenerator 8 which desulfurizes an organic sulfur compound in the natural gas to provide hydrogen sulfide mixed with natural gas. Natural gas then flows through the sulfur adsorber 10 which, when the hydrodesulphurization catalyst is activated, removes hydrogen sulfide from natural gas. In the typical existing startup process, natural gas is then vented through the flare at the right hand side of FIG. 1.
As illustrated in FIG.2, Natural gas heats the hydrogenerator 8 and the hydrodesulfurization section 10 to a temperature which activates the hydrodesulfurization catalyst during startup. In another aspect, the desired temperature of the hydrogenator 8 and the hydrodesulfurization section 10 ranges from 350° C. to 380° C. In the process depicted in FIG. 2, natural gas is not vented to the flare but is instead directed by recirculation via recycle line 20 to natural gas cooler 12 from a point after the sulfur adsorber and before the natural gas saturator. At the natural gas cooler 12, the natural gas is cooled to a temperature ranging from 20° C. to 60° C.
In one aspect, the temperature of the natural gas is cooled to 40° C. at the natural gas cooler 12. After cooling, natural gas flows to the suction drum 2 via recycle line 30 to re-traverse the steps recited above. In another aspect, the recycle loop comprises recycle line 20, the natural gas cooler 12, and recycle line 30. In a further aspect, the recycle loop comprises recycle line 20 and recycle line 30. In a yet further aspect, the recycle loop comprises recycle line 20 connected to recycle line 30. The recycling process continues until the hydrogenator 8 and hydrodesulfurization section 10 have reached a temperature ranging from 350° C to 380° C. Natural gas is not sent to the flare vent but instead is recycled until the HDS catalyst in the hydrodesulfurization section is activated.
So, the process of Khurram et al. teach or suggest a portion of the recycled natural gas through line 30 is mixed with a fresh natural gas to the natural gas booster suction drum, and a part of the desulfurized natural gas stream is sent to reformer feed gas as fuel as the instant claim.
Khurram et al. do not specifically teach the use of a hydrogenator catalyst.
Khurram et al. indicated the sulfur component present in the natural gas are removed in the sulfur adsorber ([0045], [0072] and [0088).
It is known a pipeline quality gas contains total sulfur 5-20 g/100 scf (about 0.11 ppm-0.44 ppm).
One of ordinary skill in the art at the time the invention was filed would consider a recycled natural gas containing a sulfur content such as 0.06 ppm as being a sulfur removed natural gas taught by Khurram et al.
Regarding claim 2, although the combined reference of Khurram et al. do not specific limit sulfur content above 0.05 ppm as per applicant claim 2, the differences in concentration will not support the patentability of subject matter, this is a case of prima facie obviousness, as one having ordinary skill in the art at the time the invention was made, given the general conditions taught by Khurram et al., in particular in view of the natural gas is recycled for removing sulfur content to a desired level.
Regarding claims 3-4, as discussed above, the process taught by Khurram et al. is continued and the temperature of the hydrodesulfurization section is at a temperature ranging from 350° C to 380° C which is encompassed by the instant claimed ranges. A part of desulfurized natural gas is feed to a reformer and the reforming section is started (FIG. 2, [0031]-[0053]).
Regarding claim 8, as discussed illustrated in FIG.1, the process of Khurram et al. teach or suggest a portion of the recycled natural gas through line 30 is mixed with a fresh natural gas as the instant claim.
Response to Arguments
With regards to the previous Grounds of Rejection
Applicant's arguments filed 4/22/2026, have been considered but are not persuasive. The examiner would like to take this opportunity to address the Applicant's arguments.
Applicant argued In Khurram, sulfur compounds present in the natural gas are converted in the hydrogenator and are subsequently removed in the sulfur adsorber.
As a result, the recycle loop in Khurram circulates gas that becomes progressively depleted in sulfur content. Khurram does not disclose any mechanism for maintaining or controlling the sulfur concentration at the inlet to the hydrogenator. Nor does Khurram suggest that maintaining a particular sulfur concentration is necessary to preserve catalyst activity.
Ultimately, Khurram is a sulfur-removal system, not a sulfur-maintenance system.
In contrast, the amended claim requires that the sulfur concentration at the
hydrogenator inlet be maintained at a level sufficient to keep the hydrogenator catalyst in a sulfurized state during start-up. This requirement reflects a deliberate control of sulfur balance in the system. It is not satisfied merely by the presence of sulfur in the feed, but instead requires that sulfur be supplied in an amount sufficient to counteract sulfur removal and thereby prevent desulfurization of the catalyst.
Any assertion that this limitation is inherent in Khurram would be incorrect. The
processes described in Khurram involve conversion and removal of sulfur species, and therefore would tend to reduce the sulfur concentration in the circulating gas over time. In the absence of deliberate control of sulfur input, there is no basis to conclude that the sulfur concentration at the hydrogenator inlet would remain sufficient to maintain the catalyst in a sulfurized state.
The present Specification expressly identifies this issue and provides the claimed solution of maintaining sulfur input via the fresh natural gas feed.
The claimed subject matter therefore addresses a technical problem that is not
recognized in Khurram, namely the preservation of hydrogenator catalyst activity during start- up by maintaining sulfurization. Because Khurram does not recognize this problem, it does not provide any teaching or suggestion of the claimed solution.
Accordingly, the amended claim recites a process condition requiring maintenance of sulfur concentration sufficient to keep the hydrogenator catalyst sulfurized during start-up (Remarks, pages 2-4).
The Office respectfully disagrees. As discussed above, Khurram et al. discloses a method for recycling natural gas during a steam reformer startup in a methanol plant is provided. The method comprises suctioning natural gas by a suction drum, boosting natural gas by a natural gas booster downstream of the suction drum, heating a steam reformer (i.e., a waste heat section in the claimed sense) to heat a reformer feed gas downstream of the natural gas booster, heating a hydrogenator downstream of the steam reformer, heating a sulfur adsorber downstream of the hydrogenator, recycling natural gas by a recirculation line downstream of the sulfur adsorber and upstream of the reformer, cooling the recycled natural gas by a heat exchanger downstream of the sulfur adsorber, and suctioning the cooled recycled natural gas into the suction drum downstream of the heat exchanger where the natural gas is recycled until the reformer feed gas reaches a desired temperature. In some aspects, the desired temperature of
the natural gas ranges from 350° C. to 380° C. In further aspects, the temperature can
be in a range derived from any two exemplary values. For example, the desired
temperature of the natural gas ranges from 355° C. to 380° C. After the desired
temperature is reached and the HDS catalyst is activated, the natural gas can feed into
the HDS reactor to remove the sulfur by preheating from the reformer to produce a clean natural gas. The clean natural gas can feed into the reforming section to be converted to syn gas, also called synthesis gas ([0031]-[0053]).
As illustrated in FIG.1, Natural gas then passes through hydrogenerator 8 which desulfurizes an organic sulfur compound in the natural gas to provide hydrogen sulfide mixed with natural gas. Natural gas then flows through the sulfur adsorber 10 which, when the hydrodesulphurization catalyst is activated, removes hydrogen sulfide from natural gas. In the typical existing startup process, natural gas is then vented through the flare at the right hand side of FIG. 1.
As illustrated in FIG.2, Natural gas heats the hydrogenerator 8 and the hydrodesulfurization section 10 to a temperature which activates the hydrodesulfurization catalyst during startup. In another aspect, the desired temperature of the hydrogenator 8 and the hydrodesulfurization section 10 ranges from 350° C. to 380° C. In the process depicted in FIG. 2, natural gas is not vented to the flare but is instead directed by recirculation via recycle line 20 to natural gas cooler 12 from a point after the sulfur adsorber and before the natural gas saturator. At the natural gas cooler 12, the natural gas is cooled to a temperature ranging from 20° C. to 60° C.
In one aspect, the temperature of the natural gas is cooled to 40° C. at the natural gas cooler 12. After cooling, natural gas flows to the suction drum 2 via recycle line 30 to re-traverse the steps recited above. In another aspect, the recycle loop comprises recycle line 20, the natural gas cooler 12, and recycle line 30. In a further aspect, the recycle loop comprises recycle line 20 and recycle line 30. In a yet further aspect, the recycle loop comprises recycle line 20 connected to recycle line 30. The recycling process continues until the hydrogenator 8 and hydrodesulfurization section 10 have reached a temperature ranging from 350° C to 380° C. Natural gas is not sent to the flare vent but instead is recycled until the HDS catalyst in the hydrodesulfurization section is activated.
So, the process of Khurram et al. teach or suggest a portion of the recycled natural gas through line 30 is mixed with a fresh natural gas to the natural gas booster suction drum, and a part of the desulfurized natural gas stream is sent to reformer feed gas as fuel as the instant claim.
Khurram et al. do not specifically teach the use of a hydrogenator catalyst.
Khurram et al. indicated the sulfur component present in the natural gas are removed in the sulfur adsorber ([0045], [0072] and [0088).
It is known a pipeline quality gas contains total sulfur 5-20 g/100 scf (about 0.11 ppm-0.44 ppm).
One of ordinary skill in the art at the time the invention was filed would consider a recycled natural gas containing a sulfur content of 0.06 ppm which reads on the instant claim 2 as being a sulfur removed natural gas taught by Khurram et al.
As such, the rejection of claim 1 as set forth in the office action above is proper and stands.
The rejection for the remaining claims were either directly or indirectly dependent thereon stands.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to YUN QIAN whose telephone number is (571)270-5834. The examiner can normally be reached Monday-Thursday 10:00am-4:00pm.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Sally A Merkling can be reached at 571-272-6297. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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YUN . QIAN
Examiner
Art Unit 1732
/YUN QIAN/ Primary Examiner, Art Unit 1738
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