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 .
Information Disclosure Statement
The information disclosure statement filed 8/28/2024 fails to comply with 37 CFR 1.98(a)(2), which requires a legible copy of each cited foreign patent document; each non-patent literature publication or that portion which caused it to be listed; and all other information or that portion which caused it to be listed. It has been placed in the application file, but the information referred to therein has not been considered.
There is no copy for references that have cite No. 15-17.
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 27 and 31 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.
Claim 27 is indefinite because it is unclear whether the claimed "third heat-transfer fluid" is liquid water, steam, or a two-phase water/steam mixture. The claim first identifies the heat-transfer fluid as water in claim 23, but later recites that high-pressure steam is the third heat-transfer fluid. Consequently, the metes and bounds of the claim cannot be determined with reasonable certainty.
Claim 31 is indefinite because the limitation "discharging high pressure steam...as the third water" is internally inconsistent. The claim equates steam with the recited "third water," rendering the scope of the claim unclear.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 21, 23, 25-27, and 36 are rejected under 35 U.S.C. 103 as being unpatentable over Stine et al. (US 20140371504 A1) in view of Sookraj et al. (US 20180305289 A1).
Claim 21
Stine teaches a method of contacting a feed comprising a lower alkane with a first oxidative dehydrogenation catalyst in a first reactor to convert the lower alkane to the corresponding alkene, passing the first reactor effluent to a second oxidative dehydrogenation reactor containing a second catalyst, and passing the second reactor effluent to a third oxidative dehydrogenation reactor containing a third catalyst. Stine further teaches staged ODH conversion of lower alkanes to corresponding alkenes using multiple reactors. (Fig. 1; ¶¶[0001], [0014], [0029], [0036]; claims 1 and 16).
Stine does not expressly teach reactor jackets containing circulating heat-transfer fluid for steam generation.
Sookraj teaches reactor jackets surrounding exothermic reactors through which a heat-transfer fluid flows to recover reaction heat and facilitate steam generation. (¶[0169]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the reactors of Stine to include reactor jackets containing circulating heat-transfer fluid as taught by Sookraj because recovering heat from highly exothermic reactors to generate steam improves thermal efficiency, reduces external utility requirements, and represents a well-known heat-integration technique.
Claim 23
Sookraj teaches discharging heated heat-transfer fluid from the reactor jacket for steam generation. (¶[0169]).
It would have been obvious to discharge the heated water to a flash vessel to produce low-pressure steam because flash separation of heated boiler water is a conventional steam-generation technique.
Claim 25
Neither reference expressly teaches discharging water from a first flash vessel as the second heat-transfer fluid to a downstream reactor jacket.
However, it would have been obvious to cascade the water discharged from one flash vessel for use as the heat-transfer fluid of a downstream reactor jacket because doing so predictably maximizes recovery of sensible heat, reduces boiler-feed-water consumption, and improves the thermal efficiency of the integrated reactor system through known process heat-integration techniques.
Claim 26
Neither reference expressly teaches routing the second heat-transfer fluid directly through the third reactor jacket before flashing.
However, routing the heat-transfer fluid through an additional reactor jacket before flash separation merely represents an obvious design choice to recover additional sensible heat prior to steam generation, thereby increasing overall energy recovery and reducing utility consumption.
Claim 27
Neither reference expressly teaches passing high-pressure steam through the third reactor jacket as the third heat-transfer fluid.
However, it would have been obvious to utilize the highest-temperature reactor as a steam superheater because employing available process heat to superheat steam increases steam quality and overall thermal efficiency, yielding the predictable result of improved energy recovery.
Claim 36
Stine expressly teaches oxidative dehydrogenation of ethane to produce ethylene. (¶¶[0001], [0014], claims 1 and 16).
Claims 22 and 37 are rejected under 35 U.S.C. 103 as being unpatentable over references as applied to claim 21 above, and further in view of Bos et al. (WO 2017/144584 A1).
Claim 22
Stine and Sookraj do not expressly teach that each reactor comprises a tubular fixed-bed reactor.
Bos teaches an oxidative dehydrogenation reactor having a plurality of catalyst-filled reactor tubes disposed within a shell, with independent shell-side coolant circuits for removing reaction heat and generating steam. (Fig. 1; description of the reactor shell, tube bundle, upstream/downstream shell spaces, and coolant circuits).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Stine by employing the tubular fixed-bed ODH reactor of Box as suggested by Box because such reactors provide superior temperature control, improved catalyst life, efficient heat removal, and facilitate recovery of reaction heat.
Claim 37
Bos teaches that the reactor is a tubular fixed-bed reactor containing a plurality of catalyst-filled tubes within a reactor shell. (Fig. 1).
It would have been obvious to employ tubular fixed-bed reactors for each of the reactors of Stine for the reasons discussed above.
Claims 24 and 28-35 are rejected under 35 U.S.C. 103 as being unpatentable over references as applied to claims 21 and 23 above, and further in view of Van Wees et al. (US 2008/0289588 A1).
Claim 24
Stine and Sookraj do not expressly teach discharging separate heat-transfer fluids to separate flash vessels to generate low-, medium-, and high-pressure steam.
Van Wees teaches recovering heat from multiple hot process streams using multiple heat exchangers connected to steam drums operating at different pressure levels, thereby producing steam at different pressures from different heat-recovery circuits. (Abstract; Fig. 1; ¶¶[0006]-[0015]).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the heat recovery system of Stine/Sookraj with separate steam-generation circuits operating at different pressures as taught by Van Wees because different portions of the ODH reactor system operate at different temperatures. Matching each heat source with an appropriate steam pressure improves thermodynamic efficiency, increases the amount of recoverable heat, and minimizes exergy losses associated with recovering heat from multiple temperature levels.
Claim 28
Neither Stine nor Sookraj teaches the steps as in claim 28.
Van Wees teaches directing separate hot process streams through first, second, and third heat exchangers to heat corresponding water streams for steam generation. (Fig. 1; ¶¶[0006]–[0015]).
It would have been obvious to recover heat from each ODH reactor independently using separate heat exchangers because the reactors operate at different temperatures and therefore possess different heat recovery potentials. Employing dedicated heat exchangers for each reactor permits more effective utilization of the available thermal energy, improves controllability of each heat-recovery circuit, and maximizes overall steam generation.
Claims 29 and 30
Neither Stine nor Sookraj teaches the steps in claims 29 and 30.
Van Wees teaches passing the heated water from the heat exchangers to steam drums where steam is generated at selected pressure levels. (¶¶[0009]–[0015]).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Stine by
discharging the heated water from each heat exchanger into an associated steam drum or flash vessel as suggested by Van Wees because separating generated steam from heated circulating water is the conventional manner of recovering steam from indirect heat-exchange systems.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Stine by dedicating the highest-temperature heat exchanger to production of high-pressure steam because higher-temperature process streams are capable of generating higher-pressure steam with greater thermodynamic efficiency, while lower-temperature streams are more suitably matched to lower-pressure steam generation.
Claim 31
Van Wees does not expressly teach routing the generated high-pressure steam through a downstream heat exchanger for superheating.
However, It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Stine/Van Wees by passing the generated high-pressure steam through the highest-temperature downstream heat exchanger before distribution because steam superheating increases steam enthalpy, prevents condensation during transport or expansion, and recovers sensible heat that would otherwise be rejected. Utilizing the hottest available heat source for steam superheating is a predictable application of established steam-cycle engineering principles.
Claim 32
Van Wees does not disclose steps in claim 32.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Stine/Van Wees by combining multiple heated water streams into a common steam-generation vessel where their pressures and temperatures are compatible because doing so reduces equipment count, simplifies plant layout, and centralizes steam generation while maintaining the same heat recovery function.
Claims 33 and 34
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Stine/Van Wees by reducing the pressure of a portion of the steam through pressure-control valves to satisfy downstream process users requiring lower-pressure steam because industrial facilities routinely distribute steam at multiple pressure levels. Pressure-reducing valves permit a single high-pressure steam source to simultaneously supply high-, medium-, and low-pressure steam users while avoiding installation of separate steam generators.
Claim 35
Van Wees does not expressly teach superheating steam using the third reactor effluent or third heat-transfer fluid.
However, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Stine/Van Wees by
employing the highest-temperature available process stream, including the third reactor heat-transfer fluid or the third reactor effluent, as the heat source for steam superheating because the third reactor operates at the highest temperature of the staged ODH process. Selecting the hottest available stream for superheating predictably maximizes recovery of otherwise wasted sensible heat, increases steam enthalpy, and improves the overall thermal efficiency of the integrated process without requiring additional fuel consumption.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TAM M NGUYEN whose telephone number is (571)272-1452. The examiner can normally be reached Mon - Frid.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Prem C Singh can be reached at 571-273-6381. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/TAM M NGUYEN/Primary Examiner, Art Unit 1771
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