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 .
Response to Amendment
The rejection of claims 21-37 in the Office Action mailed on 5/13/2026 has been withdrawn in view of the response filed on 8/12/2026. Because the rejection has been withdrawn, the arguments concerning it are considered moot and will not be addressed.
A new None-Final Office Action follows.
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 28-35 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 28 first recites discharging “the third heat-transfer fluid from the third-reactor jacket” to the third heat exchanger, but subsequently recites heating the third water “with the third heat-transfer fluid from the first-reactor jacket.” It is therefore unclear whether the third heat-transfer fluid supplied to the third heat exchanger is discharged from the first-reactor jacket or the third-reactor jacket. Amendment is required to clarify the intended reactor jacket.
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, 36, and 37 are rejected under 35 U.S.C. 103 as being unpatentable over Manyik et al. (US 4,899,003, “Manyik”) in view of Stine et al. (US 2014/0371504 A1, “Stine”) and Sookraj et al. (US 2018/0305289 A1, “Sookraj”).
Regarding claim 21, Manyik teaches oxidative dehydrogenation of ethane to ethylene in a plurality of reactors arranged in open continuous series, wherein the output of one reactor forms the input to the succeeding reactor such that unreacted ethane is further converted in successive stages, and specifically discloses a three-reactor arrangement (Fig. 3; pp. 7–8). Manyik further teaches reactor tubes containing ODH catalyst beds, with a heat-transfer liquid circulated around the tubes within the reactor shell for temperature control (pp. 7–8).
Manyik does not teach operating the second reactor at a second temperature greater than the first temperature and the third reactor at a third temperature greater than the first temperature.
Stine teaches sequential ODH reaction regions and expressly teaches that the preselected temperatures of successive ODH reaction segments may be increased from the inlet toward the outlet (¶¶[0031], [0042]).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to operate the successive ODH reactors of Manyik according to the increasing-temperature profile taught by Stine, including operating the second and third reactors at temperatures greater than the first reactor, in order to provide the temperature profile taught by Stine for increasing conversion while maintaining selectivity.
Manyik and Stine do not teach flowing respective heat-transfer fluids through reactor jackets to facilitate steam generation.
Sookraj teaches recovering heat generated by exothermic reactions using a heat-transfer medium and expressly teaches generating steam by heat transfer between process fluid and water/steam in heat-transfer equipment including a reactor cooling jacket (¶[0169]).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to employ the reactor cooling-jacket heat-recovery arrangement of Sookraj with each of Manyik's serial ODH reactors to control the exothermic reaction temperature while recovering the removed heat for useful steam generation.
Regarding claim 36, Manyik teaches ethane as the lower alkane and oxidative dehydrogenation thereof to ethylene as the corresponding alkene (pp. 6–8).
Regarding claim 37, Manyik teaches the serial ODH reactors employing reactor tubes containing catalyst beds, with the tubes enclosed within a shell through which temperature-control fluid is circulated (Fig. 3; pp. 7–8), thereby teaching the claimed tubular fixed-bed reactors.
Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Manyik in view of Stine and Sookraj as applied to claim 21 above, and further in view of Bos et al. (US 2019/0055177 A1, “Bos”).
The combination applied to claim 21 teaches the serial ODH process and tubular fixed-bed reactors but does not expressly teach a first-reactor temperature below 400°C and a third-reactor temperature of at least 500°C.
Bos teaches independently controlling temperatures associated with sequential ODH catalyst beds according to the desired activity of the respective catalysts (¶¶[0026]–[0027], [0059]). Bos teaches an upstream coolant temperature of about 250–400°C (¶[0060]), downstream coolant temperatures extending to about 500°C (¶¶[0061]–[0062]), and that catalyst-bed temperatures typically exceed the corresponding coolant temperatures by about 1–30°C (¶[0059]). Bos further teaches tubular reactor construction containing sequential catalyst beds (¶¶[0010]–[0014], [0029], [0032]–[0042]).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to select the operating temperature of each ODH reactor according to the activity and effective operating-temperature range of the catalyst employed therein, including a temperature below 400°C for the first reactor and at least 500°C for the third reactor. Bos teaches that the respective temperatures are independently selected to obtain desired catalyst activity and provides known ODH operating-temperature ranges encompassing the claimed temperatures (¶¶[0059]–[0062]). Selection of particular effective operating temperatures within known operative ranges according to the catalysts employed would have been within the level of ordinary skill in the art.
Claims 23, 24, 28–30, and 32 are rejected under 35 U.S.C. 103 as being unpatentable over Manyik in view of Stine and Sookraj as applied to claim 21 above, and further in view of Wees et al. (US 2008/0289588 A1, “Wees”).
Regarding claim 23, the combination applied to claim 21 does not expressly teach discharging water from the first-reactor jacket to a flash/steam vessel to produce low-pressure steam at 150 psig or less. Wees teaches recovering heat from hot process streams by circulating drum water through heat exchangers and returning the heated water/water-vapor mixture to a steam drum to generate steam (¶¶[0006]–[0010], [0014]–[0015]). Van Wees further teaches conventional steam pressure levels including low-pressure steam at approximately 35–65 psig (¶[0003]). It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to direct the water heated by the first-reactor jacket to a flash/steam vessel as taught by Wees to separate generated steam from liquid water and recover the first reactor's heat as useful low-pressure steam.
Regarding claim 24, the preceding combination does not expressly teach respective first, second, and third water/steam recovery circuits producing the claimed low-, medium-, and high-pressure steam. Wees teaches recovery of heat from multiple hot process streams using water circuits and steam drums and teaches multiple steam pressure levels, including low-pressure steam at about 35–65 psig, medium-pressure steam at about 125–175 psig, and high-pressure steam at about 600 psig and above (¶¶[0003], [0006]–[0010]).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to recover heat from the different-temperature reactor stages at corresponding steam-pressure levels, including the claimed ≤150 psig, 150–600 psig, and ≥600 psig ranges as taught by Wees, in order to recover available heat at useful pressure levels appropriate to the temperatures of the respective heat sources.
Regarding claim 28, the preceding combination does not expressly teach transferring heat from the respective reactor heat-transfer fluids indirectly to corresponding water streams through separate heat exchangers. Wees teaches separate hot process streams exchanging heat with corresponding water circuits through heat exchangers for steam generation (¶¶[0006]–[0010], [0014]–[0015]). It would have been obvious to employ separate heat exchangers between the reactor heat-transfer fluids and water circuits as taught by Wees to permit indirect heat recovery and independent control of the respective process and steam-generation circuits.
Regarding claims 29–30, Wees teaches transferring heated water to steam drums and generating steam at multiple pressure levels, including LP, MP, and HP steam, with HP steam at about 600 psig or greater (¶¶[0003], [0006]–[0010]). It would have been obvious to operate the respective steam-generation vessels at the claimed pressure levels according to the temperature of the corresponding heat source and the desired steam service.
Regarding claim 32, Wees teaches a plurality of parallel water/heat-exchange circuits supplying a common steam drum to generate steam at a selected pressure (¶¶[0006]–[0010], [0014]–[0015]). It would have been obvious to introduce water heated by the first, second, and third heat-recovery exchangers into a common flash/steam vessel and operate the vessel at high pressure, including ≥600 psig as taught by Wees, to consolidate steam separation and instrumentation while recovering heat from the multiple reactor stages.
Claim 25 and 26 are rejected under 35 U.S.C. 103 as being unpatentable over Manyik in view of Stine, Sookraj, and Wees as applied to claim 24 above, and further in view of Vera-Castañeda et al. (US 2014/0322125 A1, “Vera-Castañeda”).
Regarding claim 25, the preceding combination does not expressly teach discharging liquid water remaining in the first flash vessel as the heat-transfer fluid supplied to the second-reactor jacket and thereafter using liquid water discharged from the second flash vessel as the heat-transfer fluid supplied to the third-reactor jacket.
Vera-Castañeda teaches boiler-feed water flowing through an array of heat exchangers in series and teaches flashing boiler-feed water in a reduced-pressure zone between successive heat exchangers, separating generated steam from the cooled liquid boiler-feed water, pressurizing the remaining liquid water, and thereafter transferring the water downstream for further heating (¶¶[0039]–[0041]; claim 1).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to use liquid water remaining after steam separation as the heat-transfer water for a subsequent hotter reactor heat-recovery stage and to repeat the staged heat-recovery arrangement, as taught by Vera-Castañeda, thereby maintaining a useful temperature difference between the water and successive heat sources and recovering additional available process heat.
Regarding claim 26, the preceding combination does not expressly teach passing the same water heat-transfer stream successively through the second-reactor jacket and third-reactor jacket before introducing the heated stream into a flash vessel.
Vera-Castañeda teaches serial recovery of process heat into a common boiler-feed-water stream and specifically teaches passing high-pressure boiler-feed water successively through multiple heat exchangers heated by different process streams before the heated water is supplied to a steam drum (¶¶[0138]–[0139]).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to pass the water successively through the second- and third-reactor heat-recovery jackets before supplying the heated water to the flash vessel, as suggested by Vera-Castañeda's serial boiler-water heat-recovery arrangement, thereby progressively recovering heat from multiple available process heat sources into a common water stream before steam generation.
Claims 27 and 31 are rejected under 35 U.S.C. 103 as being unpatentable over Manyik in view of Stine, Sookraj, and Wees as applied to claim 23 above, and further in view of Osman et al. (US 4,545,976, “Osman”).
Regarding claim 27, the preceding combination does not expressly teach discharging high-pressure steam from the second flash vessel and passing that steam through the third-reactor heat-recovery zone as the third heat-transfer fluid to superheat the high-pressure steam.
Osman teaches recovery of high-temperature reactor waste heat by first generating high-pressure saturated steam and thereafter heating the high-pressure saturated steam by indirect heat exchange with hotter reactor effluent to produce high-pressure superheated steam (see Abstract; col. 2, lines 21–46; col. 5, lines 1–35). Osman teaches high-pressure steam in approximately the 400–2200 psig range (col. 5, lines 1–35).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to pass previously generated high-pressure steam through the heat-transfer zone associated with the higher-temperature third reactor, thereby using the higher-grade heat available at the third reactor to superheat the high-pressure steam, consistent with Osman's teaching of recovering higher-temperature reactor heat by superheating previously generated high-pressure saturated steam.
Regarding claim 31, the preceding combination does not expressly teach discharging the third water as high-pressure steam at 600 psig or greater from the second flash vessel and passing the high-pressure steam through the third heat exchanger to superheat the steam.
Osman teaches generating high-pressure saturated steam and thereafter passing the steam through a separate steam-superheating heat-exchange zone heated by higher-temperature reactor effluent to form superheated high-pressure steam (Abstract; col. 2, lines 21–46; col. 5, lines 1–35; claims 1 and 4).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to direct the high-pressure steam generated in the flash/steam vessel through the third heat exchanger to recover the higher-grade heat associated with the third reactor as steam superheat as suggested by Osman, thereby increasing useful recovery of available process heat.
Claims 33 and 34 are rejected under 35 U.S.C. 103 as being unpatentable over Mayik in view of Stine, Sookraj, and Van Wees as applied to claim 32 above, and further in view of Janvier (US 2012/0151924 A1, “Janvier”).
Regarding claims 33–34, the preceding combination does not expressly teach diverting a portion of the generated high-pressure steam through a control valve to reduce its pressure to medium- or low-pressure steam.
Janvier teaches that high-pressure steam may have its pressure stepped down through a pressure-regulating valve to provide lower-pressure steam (¶[0018]) and expressly teaches a steam pressure-reducing valve that reduces high-pressure steam to generate low-pressure steam (¶[0021]). Janvier further exemplifies a refinery having low-pressure steam at 120 psig and high-pressure steam at 900 psig (¶¶[0049]–[0050]). Thus, Janvier expressly demonstrates reduction from a pressure within the claimed HP range to a pressure within the claimed LP range.
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to divert a portion of the high-pressure steam through a pressure-regulating/control valve, as taught by Janvier, and select the reduced pressure according to the steam pressure required by the downstream steam system, including the known medium-pressure range of 150–600 psig recited in claim 33 or the low-pressure range of 150 psig or less recited in claim 34. Such pressure reduction would permit high-pressure steam generated by the heat-recovery system to supply medium- and low-pressure steam users without requiring separate steam generation.
Claim 35 is rejected under 35 U.S.C. 103 as being unpatentable over Manyik in view of Stine, Sookraj, and Wees as applied to claim 32 above, and further in view of Paul et al. (US 4,099,382, “Paul”).
The preceding combination does not expressly teach superheating the high-pressure steam using heat from the third heat-transfer fluid or from the third-reactor effluent.
Paul teaches recovering heat from hot reactor effluent to generate and thereafter superheat steam. Paul teaches directly superheating generated steam by indirect heat exchange with hot reactor effluent and alternatively heating a heat-transfer fluid with the reactor effluent and using the heated heat-transfer fluid in a separate heat exchanger to superheat the steam (Abstract; col. 2, lines 1–45; col. 4, lines 1–45). Paul further teaches superheated steam over a broad pressure range encompassing 600 psig and above (col. 3, lines 1–20).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to use the higher-temperature heat available from the third-reactor effluent or from the third heat-transfer fluid to superheat the high-pressure steam, as taught by Paul, in order to recover higher-grade available process heat as useful steam superheat and thereby improve overall thermal efficiency.
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
