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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 1/21/2029 has been entered.
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 25-26 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 term “near ambient” in claim 25 is a relative term which renders the claim indefinite. The term “ambient” is 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. Ambient is a relative term that is reflective of an environment that it is in. The specification does not specify how to define ambient or what qualifies as near ambient which renders the limitation indefinite. For the purpose of examination, this limitation is interpreted that both streams are in the same range on the warm side of the system.
Claim 26 is rejected as being dependent upon a rejected claim.
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.
Claim(s) 14-16, 18, 20, 23-26 is/are rejected under 35 U.S.C. 103 as being unpatentable over Watanabe et al. (US PG Pub 20190063824), hereinafter referred to as Watanabe and Decker et al. (US PG Pub 20210381756), hereinafter referred to as Decker and Cardella et al. (US PG Pub 20180320957), hereinafter referred to as Cardella and Allam et al. (US PG Pub 20050210914), hereinafter referred to as Allam and Nilsen (US PG Pub 20100154470), hereinafter referred to as Nilsen and Smith (XP-001277343), hereinafter referred to as Smith.
With respect to claim 14, Watanabe teaches a process for liquefying hydrogen gas (Figure 4), the process comprising: providing a stream of hydrogen feed gas (raw material hydrogen 10, paragraph 97);
providing a stream of recycled hydrogen gas (hydrogen recycled from 17, paragraph 97);
admitting the stream of hydrogen feed gas and the stream of recycled hydrogen gas to a first hydrogen compressor (the two streams are together compressed in the raw material hydrogen compressor, paragraph 97), the first hydrogen compressor having a combined discharge stream with a pressure of between 10 bar and 200 bar (the stream exiting the compressor includes both hydrogen streams and is at 30.4 bara, Table 1)
cooling said combined discharge stream in a first hot passage of a first heat exchanger section, said first hot passage having a first outlet stream (plate heat exchanger 13 has 10 sections as seen in the figure, the third from the top of the figure can be considered a first heat exchanger section and the hydrogen is cooled in a first hot passage there and removed from a second outlet);
cooling said first outlet stream in a second hot passage of a second heat exchanger section, said second hot passage having a second outlet stream (the fourth section from the top of the figure can be considered a second heat exchanger section and the hydrogen is cooled in a second hot passage there and removed in a second outlet);
cooling said second outlet stream in a third hot passage of a third heat exchanger, said third hot passage having a third outlet stream (the fifth section from the top of the figure can be considered a third heat exchanger section and the hydrogen is cooled in a third hot passage there and removed in a third outlet);
passing the third outlet stream to a hydrogen liquefier unit (the remaining heat exchanger sections, expansion valve 14, flash drum 15 and hydrogen refrigerant loop 40, are all together a hydrogen liquefier unit);
reheating the stream of gaseous hydrogen from the hydrogen liquefier unit in a first cold passage of the third heat exchanger section to provide a first reheated outlet stream, then in a first cold passage of the second heat exchanger section to provide a second reheated outlet stream, then in a first cold passage of the first heat exchanger section to provide a third reheated outlet stream from the first heat exchanger to form a stream of recycled hydrogen gas (the stream 17 is heated in all of the heat exchanger sections before recycling to the compressor, paragraph 97, which would be in a series of cold passages);
providing a stream of refrigerant gas at a pressure of from 10 bar to 150 bar (nitrogen refrigerant has a pressure of 22.6 bara, Paragraph 98, Table 1);
dividing the stream of first refrigerant gas into first and second parts (as seen in the figure nitrogen refrigerant is split into a stream that passes to 34 and the rest of the refrigerant stream, paragraph 98);
passing said first part to a first refrigerant gas expander to provide an outlet stream from the first gas expander (nitrogen, which would still be gaseous, is passed to expansion turbine 34, paragraph 98);
reheating the first refrigerant gas expander outlet stream in a second cold passage of the first heat exchanger section to form a reheated first refrigerant gas stream (the stream from the outlet of the first refrigerant gas expander outlet is heated in a second cold passage of the first heat exchanger);
compressing the reheated refrigerant gas stream in a second compressor to a pressure of from 10 to 150 bar to form a first constituent of the refrigerant gas (the refrigerant from 34 is part of the stream compressed in 32 to 22.6 bar, Table 1);
passing the second part of the first refrigerant gas to a second hot passage of the first heat exchanger section to provide a cooled outlet stream (another part of the refrigerant not sent to 34 is cooled in the first heat exchanger section)
passing said cooled outlet stream to a second refrigerant gas expander to provide an outlet stream from said second refrigerant gas expander and comprising a mixture of vapor and liquid (part of the stream not sent to 34 that has been cooled is expanded in valve 36, paragraph 98);
separating the outlet stream of the second refrigerant gas expander in a vapor/liquid separator to form a vapor stream and a liquid stream (stream from 36 is separated into liquid and gas in flash drum 37, paragraph 98);
reheating said liquid stream in a second cold passage of third heat exchanger section (the liquid portion is heated, paragraph 98 in the third heat exchanger section which would be in a second cold passage);
combining the vapor stream and the reheated liquid outlet stream to form a combined vapor stream (the two streams are mixed as seen in the figure);
reheating the combined vapor stream in the second cold passage of the second heat exchanger section to form a third reheated outlet stream (the stream is heated as seen in the figure in a second cold passage of the third heat exchanger section) and then in the first heat exchanger section to form a reheated outlet stream (the stream is also heated in the first heat exchanger section); and, compressing the reheated outlet stream in the second compressor to a pressure of from 10 to 150 bar to form a second constituent of the refrigerant gas (the combined stream is compressed also in 32 to 22.6 bara, and is a second constituent of the refrigerant gas).
Watanabe does not teach the recycled hydrogen gas at a pressure of from 1 bar to 50 bar. Watanabe does teach the feed gas has a pressure of 1.06 bar (but it is not explicit that the pressure of the feed is the same as that of the recycle, though this is likely the pressure, as the mixing is directly between the streams).
Allam teaches a reheated recycle hydrogen gas stream (62) is at a pressure of about 0.1 MPa (1 bar), (paragraph 112). The cooled stream after expansion (52 form 50) is at 0.1 MPa (paragraph 112), therefore the overhead stream (58) which is used to form the recycled stream (62) would be at the same pressure. This is upstream of compression and would be the equivalent stream to the claimed recycled hydrogen gas and the stream in Watanabe.
Therefore, it would have been obvious to a person having ordinary skill in the art at the time the invention was filed for the recycled hydrogen gas stream of Watanabe to be at a pressure of 1 bar based on the teaching of Allam as applicant appears to have placed no criticality on the claimed limitation (indicating simply that the pressure is between 1 to 50 bar, page 5 of applicants specification) and since it has been held that “[i]n the case where the claimed ranges ‘overlap or lie inside ranges disclosed by the prior art’ a prima facie case of obviousness exists.” In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). The second liquefier outlet stream is the same stream that is ultimately the recycled hydrogen gas stream and would be considered to be at the same pressure of 1 bar by one having ordinary skill in the art as there are no expanders between the two locations.
Watanabe does not teach that the heat exchanger sections are individual heat exchangers.
Decker teaches that individual heat exchangers are used (96, 84, 78, 70, 58, 46, paragraph 61, 63) for the different stages of cooling in a hydrogen liquefaction system.
Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to have based on the teaching of Decker to have in Watanabe provided the individual heat exchanger sections as separate heat exchangers since it has been shown that a simple substitution of one known element (a single heat exchanger) for another (individual heat exchangers) to yield predictable results is obvious whereby it would be common knowledge in the art that providing separate invidious heat exchangers for each section would allow for the heat exchangers to be better tailored for the temperature ranges that they operate at which would provide for better overall heat exchanger efficiency.
Watanabe does not teach that the first refrigerant gas consist essentially of methane.
Nilsen teaches that a suitable cryogenic refrigerant can be pure nitrogen, methane, a hydrocarbon mixture or a mixture of nitrogen and hydrocarbons (paragraph 46).
Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention was filed for the first refrigerant and thus the first refrigerant gas of Watanabe to have been methane based on the teaching of Nilsen since it has been shown that a simple substitution of one known element (in this case one refrigerant for another) to yield predictable results is obvious where as it has been shown by Nilsen that they are known refrigerants that can be used in the same system instead of each other it would have been prima facie obvious to substitute one refrigerant for the other resulting in a showing that it would be obvious to have utilized a methane refrigerant for the first refrigerant gas for the predictable result of providing what would be common knowledge in the art of a suitable refrigerant.
Watanabe does not teach the outlet stream from said first refrigerant gas expander having a pressure between 5 bar and 50 bar.
Decker teaches that an expanded refrigerant stream is expanded in a way to provided it with a pressure and a temperature sufficiently low to ensure proper cooling of the stream is it cooling (paragraph 47). As such, the pressure to which a refrigerant stream is expanded to is a result effective variable, chosen to ensure that the stream is able to provide proper cooling based on the temperature achieved by the expansion. Further, it appears that one of ordinary skill in the art would have had a reasonable expectation of success in modifying Watanabe as modified to have the pressure within the claimed range, as it involves only adjusting the dimension of a component (pressure of the expanded stream) disclosed to require adjustment. Therefore, it would have been obvious to one having ordinary skill in the art at the time of the invention to have in Watanabe when expanding the stream in the first refrigerant gas expander for the stream to have been expanded to a pressure of between 5 and 50 bar as a matter of routine optimization since it has been held that “where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Watanabe does not teach said outlet stream from said second refrigerant gas expander having a pressure of between 3 bar and 50 bar.
Decker teaches that an expanded refrigerant stream is expanded in a way to provided it with a pressure and a temperature sufficiently low to ensure proper cooling of the stream is it cooling (paragraph 47). As such, the pressure to which a refrigerant stream is expanded to is a result effective variable, chosen to ensure that the stream is able to provide proper cooling based on the temperature achieved by the expansion. Further, it appears that one of ordinary skill in the art would have had a reasonable expectation of success in modifying Watanabe as modified to have the pressure within the claimed range, as it involves only adjusting the dimension of a component (pressure of the expanded stream) disclosed to require adjustment. Therefore, it would have been obvious to one having ordinary skill in the art at the time of the invention to have in Watanabe when expanding the stream in the second refrigerant gas expander for the stream to have been expanded to a pressure of between 3 and 50 bar as a matter of routine optimization since it has been held that “where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Watanabe does not teach depressurizing the liquid stream in a valve, evaporating the depressurized liquid stream during passage through the second cold passage and compressing the vapor outlet to a same pressure as the pressure of the vapor stream from the vapor liquid separator by a low-pressure refrigerant compressor having a compressor outlet stream such that the combination of the vapor stream and the liquid outlet stream is a combination of the vapor stream and compressed outlet stream.
Smith (Figure 3, following along Table 1) teaches that an expanded stream (21) from an expander (C) is passed to a separator forming a vapor stream (14) and a liquid stream which is expanded in a valve (valve shown upstream of 18, as stream 18 has a lower pressure than stream 21) and that after passing through a heat exchanger the stream is evaporated (19 is an evaporated stream) and compressed (X) it to the same pressure as the vapor stream prior to combining with the vapor portion of the stream (20 becomes 30 and is combined with 15 to form 31 as seen in the figure).
Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to have based on the teaching of Smith to have in Watanabe further expanded the liquid stream (liquid stream from 37) in a valve and prior to recombining it with the overhead vapor stream compressed it back to the pressure of the since it has been shown that combining prior art elements to yield predictable results is obvious whereby expanding the stream prior to heat exchanger and then compressing it after would increase the cooling capacity of the stream allowing it to provide additional refrigeration to the heat exchanger while also allowing it to still be mixed back with the vapor stream after heat exchange.
Watanabe does not teach depressurized stream having a pressure of between 0.5 bar and 10 bar.
Decker teaches that an expanded refrigerant stream is expanded in a way to provided it with a pressure and a temperature sufficiently low to ensure proper cooling of the stream is it cooling (paragraph 47). As such, the pressure to which a refrigerant stream is expanded to is a result effective variable, chosen to ensure that the stream is able to provide proper cooling based on the temperature achieved by the expansion. Further, it appears that one of ordinary skill in the art would have had a reasonable expectation of success in modifying Watanabe as modified to have the pressure within the claimed range, as it involves only adjusting the dimension of a component (pressure of the expanded stream) disclosed to require adjustment. Therefore, it would have been obvious to one having ordinary skill in the art at the time of the invention to have in Watanabe when expanding the stream in the valve for the stream to have been expanded to a pressure of between 0.5 bar and 10 bar as a matter of routine optimization since it has been held that “where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Watanabe does not teach the combined stream is heated in a third cold passage of the first heat exchanger to form a fourth reheated outlet stream as Watanabe teaches the streams are combined and heated together.
Cardella (Figure 1) teaches that a side stream of a refrigerant (removed at 23) is expanded (53/30) and used for heating in the heat exchangers is kept separate and mixed after heart exchange with the remaining portion of the refrigerant (stream 22). The pressure of the first stream (23) after expansion is at a higher pressure than the pressure of the second stream (22) after expansion (22 is expanded in 52 to a medium pressure and is expanded in a way that allows the heat exchanger cooled by those streams to have better matching to reduce the loss of exergy in the heat exchanger, paragraph 172 and then compressed in 62 alongside the stream from 22 that is expanded to a lower pressure, paragraph 177 after compression in 61).
Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention as filed to have in Watanabe as modified based on the teaching of Cardella to have expanded the stream from the expanders (34 and 36 respectively) to separate pressures and then when recycling the streams back through the heat exchanger kept them separate using the configuration of Cardella (thus forming a reheated refrigerant gas stream which is kept separate from the combined outlet stream in the heat exchangers while both streams are used for cooling those heat exchangers such that a separate reheated refrigerant gas stream and fourth reheated outlet stream is formed which is compressed before it is mixed with the reheated refrigerant gas stream which together are passed to the compressor 32) based on the teaching of Cardella whereby keeping the streams separate allows for them to be expanded to individually ideal pressure levels to maximize the efficiency of the heat exchanger.
With respect to claim 15, Watanabe as modified teaches the combined discharge stream from the first compressor has a pressure of between 20 bar and 100 bar (the pressure is 30 bara, Table 1).
With respect to claim 16, Watanabe does not teach the pressure of the depressurized stream is between 1 bar and 3 bar.
Decker teaches that an expanded refrigerant stream is expanded in a way to provided it with a pressure and a temperature sufficiently low to ensure proper cooling of the stream is it cooling (paragraph 47). As such, the pressure to which a refrigerant stream is expanded to is a result effective variable, chosen to ensure that the stream is able to provide proper cooling based on the temperature achieved by the expansion. Further, it appears that one of ordinary skill in the art would have had a reasonable expectation of success in modifying Watanabe as modified to have the pressure within the claimed range, as it involves only adjusting the dimension of a component (pressure of the expanded stream) disclosed to require adjustment. Therefore, it would have been obvious to one having ordinary skill in the art at the time of the invention to have in Watanabe when expanding the stream in the valve for the stream to have been expanded to a pressure of between 1 bar and 3 bar as a matter of routine optimization since it has been held that “where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
With respect to claim 18, Watanabe as modified does not teach the pressure of the outlet stream from the second refrigerant gas expander is between 10 bar and 50 bar.
Decker teaches that an expanded refrigerant stream is expanded in a way to provided it with a pressure and a temperature sufficiently low to ensure proper cooling of the stream is it cooling (paragraph 47). As such, the pressure to which a refrigerant stream is expanded to is a result effective variable, chosen to ensure that the stream is able to provide proper cooling based on the temperature achieved by the expansion. Further, it appears that one of ordinary skill in the art would have had a reasonable expectation of success in modifying Watanabe as modified to have the pressure within the claimed range, as it involves only adjusting the dimension of a component (pressure of the expanded stream) disclosed to require adjustment. Therefore, it would have been obvious to one having ordinary skill in the art at the time of the invention to have in Watanabe when expanding the stream in the second refrigerant gas expander for the stream to have been expanded to a pressure of between 10 and 50 bar as a matter of routine optimization since it has been held that “where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
With respect to claim 20, Watanabe as modified does not teach the pressure of the outlet stream from the second refrigerant gas expander is between 3 bar and 30 bar.
Decker teaches that an expanded refrigerant stream is expanded in a way to provided it with a pressure and a temperature sufficiently low to ensure proper cooling of the stream is it cooling (paragraph 47). As such, the pressure to which a refrigerant stream is expanded to is a result effective variable, chosen to ensure that the stream is able to provide proper cooling based on the temperature achieved by the expansion. Further, it appears that one of ordinary skill in the art would have had a reasonable expectation of success in modifying Watanabe as modified to have the pressure within the claimed range, as it involves only adjusting the dimension of a component (pressure of the expanded stream) disclosed to require adjustment. Therefore, it would have been obvious to one having ordinary skill in the art at the time of the invention to have in Watanabe when expanding the stream in the second refrigerant gas expander for the stream to have been expanded to a pressure of between 3 and 30 bar as a matter of routine optimization since it has been held that “where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
With respect to claim 23, Watanabe as modified teaches which the temperature the stream of recycled hydrogen gas to the first hydrogen compressor of compressor is between -200 °C and 40 °C (raw material hydrogen compressor has an has inlet temperature of of 35 C, Table 1).
With respect to claim 24, Watanabe as modified teaches in which the inlet stream of recycled hydrogen gas to the first hydrogen compressor is taken from the outlet stream from the hydrogen liquefier unit or form the first cold passage of the third heat exchanger (the stream passes from the heat exchangers to the compressor).
With respect to claim 25, Watanabe as modified teaches further providing a stream of a second refrigerant gas having a temperature of the second refrigerant gas and a temperature of the hydrogen feed gas being near ambient (low-pressure hydrogen at 41 which has the same temperature as the raw material hydrogen, Table 1 which is 35 C and can be considered ambient)
cooling said second refrigerant gas stream in a third hot passage of the first heat exchanger to form a fourth outlet stream (compressed hydrogen is cooled in the first heat exchanger as it passes through as seen the figure, which would create a fourth outlet stream);
cooling said fourth outlet stream in a second hot passage of the second heat exchanger to form a fifth outlet stream (the stream then cools further in the next heat exchanger, which is the second heat exchanger, where it would form a fifth outlet stream);
passing the stream into the hydrogen liquefaction unit (the hydrogen refrigerant stream passes through the hydrogen liquefaction unit through the remaining heat exchangers) in which the stream passes through one or more stages of expansion to provide refrigeration (the stream passes the liquefaction unit heat exchanger and is expanded in 46 and 47 as seen in the figure), before leaving the liquefier unit as a seventh outlet stream (the combined expanded stream leaves the liquefaction unit heat exchangers and passes up through the other heat exchangers back in the cycle as seen in the figure),
reheating the outlet stream in a third cold passage of the second heat exchanger to form a ninth stream (the expanded stream passes through the second heat exchanger as seen in the figure where it would provide heating);
further reheating the ninth outlet stream in a fourth cold passage of the first heat exchanger to form a tenth outlet stream (the ninth outlet stream would then pass as seen in the figure back through the first heat exchanger); and, recompressing the tenth outlet stream in a third compressor to form said second refrigerant gas stream (the expanded combined stream is then compressed in 44).
Watanabe does not teach that the second refrigerant gas passes to the third heat exchanger such that the fifth outlet stream is cooled in a second hot passage becomes a sixth outlet stream which is the outlet stream passed into the hydrogen liquefaction unit and the seventh outlet stream is heated in a third cold passage of the third heat exchanger to form an eighth outlet stream that is the stream passed to second heat exchanger.
Cardella (Figure 3) teaches that when multiple heat exchangers are used for pre-cooling (pre-cooling cold box with 81a, 81, paragraph 160) that the refrigerant stream is passed through all of the heat exchangers (see Figure 3, stream 21 is passed through both 81 and 81a).
Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to have based on the teaching of Cardella to have in Watanabe as modified had the second refrigerant gas pass through a second hot passage of the third heat exchanger to form a sixth outlet stream which is the stream passed into the hydrogen liquefaction unit and that prior to passing into the third heat exchanger had the seventh outlet stream heated in a third cold passage of the third heat exchanger to form an eight outlet stream that is passed to the second heat exchanger since it has been shown that combining prior art elements to yield predictable results is obvious whereby having the liquefaction refrigerant pass through each heat exchanger would provide what would be common knowledge in the art of maximizing the usage of all of the refrigerant fluids by having each stream pass through all of the heat exchangers which could result in increased heat exchanger efficiency by ensuring maximizing of the heat exchanger between all streams coming and going through the system.
With respect to claim 26, Watanabe as modified teaches in which said second refrigerant gas is hydrogen (the second refrigerant gas is hydrogen, loop 40 is a hydrogen loop).
Response to Arguments
Applicant’s arguments, see pages 8-12, filed 1/21/2026, with respect to the rejection(s) of claim(s) claim 1 under 35 USC 103(a) have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Nilsen.
Due to the amendments, the previous rejection under 35 USC 112(a) is withdrawn; however, a new rejection under 35 USC 112(b) have been presented.
Applicant’s arguments page 8-10 are considered moot as they do not take into account the additional reference Nilsen. While none of the previously applied prior art taught using methane or natural gas with impurities removed from it as a refrigerant, Nilsen teaches that a refrigerant that is suitable in cryogenic cooling includes nitrogen, methane, nitrogen and hydrocarbon, or a hydrocarbon mixture. Watanabe teaches using either nitrogen or hydrocarbon-based mixtures as a refrigerant. As such, Nilsen can be used to show that as both refrigerants are known for a cryogenic system it would have been considered obvious to one having ordinary skill in the art to use methane instead of nitrogen rendering the use of a nitrogen refrigerant obvious. There is generally always a range of different refrigerants that can be used for different applications, and choosing from between those would be well within ordinary skill in the art.
Applicant specifically argues that none of the references have conceived that a power demand with the use of methane is comparable to nitrogen.
Applicant is arguing features which are not claimed and is making a mere allegation of patentability. In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., comparable power demand and availability of methane) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). Additionally, in response to applicant's argument that using methane would be beneficial to power demand, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985). Additionally, Nilsen provides a teaching that would result in one having ordinary skill in the art to look at a system that used nitrogen refrigerant and consider it obvious to use methane instead of nitrogen.
Conclusion
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/BRIAN M KING/Primary Examiner, Art Unit 3763