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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office Action has been withdrawn pursuant to 37 CFR 1.114.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 November 10th, 2025 has been entered.
Response to Amendment
In response to the amendment received on November 10th, 2025:
Claims 1-12 and 21-23 are pending in the current application. Claims 1 and 21-22 have been amended. Claims 23 is newly added. Claims 13-20 are cancelled.
The previous rejection under 35 USC 112 is overcome in light of the amendment.
The cores of the previous prior art-based rejections have been overcome in light of the amendment. All changes made to the rejection are necessitated by the amendment.
Response to Arguments
Applicant’s arguments filed with the Remarks on November 10th, 2025 with respect to Claims 1-12 and 21-23 are based on the claims as amended. While Applicant’s arguments are acknowledged, they are found to be moot in view of the new grounds of rejection, presented below, as necessitated by Applicant’s amendments to the Claims.
Claim Interpretation
All “wherein” clauses are given patentable weight unless otherwise noted. Please see MPEP 2111.04 regarding optional claim language.
Prior Art
Previously cited Higdon US PG Publication 2014/0106247 (“Higdon”)
Lienkamp US PG Publication 2009/0117417 (“Lienkamp”)
Previously cited Skidmore US PG Publication 2005/0136296 (“Skidmore”)
Previously cited Weingaertner US PG Publication 2011/0053027 (“Weingaertner’11”)
Previously cited Kanao US PG Publication 2021/0005907 (“Kanao”)
Previously cited Weingaertner US PG Publication 2020/0328445 (“Weingaertner’20”)
Previously cited Hansen US PG Publication 2021/0032761 (“Hansen”)
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office Action.
Claims 1-3 and 23 are rejected under 35 U.S.C. 103 as being unpatentable over Higdon US PG Publication 2014/0106247 in view of Skidmore US PG Publication 2005/0136296, Weingaertner US PG Publication 2011/0053027 (“Weingaertner’11”), and Lienkamp US PG Publication 2009/0117417.
Regarding Claims 1 and 2, Higdon discloses a method of operating a fuel cell system ([0006]), comprising:
operating the fuel cell system in a start-up mode (system startup) ([0040]);
and
operating the fuel cell system in a steady state mode after the step of operating the fuel cell system in the start-up mode ([0040]).
Higdon discloses wherein during the step of operating the fuel cell system in the steady state mode, the anode exhaust is provided into a splitter 107 ([0042]) such that a first portion of the anode (fuel) exhaust stream is provided from the splitter 107 into the [anode tailgas oxidizer] ATO 10 ([0042]) and a second portion of the anode exhaust steam is provided from the splitter 107 into the anode cooler 100 (processor) ([0043]); the ATO temperature is influenced by the amount of load going into the ATO – such that a decrease in temperature corresponds with a decrease in fuel flow ([0051]); and that it is important to keep the ATO operating at in an ideal temperature range during use by controlling the variable speed of the blower 123/125 in order to maintain sufficient fuel load ([0046]-[0048], [0051]-[0052]).
Higdon fails to explicitly disclose wherein during the step of operating the fuel cell system in the start-up mode, the fuel cell system cycles between operating in an exhaust export mode and in a thermal recovery mode a plurality of times.
However, Skidmore discloses a usable fuel cell system (Abstract). Skidmore teaches alternating between an exhaust export mode which includes turning off the incoming exhaust stream into the ATO to allow the temperature inside the ATO to slowly decrease and once the temperature has reached a predetermined threshold, operating in a thermal recovery mode by turning on the incoming exhaust stream into the ATO to allow the temperature inside the ATO to slowly increase, and repeating the process such that the ATO operates between a predetermined temperature range (Fig. 4, [0042]-[0044], [0046]-[0048]) and runs on a cycle based on the startup times of the processors in use, such as the ATO in order to maximize efficiency ([0040]-[0041]).
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of instant application to modify the method of operating a fuel cell system of Higdon such that during the step of operating the fuel cell system in the steady state mode, the fuel cell system cycles between operating in an exhaust export mode and in a thermal recovery mode a plurality of times, wherein during the exhaust export mode, an anode exhaust generated by fuel cells of the fuel cell system is provided to an exhaust processing system (cooler 100), and no anode exhaust is provided to an anode tailgas oxidizer (ATO) by adjusting the blower speed such that the first portion comprises none of the anode exhaust and the second portion comprises all of the anode exhaust; and during the thermal recovery mode, all of the anode exhaust is provided to the ATO (which meets the claim limitation for at least a portion of the anode exhaust), and none of the anode exhaust is provided to the exhaust processing system by adjusting the blower speed such that the first portion comprises all of the anode exhaust and the second portion comprises none of the anode exhaust based on the temperature of the ATO and the startup times required to maintain operation in order to keep the ATO operating within an ideal temperature range to maximize efficiency, as taught by Skidmore.
Higdon in view of Skidmore fails to disclose wherein the anode exhaust generated by the fuel cells of the fuel cell system is provided to the exhaust processing system to remove water from the anode exhaust.
However, Weingaertner’11 discloses a method of operating a fuel cell system ([0002]), wherein the system runs through both startup and steady-state operating modes ([0031]). And, wherein the system comprises a control valve that controls the amount of anode exhaust traveling between the ATO and the recycling fuel inlet stream of the conduit ([0063]). Weingaertner’11 teaches the use of a water trap 109 that is used to store water that has been removed from the anode exhaust stream prior to the anode exhaust entering the ATO ([0046]) in order to avoid excess condensation building up within the ATO as the system operates ([0044]).
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the instant application to modify the method of Higdon in view of Skidmore such that while the anode exhaust that was generated by the fuel cells of the fuel cell system is provided to the exhaust processing system and no anode exhaust is provided to the ATO, water is removed from the anode exhaust and stored in a water trap such that no excess condensation will build up within the ATO as the system operates, as taught by Weingaertner’11.
Higdon in view of Skidmore and Weingaertner’11 fails to explicitly disclose wherein during the exhaust export mode and the thermal recovery mode, the fuel cells operate to generate the anode exhaust.
However, Lienkamp discloses a fuel cell system comprising a cathode side and an anode side of a stack ([0013], entire disclosure dependent upon). Wherein the system further comprises a bypass valve (i.e. bleed valve) at an anode gas output to remove nitrogen from the anode side of the stack during operation of the fuel cell system ([0008]). Lienkamp teaches that an anode control module adjusts the differential pressure across the bleed valve to control anode gas flow ([0021]-[0022]), and wherein the flow rate of the anode exhaust gas never reaches zero during operation ([0030]-[0060]), to keep the system operating below a predetermined safety level ([0021]-[0022]).
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the instant application to modify the method of Higdon in view of Skidmore and Weingaertner’11 such that during the exhaust export mode and the thermal recovery mode, the fuel cells are operating to continuously generate the anode exhaust in order to keep the system operating below a predetermined safety level, as taught by Lienkamp.
Regarding Claim 3, Higdon in view of Skidmore, Weingaertner’11, and Lienkamp teaches the instantly claimed method according to Claim 1, and Higdon discloses wherein the fuel cells are arranged in a fuel cell column ([0037]).
Regarding Claim 23, Higdon in view of Skidmore, Weingaertner’11, and Lienkamp teaches the instantly claimed method according to Claim 1, and Higdon discloses wherein the fuel cells generate electric power in addition to generating the anode exhaust during both the exhaust export mode and the thermal recovery mode ([0035]).
Claims 4-7 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Higdon US PG Publication 2014/0106247 in view of Skidmore US PG Publication 2005/0136296, Weingaertner US PG Publication 2011/0053027, and Lienkamp US PG Publication 2009/0117417, as applied to Claim 3, further in view of Kanao US PG Publication 2021/0005907.
Regarding Claim 4, Higdon in view of Skidmore, Weingaertner’11, and Lienkamp teaches the instantly claimed method according to Claim 3.
While Higdon discloses that during the thermal recovery mode, oxidation of the anode exhaust in the ATO heats the fuel cell column ([0051]), and therefore the skilled artisan would recognize that during the thermal recovery mode the temperature of the fuel cell column would increase due to the oxidation of the anode exhaust.
However, Higdon in view of Skidmore, Weingaertner’11, and Lienkamp fails to explicitly disclose that during exhaust export mode, a temperature of the fuel cell column decreases from a first temperature to a second temperature which is at least 10oC lower than the first temperature; and during thermal recovery mode, the temperature of the fuel cell column increases from the second temperature to the first temperature.
However, Kanao discloses a fuel cell system comprising a fuel cell stack ([0010]). Kanao teaches a stack temperature operating temperature range including a lower limit Tl and an upper limit Th such that when the temperature measured as Ts falls outside of the range the stack temperature can be changed to maintain the desired temperature range by modifying the fuel rate ([0097]-[0101]) in order to avoid any damage to the fuel cell stack ([0007], [0010], [0101]).
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the instant application to modify the method of Higdon in view of Skidmore, Weingaertner’11, and Lienkamp such that during the exhaust export mode when there is no oxidation of the anode exhaust in the ATO, a temperature of the fuel cell column decreases from a first temperature between Th and Tl to a second temperature lower than Tl, and during the thermal recovery mode when there is oxidation of the anode exhaust in the ATO, the temperature of the fuel cell column increases from the second temperature lower than Tl to the first temperature between Th and Tl in order to avoid any damage to the fuel cell stack while operating, as taught by Kanao.
The skilled artisan would recognize that the second temperature is at least 0oC lower (which overlaps the claimed range of at least 10oC lower) than the first temperature (such that the second temperature is less than Tl). In 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).
Regarding Claim 5, Higdon in view of Skidmore, Weingaertner’11, Lienkamp, and Kanao teaches the instantly claimed method according to Claim 4, and Higdon in view of Skidmore, Weingartner’11, Lienkamp and Kanao discloses wherein the fuel cell system cycles between the exhaust export mode and the thermal recovery mode based on a fixed time cycle determined by the startup times of the processors used (Higdon [0089], Skidmore [0040]-[0041]).
Regarding Claim 6, Higdon in view of Skidmore, Weingaertner’11, Lienkmap, and Kanao teaches the instantly claimed method according to Claim 4, and Higdon in view of Skidmore, Weingaertner’11, Lienkamp, and Kanao discloses wherein the fuel cell system cycles between the exhaust export mode and the thermal recovery mode based on a detected temperature of the ATO within the fuel cell column (Higdon [0048], Skidmore Fig. 4, [0042]-[0044], [0046]-[0048]) and based on the temperature of the fuel cell column (Higdon [0051], Kanao [0097]-[0101]).
Regarding Claim 7, Higdon in view of Skidmore, Weingaertner’11, Lienkamp, and Kanao teaches the instantly claimed method according to Claim 6, and Higdon in view of Skidmore, Weingaertner’11, Lienkamp, and Kanao discloses switching from the exhaust export mode to the thermal recovery mode after the temperature of the fuel cell column is reduced to the second temperature during the exhaust export mode; and
switching from the thermal recovery mode to the exhaust export mode after the temperature of the fuel cell column is increased from the second temperature to the first temperature during the thermal recovery mode by changing the blower speed (Higdon [0048], Kanao [0097]-[0101]).
Regarding Claim 21, Higdon in view of Skidmore, Weingaertner’11, Lienkamp, and Kanao teaches the instantly claimed method according to Claim 4, and Higdon in view of Skidmore, Weingaertner’11, Lienkamp, and Kanao discloses operating the fuel cell system in the start-up mode until the fuel cell column reaches the first temperature (the operating temperature range between Th and Tl as defined by Kanao [0097]-[0101]) as achieved by the blower 123/125 speed (Higdon [0045]-[0046]); and
providing the at least a portion of the anode exhaust to the ATO during the thermal recovery mode, such that the ATO increases the temperature of the fuel cell column by oxidating the anode exhaust from the second temperature to the first temperature (Higdon [0051], Kanao [0097]-[0101]).
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Higdon US PG Publication 2014/0106247 in view of Skidmore US PG Publication 2005/0136296, Weingaertner US PG Publication 2011/0053027, and Lienkamp US PG Publication 2009/0117417, as applied to Claim 3, further in view of Weingaertner US PG Publication 2020/0328445 (Weingaertner’20).
Regarding Claim 8, Higdon in view of Skidmore, Weingaertner’11, and Lienkamp teaches the instantly claimed method according to Claim 3, and Higdon discloses wherein the fuel cells comprise solid oxide fuel cells ([0037]).
Higdon in view of Skidmore, Weingaertner’11, and Lienkamp fails to disclose the fuel utilization rate of the fuel cell column is less than 85% during both the thermal recovery mode and the exhaust export mode.
However, Weingaertner’20 discloses a fuel cell system (Abstract). Weingaertner’20 teaches a steady-state mode fuel utilization rate of about 75% in order to maximize the electrical efficiency of the fuel cell system ([0045]).
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the instant application to modify the method of Higdon in view of Skidmore, Weingaertner’11, and Lienkamp such that the fuel utilization rate of the fuel cell column is about 75% (which falls within and therefore anticipates the claimed range of less than 85%) during both the thermal recovery mode and the exhaust export mode during steady-state mode operations in order to maximize the electrical efficiency of the fuel cell system, as taught by Weingaertner’20.
Claims 9-10 are rejected under 35 U.S.C. 103 as being unpatentable over Higdon US PG Publication 2014/0106247 in view of Skidmore US PG Publication 2005/0136296, Weingaertner US PG Publication 2011/0053027, and Lienkamp US PG Publication 2009/0117417, as applied to Claim 1, further in view of Hansen US PG Publication 2021/0032761.
Regarding Claims 9-10, Higdon in view of Skidmore, Weingaertner’11, and Lienkamp teaches the instantly claimed method according to Claim 1.
Higdon in view of Skidmore, Weingaertner’11, and Lienkamp fails to disclose a first and second electrolyzer system of the exhaust processor.
However, Hansen discloses a method of generating synthetic gas by electrolysis using electrolysis units (Abstract). Hansen teaches the use of a plurality of electrolysis units that are solid oxide electrolysis cell (SOEC) stacks ([0006]) such that the operating voltage of the system can be relatively low ([0012]).
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the instant application to modify the method of Higdon in view of Skidmore, Weingaertner’11, and Lienkamp to further comprise using a first electrolyzer system of the exhaust processor and a second electrolyzer system of the anode exhaust processor in order to operate at a relatively low voltage, as taught by Hansen.
The skilled artisan would recognize that using a first electrolyzer system of the exhaust processor would electrolyze water and carbon dioxide present in the anode exhaust and output an anode exhaust having an increased hydrogen and carbon monoxide content and that supplying hydrogen from the second electrolyzer system to the anode exhaust would increase the hydrogen content of the anode exhaust (as evidenced by Applicant’s own Specification [0049] wherein it is described that SOEC systems convert CO2 and H2O into CO and H2).
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Higdon US PG Publication 2014/0106247 in view of Skidmore US PG Publication 2005/0136296, Weingaertner US PG Publication 2011/0053027, Lienkamp US PG Publication 2009/0117417, and Hansen US PG Publication 2021/0032761, as applied to Claim 9, further in view of Weingaertner US PG Publication 2020/0328445.
Regarding Claim 11, Higdon in view of Skidmore, Weingaertner’11, Lienkamp, and Hansen teaches the instantly claimed method according to Claim 9.
Higdon in view of Skidmore, Weingaertner’11, Lienkamp, and Hansen fails to disclose using a water gas shift (WGS) reactor and using a condenser.
However, Weingaertner’20 discloses a fuel cell system (Abstract). Weingaertner’20 teaches using a WGS reactor of the fuel exhaust processor (conduit) to increase the hydrogen and carbon dioxide content of the anode exhaust ([0024]) and using a condenser of the anode exhaust processor to reduce a liquid water content (by removing the liquid water) of the anode exhaust output from the WGS reactor within the fuel cell system ([0007], [0084]) in order to provide for easy separation of hydrogen ([0090]).
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the instant application to modify the method of Higdon in view of Skidmore, Weingaertner’11, Lienkamp, and Hansen to further include using a WGS reactor of the exhaust processor to increase the hydrogen and carbon dioxide content of the anode exhaust and using a condenser of the anode exhaust processor to reduce a water content of the anode exhaust output from the WGS reactor in order to provide for easy separation of hydrogen, as taught by Weingaertner’20.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Higdon US PG Publication 2014/0106247 in view of Skidmore US PG Publication 2005/0136296, Weingaertner US PG Publication 2011/0053027, and Lienkamp US PG Publication 2009/0117417, as applied to Claim 1, further in view of Weingaertner US PG Publication 2020/0328445.
Regarding Claim 12, Higdon in view of Skidmore, Weingaertner’11, and Lienkamp teaches the instantly claimed method according to Claim 1.
Higdon in view of Skidmore, Weingaertner’11, and Lienkamp fails to disclose separating water and carbon dioxide in the anode exhaust from syngas consisting essentially of a mixture of hydrogen and carbon monoxide; and providing the syngas to a syngas user.
However, Weingaertner’20 discloses a fuel cell system (Abstract). Weingaertner’20 teaches separating water (vapor) and carbon dioxide in the anode exhaust from syngas (fuel) consisting essentially of a mixture of hydrogen and carbon monoxide, and providing the syngas to a syngas user (fuel inlet conduit 111) in order to increase the amount of hydrogen in the system ([0024]-[0025]).
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the instant application to modify the method of Higdon in view of Skidmore, Weingaertner’11, and Lienkamp to further comprise separating water and carbon dioxide in the anode exhaust from syngas consisting essentially of a mixture of hydrogen and carbon monoxide; and providing the syngas to a syngas user in order to increase the amount of hydrogen in the system, as taught by Weingaertner’20.
Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Higdon US PG Publication 2014/0106247 in view of Skidmore US PG Publication 2005/0136296, Weingaertner US PG Publication 2011/0053027, Lienkamp US PG Publication 2009/0117417, and Kanao US PG Publication 2021/0005907, as applied to Claim 21, further in view of Weingaertner US PG Publication 2020/0328445.
Regarding Claim 22, Higdon in view of Skidmore, Weingaertner’11, Lienkamp, and Kanao teaches the instantly claimed method according to Claim 21.
Higdon in view of Skidmore, Weingaertner’11, Lienkamp, and Kanao fails to disclose wherein during the exhaust export mode and the thermal recovery mode, a fuel utilization rate of the column is lower than a thermal stability point of the column.
However, Weingaertner’20 discloses a fuel cell system (Abstract). Weingaertner’20 teaches a steady-state mode fuel utilization rate of about 75% in order to maximize the electrical efficiency of the fuel cell system ([0045]).
Therefore, it would have been obvious to a person having ordinary skill in the art prior to the effective filing date of the instant application to modify the method of Higdon in view of Skidmore, Weingaertner’11, Lienkamp, and Kanao such that the fuel utilization rate of the fuel cell column is about 75% during both the thermal recovery mode and the exhaust export mode during steady-state mode operations in order to maximize the electrical efficiency of the fuel cell system, as taught by Weingaertner’20.
Conclusion
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/O.M.R./Examiner, Art Unit 1729
/ULA C RUDDOCK/Supervisory Patent Examiner, Art Unit 1729