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 .
Claims 1-20 are pending.
Specification
The disclosure is objected to because of the following informalities:
In paragraph 0038, line 10, “102” is redundantly repeated.
Appropriate correction is required.
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.
Claims 1, 5 and 7-9 are rejected under 35 U.S.C. 103 as being unpatentable over O’Brien et al. (“Test Plan for Long-Term Operation of a Ten-Cell High Temperature Electrolysis Stack”, INL, 2008) in view of Yoshida et al. (JP 5241157 B2, citations based on translation).
Regarding claim 1, O’Brien teaches an electrolyzer system (see e.g. Fig. 1, apparatus comprising electrolysis stack) comprising:
a vaporizer configured to store a first volume of liquid water and to vaporize water to humidify a cathode inlet stream of an electrolyzer cell module (see e.g. Fig. 1, heater humidifier containing demineralized water in which water vapor is generated and mixed with nitrogen/hydrogen gas to be fed to cathode of electrolysis stack; Page 6, lines 2-6, and Page 9, lines 9-10);
a cold water source (see e.g. Fig. 1, non-heated, i.e. cold, demineralized water); and
a valve configured to open and close, wherein the water from the cold water tank is allowed to flow through the valve and into the vaporizer when the valve is open (see e.g. Fig. 1, solenoid valve through which the non-heated demineralized water is fed to the heated humidifier when open; Page 6, lines 4-8).
O’Brien does not explicitly teach the cold water source being a tank positioned at a height greater than that of the first volume of liquid water and configured to store a second volume of liquid water.
Yoshida teaches a solid oxide electrochemical cell system (see e.g. Paragraphs 0001 and 0011) comprising a vaporizer to which water is supplied by via a water storage tank positioned at a height greater than the vaporizer in order to ensure a sufficient water flow rate(see e.g. Fig. 1, water storage tank 7 with water at height h above vaporizer 6; Paragraph 0012).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the cold water source of O’Brien to comprise a water tank positioned at a height greater than the vaporizer as taught by Yoshida as a suitable arrangement for supplying water to a vaporizer in an electrochemical cell system that ensures sufficient water flow rate. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Regarding claim 5, O’Brien as modified by Yoshida above does not teach the valve being a fail open valve that requires an electrical signal to remain closed.
Yoshida further teaches water from the water storage tank continuing to be supplied to the vaporizer even after power outage to prevent oxidation or deterioration of the fuel electrode by supplying water vapor, and thus preventing entrance of air, while the solid oxide cell cools down (see e.g. Yoshida Paragraphs 0016 and 0033), this process assisted by a purge valve of the normally open type, i.e. fail open, such that it can be kept open without external power supply when power is lost in the outage (see e.g. Yoshida Paragraph 0020 and Paragraph 0030, lines 9-12).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the valve of modified O’Brien to be a normally open, i.e. fail open, valve as taught by Yoshida to enable water from the storage tank to continue to flow into the vaporizer without external power supply even after a power outage and thereby prevent oxidation or deterioration of an electrode of the electrolyzer system by supplying water vapor and preventing entrance of air while it cools down.
Regarding claim 7, O’Brien as modified by Yoshida further teaches the cold water tank comprising a cold water inlet configured to receive additional water (see e.g. Yoshida Fig. 1, water supply means 5 supplying water storage tank 7; Paragraph 0012, lines 5-7); and the electrolyzer system further comprising a pipe with a first end fluidly coupled to the cold water tank at a first height above the bottom of the cold water tank and a second end fluidly coupled to the vaporizer at a position above a water level of the first volume of liquid water (see e.g. Yoshida Fig. 1, water supply pipe Lw shown connected above bottom of water storage tank 7 and coupled to top, i.e. above water volume, of vaporizer 6; Paragraph 0012, lines 1-4).
Regarding claim 8, O’Brien as modified by Yoshida teaches the pipe being configured to allow water from the second volume of water to flow into the vaporizer via the pipe when the second volume of water exceeds the first height (see e.g. Yoshida Fig. 1, water at a height suitable to reach supply pipe Lw, i.e. exceeding its height, necessarily capable of flowing from storage tank 7 to vaporizer 6 via gravity; Paragraph 0014, lines 6-10).
Regarding claim 9, O’Brien as modified by Yoshida teaches the pipe being configured to allow gas to flow from the vaporizer into the cold water tank when the second volume of water flows into the vaporizer (see e.g. Yoshida Fig. 1, water storage tank 7 comprises steam purge valve 8, indicating that water vapor or other gases from lower vaporizer 6 could be passed through the connecting supply pipe Lw to be released via said purge valve in the higher storage tank; Paragraphs 0014 and 0025).
Claims 2-4 are rejected under 35 U.S.C. 103 as being unpatentable over O’Brien in view of Yoshida, as applied to claim 1 above, and further in view of Rusta-Sallehy et al. (U.S. 2005/0183948).
Regarding claim 2, modified O’Brien teaches all the elements of the system of claim 1 as stated above. Modified O’Brien further teaches the system comprising a controller (see e.g. O’Brien Page 9, lines 24-26). Modified O’Brien does not teach the controller being configured to reduce the pressure in the vaporizer and to open the valve in response to receiving an indication of a malfunction in the electrolyzer system. O’Brien does however teach the vaporizer comprising a pressure release valve to avoid any possibility of over-pressurization (see e.g. O’Brien Page 7, lines 8-9), as well as parameters such as current and voltage of the electrolyzer system being continuously monitored (see e.g. O’Brien Page 10, lines 5-7).
Rusta-Sallehy teaches an electrolyzer cell module (see e.g. Abstract) comprising a safety system for monitoring parameters related to operation of the electrolyzer cell module, such as current and voltage, and evaluating whether or not at least one alarm threshold of at least one of the parameters has been violated (see e.g. Paragraph 0006, lines 7-13, and Paragraphs 0032 and 0038), with a computer programmed for emergency stoppage of normal operation of the electrolyzer cell module upon violation of the alarm threshold(s) (see e.g. Paragraph 0006, lines 13-17), such stoppage including flushing out residual gases in the electrolyzer module by continuing to supply water via a feed circulation pump and other related elements (see e.g. Paragraph 0006, lines 17-24, and Paragraph 0074, lines 1-11) and releasing of pressure via valves when the electrolyzer module is shut down (see e.g. Paragraph 0008 and Paragraph 0074, lines 12-21), this safety system allowing controllable shutdown of the electrolyzer cell module in an emergency situation while preventing residual effects that make it difficult to restart the electrolyzer cell module (see e.g. Paragraph 0018).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the system of modified O’Brien to have the controller configured to implement initiate an emergency stoppage of normal operation of the electrolyzer system including release of pressure of system elements and continuation of water supply, i.e. via opening of the water supply valve to the vaporizer, to flush out residual gases in the system upon evaluating that monitored parameters have exceeded an alarm threshold as taught by Rusta-Sallehy to allow controllable shutdown of the electrolyzer system in an emergency situation while preventing residual effects that make it difficult to restart the system.
Regarding claim 3, O’Brien as modified by Rusta-Sallehy teaches the indication of the malfunction comprising a sudden change in voltage in the electrolyzer cell module or a sudden change in current generated in the electrolyzer cell module (see e.g. O’Brien Page 10, lines 5-7, current and voltage monitored; see e.g. Rusta-Sallehy Paragraphs 0032 and 0038, current and voltage sensors used as control input for regulation/shut down).
Regarding claim 4, O’Brien as modified by Rusta-Sallehy teaches a pressure release valve configured to open to reduce the pressure in the vaporizer in response to a command from the controller (see e.g. O’Brien Page 7, lines 8-9, pressure release valve on humidifier to avoid over-pressurization; see e.g. Rusta-Sallehy Paragraph 0074, lines 12-21, release of pressure via valves during shutdown).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over O’Brien in view of Yoshida, as applied to claim 1 above, and further in view of Rueger et al. (U.S. 2018/0287179).
Regarding claim 6, modified O’Brien teaches all the elements of the system of claim 1 as stated above. Modified O’Brien does not teach the vaporizer being configured to receive a recycle stream from the electrolyzer cell module and to humidify the recycle stream to form the cathode inlet stream. O’Brien does however teach hydrogen being humidified in the vaporizer to form the cathode inlet stream (see e.g. O’Brien Page 6, lines 2-6, and Page 9, lines 9-10).
Rueger teaches a solid oxide electrolysis system (see e.g. Abstract) comprising an evaporator for generating steam for a solid oxide electrolysis cell from feed water (see e.g. Fig. 7, evaporator 53; Paragraphs 0122-0126), wherein the evaporator receives a recirculated hydrogen stream from the from the electrolysis cell to be mixed with the generated steam and supplied to the cathode of the solid oxide electrolysis cell (see e.g. Fig. 7, recirculated hydrogen 2 entering steam generator 53 to produce hydrogen-steam mixture supplied to SOEC 5; Paragraphs 0084 and 0127), this recirculated hydrogen being useful for reducing the heat demand for evaporation of water (see e.g. Paragraph 0129).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the system of modified O’Brien to have the vaporizer configured to receive and humidify a recirculated, i.e. recycled, hydrogen stream from the electrolyzer cell module to form the cathode inlet as taught by Rueger to reduce the heat demand for evaporation of water in the vaporizer.
Claims 10 and 12-18 are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida in view of O’Brien.
Regarding claim 10, Yoshida teaches a method of cooling a vaporizer in an electrochemical system (see e.g. Paragraphs 0001 and 0033, shut down method for solid oxide fuel cells in which water is supplied to vaporizer until it cools to a point that no more water vapor is generated), the vaporizer containing a volume of hot liquid water (see e.g. Fig. 1, heated vaporizer 6 containing supplied liquid water; Paragraph 0012, lines 5-6, and Paragraph 0015, lines 1-2), the method comprising:
detecting a malfunction in the electrochemical system (see e.g. Paragraph 0014, cut off of water and fuel due to power outage), and, in response to detecting such malfunction:
reducing a gas pressure in the vaporizer (see e.g. Paragraph 0014, lines 8-9, internal pressure of vaporizer falls); and
releasing a volume of cold water into the vaporizer from a cold water tank that is positioned at a height greater than that of the volume of hot liquid water (see e.g. Fig. 1, unheated, i.e. cold, water from water storage tank 7 positioned at a height above vaporizer 6 drips into the vaporizer; Paragraph 0014, lines 6-10).
Yoshida does not teach the electrochemical system being an electrolyzer system, instead teaching it being a fuel cell system, but does teach it comprising a solid oxide electrochemical cell (see e.g. Paragraph 0001), wherein the method prevents oxidation or deterioration of a fuel electrode by supplying water vapor, and thus preventing entrance of air, while the high temperature solid oxide cell cools down (see e.g. Paragraphs 0016 and 0033).
O’Brien teaches a high temperature electrolysis system comprising solid oxide electrolysis cells (see e.g. Page 5, lines 1-2), wherein hydrogen mixed with steam via a heated humidifier, i.e. vaporizer, is delivered to an electrode which would otherwise be at risk of oxidation (see e.g. Page 6, lines 1-6).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Yoshida to be applied to the vaporizer of the electrolyzer system of O’Brien as a particular solid oxide electrochemical system that can benefit from the electrode oxidation protection provided by the method of Yoshida. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Regarding claim 12, modified Yoshida teaches the cold water tank and the vaporizer being arranged such that the cold water flows into the vaporizer under the force of gravity (see e.g. Yoshida Paragraph 0014, lines 8-10, and Paragraph 0016, liens 4-6).
Regarding claim 13, modified Yoshida teaches reducing the gas pressure in the vaporizer comprising opening a pressure release valve (see e.g. Yoshida Paragraph 0030, lines 1-12, steam purge valve opened and vaporizer pressure decreases).
Regarding claim 14, modified Yoshida teaches reducing the gas pressure in the vaporizer comprising reducing the gas pressure from a pressure above ambient pressure to ambient pressure (see e.g. Yoshida Paragraph 0030, lines 1-12, vaporizer pressure decreases from a higher pressure to approach ambient pressure).
Regarding claim 15, Yoshida as modified by O’Brien teaches the malfunction comprising a sudden change in gas flow rate to the electrolyzer cell module (see e.g. Yoshida Paragraph 0014, cut off of water and fuel due to power outage; see e.g. O’Brien Fig. 1, steam and H2 delivered to electrolysis stack, Page 6, lines 2-6).
Regarding claim 16, Yoshida as modified by O’Brien teaches the cold water being released into the vaporizer at a position below the top of the volume of hot liquid water (see e.g. O’Brien Fig. 1, demineralized water entering heated humidifier below top of water volume).
Regarding claim 17, modified Yoshida teaches the volume of cold water having a volume and temperature such that, when the volume of cold water flows into the vaporizer, the temperature of a volume of hot liquid water in the vaporizer drops from 100 degrees Celsius or higher to below 100 degrees Celsius (see e.g. Yoshida Paragraph 0033, vaporizer first at a temperature high enough for water vapor production, i.e. at least 100°C, dropped to a temperature at which no water vapor produced, i.e. below 100°C, upon addition of water from storage tank).
Regarding claim 18, modified Yoshida teaches supplying additional water to the cold water tank (see e.g. Yoshida Fig. 1, water supply means 5 supplying water storage tank 7; Paragraph 0012, lines 5-7), wherein cold water is allowed to flow into the vaporizer when the volume of cold water exceeds a first height in the cold water tank (see e.g. Yoshida Fig. 1, water at a height suitable to reach supply pipe Lw, i.e. exceeding its height, necessarily capable of flowing from storage tank 7 to vaporizer 6 via gravity; Paragraph 0014, lines 6-10).
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Yoshida in view of O’Brien, as applied to claim 10 above, and further in view of Chung et al. (U.S. 2017/0018790).
Regarding claim 11, modified Yoshida teaches all the elements of the method of claim 10 as stated above. Modified Yoshida does not teach releasing the volume of cold water into the vaporizer comprising opening a valve positioned between the cold water tank and the vaporizer. O’Brien does however teach a valve positioned along an inlet line to the vaporizer being opened to provide cold water (see e.g. O’Brien Fig. 1, solenoid valve through which the non-heated demineralized water is fed to the heated humidifier when open; Page 6, lines 4-8).
Chung teaches a stack protection method for a solid oxide fuel system (see e.g. Abstract) comprising an opened flow control valve positioned between a water reservoir tank and vaporizer, such that a flow between the two can be controlled (see e.g. Paragraph 0022).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of modified Yoshida to have releasing the volume of cold water comprise opening a valve positioned between the cold water tank and the vaporizer as taught by Chung to control the flow between the two elements. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Yoshida in view of O’Brien, as applied to claim 10 above, and further in view of Schatton et al. (U.S. 2002/0060158).
Regarding claim 19, modified Yoshida teaches all the elements of the method of claim 18 as stated above. Modified Yoshida further teaches the volume of cold water having a temperature, such that, when the volume of cold water flows into the vaporizer, the temperature of a volume of hot liquid water in the vaporizer drops from 100 degrees Celsius or higher to below 100 degrees Celsius (see e.g. Yoshida Paragraph 0033, vaporizer first at a temperature high enough for water vapor production, i.e. at least 100°C, dropped to a temperature at which no water vapor produced, i.e. below 100°C, upon addition of water from storage tank).
Modified Yoshida does not teach the volume of cold water having a volume below the first height and being able to flow into the vaporizer, but does teach the cold water flowing into the vaporizer which is at a lower height due to gravity (see e.g. Yoshida Paragraph 0016, lines 4-6).
Schatton teaches an electrolysis plant (see e.g. Paragraphs 0003-0004) wherein liquid from an upper container can be discharged into a lower container via a siphon line upon exceeding a certain height and can continue to flow from the upper container to the lower container until reaching a lower height (see e.g. Fig. 1, electrolyte in container 10 has upper filling level A at which electrolyte flows out and down syphon line 12 to lower container 11 until filling lower filling level B is reached; Paragraph 0009, lines 1-7, and Paragraph 0010).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of modified Yoshida to have the cold water able to flow from the cold water into the vaporizer when exceeding a certain height and continue to be supplied until reaching a lower height as taught by Schatton as an alternate suitable method of supplying liquid from an upper storage container to a lower container in an electrochemical system under the influence of gravity. MPEP § 2143(I)(B) states that “simple substitution of one known element for another to obtain predictable results” may be obvious.
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Yoshida in view of O’Brien, as applied to claim 10 above, and further in view of Rueger.
Regarding claim 20, modified Yoshida teaches all the elements of the method of claim 10 as stated above. Modified Yoshida does not teach supplying an electrolyzer cell recycle stream to the vaporizer; and vaporizing water in the vaporizer to humidify the electrolyzer cell recycle stream. O’Brien does however teach hydrogen being humidified in the vaporizer to form the cathode inlet stream (see e.g. O’Brien Page 6, lines 2-6, and Page 9, lines 9-10).
Rueger teaches a solid oxide electrolysis system (see e.g. Abstract) comprising an evaporator for generating steam for a solid oxide electrolysis cell from feed water (see e.g. Fig. 7, evaporator 53; Paragraphs 0122-0126), wherein the evaporator receives a recirculated hydrogen stream from the from the electrolysis cell to be mixed with the generated steam and supplied to the cathode of the solid oxide electrolysis cell (see e.g. Fig. 7, recirculated hydrogen 2 entering steam generator 53 to produce hydrogen-steam mixture supplied to SOEC 5; Paragraphs 0084 and 0127), this recirculated hydrogen being useful for reducing the heat demand for evaporation of water (see e.g. Paragraph 0129).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of modified Yoshida to comprise the vaporizer receiving and humidifying a recirculated, i.e. recycled, hydrogen stream from the electrolyzer cell module as taught by Rueger to reduce the heat demand for evaporation of water in the vaporizer.
Conclusion
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/MOFOLUWASO S JEBUTU/Examiner, Art Unit 1795
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