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 .
Claim Rejections - 35 USC § 103
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.
Claims 1-4, 8, 10-12, 16-18 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Moon et al (WO 2022/181875) in view of Ashby et al (US 5,356,516).
Regarding claim 1, Moon et al teach (see English abstract, figs. 1 and 5, paragraph [0059] of machine translation) a hydrogen electrochemical system comprising a cell (420) including a membrane (106) and catalyst-loaded catalyst layers (104, 108) and a deionization subsystem (600) including a chelator (“chelate resin”) located in a water recirculation loop of the cell. The chelator had the effect of removing metal ion impurities from the water.
Moon et al fail to teach the identity of the chelator such that it is impossible to determine if the pKa value(s) of the chelator was different from the pH of the cell during operation.
However, it was well known in the art of heavy metal removal using chelating agents that the selection of an optimal chelating agent was necessarily based upon the pH of the solution to be treated, as shown by Ashby et al (see paragraph spanning cols. 4 and 5). It was important to select the chelating agent such that it is entirely deprotonated at the pH of the solution to ensure stronger bonding of the metal ions to the chelating agent. Ashby et al also recognized that the pH at which the chelating agent was deprotonated was easily determined upon knowing the equilibrium constant for chelating as a function of pH, i.e. the pKa value of the chelating agent.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified the system of Moon et al according to the suggestion of Ashby et al by selecting a chelating agent which was entirely deprotonated at the pH of the cell during operation to ensure maximum metal bonding by the chelating agent. The pH was thus necessarily different from the pKa value of the chelating agent.
Regarding claim 2, it would have been well within the ordinary level of skill in the art to have determined a suitable pH vs pKa difference to ensure that the chelating agent was fully deprotonated.
Regarding claim 3, the cell of Moon et al was an electrolyzer.
Regarding claim 4, Moon et al teach (see paragraph [0059] of machine translation) the chelating agent being selective for heavy metal removal. Moon et al also teach (see paragraph [0036] of machine translation) that iron ions were known to lead to membrane degradation. Thus, it would have been obvious to one of ordinary skill in the art at the time of filing to have ensured that iron was included among the heavy metals that the chelating agent removed.
Regarding claim 8, the cell of Moon et al was capable of operating with a pH between 0 and 4. In view of the suggestion of Ashby et al, it would have been obvious to one of ordinary skill in the art to have selected a chelating agent which possessed a pKa value lower than the pH of operation of the cell.
Regarding claim 10, Moon et al teach (see English abstract, figs. 1 and 5, paragraph [0059] of machine translation) a hydrogen electrochemical system comprising a water input source (“H2O”), an electrolyzer (420) including a membrane electrolyte (106) and catalyst-loaded catalyst layers (104, 108) receiving water from the water input source and a deionization subsystem (600) including a chelator (“chelate resin”) located in a water recirculation loop of the cell, wherein the deionization subsystem was located upstream of the electrolyzer cell and downstream of the water input source. The chelator had the effect of removing metal ion impurities from the water.
Moon et al fail to teach the identity of the chelator such that it is impossible to determine if the pKa value(s) of the chelator was different from the pH of the electrolyzer during operation.
However, it was well known in the art of heavy metal removal using chelating agents that the selection of an optimal chelating agent was necessarily based upon the pH of the solution to be treated, as shown by Ashby et al (see paragraph spanning cols. 4 and 5). It was important to select the chelating agent such that it is entirely deprotonated at the pH of the solution to ensure stronger bonding of the metal ions to the chelating agent. Ashby et al also recognized that the pH at which the chelating agent was deprotonated was easily determined upon knowing the equilibrium constant for chelating as a function of pH, i.e. the pKa value of the chelating agent.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified the system of Moon et al according to the suggestion of Ashby et al by selecting a chelating agent which was entirely deprotonated at the pH of the cell during operation to ensure maximum metal bonding by the chelating agent. The pH was thus necessarily different from the pKa value of the chelating agent.
Regarding claim 11, as suggested by Ashby et al, it was desired to have the chelating agent by deprotonated at the operating pH.
Regarding claim 12, Moon et al teach (see paragraph [0059] of machine translation) the chelating agent being selective for heavy metal removal. Moon et al also teach (see paragraph [0036] of machine translation) that iron ions were known to lead to membrane degradation. Thus, it would have been obvious to one of ordinary skill in the art at the time of filing to have ensured that iron was included among the heavy metals that the chelating agent removed.
Regarding claim 16, the cell of Moon et al was capable of operating with a pH oof about 2. In view of the suggestion of Ashby et al, it would have been obvious to one of ordinary skill in the art to have selected a chelating agent which possessed a pKa value lower than the pH of operation of the cell.
Regarding claim 17, Moon et al teach (see English abstract, figs. 1 and 5, paragraph [0059] of machine translation) an electrolyzer deionization subsystem (600) including a reservoir containing a chelator (“chelate resin”) located in a water recirculation loop of the cell. The chelator had the effect of removing metal ion impurities from the water.
Moon et al fail to teach the identity of the chelator such that it is impossible to determine if the pKa value(s) of the chelator was different from the pH of the electrolyzer during operation.
However, it was well known in the art of heavy metal removal using chelating agents that the selection of an optimal chelating agent was necessarily based upon the pH of the solution to be treated, as shown by Ashby et al (see paragraph spanning cols. 4 and 5). It was important to select the chelating agent such that it is entirely deprotonated at the pH of the solution to ensure stronger bonding of the metal ions to the chelating agent. Ashby et al also recognized that the pH at which the chelating agent was deprotonated was easily determined upon knowing the equilibrium constant for chelating as a function of pH, i.e. the pKa value of the chelating agent.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified the system of Moon et al according to the suggestion of Ashby et al by selecting a chelating agent which was entirely deprotonated at the pH of the cell during operation to ensure maximum metal bonding by the chelating agent. The pH was thus necessarily different from the pKa value of the chelating agent.
Regarding claim 18, as suggested by Ashby et al, it was desired to have the chelating agent by deprotonated at the operating pH.
Regarding claim 20, the deionization device of Moon et al was located upstream of the electrolyzer cell.
Claims 5 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Moon et al (WO 2022/181875) in view of Ashby et al (US 5,356,516) as applied to claims 1 and 10, respectively, above, and further in view of Han et al (US 2018/0230606).
Moon et al teach (see paragraph [0059] of machine translation) the chelating agent being selective for heavy metal removal. Moon et al also teach (see paragraph [0036] of machine translation) that iron ions were known to lead to membrane degradation. Thus, it would have been obvious to one of ordinary skill in the art at the time of filing to have ensured that iron was included among the heavy metals that the chelating agent removed.
Moon et al fail to teach the chelating agent comprising one or more carboxylic acid groups.
Han et al teach (see e.g. paragraph [0037]) that acetic acid containing chelating compounds, such as EDTA, were known in the prior art as being exceptionally good for chelating divalent iron ions.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have selected a chelating agent that contained one or more carboxylic acid groups, such as EDTA, as taught by Han et al because the EDTA was known to exhibit excellent chelation of iron.
Claims 6, 14, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Moon et al (WO 2022/181875) in view of Ashby et al (US 5,356,516) as applied to claims 1, 10, and 17, respectively, above, and further in view of Saniewski et al (“The Biological Activities of Troponoids and Their Use in Agriculture: A Review”).
Moon et al teach (see paragraph [0059] of machine translation) the chelating agent being selective for heavy metal removal. Moon et al also teach (see paragraph [0036] of machine translation) that iron ions were known to lead to membrane degradation. Thus, it would have been obvious to one of ordinary skill in the art at the time of filing to have ensured that iron was included among the heavy metals that the chelating agent removed.
Moon et al fail to teach the chelating agent comprising one or more carboxylic acid groups.
Saniewski et al teach (see abstract) that β-thujaplicin exhibited excellent properties for iron chelation.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have selected β-thujaplicin as the chelating agent of Moon et al because Saniewski et al teach that it was well established that β-thujaplicin possessed excellent ability for iron chelation.
Claims 7 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Moon et al (WO 2022/181875) in view of Ashby et al (US 5,356,516) as applied to claims 1 and 10, respectively, above, and further in view of Depree (US 3,882,018).
Moon et al and Ashby et al fail to teach the presence of a regeneration device structured to strip the heavy metal ions from the chelating agent.
In the field of ion removal from water, Depree teaches (see abstract, figure, col. 2, lines 7-50) that an adsorbent leaden with heavy metal ions may be subjected to regeneration to leach the heavy metal ions to permit reuse of the adsorbent.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have added a conventional regeneration device as taught by Depree to the system of Moon et al for the purpose of removing the chelated iron to permit the chelating agent to adsorb more iron without having to obtain fresh chelating agent.
Allowable Subject Matter
Claim 9 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: the prior art teaches the presence of the deionization subsystem for removing heavy metal ions, such as iron ions, from the water being utilized for PEM water electrolysis, see e.g. Moon et al. However, in the prior art the heavy metal ions were removed from the water at a location outside of the electrolysis cell before the water was provided to the cell. There was no teaching or suggestion in the prior art to provide the deionization subsystem including a chelating agent at a location within one of the catalyst layers adjacent the membrane of the electrolysis cell. The prior art recognized that the heavy metals may cause damage to the membrane which would have led one of ordinary skill in the art away from placing the deionization subsystem within the electrolysis cell, let alone in a layer adjacent to the membrane.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Arrathoon discusses (see col. 5) the need for removing metal ions by deionization from water being subjected to electrolysis to avoid damage to the membrane. Lapeyre and Young et al each discuss providing a deionization device to remove excess ions from recirculating water being subjected to electrolysis. .
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/HARRY D WILKINS III/Primary Examiner, Art Unit 1794