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 .
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 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 1-10 and 21-27 are rejected under 35 U.S.C. 103 as being unpatentable over CN 113896168B in view of Kordesch et al (US 6,936,363). CN 113896168B discloses a method for preparing hydrogen by cracking ammonia wherein the heat sources required for the ammonia cracking reaction is provided by het exchange of a second-stage high-temperature ammonia cracking reaction gas. (See Paragraph [0037] of the English translation.) CN 113896168B teaches in Paragraphs [0014] and [0015] that both the first and second cracking reactors are filled with catalyst, and in Paragraph [0016] that the ammonia cracking reaction in the first stage is carried out with a fuel and oxygen, and the cracking for the second stage is provided by electric heating. CN 113896168B further teaches in Paragraph [0020] that the reducing gas (cracked gas) is cooled to normal temperature by a cooler and then enters a PSA hydrogen extraction system to prepare product hydrogen, and that the fuel for the first stage of ammonia cracking can be tail gas after the PSA extracts the hydrogen. The differences between the process disclosed by CN 113896168B, and that recited in applicant’s claims, is that CN 113896168B does not disclose that the first stage reaction is carried out in tubes, and that there is more volume of the second catalyst used in the electrically heated reactor as compared to a volume of the first catalyst used in the fired reactor. Kordesch et al disclose an ammonia cracker for hydrogen production wherein the cracking takes place in burner tubes (see FIG. 2 and the description thereof),, and teaches at col. 3, lines 9-14 that product gas from the ammonia cracker is used as fuel for fuel cell (6) and that off-gas from the hydrogen electrode (6b) is fed to the heating unit (5) of the ammonia cracker, which may a lean gas combustor or a catalytic burner. It would have been obvious from Kordesch et al to carry out the first stage ammonia cracking step of CN 113896168B in tubes. One of ordinary skill in the art would have been motivated to do so, since the processes of CN 113896168B and Kordesch et al are analogous in that both are directed to ammonia cracking, and both employ offgas from a subsequent reaction as fuel in the ammonia cracker. It would have been further obvious to provide more volume of the second catalyst used in the electrically heated reactor as compared to a volume of the first catalyst used in the fired reactor. One of ordinary skill in the art would have been motivated to do so, since it would be a matter of routine process design to determine suitable amounts of the first and second catalyst.
Regarding claims 2 and 3, CN 113896168B teaches in Paragraph [0007] that a heat source required by the second section of high temperature ammonia cracking reaction can be provided by electric externa heating or other fuel combustion external heating and oxygen combustion self-heating. It would be obvious from such disclosure of CN 113896168B to heat the partially cracked ammonia gas by heat exchange by heat exchange with the cracked gas, since CN 113896168B also discloses in Paragraph [0007] that the second stage high-temperature ammonia cracking gas enters the heat exchange gasification system.
Regarding claim 4, CN 113896168B discloses in Paragraph [0037] that a partial ammonia cracking reaction occurs in the first stage. It would be obvious from such disclosure to provide to provide a partially cracked ammonia gas having a mole fraction of ammonia in a range from about 10 mol % to about 90 mol %, since one would expect that any degree of partial cracking would be suitable.
Regarding claim 5, it would be obvious to provide a cracked gas having a mole fraction of ammonia in a range from 0.1 mol. % to about 5 mol. 5% in the process of CN 113896168B, since the purpose of the process of CN 113896168B is to form hydrogen from the cracked ammonia which would suggest that a high degree of cracking would be desirable to form more hydrogen.
Regarding claims 6 and 7, CN 113896168B teaches in Paragraph [0037] that partial cracking of the ammonia takes place in the first stage and the residual ammonia cracking is carried out with electric heating. It would be obvious to provide from about 20 % to about 80 % of the energy required for the process in the fired reactor, depending on the relative costs of combustion heating versus electric heating.
Regarding claim 9, it is clear from FIG.2 of Kordesch et al that a plurality of reaction tubes are employed for the cracking, and CN 113896168B discloses in Paragraph [0051] that the ammonia cracking for the second stage occurs in a catalyst tube array.
Regarding claim 10, Kordesch et al disclose in FIG.1 and the description thereof that part of the lean gas is sent to ammonia cracker 3 before being sent to ammonia cracker 4 via line 3b.
Regarding claims 21-23, it would be within the level of skill of one of ordinary skill in the art to determine a suitable mole fraction of ammonia in the cracked gas.
Regarding claims 24 and 25, it would be within the level of skill of one of ordinary skill in the art to determine suitable relative amounts of the first and second catalysts.
Regarding claims 26 and 27, it would be a matter of routine design choice as to the types of catalysts to use as the first and second catalysts.
Response to Arguments
Applicant’s argument, that the written opinion of the International Searching Authority for the child PCT application found that CN 113896168B fails to disclose a fired reactor followed by an electrically heated reactor, is not convincing, since the issue is whether or not it would have been obvious from Kordesch et al to provide a fired reactor to carry out the first stage cracking step in CN 113896168B.
Applicant’s argument, that claim 5 requires the cracked gas output from the electrically heated reactor to have a mole fraction of ammonia in a range from 0.1 mol. % to about 5 mol.%, is not convincing. It would haven obvious to provide partial cracking of the ammonia from the electrically heated reactor of CN 113896168B, since CN 113896168B describes the high energy consumption for ammonia cracking to produce hydrogen, in Paragraph[0003].
Applicant’s argument, that claim 6 requires about 30% to about 35% of the energy required in the process to crack the heated ammonia gas be provided by the combustion of the offgas, or of the cracked gas derived therefrom, in the fired reactor, is not convincing. CN 113896168B teaches in Paragraph [0020] that the heat source for the second-stage high-temperature ammonia cracking step can be provided by oxygen combustion self-heating. It would have been a matter of routine process design to determine the degree to which such combustion provides the energy for the process.
Applicant’s argument regarding claims 22 and 23, that there is no teaching or suggestion in the prior art of the recited ammonia contents, is not convincing It would haven obvious to provide partial cracking of the ammonia from the electrically heated reactor of CN 113896168B, since CN 113896168B describes the high energy consumption for ammonia cracking to produce hydrogen, in Paragraph [0003].
Applicant’s argument, that the catalyst volume requirements recited in claims 24 and 25 are not disclosed or suggested in the prior art, is not convincing, since it would be a matter of routine process design to determine suitable volumes of catalyst for the first and second catalysts in the process of CN 113896168B.
Claims 28 and 29 are objected to as based on a rejected parent claim, and would be allowed if written in in dependent form.
The following is a statement of reasons for the indication of allowable subject matter: CN 113896168B discloses a method for preparing hydrogen by cracking ammonia wherein the heat sources required for the ammonia cracking reaction is provided by het exchange of a second-stage high-temperature ammonia cracking reaction gas. (See Paragraph [0037] of the English translation.) CN 113896168B teaches in Paragraphs [0014] and [0015] that both the first and second cracking reactors are filled with catalyst, and in Paragraph [0016] that the ammonia cracking reaction in the first stage is carried out with a fuel and oxygen, and the cracking for the second stage is provided by electric heating. CN 113896168B further teaches in Paragraph [0020] that the reducing gas (cracked gas) is cooled to normal temperature by a cooler and then enters a PSA hydrogen extraction system to prepare product hydrogen, and that the fuel for the first stage of ammonia cracking can be tail gas after the PSA extracts the hydrogen. Kordesch et al disclose an ammonia cracker for hydrogen production wherein the cracking takes place in burner tubes (see FIG. 2 and the description thereof),, and teaches at col. 3, lines 9-14 that product gas from the ammonia cracker is used as fuel for fuel cell (6) and that off-gas from the hydrogen electrode (6b) is fed to the heating unit (5) of the ammonia cracker, which may a lean gas combustor or a catalytic burner. It would have been obvious from Kordesch et al to carry out the first stage ammonia cracking step of CN 113896168B in tubes. One of ordinary skill in the art would have been motivated to do so, since the processes of CN 113896168B and Kordesch et al are analogous in that both are directed to ammonia cracking, and both employ offgas from a subsequent reaction as fuel in the ammonia cracker. It would have been further obvious to provide more volume of the second catalyst used in the electrically heated reactor as compared to a volume of the first catalyst used in the fired reactor. One of ordinary skill in the art would have been motivated to do so, since it would be a matter of routine process design to determine suitable amounts of the first and second catalysts. However there is no teaching, disclosure or suggestion in either CN 113896168B or Kordesch et al to operate the electrically heated reactor via electricity having a carbon dioxide intensity of no more than 230 (or 200) grams carbon dioxide per kWh, as required by claims 28 and 29. Nor would there have been any motivation from the prior art to do so. Applicant’s specification states in Paragraph [0068] that the inventors have determined that for an electrical cracker to have a lower carbon intensity than a cracker using natural gas as the fuel, the electricity must have a carbon dioxide intensity of no more than about 230 gCO2/kWh. Accordingly claims 28 and 29 are not rejected over CN 113896168B in view of Kordesch et al.
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Wall, II (US 11,840,449) is made of record for disclosing a method for cracking ammonia including an electric cracking unit.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to WAYNE A LANGEL whose telephone number is (571) 272-1353. The examiner can normally be reached Monday through Friday from 8:15 am to 4:15 pm.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Anthony Zimmer can be reached at 571-270-3591. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/WAYNE A LANGEL/Primary Examiner, Art Unit 1736
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