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 .
Response to Arguments
With respect to the rejection of Claims 27 and 33-37 under 35 U.S.C. 112(b), as understood the traversal relies on amendments. Claim 27 has been amended to replace “the steam turbine” with “a steam turbine”. Claim 33 has been amended to include the phrase “by weight” and to remove the phrase “preferably no more than 5% of carbon”. Claim 34 has been amended to replace the phrase “low steam to carbon ratio” with “a steam to carbon molar ratio of no more than 2.0”. Claim 35 has been amended to remove the phrase “a steam to carbon ratio of no more than 2.0”. Claim 36 has been amended to depend upon Claim 34 instead of Claim 22. Claim 34 provides the antecedent basis for the phrase “the carbon dioxide removed”. Accordingly these rejections have been WITHDRAWN.
With respect to the rejection of Claims 22-26, 32, and 38 under 35 U.S.C. 102(a)(1) as being anticipated by Inui et al., as understood the traversal relies on amendments. Applicant has amended Claim 22 (upon which Claims 23-26, 32, and 38 depend) has been amended to include subject matter from Claims 30-31 and 39. Applicant argues “Applicant respectfully submits claim 22 has been amended to at least partially include the subject matter of dependent claims 30, 31, 32 (in part), and 39. As acknowledged by the PTO, Inui does not disclose this subject matter. For at least the above reason(s), currently amended independent claim 22 is not anticipated by Inui.” [Remarks, Page 8, final Paragraph – Page 9, Paragraph 1]. This is persuasive. The rejection is WITHDRAWN.
With respect to the rejection of Claims 22, 29-31, 33, and 39 under 35 U.S.C. 103 as being unpatentable over HEI, as understood the traversal relies on amendments. Claim 22 (upon which Claims 29-31, 33, and 39 depend) has been amended to include subject matter from Claim 32. Applicant argues “the PTO has not demonstrated that HEI discloses "using the hydrogen-containing synthesis gas as a makeup gas for the synthesis of ammonia"” [Remarks Page 9, final Paragraph]. This is persuasive. The rejection is WITHDRAWN.
Applicant further argues “that one of ordinary skill in the art would consider HEI as a non-analogous reference with respect to the subject matter of amended claim 22 because this reference is unrelated to a process comprising the provision of a hydrogen- containing synthesis gas as a makeup gas for the synthesis of ammonia. In order for a reference to be proper for use in an obviousness rejection under 35 U.S.C. 103, the reference must be analogous art to the claimed subject matter. "A reference is analogous art to the claimed invention if. (1) the reference is from the same field of endeavor as the claimed invention (even if it addresses a different problem); or (2) the reference is reasonably pertinent to the problem faced by the inventor." MPEP 2141.01(a)(I). HEI relates to a process for the production of carbon dioxide in concentrated form from a hydrocarbon feedstock. Accordingly, HEI is not from the same field of endeavour as the subject matter of claim 22 and is not reasonably pertinent to the problem faced by the inventor.” [Remarks, Page 9, Paragraph 4]. This is unpersuasive. Firstly it is noted that summarizing HEI as being directly solely to the production of CO2 is overly narrow. The first paragraph of HEI reads “A process for the production of carbon dioxide in concentrated form and electricity from a hydrocarbon feedstock” [Abstract, emphasis added]. This electricity comes from burning hydrogen “combusting at least part of the hydrogen stream in a gas turbine wherein the gas turbine drives an electric generator thereby producing electricity and wherein combustion of the hydrogen stream generates an exhaust gas.” [0006]. Therefore it is understood that one of ordinary skill in the art would realize that the conversion of hydrocarbons to hydrogen is a necessary feature of HEI and it would belong to the field of recovering and using hydrogen derived from hydrocarbons, even if the end use of the hydrogen was different. Furthermore, the present invention relates to the enhanced hydrogen production via recovery of waste heat. Even if HEI was not in the same field of endeavor as the present invention (no such concession is given) they would still be considered analogous art because the teachings of HEI (regarding the enhanced hydrogen production via recovery of waste heat) are relevant to the problem addressed by the current invention.
Furthermore Applicant argues “Even assuming, arguendo, HEI discloses that a hydrogen stream may be used as fuel for a post-firing burner of a heat recovery unit of the power plant, Applicant respectfully submits such a disclosure is not the same as the subject matter of currently amended independent claim 22 because such definition does not clearly and unambiguously anticipate a post-firing of the exhaust gas performed by mixing the exhaust gas with a CO2- depleted hydrogen-containing gas generated in the process.” [Remarks, Page 10, Paragraph 1]. It is noted that Applicant is arguing against a 103 rejection by stating that it does not meet the requirements of a 102 rejection. Applicant fails to argue that the teachings of HEI do not render “a post-firing of the exhaust gas performed by mixing the exhaust gas with a CO2- depleted hydrogen-containing gas generated in the process” obvious. This is unpersuasive.
With respect to the rejection of Claim 36 under 35 U.S.C. 103 as being unpatentable over HEI in view of Gozalpour et al., Applicant does argue against the Gozalpour et al. reference specifically. Therefore it is understood that the arguments against HEI (see above) are believed to be sufficient for Claim 36. This is persuasive. The rejection is WITHDRAWN.
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.
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) 22-27, 29, 32-33, and 38 is/are rejected under 35 U.S.C. 103 as being unpatentable over EP 2233433 A1 Hydrogen Energy International Limited Weybridge, herein after referred to as HEI in view of US 2005176831 A1 Inui et al. Claim 22 requires “A process, comprising: reforming a hydrocarbon-containing gas to obtain a hydrogen-containing synthesis gas”. HEI discloses “(a) introducing to an autothermal reactor an oxidant feed stream comprising oxygen or enriched air comprising at least 25 mol % oxygen (on a dry basis) and optionally steam and a fuel feed stream comprising methane and optionally hydrogen and/or steam to an autothermal reactor unit (ATR) for the production of synthesis gas … (b) withdrawing a synthesis gas stream comprising methane, hydrogen, carbon monoxide, carbon dioxide, steam and optionally nitrogen from the ATR” [0006].
Claim 22 further requires “producing mechanical power with a gas turbine engine”. HEI discloses “combusting at least part of the hydrogen stream in a gas turbine wherein the gas turbine drives an electric generator” [0006]. Driving an electric generator requires mechanical power.
Claim 22 further requires “preheating at least one process stream of the reforming process, wherein: a heat source of the preheating includes exhaust gas of the gas turbine engine”. HEI discloses as a non-preferred embodiment using exhaust gas heat for the preheating “the present invention does not exclude boosting the temperature of the pre-reformer feed stream by heat exchange with the gas turbine exhaust.” [0027].
Claim 22 further requires “the preheating includes a heat transfer from the exhaust gas to the process stream and the heat transfer is performed in an indirect heat exchanger wherein the exhaust gas and the process stream do not mix”. HEI discloses “The pre-reformer feed stream 8 is heated to a temperature of at least 560°C against stream 23 (described below) in heat exchanger 23a.”. It is noted that stream 23 is the synthesis gas stream, as in the preferred embodiment of HEI, however if the non-preferred embodiment using the exhaust stream was used It would have been obvious to use the same heat exchanger because the intended use (to exchange heat) would be the same. Furthermore HEI does not explicitly disclose that the heat exchanger does not allow the streams to mix, however one of ordinary skill in the art would know that in the conventional use of a heat exchanger fluids remain separated.
Claim 22 further requires “wherein the step of preheating at least one process stream of the reforming process includes at least a) preheating a hydrocarbon-containing gas prior to reforming of the hydrocarbon-containing gas in a reformer including an autothermal reformer (ATR)” HEI discloses “It is therefore preferred that the pre-reformer feed stream (mixture of desulfurised natural gas feedstock and steam) that is passed into the pre-reformer is heated to a temperature in the range 400 to 650°C, more preferably 500 to 600°C so that the fuel feed stream that exits the pre-reformer is within the preferred temperature range of 400 to 570°C.” [0027]. It is noted that preheating the hydrocarbons prior to the pre-reformer also includes preheating hydrocarbons prior to the reformer because pre-reforming is performed before reforming.
Claim 22 further requires “said process further including: using the hydrogen-containing synthesis gas as a makeup gas for the synthesis of ammonia”. HEI does not disclose ammonia synthesis.
Claim 22 further requires “firing the gas turbine engine with a fuel gas including a CO2-depleted hydrogen-containing gas generated in the process, optionally mixed with natural gas”. HEI discloses “(e) passing the shift converted gas stream to a carbon dioxide separation unit for the separation of a concentrated carbon dioxide stream from a hydrogen stream comprising hydrogen and optionally nitrogen; (f) combusting at least part of the hydrogen stream in a gas turbine” [0006].
Claim 22 further requires “and post-firing of the exhaust gas prior to one or more pre-heating process, the post-firing being performed by mixing the exhaust gas with a CO2-depleted hydrogen-containing gas generated in the process.”. HEI discloses post firing of the exhaust gas with hydrogen from the process “Suitably, the various process streams are heat exchanged with the exhaust gas in a heat recovery unit that is arranged downstream of the gas turbine. Optionally, the temperature of the exhaust gas of the gas turbine is increased by providing the heat recovery unit with a post-firing system, for example, a post-firing burner. Suitably, the post-firing burner is fed with a portion of the hydrogen stream produced in step (e) and the hydrogen is combusted in the burner using residual oxygen contained in the exhaust gas.” [0049]. It is noted that step (e) is a CO2 removal process (“(e) passing the shift converted gas stream to a carbon dioxide separation unit for the separation of a concentrated carbon dioxide stream from a hydrogen stream comprising hydrogen and optionally nitrogen” [0006]) and is therefore a CO2-depleted hydrogen-containing gas. Furthermore HEI does not explicitly disclose that the post firing of the exhaust gas is prior to the preheating processes however this would have been obvious to one of ordinary skill in the art because otherwise the heat energy is wasted.
Regarding the limitations not taught by HEI, namely using the hydrogen as a make-up gas for ammonia synthesis, Inui et al. is similarly directed to methods of enhancing the hydrogen yield of hydrocarbon reforming to syngas by recovering waste heat. Inui et al. discloses producing hydrogen and ammonia “a steam reforming system equipped with a pre-reformer, which is used for a plant producing hydrogen, ammonia, methanol, etc.” [0018].
It would have been obvious to one of ordinary skill in the art to have combined the method of HEI with the method of Inui et al. because they are both related to solving the same problem: enhanced recovery of hydrogen from hydrocarbons by utilizing waste heat.
The motivation to use the hydrogen formed to synthesizing ammonia (as per Inui et al.) instead of to generate electric power (as per HEI) could be one of economics. If renewable power sources caused local electricity prices to fall it would be obvious to put the hydrogen to more profitable alternative uses already known in the art, such as ammonia synthesis. Doing so represents a combining prior art elements according to known methods to yield predictable results.
Regarding Claim 23, HEI in view of Inui et al. teach all of the limitations of Claim 22. Claim 23 further requires “wherein the gas turbine engine operates with a simple cycle where no heat from the exhaust gas of the gas turbine engine is used in a heat recovery steam generator to produce steam for a steam turbine.”. HEI discloses “optionally, any steam generated in steps (b) and/or (d) may be supplied to a steam turbine that drives an electric generator thereby producing additional electricity. The steam generated in steps (b) and/or (d) may also be used to drive mechanical process equipment such as pumps and/or compressors, to heat the fuel feed stream, to provide energy for the carbon dioxide separation unit, to provide energy to dehydrate the concentrated carbon dioxide stream, or the steam may be exported to an external process duty. These uses may be as an alternative or, in addition, to using the steam to generate electricity.” [0008]. In other words, HEI presents multiple embodiments of their invention, including at least one wherein no steam is sent to a steam turbine.
Regarding Claim 24, HEI in view of Inui et al. teach all of the limitations of Claim 22. Claim 24 further requires “wherein the heat exhaust gas traverses a first side of the indirect heat exchanger and the process fluid traverses a second side of the heat exchanger, and heat is transferred from the exhaust gas to the process fluid while they traverse the first side and second side of the heat exchangers.”. HEI discloses “Combustion of the hydrogen stream in the gas turbine in step (f) generates an exhaust gas. Optionally, the exhaust gas from the gas turbine may be heat exchanged with the steam produced in step (b) … The superheated steam that is generated by heat exchange with the exhaust gas may be used for one or more purposes including … using the steam to heat the fuel feed stream” [0061]. HEI does not explicitly disclose a first side and a second side of a heat exchanger, however one of ordinary skill in the art being familiar with heat exchangers, would understand that this is the conventional operation of a heat exchanger. Therefore a first and second side of the heat exchanger is considered implicitly disclosed.
Regarding Claim 25, HEI in view of Inui et al. teach all of the limitations of Claim 22. Claim 25 further requires “wherein: the step of preheating at least one process stream of the reforming process further includes at least one of: b) preheating a hydrocarbon-containing gas prior to pre-reforming of the hydrocarbon-containing gas in a pre-reformer; or c) preheating a hydrocarbon-containing gas directed to a reforming process prior to removal of sulphur from the hydrocarbon-containing gas”. HEI discloses step b) “the present invention does not exclude boosting the temperature of the pre-reformer feed stream by heat exchange with the gas turbine exhaust.” [0027].
Claim 25 further requires “exhaust gas from the gas turbine engine transfers heat to preheating processes according to two or more of the options a) to c); or in a sequence according to the order a) to c), so that the exhaust gas effluent of one preheating process of the sequence is used as heat source for the subsequent process of the sequence, in accordance with the order.” HEI discloses step a) (see Claim 22) and step b) (see above) which is two or more of the options a) to c).
Regarding Claim 26, HEI in view of Inui et al. teach all of the limitations of Claims 22 and 25. Claim 26 further requires “a first preheating process according to option a) wherein exhaust gas from the gas turbine engine transfers heat to a hydrocarbon gas prior to reforming;”. “In the heat recovery exchanger 6, the feed preheater 9 and the feed heaters 10, 11 perform heat exchange between the GT flue gases and feedstocks supplied to the reformer” [0022]. The numbers reference Figure 1, reproduced below, the relevant section of the figure (heat recovery unit) has been highlighted.
Claim 26 further requires “a second preheating process according to option b) wherein exhaust gas cooled after the first preheating process transfers heat to a hydrocarbon gas prior to a pre- reforming”. In Figure 1 (below) it can be seen that the gasses pre-heat stream 10 which flows into pre-reformer 12, meeting the requirements of option b).
Claim 26 further requires “a third preheating process according to step c) wherein exhaust gas further cooled after the second preheating process transfers heat to a hydrocarbon gas prior to a desulphurization process.”. Inui et al. discloses heat transfer prior to desulfurization in stream 9, which flows into desulfurization column 3 as seen in Figure 1 (below). Regarding the order of this process it can be seen from Figure 1 (above) that flue gas enters from the left, flows past stream 11 first, then stream 10, then stream 9, then further streams making use of heat before exiting to the right to be vented.
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Regarding Claim 27, HEI in view of Inui et al. teach all of the limitations of Claim 26. Claim 27 further requires “the full amount of heat transferred to the hydrocarbon gas in each of the preheating processes according to a), b) and c) is provided by the exhaust gas of a steam turbine.”. Inui et al. discloses the full amount of heat transferred to the hydrocarbon gas in each of the preheating processes according to a), b) and c) is provided by the exhaust gas of a gas turbine (see Claim 26). Inui et al. does not disclose a steam turbine, however it would have obvious to substitute the steam turbine of HEI for the gas turbine of Inui et al. Doing so represents a simple substitution of one known element (gas turbine) for another (steam turbine) to obtain predictable results (electrical power).
Regarding Claim 29, HEI in view of Inui et al. teach all of the limitations of Claims 22 and 25. Claim 29 further requires “steam superheating with exhaust gas as heat source, the steam superheating being performed first in the sequence.”. HEI discloses using exhaust gas to superheat steam “Optionally, the exhaust gas from the gas turbine may be heat exchanged with the steam produced in step (b) and/or with any steam produced in step (d) for the production of superheated steam.” [0009]. It is noted that step (b) of HEI is the first step that requires heat exchanging which is understood as implicitly disclosing performing the heat exchange on steam first.
Regarding Claim 32, HEI in view of Inui et al. teach all of the limitations of Claim 22. Claim further requires “wherein said hydrogen-containing gas is used as a makeup gas for the synthesis of ammonia after addition of nitrogen.”. Inui et al. discloses producing hydrogen and ammonia (see Claim 22). Inui et al. does not disclose the limitation of adding nitrogen, however one of ordinary skill in the art would recognize nitrogen as a necessary ingredient in the synthesis of ammonia, making the use of nitrogen gas obvious.
Regarding Claim 33, HEI in view of Inui et al. teach all of the limitations of Claim 22. Claim 33 further requires “a post- firing of exhaust gas of the gas turbine engine wherein the fuel of the gas turbine engine and the fuel used to post-fire the exhaust gas is a hydrogen-containing gas produced internally in the process and contain no more than 10% by weight of carbon”. HEI discloses post firing of the exhaust gas with CO2 depleted hydrogen gas (see Claim 22). Regarding the wt. % of CO2, HEI discloses leaving only trace CO2 remaining “Typically, the hydrogen gas stream may comprise trace amount of carbon oxides (CO and CO2) and methane, for example, less than 500 ppm on a molar basis.” [0041]. It is noted that 500 ppm is equivalent to 0.05%. While HEI does not disclose if ppm is on a weight basis or mole basis a gas mixture that is essentially H2 with 500 ppm (mol basis) CO2 would be only 1.1 wt. % ((0.0005 mol CO2 * 44 g/mol CO2 )/(0.9995 mol H2 * 2 g/mol H2 + 0.0005 mol CO2 * 44 g/mol CO2)*100% = 1.1 %). Any further impurities (N2, H2O, etc.) would only increase the mass of the gas, further reducing the CO2 wt. %.
Regarding Claim 38, HEI in view of Inui et al. teach all of the limitations of Claim 22. Claim 38 further requires “producing electrical energy with a generator coupled to the gas turbine engine”. HEI discloses “combusting at least part of the hydrogen stream in a gas turbine wherein the gas turbine drives an electric generator” [0006].
Potentially Allowable Subject Matter
Claims 28 and 34-37 are 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 closest prior art to Claim 28 is given by HEI in view of Inui et al. by virtue of teaching Claim 27 from which Claim 28 depends (see above). Claim 28 requires “a process of pre- heating of a boiler feed water which is in parallel to the third preheating process of option c)”. Inui et al. teaches a preheating of boiler feed water parallel to the third heating process of option c) in Figure 3 (see below)
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Where heat exchanger 11, 10, and 9 correspond to options a, b, and c (respectively) and heat exchanger 13 is a boiler feed. It can be seen that exhaust gas travels from turbine 7 and splits into parallel streams 31 and 34 to feed two parallel heat recovery units.
Claim 28 further requires “and wherein the exhaust gas from the second pre-heating process of option b) is split between the third pre-heating process and the parallel pre-heating of boiler feed water.”. Inui et al. does not disclose splitting the exhaust gas after heat exchanger 10 to be split between heat exchanger 9 and 16, 15, and 13 but rather recombining the parallel streams after steam has been superheated (heat exchanger 16). Furthermore Inui et al. does not motivate an alternative embodiment wherein the streams are split according to Claim 28.
The closest prior art to Claim 34 is given by HEI in view of Inui et al. by virtue of teaching Claim 22 from which Claim 34 depends (see above). Regarding Claim 34, HEI in view of Inui et al. teach all of the limitations of Claim 22. Claim 34 further requires “reforming is performed by pure autothermal reforming with low a steam to carbon molar ratio of no more than 2.0”. HEI discloses “Preferably, the molar ratio of steam to carbon (in hydrocarbons) in the fuel feed stream is within the range of 0:1 to 3:1, preferably, 0.3:1 to 3:1, in particular 0.5:1 to 2.0:1.” [0013].
Claim 34 further requires “possibly with pre-reforming in an adiabatic reactor, but without a previous primary reforming in a furnace with a radiant section including tubes filled with catalyst”. HEI is silent towards primary reforming and therefore it is understood that they implicitly disclose no primary reforming.
Claim 34 further requires “superheated steam is generated by cooling the hot effluent of the autothermal reforming, prior to removal of carbon dioxide”. HEI discloses forming superheated steam in step b “(b) withdrawing a synthesis gas stream comprising methane, hydrogen, carbon monoxide, carbon dioxide, steam and optionally nitrogen from the ATR and heat exchanging the synthesis gas stream with at least one process stream selected from the group consisting of … and steam for the production of superheated steam” [0006] and removing CO2 in step e “(e) passing the shift converted gas stream to a carbon dioxide separation unit” [0006].
Claim 34 further requires “after removal of carbon dioxide the reformed gas is further purified by cryogenic condensation and removal of methane followed by liquid nitrogen wash to remove inerts”. Neither HEI nor Inui et al. disclose further purification of the exhaust gasses by cryogenic condensation. Inui et al. is silent towards cryogenic condensation and HEI mentions cryogenic purification as a means of CO2 separation but does not motivate further use of cryogenic separation.
Claims 35-37 depend upon Claim 34 and would be allowable for similar reasons.
As potentially allowable subject matter has been indicated, applicant's reply must either comply with all formal requirements or specifically traverse each requirement not complied with. See 37 CFR 1.111(b) and MPEP § 707.07(a).
Conclusion
Applicant's amendment necessitated the/any new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
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/JOSHUA MAXWELL SPEER/
Examiner
Art Unit 1736
/DANIEL BERNS/Primary Examiner, Art Unit 1736