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 § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 19-44 rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 19 is indefinite due to internally inconsistent step designations. The claim recites steps (a)–(h), followed by a step labeled “1.” and a step labeled “J.”, while later referring to “step (i).” These inconsistencies create ambiguity as to the claimed steps and their sequence.
Claim 21 recites that the separated portion of make-up gas is a “minor portion,” which is a term of degree lacking an objective boundary in the claim. Claim 21 does not define “minor,” nor does it specify a quantitative standard by which the scope of the claim can be determined. Accordingly, the claim fails to particularly point out and distinctly claim the subject matter regarded as the invention.
Claim 23 is rejected for improper dependency and lack of antecedent basis. Claim 23 depends from claim 20, which does not recite a separated portion of make-up gas. Claim 23 nevertheless limits “said separated portion of make-up gas,” rendering the scope of the claim unclear.
Claims 19 and 40 recite “obtaining an adjusted make-up gas with an adjusted content of hydrogen.” The term “adjusted” is relative and does not specify a target hydrogen concentration, ratio, or other objective endpoint. The absence of a clear standard renders the scope of the claims uncertain.
Claims 19, 24, 40 rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
The claims recite separating a portion of the make-up gas during cooling and before cooling is completed, such that the separated portion is at a higher temperature than the main stream, followed by water-gas shift conversion of the separated portion and subsequent hydrogen recovery. The claims further recite specific structural and process integration, including separation from an intermediate location of a cooling section comprising a plurality of heat exchangers arranged in series (claim 24; claim 40).
The specification describes methanol production, reforming, gas cooling, water-gas shift, and hydrogen recovery in general terms. However, the specification does not reasonably convey that the inventors were in possession of the specific intermediate separation configuration now claimed, namely: a defined separation of make-up gas during cooling and before completion of cooling; a requirement that the separated stream is thermally hotter than the main stream; a cooling section explicitly comprising multiple heat exchangers in series with separation after passage through at least one exchanger.
The disclosure does not identify: specific take-off locations, temperature relationships or ranges at the separation point, or structural configurations enabling such intermediate separation across the full scope of the claims.
Accordingly, the specification fails to demonstrate possession of the claimed intermediate separation architecture, and the claims exceed the written description support of the application as filed.
Claims 19, 21–23, 27–31, 36–38 and 40 rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
Claims 19 and 40 are rejected under 35 U.S.C. §112(a) for lack of enablement, because the specification does not enable the full scope of the claimed integrated process and plant without undue experimentation, as evaluated under the Wands factors.
(1) Breadth of the claims
The claims broadly encompass: separating an undefined portion of make-up gas during cooling, subjecting the separated portion to one or more water-gas shift steps,
recovering hydrogen in a first hydrogen recovery section, recombining hydrogen streams from two different recovery sections, and recycling a methane-containing tail gas to reforming.
These steps are recited without limitation as to gas composition, flow rates, temperature ranges at separation, or hydrogen recovery efficiency.
(2) Nature of the invention
The invention involves highly integrated chemical process operations, including reforming, staged cooling, water-gas shift chemistry, hydrogen separation, methanol synthesis, purge handling, and recycle control. Such systems are sensitive to gas composition, temperature, pressure, and flow balance.
(3) State of the prior art
While individual elements such as reforming, water-gas shift, hydrogen recovery, and methanol synthesis were known, the specific integration claimed—particularly the interaction between intermediate cooling separation, dual hydrogen recovery sections, and tail-gas recycle—is not shown to be routine or straightforward from the disclosure.
(4) Level of skill in the art
A person of ordinary skill in the art would be highly skilled in chemical process engineering. However, even with such skill, implementing the claimed system would require detailed guidance to avoid instability in reformer operation, hydrogen imbalance, or degradation of methanol synthesis performance.
(5) Amount of direction or guidance in the specification
The specification lacks sufficient guidance regarding: selection of the separation point during cooling, acceptable temperature and composition ranges of the separated stream, operating conditions for water-gas shift of partially cooled make-up gas,
coordination between first and second hydrogen recovery sections, limits on methane recycle to reforming. No working examples or detailed embodiments demonstrate how these variables are controlled in combination.
(6) Presence or absence of working examples
The specification does not provide a working example illustrating: intermediate separation during cooling, subsequent water-gas shift and hydrogen recovery,
recombination of hydrogen streams, and stable operation of the reforming and methanol synthesis sections.
(7) Quantity of experimentation required
In view of the breadth of the claims and the lack of specific guidance, a person of ordinary skill in the art would be required to engage in substantial trial-and-error experimentation to determine workable separation points, operating conditions, and recycle ratios to practice the claimed invention across its full scope.
(8) Predictability of the art
Chemical process integration involving multiple recycle streams and reaction equilibria is not fully predictable, particularly where reforming, water-gas shift, and methanol synthesis are thermally and compositionally coupled.
Considering the Wands factors as a whole, the specification does not enable the full scope of claims 19 and 40 without undue experimentation. Accordingly, these claims fail to comply with the enablement requirement of 35 U.S.C. §112(a).
Claims 21–23, 27–31, 36–38
Claims 21–23, 27–31, and 36–38 are rejected under 35 U.S.C. §112(a) for lack of enablement to the extent they recite: specific volumetric flow percentages for the separated portion, steam-to-carbon ratios, pressure ranges, and integration with air separation unit operation using recovered steam, without corresponding disclosure explaining how these parameters are selected, controlled, or coordinated with the claimed intermediate separation, water-gas shift, and dual hydrogen recovery architecture.
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.
Claim(s) 19-44 is/are rejected under 35 U.S.C. 103 as being unpatentable over GB 2 585 477 (hereafter GB’477) in view of Stuckert et al. (US Pub. 2014/0323597, hereafter USPub’597), and further in view of Hansen et al. (US 2017/0197894, hereafter USPub’894), Fuchs et al. (US Pat. 4,226,795, hereafter US”795), Muller et al. (US Pat. 8,623,926, hereafter US’926), Weiss et al. (US Pat. 4,744,869869), and Rostrup-Nielsen et al. (US Pat. 7,470,811), as evidence of conventional features.
GB’477 discloses a methanol production process comprising reforming a hydrocarbon feedstock to produce a make-up synthesis gas, cooling the make-up gas, feeding the make-up gas to a methanol synthesis loop under methanol synthesis conditions, withdrawing a purge stream from the loop, recovering hydrogen from the purge stream, recycling the recovered hydrogen to the make-up gas, purifying crude methanol in a distillation section, and recycling a methane-containing tail gas to the reforming section.
USPUB’597 teaches that methanol synthesis efficiency is improved by conditioning synthesis gas to achieve a desired hydrogen/carbon oxide stoichiometry, including adjusting hydrogen content of synthesis gas streams produced in the reforming section prior to methanol synthesis.
Claim 19 differs from GB’477 in that a portion of the make-up gas is separated during cooling, subjected to water-gas shift conversion, hydrogen is recovered from the shifted gas, and the recovered hydrogen is recombined with the main make-up gas to obtain an adjusted make-up gas.
A person of ordinary skill in the art, starting from GB’477 and faced with the problem of operating the methanol synthesis loop efficiently when the make-up gas has sub-stoichiometric hydrogen content, would have been motivated by USPUB’597to condition a portion of the synthesis gas to increase hydrogen availability and to recombine recovered hydrogen with the make-up gas in order to achieve a desired stoichiometric balance. The combination represents the predictable use of known synthesis-gas conditioning techniques to improve methanol synthesis performance.
Claim 40 recites a plant comprising structural elements corresponding to the process steps of claim 19. For the same reasons set forth above, the subject matter of claim 40 would likewise have been obvious over GB’477 in view of USPUB’597.
The additional limitations recited in the dependent claims represent well-known and conventional options in methanol production and synthesis-gas processing, as evidenced by the following U.S. patents:
Hydrogen recovery from purge gas and recycle to synthesis gas:
US Pub 2017/0197894 teaches withdrawing purge gas from a synthesis section, conditioning the gas, recovering hydrogen, and returning hydrogen to improve synthesis gas composition.
Pressure swing adsorption (PSA) for hydrogen recovery (claims 32, 42):
US Pat. 4,226,795 teaches the use of PSA units to recover hydrogen from purge gases in methanol synthesis processes.
Membrane-based hydrogen recovery (claims 33, 42):
US Pat. 8,623,926 teaches hydrogen-selective membrane separation for hydrogen recovery in methanol production systems.
Methanol purification using multi-column distillation, including topping columns (claims 20, 39, 41, 43):
US Pat. 4,744,869 teaches purification of crude methanol using multiple distillation columns, including a topping column for removal of volatile components, followed by refining columns.
Autothermal reforming and pre-reforming as front-end options (claims 25–30, 42):
US Pat. 7,470,811 teaches integrated reforming systems for methanol production including autothermal reforming and optional pre-reforming stages, with conventional operating ranges of temperature, pressure, and steam-to-carbon ratio.
The selection and combination of these features involve routine design choices and optimization within the level of ordinary skill in the art and do not result in any unexpected technical effect when applied to the process and plant of GB’477 as modified by USPUB’597.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DEBORAH D CARR whose telephone number is (571)272-0637. The examiner can normally be reached Monday-Friday (10:30 am -6:30 pm).
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/DEBORAH D CARR/ Primary Examiner, Art Unit 1691