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 Objections
Claim 6 is objected to because of the following informalities: In lines 4-5, Applicant claims “maintained at a different temperature for 1)”. The term “for 1)” appears to be a typographical error and should not be there and will be examined as such. Appropriate correction is required.
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 6, 9 and 10 are 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 6 recites the limitation "the heat recovery unit" in line 11. There is insufficient antecedent basis for this limitation in the claim. As best understood, it appears that Applicant intended for this to recite “the heat recovery system” and will be examined as such.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 6, 9 and 10 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Sakurai (US 2017/0096333).
Regarding claim 6, Sakurai discloses a system for heating a feed of natural gas, used as feed for a steam reformer (14) of an ammonia production system (46) (this limitation is directed toward an intended use of the claimed system and does not further limit the apparatus, see MPEP §2111.02), comprising:
a heat recovery system for recovering heat (such as heat exchangers 12, 89, 84, 20), comprising an inlet and an outlet and at least two heating coils (see Fig. 12 which illustrates and inlet and outlet for each of these heat exchangers) maintained at a different temperature (this limitation does not further define the claimed apparatus as it is directed to an operational limitation and Sakurai is capable of operating the heat exchangers at different temperatures), thereby providing a heated feed of natural gas (such as in lines L13-4, L11, and the exit of desulfurizer 13);
a steaming unit, comprising an inlet in fluid communication with the heated feed of natural gas and an outlet (where steam 24 and natural gas out of heat exchanger 84 are combined just upstream of reformer 14); and
a steam reformer (14), comprising an inlet for the heated feed of natural gas in fluid communication with the heated feed of natural gas (see inlet of reformer 14 in Fig. 12 which is in communication with the natural gas stream of L13-4, for example), and an outlet for a flue gas (flue gas comes out of the top of reformer 14 in Fig. 12 and is labeled as L12);
wherein the heat recovery unit is positioned upstream the steaming unit (see Fig. 12 where steaming unit, as mentioned above, is downstream of heat recovery unit 84);
the system being characterized in that:
the flue gas outlet of the steam reformer is in fluid communication with the heating coils of the heat recovery system (see Fig. 12 where the outlet of the reformer, L12, is in fluid communication with the heat exchanger 84), such that heat is recovered from the flue gas produced in the steam reformer (heat is transferred to the natural gas stream) and;
a first heating coil (such as heating coil 12) is configured for heating the feed of natural gas (as is illustrated in Fig. 12 where natural gas feed is fed into heat exchanger 12) from a temperature ranging from 10° C. to 40° C to a temperature ranging from 180° C. to 210° C, thereby providing a pre-heated feed of natural gas (at the exit of heat exchanger 12), and a second heating coil is configured for heating the pre-heated feed of natural gas from a temperature ranging from 180° C. to 210° C. to a temperature ranging from 360° C. to 380° C., thereby providing a heated feed of natural gas (such as second heating coil/heat exchanger 84 which further heats the pre-heated natural gas from heat exchanger 12), and the first heating coil is located upstream the second heating coil (see Fig. 12 where heat exchanger 12 is upstream of heat exchanger 84);
means for splitting the pre-heated feed of natural gas into a pre-heated feed stream fed to the second heating coil of the heat recovery unit and a gas stream having a temperature ranging from 180° C. to 210° C. used as fuel in the steam reformer (see the outlet of heat exchanger 12 which is divided up into a stream headed for heat exchanger 84, which corresponds to the pre-heated feed stream fed to the second heating coil, and a stream labeled L11 which is fed to the reformer burner via conduit L15); and
means for mixing the gas stream having a temperature ranging from 180° C. to 210° C. used as fuel in the steam reformer with natural gas (see the embodiment in Fig. 8 which illustrates the gas stream having a temperature ranging from 180C to 210C, or L11, being mixed with natural gas via line L21).
Regarding limitations recited in claim 6 which are directed to a manner of operating disclosed system (such as the limitations directed to the temperature of the streams), neither the manner of operating a disclosed device nor material or article worked upon further limit an apparatus claim. Said limitations do not differentiate apparatus claims from prior art. See MPEP §2114 and 2115. Further, process limitations do not have a patentable weight in an apparatus claim. See Ex parte Thibault, 164 USPQ 666, 667 (Bd. App. 1969) that states "Expressions relating the apparatus to contents thereof and to an intended operation are of no significance in determining patentability of the apparatus claim.
Regarding claim 9, Sakurai further discloses a sulfur removal unit (13) for removing sulfur from the feed of natural gas heated by the second heating coil (see Fig. 3 which illustrates the natural gas stream exiting the second heat exchanger 12 and going to desulfurizer 13), comprising an inlet and an outlet (as depicted in Fig. 3);
a steaming unit (such as vaporizer 14-3, see Fig. 5) , having an inlet and an outlet (as depicted in Fig. 12); and
a heating unit for a natural gas/steam mixture from a temperature ranging from 360° C to 380° C to a temperature ranging from 590° C to 610° C, and comprising an inlet and an outlet (the heating unit is the burner of the reformer which combusts natural gas to achieve the desired temperature for the steam/natural gas mixture to achieve reforming);
wherein the inlet of the sulfur removal unit is in fluid communication with the outlet of the heat recovery unit (see Fig. 3 where the second heat exchanger 12 feeds the desulfurizer), and wherein the inlet of the steaming unit is in fluid communication with the outlet of the sulfur removal unit (via process flow path from the sulfur removal unit 13 to the steaming unit 14-3), and wherein the outlet of the steaming unit is in fluid communication with the inlet of the heating unit (outlet of steaming unit leads steam to the heating unit/steam reformer), and wherein the outlet for the heating unit is in fluid communication with the inlet for the heated feed of natural gas of the steam reformer (see Fig. 19 which illustrates that the outlet of the heating unit (burner that is fed by L15) is followed by a reformer, 14-4).
Regarding claim 10, Sakurai further discloses
a shift conversion unit (41) for reacting carbon monoxide gas produced in the steam reformer with water, thereby producing a mixture of carbon dioxide and hydrogen, in direct fluid communication with the steam reformer (such is the case with a shift reactor and see Fig. 12 where the outlet of the reformer 14 goes to shifter 70);
a carbon dioxide removal unit (42) in direct fluid communication with the shift conversion unit (see Fig. 12), for separating hydrogen from carbon dioxide in the mixture of carbon dioxide and hydrogen formed in the shift conversion unit;
a methanation unit (43) in direct fluid communication with the carbon dioxide removal unit for converting amounts of carbon monoxide gas formed in the steam reformer and of carbon dioxide formed in the shift conversion unit remaining in the hydrogen gas into methane, thereby providing hydrogen gas essentially free in carbon monoxide and carbon dioxide; and
an ammonia synthesis unit (46) for reacting the hydrogen gas provided by the methanation unit with nitrogen gas, thereby forming ammonia, in direct fluid communication with the methanation unit.
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.
Claim(s) 1 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sakurai (US 2017/0096333) in view of Bai (US 2006/0199051).
Regarding claim 1, Sakurai discloses a method for heating a feed of natural gas, used as feed for a steam reformer of an ammonia production system (as disclosed in paragraph 14), wherein the system comprises a steam reformer (14) operably connected to a heat recovery unit comprising at least two heating coils maintained at a different temperature (see Fig. 12 where there are a plurality of heat exchangers that heat the natural gas streams such as 84, 89, 12), wherein the feed of natural gas passes through the at least two heating coils (see Fig. 12 where the natural gas stream 21 flows through multiple heat exchangers in preheating steps), comprising the steps of:
a) recovering heat in the heat recovery unit from the ammonia production system (see paragraph 7 which discloses the importance of recovering heat from the system to improve efficiency) ; and
b) exchanging at least part of the heat recovered in step a) with at least a portion of the feed of natural gas, thereby obtaining a heated feed of natural gas (see Fig. 12 where heat is recovered from the outlet of the reforming flue gas L12 via exchanging with the natural gas feed 21 in heat exchanger 12);
wherein the feed of natural gas does not comprise steam (the natural gas feed does not comprise steam… steam is added later via conduit 24);
the method being characterised in that:
the heat recovered in step a) is heat recovered from flue gas produced in the steam reformer (see outlet L12 from steam reformer burner that forms the heat exchanging stream for the natural gas and see the abstract which identifies L12 as a flue gas stream) and;
step b) comprises the consecutive steps of:
b1) heating the feed of natural gas upon contacting the feed with a first heating coil of the heat recovery unit, thereby obtaining a pre-heated feed of natural gas (see Fig. 12 where the first heat exchanger/coil heats the natural gas 21 to a first temperature of 300C, as described in paragraph 94); and
b2) subsequently further heating the pre-heated feed of natural gas from step b1) upon contacting the feed with a second heating coil of the heat recovery unit, thereby obtaining the heated feed of natural gas (see Fig. 12 which illustrates the pre-heated feed in conduit L13-4 being routed to a second heat exchanger 84 which brings the natural gas to its reaction temperature of 350C, as taught in Fig. 10 which shows the stream going into the reactor is at 350C by the illustration of the temperature of line L11);
step c) splitting the pre-heated feed of natural gas obtained in step b1) into a pre-heated feed stream fed to the second heating coil of the heat recovery unit and a gas stream having a temperature ranging from 180° C. to 210° C. used as fuel in the steam reformer (see the outlet of heat exchanger 12 which is divided up into a stream headed for heat exchanger 84, which corresponds to the pre-heated feed stream fed to the second heating coil, and a stream labeled L11 which is fed to the reformer burner via conduit L15),
wherein the gas stream, having a temperature ranging from 180° C. to 210° C., used as fuel in the steam reformer obtained from step c) is further mixed with natural gas(see the embodiment in Fig. 8 which illustrates the gas stream having a temperature ranging from 180C to 210C, or L11, being mixed with natural gas via line L21).
Sakurai teaches the heating an incoming natural gas stream to a temperature of approximately 350C by heat exchange with 2 heat exchangers (such that the second heat exchanger heats the stream to 350C). However, Sakurai does not explicitly teach the claimed temperature ranges for the pre-heated feed of natural gas (180C to 210C).
Bai also discloses a reforming process (see abstract).
Bai, like Sakurai, teaches heating a natural gas stream (103) in a first heat exchanger (14) and then sends the heated stream to a desulfurization unit (92). Bai, however teaches that the first heat exchanger heats the natural gas stream to a temperature of 200-250C (paragraph 61) and teaches such a temperature as a suitable temperature for the adjacent hydro desulfurizer (R-2). It is noted that Sakurai teaches a higher first heat exchanger temperature of the natural gas feed (300C, see Fig. 9), but teaches a different type of desulfurizer, as described in paragraph 51.
As such, it would have been obvious to one of ordinary skill in the art at the time of the invention to utilize the hydro desulfurizer of Bai, instead of the desulfurizer of Sakurai as such a modification is nothing more than a simple substitution of one known desulfurizer for another to yield entirely predictable results.
Furthermore, such a modification would incentivize one of ordinary skill in the art at the time of the invention to change the pre-heating of the first heat exchanger of Sakurai to align with the natural gas feed stream temperature entering the hydro desulfurizer of Bai (200-250C) such that the hydro desulfurizer operates at the appropriate temperature range.
Furthermore, while modified Sakurai does not explicitly teach the claimed range, of 180-210C, it does teach an overlapping range (200-250C). As such, arriving at the claimed range would have been obvious to one of ordinary skill in the art at the time of the invention. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (see MPEP §2144.05(I)).
Allowable Subject Matter
Claims 4 and 5 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 following is a statement of reasons for the indication of allowable subject matter: The closest prior art, Sakurai, teaches a process in which steam is added to the heated natural gas stream and is then sent to the reformer at a temperature significantly lower than the claimed temperature (590-610C). The prior art neither teaches nor suggests a motivation to change the temperature of this stream to the claimed temperature in addition to placing the sulfur removal unit downstream from both the first and second heating coils.
Relevant Prior Art
US 2011/0085967 - Discloses a natural gas reforming system in which the natural gas is preheated by exhaust streams from the reformer as well as the burner that heats the reformer and the pre-heating takes place in multiple stages. This document is silent regarding the claimed temperature ranges as well as the recovery of heat from an ammonia production system.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MATTHEW J MERKLING whose telephone number is (571)272-9813. The examiner can normally be reached Monday - Thursday 8am-6pm.
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/MATTHEW J MERKLING/Primary Examiner, Art Unit 1725