Prosecution Insights
Last updated: April 19, 2026
Application No. 18/677,242

GAS TURBINE PLANT WITH AMMONIA DECOMPOSITION SYSTEM

Non-Final OA §103§112
Filed
May 29, 2024
Examiner
KIM, TAE JUN
Art Unit
3799
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
DOOSAN ENERBILITY CO., LTD.
OA Round
3 (Non-Final)
64%
Grant Probability
Moderate
3-4
OA Rounds
3y 9m
To Grant
91%
With Interview

Examiner Intelligence

Grants 64% of resolved cases
64%
Career Allow Rate
474 granted / 740 resolved
-5.9% vs TC avg
Strong +27% interview lift
Without
With
+27.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 9m
Avg Prosecution
43 currently pending
Career history
783
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
46.0%
+6.0% vs TC avg
§102
25.8%
-14.2% vs TC avg
§112
24.1%
-15.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 740 resolved cases

Office Action

§103 §112
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 . Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 12/18/2025 has been entered. 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. Claims 1, 6, and 10-14 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 1 “a first combustor configured to generate combustion gas in such a way as to supply heat to the decomposition reactor and to be positioned upstream of the decomposition reactor in a flow of the combustion gas” is unclear. Election/Restrictions Applicant’s election without traverse of Species E (Fig. 5) in the reply filed on 4/10/2025 is acknowledged. Claims 2-5, 7, 8, 15-20 have been withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected species, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 4/10/2025. First, the underlined text appears to refer to the “first combustor.” However, it is unclear if “in a flow of the combustion gas” references the decomposition reactor or if still references the first combustor. In any event, the claim does not clearly indicate whether combustion gas flows to the decomposition reactor since “upstream .. in a flow of combustion gas” broadly sets forth a direction of the flow vs actually receiving the flow. 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, 6, 10-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over UECHI et al (2022/0099021) in view of Lin et al (2024/0167417) in view of an alternative embodiment of UECHI et al and further in view of Bulat et al (2018/0355794). UECHI et al teach [Fig. 9] A gas turbine plant with an ammonia decomposition system, the gas turbine plant comprising: a storage tank T configured to store liquid ammonia; a supply pump 43 configured to supply the liquid ammonia of the storage tank; a preheater 44e configured to preheat the liquid ammonia supplied by the supply pump; a vaporizer 44f-44h configured to vaporize the liquid ammonia preheated by the preheater; a superheater 44i configured to superheat [appears it may be inherently capable] the gaseous ammonia vaporized by the vaporizer; a decomposition reactor 45a configured to thermally decompose the gaseous ammonia superheated by the superheater; a separator 130 configured to separate residual ammonia from the decomposition gas RG decomposed by the decomposition reactor 45a; and a first combustor 45b configured to generate combustion gas in such a way as to supply heat to the decomposition reactor 45a via the heated steam 51b, 51a [45b is taught as having combustion in paragraph 0319 thus the 45b is the first combustor], wherein synthesis gas 12b consisting of hydrogen and nitrogen with the residual ammonia removed by the separator 130 is supplied to a second combustor 11c of a gas turbine, wherein exhaust gas EG that is discharged from the gas turbine is supplied to a heat recovery steam generator 21, steam generated by heat of the exhaust gas in the heat recovery steam generator is supplied to a steam turbine 33 and drives the steam turbine, and then flows into a condenser 34, and the water [from 36] condensed in the condenser is supplied back to the heat recovery steam generator, and wherein the water or steam extracted from the heat recovery steam generator or downstream of the condenser receives heat [via s, 91, which are labeled multiple times, at least in 46d and also connected to line 35 which is downstream condenser 34] from the decomposition gas 41c in a first heat exchanger 46d, and then is recovered 75, t to the heat recovery steam generator 21 or upstream of the steam turbine 33. (6) a booster pump 53 that increases a pressure of the water a1, 51b or 1, 51a extracted from the heat recovery steam generator and supplies the water to the first heat exchanger 46d. (13) wherein water or steam heated by the heat of the exhaust gas in the heat recovery steam generator supplies heat [via, i, q, p, m] to the liquid ammonia or the gaseous ammonia. (14) wherein the separator 130 comprises: an ammonia absorption tower 131 that separates the residual ammonia included in the decomposition gas by dissolving the residual ammonia in water; and an ammonia regeneration tower 132 that evaporates and regenerates ammonia from ammonia water generated by dissolving the residual ammonia in water in the ammonia absorption tower, wherein a portion of the water discharged [left of 139] from the ammonia regeneration tower 132 is supplied to the ammonia absorption tower 131, and the rest of the water is vaporized through a reboiler 139 and is supplied back to the ammonia regeneration tower, and wherein water or steam c, d, 71, 85b heated by the heat of the exhaust gas in the heat recovery steam generator supplies heat to the water passing through the reboiler 139. For claim 1, UECHI et al appears to teach 44i may be a superheater configured to superheat the gaseous ammonia vaporized by the vaporizer. Alternately, Lin et al teach the vaporized ammonia is superheated [end of paragraph 0157] is typically done for decomposition reactors. It would have been obvious to one of ordinary skill in the art to utilize a superheater to superheat the gaseous ammonia, as taught by Lin et al, as the standard practice in the art and typical conditions experienced by gasified ammonia. The previously applied embodiments (Fig. 9) of UECHI et al do not teach (9) a third heat exchanger in which heat exchange occurs between the combustion gas and an oxidant supplied to the first combustor. (10) a fourth heat exchanger in which heat exchange occurs between the oxidant and water or steam heated by the heat of the exhaust gas in the heat recovery steam generator. (11) wherein the oxidant passes through the fourth heat exchanger and the third heat exchanger in turn, and then is supplied to the first combustor. (12) wherein water or steam extracted from the heat recovery steam generator to the fourth heat exchanger is recovered back to the heat recovery steam generator or downstream of the condenser. UECHI et al [Fig. 14] teach (9) a third heat exchanger 46i in which heat exchange occurs between the combustion gas 47a and an oxidant 61, 65a, 65, 65c supplied to the first combustor 45b [taught as having combustion in paragraph 0319]. (10) a fourth heat exchanger 62 in which heat exchange occurs between the oxidant 61 and water or steam 79, z1 heated by the heat of the exhaust gas in the heat recovery steam generator 21. (11) wherein the oxidant passes through the fourth heat exchanger 62 and the third heat exchanger 64 in turn, and then is supplied to the first combustor 45b [taught as having combustion in paragraph 0319]. (12) wherein water or steam 79, z1 extracted from the heat recovery steam generator to the fourth heat exchanger 62 is recovered back 80, z2 to the heat recovery steam generator or downstream of the condenser. Preheating the air / oxidant supplied to the first combustor, facilitates combustion by heating the air/oxidant prior to combustion and recovers heat that would otherwise be lost and thus increases system efficiency. It would have been obvious to one of ordinary skill in the art to employ (9) a third heat exchanger in which heat exchange occurs between the combustion gas and an oxidant supplied to the first combustor, (10) a fourth heat exchanger in which heat exchange occurs between the oxidant and water or steam heated by the heat of the exhaust gas in the heat recovery steam generator, (11) wherein the oxidant passes through the fourth heat exchanger and the third heat exchanger in turn, and then is supplied to the first combustor, (12) wherein water or steam extracted from the heat recovery steam generator to the fourth heat exchanger is recovered back to the heat recovery steam generator or downstream of the condenser, as taught by the alternate embodiment of Fig. 14, as preheating the air / oxidant supplied to the first combustor, facilitates combustion by preheating the air/oxidant prior to combustion and recovers heat that would otherwise be lost and thus increases system efficiency. As set forth above, UECHI et al teach a first interpretation [Fig. 9] with a first combustor 45b configured to generate combustion gas in such a way as to supply heat to the decomposition reactor 45a [45b is taught as having combustion in paragraph 0319 thus the 45b is the first combustor] and to be positioned upstream of the decomposition reactor 45a in a flow of the combustion gas [RG from 45b through heat exchangers 46c, 46d] show the direction of the combustion gas flow and in this direction downstream of the first combustor 45b, 45b is broadly upstream of the decomposition reactor 45a. UECHI et al do not teach a narrow interpretation of a first combustor configured to generate combustion gas in such a way as to supply heat to the decomposition reactor and to be positioned upstream of the decomposition reactor in a flow of the combustion gas. In other words, in a narrow interpretation of this limitation, combustion gas from the first combustor from 45b does not return to the decomposition reactor 45a, rather only hot steam 52b, 51b which is heated by the first combustor is transferred to the decomposition reactor 45a. In other words, combustion gas RG from first combustor 45b is not taught as being sent to the decomposition reactor 45a. However, Bulat et al teach a first combustor 7 configured to generate combustion gas 36, 20 in such a way as to supply heat to the decomposition reactor 5 and to be positioned upstream of the decomposition reactor 5 in a flow of the combustion gas 35, 20, where the decomposition reactor 5 is configured to thermally decompose 24 the gaseous ammonia. Bulat et al teach the combustion gas facilitate control over the elevated temperature for the decomposition reactor 5 [see end of paragraph 0016]. It would have been obvious to supply the heat to the decomposition reactor from a first combustor configured to generate combustion gas and to be positioned upstream of the decomposition reactor in a flow of the combustion gas, as taught by Bulat et al, in order to facilitate control of an elevated temperature for the decomposition reactor or as equivalent heat source to other heat producing turbine systems used in UECHI et al [e.g. hot water / steam]. This combination entails combustion gas flow RG from 45b being recirculated at some point back to the decomposition reactor 45a, e.g. in replacement of the hot steam 52b, 51b or in addition to the hot steam 52b, 51b. Prior Art It has come the Examiner’s attention that applicant appears to have a highly analogous application 18/665376, which has been allowed. Note that claim 1 of that application claims the third [first] heat exchanger in which heat exchange occurs between the combustion gas and an oxidant supplied to the first combustor and has analogous heat recovery steam generator limitations in claims 5-10 to that of the instant application’s cliam 1. Response to Arguments Applicant's arguments filed 12/18/2025 have been fully considered but they are not persuasive. Smith has been withdrawn as additive. To address applicant’s amendments and arguments, Uechi has now been construed as 45b being the first combustor and 45a being the decomposition reactor. In this interpretation 45b, the third reaction gas cooler (46i) of Uechi heats the oxidant 65c supplied to the first combustor 45b [Fig. 14]. Uechi “Even when considering the teachings in Bulat or Smith, there is no motivation to modify Uechi to provide heat exchange between the combustion gas generated in the first combustor and the oxidizer supplied to the first combustor as in the present invention. In Bulat, a combustor (7) is supplied with high-temperature exhaust gas (34) from a turbine (6), so there is no need to heat an oxidizer supplied to the combustor (7).]” Applicant’s argument is not persuasive, as Bulat is not applied for teaching heating an oxidizer supplied to the combustor. Rather this is already taught by Fig. 14 of Uechi et al. Bulat was applied only for “a first combustor configured to generate combustion gas in such a way as to supply heat to the decomposition reactor and to be positioned upstream of the decomposition reactor in a flow of the combustion gas” and is compatible with the teachings of Uechi et al as he teaches the combustion gas facilitates control over the elevated temperature for the decomposition reactor 5 [see end of paragraph 0016]. Accordingly, applicant’s arguments are not persuasive. Contact Information Any inquiry concerning this communication or earlier communications from the Examiner should be directed to TED KIM whose telephone number is 571-272-4829. The Examiner can be reached on regular business hours before 5:00 pm, Monday to Thursday and every other Friday. The fax number for the organization where this application is assigned is 571-273-8300. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Devon Kramer, can be reached at 571-272-7118. Alternate inquiries to Technology Center 3700 can be made via 571-272-3700. Information regarding the status of an application may be obtained from Patent Center https://www.uspto.gov/patents/apply/patent-center. Should you have questions on Patent Center, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). General inquiries can also be directed to the Inventors Assistance Center whose telephone number is 800-786-9199. Furthermore, a variety of online resources are available at https://www.uspto.gov/patent /Ted Kim/ Telephone 571-272-4829 Primary Examiner Fax 571-273-8300 March 20, 2026
Read full office action

Prosecution Timeline

May 29, 2024
Application Filed
Mar 26, 2025
Applicant Interview (Telephonic)
Mar 26, 2025
Examiner Interview Summary
Apr 19, 2025
Non-Final Rejection — §103, §112
Jul 24, 2025
Response Filed
Sep 17, 2025
Final Rejection — §103, §112
Dec 18, 2025
Request for Continued Examination
Feb 13, 2026
Response after Non-Final Action
Mar 20, 2026
Non-Final Rejection — §103, §112 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12595761
GENERATING ELECTRICAL ENERGY FROM HYDROGEN AND OXYGEN
2y 5m to grant Granted Apr 07, 2026
Patent 12535032
AIRCRAFT NACELLE COMPRISING A SEALED BOX STRUCTURE AND A DOOR WHICH OPENS THE BOX STRUCTURE TO THE OUTSIDE
2y 5m to grant Granted Jan 27, 2026
Patent 12510249
AUXILIARY POWER UNIT WITH PULSE DETONATION COMBUSTION
2y 5m to grant Granted Dec 30, 2025
Patent 12467419
THRUST REVERSER WITH BLOCKER DOOR FOLDING LINKAGE
2y 5m to grant Granted Nov 11, 2025
Patent 12435682
THRUST REVERSER CASCADE WITH OFFSET VANE LEADING EDGES
2y 5m to grant Granted Oct 07, 2025
Study what changed to get past this examiner. Based on 5 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

3-4
Expected OA Rounds
64%
Grant Probability
91%
With Interview (+27.1%)
3y 9m
Median Time to Grant
High
PTA Risk
Based on 740 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month