Prosecution Insights
Last updated: April 19, 2026
Application No. 18/468,083

PROCESS AND SYSTEM FOR CONTINUOUS GAS FERMENTATION

Non-Final OA §103
Filed
Sep 15, 2023
Examiner
JONES, CHRISTOPHER P
Art Unit
1776
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Lanzatech Inc.
OA Round
1 (Non-Final)
76%
Grant Probability
Favorable
1-2
OA Rounds
2y 6m
To Grant
99%
With Interview

Examiner Intelligence

Grants 76% — above average
76%
Career Allow Rate
1023 granted / 1346 resolved
+11.0% vs TC avg
Strong +25% interview lift
Without
With
+24.8%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
39 currently pending
Career history
1385
Total Applications
across all art units

Statute-Specific Performance

§101
0.7%
-39.3% vs TC avg
§103
41.6%
+1.6% vs TC avg
§102
30.9%
-9.1% vs TC avg
§112
20.4%
-19.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1346 resolved cases

Office Action

§103
DETAILED ACTION Claim Objections Claim 3 is objected to because of the following informalities: “at least a portion at least a portion” should be changed to “at least a portion”. Appropriate correction is required. 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 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over Conrado WO 2022/217275 A1 in view of Datta WO 2009/108503 A1. Regarding claim 1, Conrado discloses an apparatus and process for continuous gas fermentation comprising: a. generating, by gas fermentation of a gas stream in a bioreactor (Abstract; figures), a fermentation broth comprising gas, microbial biomass, at least one product, and at least one co-product (paragraph 23); b. passing at least a portion of the fermentation broth to a separator and separating a gas stream from a liquid stream comprising the microbial biomass, the at least one co-product, and the at least one product (paragraph 57: degasser); c. passing, at least a portion of the liquid stream to a vacuum distillation unit (paragraph 57); d. separating, in the vacuum distillation unit, a product enriched stream and a microbial biomass and co-product enriched stream (paragraph 57); and f. recycling at least a portion of a retentate stream to the bioreactor (paragraph 44). Conrado does not disclose a membrane separation unit arranged serially or in parallel to the vacuum distillation unit, where a permeate stream enriched in water and co-product and a retentate stream enriched in microbial biomass is separated in the membrane separation unit. Datta discloses a process for producing ethanol comprising: passing the dilute ethanol stream to an upper location of a vacuum stripping column; contacting the cooled vapor stream in a first vapor permeation unit with a membrane to produce a first permeate stream; contacting the retentate in a second permeation unit with a membrane to produce a dehydrated ethanol stream; and returning at least a portion of the second permeate stream to the flash column (see Datta Abstract; figure 1; claim 1). It would have been obvious to one having ordinary skill in the art before the filing date of the claimed invention to modify Conrado to include disclose a membrane separation unit arranged serially or in parallel to the vacuum distillation unit, where a permeate stream enriched in water and co-product and a retentate stream enriched in microbial biomass is separated in the membrane separation unit, as generally taught by Datta, for the purpose of additional separation. Regarding claims 2 and 3, Conrado discloses passing to the bioreactor, at least a portion of the microbial biomass and co-product enriched stream, at least a portion of the retentate, or both (paragraph 44; claim 1). Passing these to the bioreactor can be considered removing them as a bleed stream. Regarding claim 4, Conrado discloses generating a treated water stream from a wastewater treatment unit (claim 16), but does not disclose passing at least a portion of the permeate stream to the wastewater treatment unit, generating a treated water stream, and passing at least a portion of the treated water stream to the bioreactor. Nevertheless, treating and utilizing recycled water is generally well-known in the art and would have been obvious to one having ordinary skill in the art before the filing date of the claimed invention. MPEP 2144.03 (A-E). Regarding claim 5, Conrado discloses passing at least a portion of the gas stream to a gas treatment unit and removing at least one contaminant from the gas stream fermenting in the bioreactor (paragraph 47). Regarding claim 6, Conrado does not disclose that the microbial biomass and co-product enriched stream comprises less than 0.2 wt. % product. Absent a proper showing of criticality or unexpected results, the amount of the of components is considered to be a general condition that would have been routinely optimized by one having ordinary skill in the art in order to provide optimal fermentation. MPEP 2144.05. Regarding claims 7 and 8, Conrado does not disclose that the vacuum distillation unit is operated at a pressure in the range of about 40 mbar(a) to about 100 mbar(a), or that the vacuum distillation unit is operated at a temperature in the range of about 35° C. to about 50° C. Datta discloses utilizing a vacuum distillation unit at a pressure of about 200 torr to 500 torr and a maximum temperature of 80 degrees C (paragraph 38). Absent a proper showing of criticality or unexpected results, the exact temperature and pressure are considered to be general conditions that would have been routinely optimized by one having ordinary skill in the art in order to provide optimal separation. MPEP 2144.05. Regarding claim 9, Conrado discloses that the product is at least one selected from ethanol, acetate, butanol, butyrate, 2,3-butanediol, lactate, butene, butadiene, methyl ethyl ketone (2-butanone), ethylene, acetone, isopropanol, lipids, 3-hydroxypropionate (3-HP), terpenes, terpenoids, isoprene, fatty acids, 2-butanol, 1,2-propanediol, 1 propanol, chorismate-derived products, 3 hydroxybutyrate, and 1,3-butanediol, 2-hydroxyisobutyrate or 2-hydroxyisobutyric acid, isobutylene, adipic acid, 1,3 hexanediol, 3-methyl-2-butanol, 2-buten-1-ol, isovalerate, isoamyl alcohol, monoethylene glycol, 2-phenylethanol, ethylene, or any combination thereof (paragraph 9). Regarding claim 10, Conrado discloses that the gas stream comprises at least hydrogen and carbon monoxide wherein at least a portion of the carbon monoxide is generated by conversion of carbon dioxide to carbon monoxide (claim 1). Regarding claims 11 and 12, Conrado discloses that the conversion of carbon dioxide comprises, contacting with a conversion catalyst that is a thermo-catalytic conversion (claim 19). Furthermore, absent a proper showing of criticality or unexpected results, the temperature of the conversion is considered to be a general condition that would have been routinely optimized by one having ordinary skill in the art in order to provide optimal thermos-catalytic conversion. MPEP 2144.05. Regarding claim 13, Conrado discloses that the carbon dioxide is generated by steam reforming, electrolysis powered by a renewable power source, or both (paragraphs 5, 6 and 27). Regarding claim 14, Conrado discloses an apparatus for continuous gas fermentation comprising: a. a bioreactor comprising a bioreactor inlet (Abstract; figures), at least one recycle inlet, and a fermentation broth outlet (inlet and outlet of bioreactor 170); b. a separator in fluid communication with the fermentation broth outlet (paragraph 57: degasser), the separator comprising a liquid outlet and a gas outlet (paragraph 57); c. a vacuum distillation unit (paragraph 57); d. the vacuum distillation unit comprising an overhead outlet and a bottoms outlet (paragraph 57). The claimed membrane separator is rejected from the teaching of Conrado in view of Datta with the same motivation as used for claim 1. Regarding claim 15, Conrado discloses that the bottoms outlet is further in fluid communication with at least one of the bioreactor recycle inlets (see figures). Regarding claim 16, Conrado discloses a wastewater treatment unit (claim 16), but does not disclose it is in fluid communication with the permeate outlet and at least one of the bioreactor recycle inlets. Nevertheless, treating and utilizing recycled water is generally well-known in the art and would have been obvious to one having ordinary skill in the art before the filing date of the claimed invention. MPEP 2144.03 (A-E). Regarding claim 17, Conrado a gas treatment unit in fluid communication with the bioreactor inlet (paragraph 47). Regarding claim 18, Conrado discloses a gas treatment unit in fluid communication with both the gas outlet and at least one of the bioreactor recycle inlets (paragraph 47; figures). Regarding claim 19, Conrado discloses in fluid communication the bioreactor inlet, a CO.sub.2 to CO conversion unit selected from a reverse water gas reaction unit, a CO.sub.2 electrolysis unit, a thermo-catalytic conversion unit, an electro-catalytic conversion unit, a partial combustion unit, a plasma conversion unit or any combination thereof (claim 19). Regarding claim 20, Conrado discloses passing to the bioreactor, at least a portion of the microbial biomass and co-product enriched stream, at least a portion of the retentate, or both (paragraph 44; claim 1). Passing these to the bioreactor can be considered removing them as a bleed stream. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRISTOPHER P JONES whose telephone number is (571)270-7383. The examiner can normally be reached 9AM-6PM EST M-F. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jennifer Dieterle can be reached at (571)270-7872. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /CHRISTOPHER P JONES/Primary Examiner, Art Unit 1776
Read full office action

Prosecution Timeline

Sep 15, 2023
Application Filed
Feb 24, 2026
Non-Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
76%
Grant Probability
99%
With Interview (+24.8%)
2y 6m
Median Time to Grant
Low
PTA Risk
Based on 1346 resolved cases by this examiner. Grant probability derived from career allow rate.

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