Prosecution Insights
Last updated: April 19, 2026
Application No. 18/234,017

METHOD FOR PRODUCING LIQUEFIED CARBON DIOXIDE FROM LIQUEFIED NATURAL GAS

Non-Final OA §102§103
Filed
Aug 15, 2023
Examiner
DAVIS, SHENG HAN
Art Unit
1732
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Chevron U S A Inc.
OA Round
1 (Non-Final)
66%
Grant Probability
Favorable
1-2
OA Rounds
3y 3m
To Grant
99%
With Interview

Examiner Intelligence

Grants 66% — above average
66%
Career Allow Rate
701 granted / 1064 resolved
+0.9% vs TC avg
Strong +36% interview lift
Without
With
+35.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 3m
Avg Prosecution
67 currently pending
Career history
1131
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
62.6%
+22.6% vs TC avg
§102
6.9%
-33.1% vs TC avg
§112
20.8%
-19.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1064 resolved cases

Office Action

§102 §103
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 . Election/Restrictions Claims 18-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 1/28/26. 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)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention. Claim(s) 1, 2, 3, 10, 11, 12 is/are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Ko (WO 2013/141454). Ko describes a CO2 management system (title) where CO2 gas is absorbed in an adsorption tower and then desorbed gaseous CO2 is mixed with liquid CO2, which then liquefies the gaseous CO2 through the connection in a heat exchanger with the liquid natural gas (page 6, para. 10). As to Claims 2 and 3, Ko describes that in some examples the liquified natural gas stream is maintained at approximately -164 degrees C (page 9, para. 5), while the CO2 gaseous stream can be heated to 220-320 degrees C (page 13, para. 3) or cooled down to 10-40 degrees C (page 14, para. 6). As to Claim 10, Ko describes a CO2 management system (title) where CO2 gas is absorbed in an adsorption tower and then desorbed gaseous CO2 is mixed with liquid CO2, which then liquefies the gaseous CO2 through the connection in a heat exchanger with the liquid natural gas (page 6, para. 10). In the reactor, the liquid natural gas is sent from a storage tank to a pressure pump 232 where it is pressurized and then sent to a heat exchanger 236 (page 9, last para) where it is heat exchanged with gaseous CO2 (page 9, second to last para). As to Claim 11, Ko teaches that the compressor used to compress CO2 pressurize the CO2 at 15-25 bar (page 10, para. 10). As to Claim 12, Ko describes a CO2 management system (title) where CO2 gas is absorbed in an adsorption tower (page 6, para. 10). The desorbed CO2 from this adsorption tower (page 6, para. 10) is then cooled in a cooler to a temperature of 10-40 degrees C (see page 14, para. 6). The liquid stream is kept at -164 degrees C (page 9, para. 5). MPEP states that prior art which teaches a range overlapping or touching the claimed range anticipates if the prior art range discloses the claimed range with “sufficient specificity.” See 2131.03. 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. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claim(s) 4, 5, 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ko (WO 2013/141454). As to Claim 4, Ko teaches that the CO2 stream is sent to a storage tanks where a liquid CO2 line is connected to (page 6, para. 7) and where CO2 stored is later vaporized (page 6, para. 10). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the CO2 from this storage tanks that is later vaporized is in liquid form. As to Claim 5, Ko teaches that the natural gas is vaporized (page 6, para. 2 and page 10, para. 1). The CO2 enters a recycling phase where it is reused (page 17, para. 3). Since Ko states that the CO2 is recycled and that CO2 from the adsorption tank is desorbed and fed as gaseous CO2 to the liquid CO2 (see page 6, para. 10), it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that recycled CO2 will go through the process of heat exchange with liquified natural gas. As to Claim 13, Ko teaches that the liquified natural gas is vaporized (page 8, para. 2) As to Claim 13, Ko teaches that the liquified natural gas is vaporized (page 8, para. 2) Claim(s) 6, 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ko as applied to claim 5 or 13 above, and further in view of Hou (CN 112875644). Ko describes a method of generates liquid CO2 (title). The reference does not teach the features of Claims 6 and 14. Hou describes a system (title) that incorporates a CO2 liquification device (abstract) with a natural gas steam reforming hydrogen production device (abstract). In this system, the gas outlet of the CO2 liquification device is connected to a natural gas steam reforming hydrogen production device (abstract). Gas from the CO2 liquification device is sent to a natural gas stream reforming system to produce H2 and CO2 using natural gas steam reforming conversion (see page 3, step S2 and Claim 7). The stream is then heated where CO is converted to obtain H2 and CO2 (Claim 9). The system then feeds the CO2 to a CO2 liquifying device (Claim 1). This can be considered a separate CO2-containing stream. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to feed the stream to a steam reforming device to produce H2, CO and CO2, where the CO2 is then fed to a separate device, as taught by Hou for use Ko because this process makes H2, which is a desirable product. Claim(s) 6, 7, 8, 9, 14, 15, 16, 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ko as applied to claims 5 and 13 above, and further in view of Kemp (US Pub.: 2023/0159330), provisional filed 11/21. Kemp describes a method of a making synthesis gas from a CO2 source (para. 1). The process employs methane gas (natural gas) and uses this to covert the product to CO and H2 (para. 24, 25). The process then reacts the methane in a steam reforming unit (6) and then process that stream in a water gas shift reaction unit to produce H2 and CO (para. 34). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to make syngas from CO2 using methane followed by use of a water gas shift reaction to make H2 and CO, as taught by Kemp for use with the process of Ko because syngas is a desirable product. As to Claims 8 and 16, Kemp teaches that after the water gas shift reaction (para. 50), the gas is fed to a H2 separation apparatus, which can include a pressure swing adsorber (para. 51). As to Claims 9 and 17, Ko teaches that after the gaseous CO2 and liquid CO2 interact in reactor 110, CO2 is then cooled (page 13, para. 10-11) and then discharged from the CO2 line 210 and extends to the adsorption tower 215 (page 13, para. 11-12). The CO2 enters a recycling phase where it is reused (page 17, para. 3). Since Ko states that the CO2 is recycled and that CO2 from the adsorption tank is desorbed and fed as gaseous CO2 to the liquid CO2 (see page 6, para. 10), it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that recycled CO2 will go through the process of heat exchange with liquified natural gas. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to SHENG HAN DAVIS whose telephone number is (571)270-5823. The examiner can normally be reached 9-5:30. 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, Fung Coris can be reached at 571-270-5713. 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. /SHENG H DAVIS/Primary Examiner, Art Unit 1732 March 17, 2026
Read full office action

Prosecution Timeline

Aug 15, 2023
Application Filed
Jul 18, 2024
Response after Non-Final Action
Mar 17, 2026
Non-Final Rejection — §102, §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
66%
Grant Probability
99%
With Interview (+35.9%)
3y 3m
Median Time to Grant
Low
PTA Risk
Based on 1064 resolved cases by this examiner. Grant probability derived from career allow rate.

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