Prosecution Insights
Last updated: April 19, 2026
Application No. 18/376,192

GAS PURIFICATION APPARATUS

Non-Final OA §102§103
Filed
Oct 03, 2023
Examiner
HOBSON, STEPHEN
Art Unit
1776
Tech Center
1700 — Chemical & Materials Engineering
Assignee
L'Air Liquide, Société Anonyme pour l'Etude et l'Exploitation des Procédés Georges Claude
OA Round
1 (Non-Final)
65%
Grant Probability
Favorable
1-2
OA Rounds
3y 2m
To Grant
86%
With Interview

Examiner Intelligence

Grants 65% — above average
65%
Career Allow Rate
398 granted / 611 resolved
At TC average
Strong +21% interview lift
Without
With
+21.2%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
53 currently pending
Career history
664
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
45.9%
+5.9% vs TC avg
§102
19.7%
-20.3% vs TC avg
§112
30.5%
-9.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 611 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 . 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. Claims 1, 3-4, and 8 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Nagai et al. GB 2177080 published 14 Jan. 1987 (hereafter Nagai). Regarding claim 1, Nagai teaches a gas purification apparatus (Figs 1-3, 5, 7-8) comprising: an impurity removal unit (4) for removing impurities in a feed gas (page 1 lines 61-63); a purification vessel (3) accommodating the impurity removal unit; and a heating unit (6) which is provided inside the purification vessel in a state of noncontact with the impurity removal unit (as shown in Figs 1-3, 5, 7-8), and heats the purification vessel from the inside (where the heating unit is inside the purification vessel), wherein the heating unit is detachably mounted in the purification vessel (where Figs 1-3, 5, 7-8 shows the heating unit mounted in the vessel and where the heating unit would be fully capable of being detached from as the heating unit is a separate part from the vessel). Regarding claim 3, Nagai teaches all the limitations of claim 1. Nagai further teaches a baffle plate (7 in fig 3) which is arranged on the inside of the purification vessel upstream of the impurity removal unit. Regarding claim 4, Nagai teaches all the limitations of claim 1. Nagai further teaches a supply unit (pipe supplying gas 1 in Fig 5) for supplying the feed gas to the purification vessel; and a discharge unit (pipe discharging gas 2 in Fig 5) for discharging, from the purification vessel, a purified gas that has passed through the impurity removal unit, wherein the supply unit and the discharge unit are arranged at one end (bottom end in Fig 5) of the purification vessel. Regarding claim 8, Nagai teaches all the limitations of claim 1. Nagai further teaches a heat insulating portion (12 in Fig 1) for suppressing heat escape from the purification vessel, wherein the heat insulating portion is arranged so as to cover the periphery of the purification vessel. 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 2 is rejected under 35 U.S.C. 103 as being unpatentable over Nagai et al. GB 2177080 published 14 Jan. 1987 (hereafter Nagai) as applied to claim 1 above. Regarding claim 2, Nagai teaches all the limitations of claim 1. Nagai does not teach the invention of claim 1 and additionally wherein the purification vessel is arranged so that the impurity removal unit surrounds a periphery thereof, the purification vessel comprising an inner cylinder portion detachably accommodating the heating unit. Nagai teaches in Fig 4 where the purification vessel comprises porous walls 26 to allow gas flow while bounding the impurity removal unit and allows for radial flow of gas (page 3 line 59 – page 4 line 4, Fig 4). Nagai teaches in Fig 5 where the gas is heated both before and after passing through the impurity removal unit in order to preheat the gas and then maintain the gas temperature after impurity removal (page 4 lines 5-11). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the Nagai Fig 5 gas purification apparatus by incorporating the inner cylinder portion (25’) and porous walls (26) of the Nagai Fig 4 embodiment in order to allow gas flow while bounding the impurity removal unit and allow for radial gas flow (page 3 line 59 – page 4 line 4, Fig 4). The modification would have resulted in wherein the purification vessel is arranged so that the impurity removal unit surrounds a periphery (periphery of wall 26 at inner space 25’ in Nagai Fig 4) thereof, the purification vessel comprising an inner cylinder portion (25’) detachably accommodating the heating unit. Claims 5-7 are rejected under 35 U.S.C. 103 as being unpatentable over Nagai et al. GB 2177080 published 14 Jan. 1987 (hereafter Nagai) as applied to claim 1 above and further in view of Weagle et al. US 2017/0304768 (hereafter Weagle). Regarding claim 5, Nagai teaches all the limitations of claim 1. Nagai further teaches a supply unit (pipe supplying gas 1 in Fig 5) for supplying the feed gas to the purification vessel and where the gas is heated both before and after passing through the impurity removal unit in order to preheat the gas and then maintain the gas temperature after impurity removal (Fig 5, page 4 lines 5-11). Nagai does not teach an internal pipe which is connected to the supply unit at one end and opens on the inside of the purification vessel at another end, wherein the heating unit is arranged in the internal pipe at a predetermined interval therefrom. Weagle teaches a gas purification device (¶8) comprising a sorbent impurity removal unit (32) where the gas can be supplied from an internal pipe (6) and discharged from an outer section (10) or gas can be discharged from an internal pipe and supplied from an outer section (¶21-23). Nagai Fig 4 teaches a gas purification device (Fig 4) comprising a sorbent impurity removal unit (4) where the gas is discharged from an internal pipe (2, 25’) and supplied from an outer section (1) wherein an internal pipe which is connected to the discharge unit (2) at one end and opens on the inside (25’) of the purification vessel at another end. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the Nagai Fig 5 gas purification apparatus by incorporating the internal pipe (25’) of the Nagai Fig 4 embodiment in order to allow gas flow while bounding the impurity removal unit and allow for radial gas flow (page 3 line 59 – page 4 line 4, Fig 4). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the Nagai Fig 4 gas purification apparatus by incorporating the inner cylinder portion (25’) of the Nagai Fig 4 embodiment connected to the supply unit as taught by Weagle (¶21-23) as a matter of obvious art recognized equivalent (MPEP 2144.06, where Weagle recognized the equivalent of the inner cylinder portion being used as a supply or discharge) and as obvious to try (MPEP 2143 I E, where a finite number of two solutions exists for the flow to be from out to in or in to out). The modification would have resulted in an internal pipe which is connected to the supply unit at one end and opens on the inside of the purification vessel at another end, wherein the heating unit is arranged in the internal pipe at a predetermined interval therefrom; wherein the purification vessel comprises an inner cylinder portion detachably accommodating the heating unit arranged in the internal pipe because the heating unit would preheat the gas in the internal pipe and where the heating unit is a separate feature which would be fully capable of being detachable. Regarding claim 6, Nagai in view of Weagle teaches all the limitations of claim 5. Nagai further teaches wherein the purification vessel comprises an inner cylinder portion (portion surrounding heater 6 in Figs 1-3 and 8) detachably accommodating the heating unit. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the Nagai Fig 5 gas purification apparatus by incorporating the inner cylinder portion (portion surrounding heater 6 in Figs 1-3 and 8) in order to protect the heating unit from direct contact with the fluid. Nagai does not teach the inner cylinder portion arranged in the internal pipe. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the Nagai Fig 5 gas purification apparatus by incorporating the inner cylinder portion arranged in the internal pipe in order to preheat the gas (page 4 lines 5-11). Regarding claim 7, Nagai in view of Weagle teaches all the limitations of claim 6. Nagai does not teach wherein an in-pipe impurity removal unit for removing impurities in the feed gas is provided between the inner cylinder portion and the internal pipe. Nagai teaches an in-pipe impurity removal unit (16 in Figs 1-3 and 8) for removing impurities in the feed gas is provided prior to the impurity removal unit (4) in order to ensure uniform flow, filter fine particles from the gas, and ensure uniform temperature distribution (page 3 lines 37-39). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the Nagai Fig 5 gas purification apparatus by incorporating the in-pipe impurity removal unit (16) of Nagai Figs 1-3 and 8 and provide the in-pipe impurity removal unit between the inner cylinder portion and the internal pipe in order to ensure uniform flow, filter fine particles from the gas, and ensure uniform temperature distribution (page 3 lines 37-39). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to STEPHEN HOBSON whose telephone number is (571)272-9914. The examiner can normally be reached 9am-5pm. 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. /STEPHEN HOBSON/Examiner, Art Unit 1776
Read full office action

Prosecution Timeline

Oct 03, 2023
Application Filed
Dec 31, 2025
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
65%
Grant Probability
86%
With Interview (+21.2%)
3y 2m
Median Time to Grant
Low
PTA Risk
Based on 611 resolved cases by this examiner. Grant probability derived from career allow rate.

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