Office Action Predictor
Last updated: April 15, 2026
Application No. 18/524,431

MIXED GAS SEPARATION METHOD AND MIXED GAS SEPARATION APPARATUS

Non-Final OA §103§112
Filed
Nov 30, 2023
Examiner
HE, QIANPING
Art Unit
1776
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Ngk Insulators, LTD.
OA Round
1 (Non-Final)
68%
Grant Probability
Favorable
1-2
OA Rounds
2y 11m
To Grant
80%
With Interview

Examiner Intelligence

Grants 68% — above average
68%
Career Allow Rate
169 granted / 248 resolved
+3.1% vs TC avg
Moderate +12% lift
Without
With
+11.7%
Interview Lift
resolved cases with interview
Typical timeline
2y 11m
Avg Prosecution
62 currently pending
Career history
310
Total Applications
across all art units

Statute-Specific Performance

§101
1.4%
-38.6% vs TC avg
§103
43.0%
+3.0% vs TC avg
§102
17.7%
-22.3% vs TC avg
§112
34.2%
-5.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 248 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. Claim Objections Claim s 1 , 3 and 13 are objected to because of the following informalities: There is a typo in the limitation of “ an Nu”. Appropriate correction is required . Claim Rejections - 35 USC § 112(b) 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 appl icant regards as his invention. Claim 5 is 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 5 is indefinite because the limitation of “said permeate side” lacks antecedent basis. 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. The claims are rejected as follows: Claim s 1 , 4, 6, 11–13 are rejected under 35 U.S.C. 103 as being obvious over Iyer et al., US 2022 / 0003503 A1 (“Iyer”) in view of Colling et al, US 2005 / 0045029 A1 (“ Colling ”) . Regarding claim 1: Iyer discloses that a mixed gas separation method comprising: a) preparing a separation membrane (Iyer’s method of forming the gas separation membrane 10a and 10a1 in Fig. 1b, Iyer Fig. 1b, [0017] and [0045]) ; and b) supplying a mixed gas (Iyer’s feed gas in Fig. 1b) that contains a plurality of types of gases to said separation membrane and causing a gas with high permeability in said mixed gas to permeate through said separation membrane to separate said gas with high permeability from said mixed gas (Iyer’s Feed Gas in Fig. 1 passing through the gas separation membrane 10a and 10a1, and Permeate Gas pass through and separated from other gases in the Feed Gas, it is therefore understood that for gas separation membrane to work properly, the feed gas has to comprise at least two components, the feed gas therefore comprises a plurality of types of gases, and Iyer’s “Permeate” is the claimed gas with high permeability, Iyer Fig. 1b, [0045]), wherein in said operation b), when ΔP is a difference between a feed pressure and a permeate pressure (Iyer discloses its invention requires operating pressure, the pressure difference between pressure at Feed Gas side and Permeate Gas side is the claimed “ ΔP ”, Iyer Fig. 1b, [0043]) , the feed pressure being a gas pressure on a primary side of said separation membrane (Iyer’s operating pressure at the Feed Gas side, Iyer Fig. 1b, [0043]) , the permeate pressure being a gas pressure on a secondary side of said separation membrane (Iyer’s operating pressure at the permeate side, Iyer Fig. 1b, [0043]) , a difference ΔT between a feed temperature and a permeate temperature, the feed temperature being a gas temperature on the primary side of said separation membrane, the permeate temperature being a gas temperature on the secondary side of said separation membrane ( Iyer discloses its invention requires operating temperature, and the temperature at Feed Gas side would be the claimed “feed temperature” and the temperature at Permeate Gas side would be the claimed “permeate temperature , ” temperature difference between Feed Gas and Permeate Gas would be the claimed “ difference ΔT ,” Iyer Fig. 1b, [0043]) , Iyer does not explicitly disclose the difference ΔT is made less than 90% A·ΔP by setting an Nu number in said mixed gas to be greater than or equal to 2 and less than or equal to 10 and A is a Joule-Thomson coefficient . However, Iyer discloses a Nusselt number of 3.66 at constant temperature boundary condition. Iyer [0074]. Iyer therefore discloses a Nusselt number falls within the claimed range of “ greater than or equal to 2 and less than or equal to 10 .” Additionally, Iyer discloses a “ difference ΔT ” of zero because it is “constant temperature.” Iyer [0074]. Furthermore, Iyer discloses its invention has a “pressure d r op.” Iyer [0058]. It is therefore understood that Iyer discloses a ΔP that is positive . One ordinary skill in the art at the time of filing understands that for the claimed relationship of ΔT < 90% of A·ΔP to be valid, all it requires is for A·ΔP to be a positive number. Since ΔP is positive as discussed earlier, the claimed relationship would be valid if a Joule-Thomson coefficient A is a positive number. Iyer does not disclose its Joule-Thomson coefficient A is a positive number . In the analogous art of gas separation membranes, Colling discloses a method of separation gas mixtures. Colling Fig. 1, [0003]. Similar to Iyer, Colling discloses a separation membrane. Colling Fig. 1, [0011] and Iyer [0048]. Colling discloses that for separation membranes, a large pressure gradient across the membrane would supply the driving force for permeation. This driving force would induce a cooling in the membrane (for materials with positive Joule-Thomson coefficients) in order to produce the low pressure permeate. Colling Fig. 1, [0011]. It would therefore have been obvious for one ordinary skill in the art at the time of filing to include a positive Joule-Thomson coefficients materials in the feed gas for the purpose of creating a large pressure gradient across the membrane. Iyer discloses a need for high pressure drop in some zones, and adding a positive Joule-Thomson coefficients materials would facilitate the forming of high pressure drop zone. With such modification, modified Iyer would disclose the claimed relationship of ΔT < 90% of A·ΔP with ΔT being zero, and 90% of A·ΔP being > 0. Regarding claim 4: Modified Iyer discloses that t he mixed gas separation method according to claim 1, wherein in said operation b), said separation membrane is heated from a permeate side (Iyer discloses a membrane separation structure—Iyer’s structure 70, includes distinct but continuous sections 70a, 70b and 70c, and Iyer discloses that the middle portion 70b acts as heat exchanger core for enhanced transport mechanism to take place, Iyer [0061]. Gas passing through Iyer’s section 70a is a permeate, and therefore, the separation membrane 70 is heated from a permeate side via section 70b.) Regarding claim 6: Modified Iyer discloses that t he mixed gas separation method according to claim 1, wherein the difference ΔT between said feed temperature and said permeate temperature is less than 60% of A·ΔP (Iyer’s ΔT is zero, and A·ΔP is a positive number, and therefore, is less than 60% of A·ΔP , see detailed discussion in claim 1). Regarding claim 11: Modified Iyer discloses that the mixed gas separation method according to claim 1, wherein a permeated gas that permeates through said separation membrane includes a condensable gas (Iyer discloses permeates could be carbon dioxide, which is a condensable gas as admitted in the instant disclosure, Iyer [0044]). Regarding claim 12: Modified Iyer discloses that t he mixed gas separation method according to claim 1, wherein said mixed gas includes one or more kinds of substances selected from among a group consisting of hydrogen, helium, nitrogen, oxygen, water, water vapor, carbon monoxide, carbon dioxide, nitrogen oxides, ammonia, sulfur oxides, hydrogen sulfides, sulfur fluorides, mercury, arsine, hydrogen cyanides, carbonyl sulfides, C1 to C8 hydrocarbons, organic acids, alcohol, mercaptans, ester, ether, ketone, and aldehyde (Iyer discloses carbon dioxide, Iyer [ 0044]). . Regarding claim 13: Iyer discloses a mixed gas separation apparatus comprising: a separation membrane (Iyer’s TPMS wall structure 10, Iyer Fig. 1b, [0045]) ; and a supplier that supplies a mixed gas that contains a plurality of types of gases to said separation membrane (Iyer’s Fig. 1 shows a Feed Gas, the source of that Feed Gas is the claimed “supplier”, Iyer Fig. 1b, [0045]) , wherein said separation membrane (Iyer’s TPMS wall structure 10) separates a gas with high permeability in said mixed gas from said mixed gas by passing said gas with high permeability therethrough (Iyer’s Fig. 1b shows a Permeate gas passing through the membrane structure 10, which would be the claimed “gas with high permeability”, Iyer Fig. 1b, [0045]) , and when ΔP is a difference between a feed pressure and a permeate pressure (Iyer discloses its invention requires operating pressure, the pressure difference between pressure at Feed Gas side and Permeate Gas side is the claimed “ ΔP ”, Iyer Fig. 1b, [0043]) , the feed pressure being a gas pressure on a primary side of said separation membrane (Iyer’s operating pressure at the Feed Gas side, Iyer Fig. 1b, [0043]) , the permeate pressure being a gas pressure on a secondary side of said separation membrane (Iyer’s operating pressure at the permeate side, Iyer Fig. 1b, [0043]) , a difference ΔT between a feed temperature and a permeate temperature, the feed temperature being a gas temperature on the primary side of said separation membrane, the permeate temperature being a gas temperature on the secondary side of said separation membrane (Iyer discloses its invention requires operating temperature, and the temperature at Feed Gas side would be the claimed “feed temperature” and the temperature at Permeate Gas side would be the claimed “permeate temperature,” temperature difference between Feed Gas and Permeate Gas would be the claimed “ difference ΔT ,” Iyer Fig. 1b, [0043]) , Iyer does not explicitly disclose the difference ΔT is made less than 90% of A·ΔP by setting an Nu number in said mixed gas to be greater than or equal to 2 and less than or equal to 10 and A is a Joule-Thomson coefficient . However, Iyer discloses a Nusselt number of 3.66 at constant temperature boundary condition. Iyer [0074]. Iyer therefore discloses a Nusselt number falls within the claimed range of “ greater than or equal to 2 and less than or equal to 10 .” Additionally, Iyer discloses a “ difference ΔT ” of zero because it is “constant temperature.” Iyer [0074]. Furthermore, Iyer discloses its invention has a “pressure d r op.” Iyer [0058]. It is therefore understood that Iyer discloses a ΔP that is positive. One ordinary skill in the art at the time of filing understands that for the claimed relationship of ΔT < 90%A·ΔP to be valid, all it requires is for A·ΔP to be a positive number. Since ΔP is positive as discussed earlier, the claimed relationship would be valid if a Joule-Thomson coefficient A is a positive number. Iyer does not disclose its Joule-Thomson coefficient A is a positive number. In the analogous art of gas separation membranes, Colling discloses a method of separation gas mixtures. Colling Fig. 1, [0003]. Similar to Iyer, Colling discloses a separation membrane. Colling Fig. 1, [0011] and Iyer [0048]. Colling discloses that for polymeric membranes, a large pressure gradient across the membrane would supply the driving force for permeation. This driving force would induce a cooling in the membrane (for materials with positive Joule-Thomson coefficients) in order to produce the low pressure permeate. Colling Fig. 1, [0011]. It would therefore have been obvious for one ordinary skill in the art at the time of filing to include a positive Joule-Thomson coefficients materials in the feed gas for the purpose of creating a large pressure gradient across the membrane. Iyer discloses a need for high pressure drop in some zones, and adding a positive Joule-Thomson coefficients materials would facilitate the forming of high pressure drop zone. With such modification, modified Iyer would disclose the claimed relationship of ΔT < 90% of A·ΔP with ΔT being zero, and 90% of A·ΔP being > 0. Claim s 2 , 5, 7–10 are rejected under 35 U.S.C. 103 as being unpatentable over Iyer in view of Colling as applied to claim 1 above, and further in view of Noda et a., US 2021 / 0016233 A1 (“Noda”) . Regarding claim 2: Modified Iyer does not disclose that t he mixed gas separation method according to claim 1, wherein in said operation b), the difference ΔP between said feed pressure and said permeate pressure is greater than or equal to 3.0 MPa. In the analogous art of carbon dioxide gas separation, Noda discloses a gas separation membrane configured to separate carbon dioxide. Noda Fig. 1, [00 11 ] and [0022] . Noda discloses a n initial gas pressure of the mixed gas supply, is in the range of 0.1 to 20.0 MPa. Noda [00 91 ]. Noda also discloses a permeation side pressure of 0.101 MPa. Noda [00 93 ]. Noda therefore gives a ΔP of 10-0.101=0.9899 MPa when we select the initial gas pressure to be 10 MPa, which falls within the claimed range of greater than or equal to 3.0 MPa. It would have been obvious to further modify Iyer to use the proposed pressure for carbon dioxide separation because Noda discloses its invention reduce energy required for fluid separation performed under high temperatures . Noda [00 10 ]. Regarding claim 5: Modified Iyer does not disclose that the mixed gas separation method according to claim 1, wherein in said operation b), a space on said permeate side of said separation membrane is insulated from an ambient atmosphere having a lower temperature than said space on said permeate side. In the analogous art of carbon dioxide gas separation, Noda discloses a thermal insulation part 242 that is arranged around its gas separation membrane 1 to thermally insulate the interior from the surroundings. Noda Fig. 9, [0120]. It would therefore have been obvious for one ordinary skill in the art at the time of filing to include Noda’s thermal insulation part 242 to thermally insulate the interior from surrounding to avoid unnecessary heat loss. Regarding claim 7: Modified Iyer does not disclose that the mixed gas separation method according to claim 1, wherein said separation membrane has a tube-like shape, and said separation membrane has an equivalent diameter of greater than or equal to 2 mm and less than or equal to 5 mm. However, Iyer discloses that its structure can be used in various configurations to support different materials and functions within the carbon capture system. Iyer [0045]. Additionally, in the analogous art of carbon dioxide gas separation, Noda discloses a membrane 12 on a honeycomb shaped support 11. Noda Fig. 2 , [0056]. Noda’s membrane 12 therefore has a tube-like shape as shown in Fig. 2. Noda Fig. 2, [0054]. Noda discloses that membrane 12 forms through holes 111, with distance between the central axes of each pair of adjacent through holes 111 is , for example, in the range of 0.3 mm to 10 mm . Noda Fig. 2, [0056]. Noda also discloses its support 11 has a wall thickness of 0.1 to 10 mm. Noda Fig. 2, [0056]. Noda’s Fig. 2 shows its support 11 and throu gh holes 111 with identical vertical height. Noda Fig. 2. Noda’s through hole 111 therefore have a diameter of about 4.5 mm if one chooses distance between the central axes of each pair of adjacent through holes 111 to be 9 mm. Noda discloses its invention reduces energy required for fluid separation performed under high temperatures. Noda [0010]. It would have been obvious for one ordinary skill in the art at the time of filing for Iyer’s membrane to form in a honeycomb shape because Iyer discloses its structured can be used in various configurations and honeycomb is disclosed in the carbon dioxide separation art as being suitable as membrane separation. Additionally, one ordinary skill in the art at the time of filing would be motivated to use Noda’s honeycomb shape to r educes energy required for fluid separation performed under high temperatures . With such modification modified Iyer’s separation membrane would have an equivalent diameter of 4.5 mm, falling within the claimed range of greater than or equal to 2 mm and less than or equal to 5 mm. Regarding claim 8: Modified Iyer discloses that t he mixed gas separation method according to claim 7, wherein said separation membrane has a cylinder-like shape into which said mixed gas is supplied (Noda discloses its support could be circular cylindrical shaped, Noda Fig. 2, [0056]), and said equivalent diameter is an inner diameter of said separation membrane (the equivalent diameter of Noda is calculated based on d istance between the central axes of each pair of adjacent through holes 111 , which is an inner diameter of the separation membrane, Noda Fig. 2, [0056]) . Regarding claim 9: Modified Iyer does not disclose that t he mixed gas separation method according to claim 1, wherein said separation membrane is a zeolite membrane. However, Noda discloses its separation membrane is zeolite membrane. Noda [0020]. Noda discloses zeolite structure reduces energy required for fluid separation performed under high temperatures. Noda Abstract. It would therefore have been obvious for one ordinary skill in the art at the time of filing to use Noda’s zeolite to make Iyer’s TPMS structure for the benefits of reducing energy consumption. Regarding claim 10: Modified Iyer discloses that t he mixed gas separation method according to claim 9, wherein said zeolite membrane is composed of a zeolite in which an 8-membered ring is maximum (Noda discloses the maximum number of membered rings in zeolite is preferably 8 or less, Noda [0064]). Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Iyer in view of Colling as applied to claim 1 above, and further in view of Tanaka et al., US 2020 / 0114307 A1 (“Tanaka”). Regarding claim 3: Modified Iyer does not disclose that t he mixed gas separation method according to claim 1, wherein a gradient of an Nu plot relative to U is greater than or equal to 1 and less than or equal to 5, where Nu is the Nu number in said mixed gas and U is a linear velocity (m/sec) of said mixed gas. In the analogous art of gas separation using membrane, Tanaka discloses that a flow rate of a supply gas is preferred to be adjusted such that the supply gas can be mixed in such a manner that the concentration of gas in the vicinity of gas with a low permeability in the supply gas matches the concentration in the entire gas . Tanaka [0085]. Tanaka discloses a preferred linear velocity of 1 mm/sec. Tanaka [0085]. It would therefore have been obvious for one ordinary skill in the art at the time of filing for Iyer as modified in claim 1 to use a linear velocity as disclosed by Tanaka such that that the concentration of gas in the vicinity of gas with a low permeability in the supply gas matches the concentration in the entire gas . With such modification, Iyer as modified would have a gradient of an Nu plot relative to U of 3.66/1 =3.66, which falls within the claimed range of greater than or equal to 1 and less than or equal to 5 . Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to FILLIN "Enter examiner's name" \* MERGEFORMAT QIANPING HE whose telephone number is FILLIN "Phone number" \* MERGEFORMAT (571)272-8385 . The examiner can normally be reached on FILLIN "Work schedule?" \* MERGEFORMAT 7:30-5:00 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, FILLIN "SPE Name?" \* MERGEFORMAT Jennifer Dieterle can be reached on FILLIN "SPE Phone?" \* MERGEFORMAT (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 an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see https://ppair-my.uspto.gov/pair/PrivatePair. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /Qianping He/ Examiner, Art Unit 1776
Read full office action

Prosecution Timeline

Nov 30, 2023
Application Filed
Dec 04, 2025
Non-Final Rejection — §103, §112
Mar 18, 2026
Response Filed

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12594518
AIR PURIFICATION APPARATUS
2y 5m to grant Granted Apr 07, 2026
Patent 12589345
FILTER ISOLATION FOR REDUCED STARTUP TIME IN LOW RELATIVE HUMIDITY EQUIPMENT FRONT END MODULE
2y 5m to grant Granted Mar 31, 2026
Patent 12558641
HONEYCOMB FILTER
2y 5m to grant Granted Feb 24, 2026
Patent 12551834
HONEYCOMB FILTER
2y 5m to grant Granted Feb 17, 2026
Patent 12544702
PILLAR-SHAPED HONEYCOMB STRUCTURE AND METHOD FOR MANUFACTURING SAME
2y 5m to grant Granted Feb 10, 2026
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

1-2
Expected OA Rounds
68%
Grant Probability
80%
With Interview (+11.7%)
2y 11m
Median Time to Grant
Low
PTA Risk
Based on 248 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in for Full Analysis

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

Free tier: 3 strategy analyses per month