Prosecution Insights
Last updated: April 19, 2026
Application No. 18/389,323

PROCESS FOR REMOVING CARBON DIOXIDE FROM ACETYLENE USING CHA-TYPE ZEOLITE MEMBRANE

Non-Final OA §112
Filed
Nov 14, 2023
Examiner
MENDOZA, WILSON GALLARDO
Art Unit
1772
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Cleveland State University
OA Round
1 (Non-Final)
Grant Probability
Favorable
1-2
OA Rounds
3y 2m
To Grant

Examiner Intelligence

Grants only 0% of cases
0%
Career Allow Rate
0 granted / 0 resolved
-65.0% vs TC avg
Minimal +0% lift
Without
With
+0.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
3 currently pending
Career history
3
Total Applications
across all art units

Statute-Specific Performance

§103
71.4%
+31.4% vs TC avg
§112
28.6%
-11.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 0 resolved cases

Office Action

§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 . Claims 1-20 are pending. Claim Objections Claims 13, 15 and 19 are objected to because of the following informalities: Claim 13 recites “a temperature in a range of from room temperature 20°C to 150 °C” in lines 1-2. It is respectfully suggested to amend the limitation to “a temperature in a range of from Claim 15 recites “a thickness in a range of about 500 nm to about 10 μm” in lines 1-2. It is respectfully suggested to amend the limitation to “a thickness in a range of from about 500 nm to about 10 μm”. Claim 19 recites “the inorganic material is selected from the group consisting of a ceramic sintered body or a sintered metal” in lines 1-2. It is respectfully suggested to amend the limitation to “the inorganic material is selected from the group consisting of a ceramic sintered body and Appropriate corrections are required. 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. 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 applicant regards as his invention. Claims 1, 3-10, 14-15 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. Claims 1, 3-10, 14-15 similarly recite the limitation “CHA-type zeolite membrane”. The term “type” renders claims 1, 3-10, 14-15 indefinite because it is unclear what is intended to be conveyed by the term “type”. See MPEP § 2173.05(b) II. Claims 2-20 are also rejected under 35 U.S. §112 by virtue of its dependence on claim 1. Allowable Subject Matter and Allowed Claims Claims 1-20 are allowed if previously presented objections to claims 13, 15 and 19, and 35 U.S.C 112 (b) rejections to claims 1-20 are resolved. The following is an examiner’s statement of reasons for allowance. A thorough search for pertinent art did not locate any prior art that discloses or suggests the invention recited in claims 1-20. The concept of a process for separating carbon dioxide from acetylene comprising the steps of feeding a feed composition comprising carbon dioxide and acetylene to a separator comprising a zeolite membrane having a CHA framework type topology, and separating the feed composition into a carbon dioxide-rich stream and an acetylene-rich stream (claim 1), is considered novel. A closest prior art to Liu et al. (2021) discloses a process for separating acetylene from carbon dioxide using Cu- decorated FAU (Cu@FAU) zeolite sorbent. Liu et al. (2021) report high adsorption selectivity favoring acetylene over carbon dioxide, arising from strong pi bond-complexation interactions between acetylene molecules and copper sites within the FAU network. The reported selectivity demonstrates that the Cu@FAU material is effective for preferentially adsorbing acetylene relative to carbon dioxide in an adsorption-based separation process. This pertinent prior art relies on adsorptive selectivity rather than membrane permselectivity and employ a FAU framework rather than a CHA-framework. Other pertinent prior art to Wang et al. (2022) discloses a process for separating acetylene from carbon dioxide using ultramicroporous metal-organic framework (MOF) adsorbents. Wang et al. (2022), report high adsorption selectivity favoring acetylene over carbon dioxide, attributable to strong host-guest interactions and pore confinement effects within the MOF structure. The reports selectivity demonstrates that adsorption-based MOF materials can effectively discriminate between acetylene and carbon dioxide. Wang et al. (2022) rely on adsorption mechanisms rather than membrane permeation. Other pertinent prior art to Zhu et al. (2021) discloses a process to separate acetylene from methane and carbon dioxide using ZIF-8 metal organic framework membranes on polyamide substrates. In this prior art, separation is achieved through molecular sieving and diffusional selectivity within the ZIF-8 pore aperture, and the membrane exhibits only slight preferential permeation of acetylene relative to methane and carbon dioxide. The high affinity of the ZIF-8 framework for acetylene and the small kinetic diameter of acetylene are the reasons for the ability to separate acetylene mixtures. The membranes disclosed therein are non-zeolitic, non-CHA framework type, and the reported acetylene selectivity is limited. Other pertinent prior art to Nobandegani et al. (2022) discloses a process for separating carbon dioxide from methane using a tubular CHA membranes and hollow fiber polymeric membranes for industrial use. The separation is achieved through size-sieving and permeability differences between carbon dioxide and methane. The reported performance demonstrates effective permeance selectivity for CO2 over CH4 under industrially relevant conditions. Other pertinent prior art to Liang et. al (2018) discloses a process involving gas permeation though high-silica SSZ-13 zeolite membranes having a CHA framework. Liang et al. (2018) report measurable permselectivity favoring carbon dioxide over larger or more weakly interacting gasses such as CO2/N2 and CO2/CH4, attributable to differences in diffusivity and framework affinity in the CHA pores. The reported permselectivity demonstrates that the CHA zeolite membranes are effective for separating carbon dioxide from gases such as methane and nitrogen. The cited prior art, alone or in combination do not teach or suggest a process for the separation of carbon dioxide and acetylene using a CHA-framework zeolite membrane, comprising the steps of feeding a feed composition comprising carbon dioxide and acetylene to a separator comprising a CHA-framework zeolite membrane and separating the feed composition into a carbon dioxide-rich stream and an acetylene-rich stream, as recited in claim 1 of claimed invention. Conclusion Any inquiry concerning this communication or earlier communication from the examiner Any inquiry concerning this communication or earlier communication from the examiner should be directed to Wilson Mendoza whose telephone number is (571) 272-8443. The examiner can normally be reached on Monday – Friday from 9:00 AM until 5:00 PM. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, an applicant is encouraged to use the USPTO Automated Interview request at http://www.uspto.gov.intwerviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, In Suk Bullock can be reached on 571-272-5954. The fax phone number for the organization where this application or processing is assigned is 571-273-8300. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, In Suk Bullock can be reached on 571-272-5954. The fax phone number for the organization where this application or processing 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 PAIR system, see http://pair-direct.uspto.gov. Should you have any 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 Serv ice Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /WILSON GALLARDO MENDOZA/Examiner, Art Unit 1772 /YOUNGSUL JEONG/Primary Examiner, Art Unit 1772
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Prosecution Timeline

Nov 14, 2023
Application Filed
Mar 06, 2026
Non-Final Rejection — §112 (current)

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Prosecution Projections

1-2
Expected OA Rounds
Grant Probability
3y 2m
Median Time to Grant
Low
PTA Risk
Based on 0 resolved cases by this examiner. Grant probability derived from career allow rate.

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