Prosecution Insights
Last updated: April 19, 2026
Application No. 18/546,906

METHOD AND APPARATUS FOR DRYING A PROCESS GAS

Non-Final OA §103§112
Filed
Aug 17, 2023
Examiner
SLAUGOVSKY, RACHEL MARIE
Art Unit
1776
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Highview Enterprises Limited
OA Round
1 (Non-Final)
62%
Grant Probability
Moderate
1-2
OA Rounds
2y 10m
To Grant
89%
With Interview

Examiner Intelligence

Grants 62% of resolved cases
62%
Career Allow Rate
13 granted / 21 resolved
-3.1% vs TC avg
Strong +27% interview lift
Without
With
+27.2%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
39 currently pending
Career history
60
Total Applications
across all art units

Statute-Specific Performance

§101
2.6%
-37.4% vs TC avg
§103
45.5%
+5.5% vs TC avg
§102
22.9%
-17.1% vs TC avg
§112
23.6%
-16.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 21 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 . Election/Restrictions Applicant’s election without traverse of claims 1-4, 6, and 9-12 in the reply filed on December 5th, 2025 is acknowledged. Claims 13-17 and 19-24 stand withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on December 5th, 2025. Claim Objections Claim 12 is objected to because of the following informalities: “wherein the apparatus is configured to change the selection one of the first and second” should read “wherein the apparatus is configured to change the selection of one of the first and second”. Appropriate correction is 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. Claim 6 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 6 recites the limitation “wherein, during a regeneration process, the heater is activated for a first time period to heat the regeneration gas and is then deactivated for a second time period, the regeneration gas being supplied throughout the regeneration process.” A single claim which claims both an apparatus and the method steps of using the apparatus is indefinite under 35 U.S.C. 112(b), as it is unclear when direct infringement occurs. See MPEP § 2173.05(p)(II). Applicant may consider amending the claim to read “wherein, the apparatus is configured to, during a regeneration process, activate the heater for a first time period to heat the regeneration gas and then deactivate the heater for a second time period, the regeneration gas configured to be supplied throughout the regeneration process.” 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 1-4, 6, and 9-12 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Publication No. US 2018/0200664 A1 to Tafreshi et al. (hereinafter referred to as Tafreshi), and further in view of U.S. Patent Publication No. US 2020/0088466 A1 to White et al. (hereinafter referred to as White). Regarding claim 1, Tafreshi teaches an apparatus for drying a process gas (¶0001 “The present disclosure relates to the field of gas dehydration units that utilize adsorption beds”), the apparatus comprising: a principal unit (Fig. 2, acid gas removal unit 9) having an inlet for receiving a process gas (Fig. 2, acid gas removal unit 9 receives gas feed stream 1), and an outlet for discharging the process gas (¶0008 “Gas from an acid gas removal unit is fed into the feed gas inlet(s) of the vessel(s) in adsorption mode.”); a first supplemental adsorption unit comprising an adsorbent for adsorbing water (¶0006 “dehydration of a gas such as natural gas feed stream 1 is typically done by flowing a wet gas 23 over a bed of zeolite-based molecular sieve adsorbent material in a vessel 2A.”); and a second supplemental adsorption unit comprising an adsorbent for adsorbing water (¶0013 “The gas dehydration unit includes at least two adsorbent bed containing vessels (2A, 2A, and 2R) arranged in parallel.”); wherein the apparatus is configured to fluidly connect the outlet of the principal unit to at least one of the first and second supplemental adsorption units (¶0014 “The moisture containing gas 23 may be provided from an acid gas removal unit (AGRU) 9 is fed into the feed gas inlet(s) of the vessel(s) 2A in adsorption mode.” ; Fig. 2, feed gas inlets 28, 26), the at least one of the first and second adsorption units being operable to adsorb water to dry the process gas discharged from the principal adsorption unit (¶0014 “Vessels 2A are shown in dehydration mode or adsorption mode, such that moisture containing gas 23 enters at the top of the vessels and dehydrated gas 4 exits at the bottom of the vessels.”). Tafreshi is silent on the exact capture mechanize of the acid gas removal unit and does not teach wherein the principal unit receives a process gas from a compressor (it should be noted that Tafreshi does teach a compressor (Fig. 2, compressor 8) but it is used in the regeneration loop as a way to transfer gas back to the acid gas removal unit). However, White teaches a gas separation apparatus that contains a compressor (Fig. 1, compressor 102) which provides a compressed gas stream to an acid gas removal unit (Fig. 1, acid gas removal unit 103), wherein the acid gas removal unit utilizes an adsorbent bed (¶0043 “There are several options for acid gas removal, including pressure swing adsorption, vacuum swing adsorption”). White further teaches that the inclusion of a compression component allows for the control of pressure (¶0050 “One advantage offered by permeate compressor 102 is that the pressure of stream 10 entering the first heat exchanger can be optimized.”). Tafreshi and White are considered analogous to the claimed invention because they are in the same field of gas separation using adsorption beds. 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 apparatus as taught by Tafreshi to further include the compressor and adsorption bed as an acid gas removal unit as taught by White. The inclusion of a compressor would allow for closer pressure regulation and adjustments. As to the use of an adsorption bed for the acid gas removal unit, such a substitution of removal techniques would result in a predictable result (removal of acid gas components from the feed stream); a simple substitution of one known element for another to obtain predictable results supports a prima facie case of obviousness. See MPEP § 2143(I)(B). Regarding claim 2, Tafreshi and White teach the apparatus as applied to claim 1 above. Tafreshi further teaches wherein the apparatus is configured to fluidly connect a selected one of the first and second supplemental adsorption units to the outlet of the principal adsorption unit, the selected one of the first and second supplemental adsorption units drying the process gas and discharging a dry process gas (¶0014 “Vessels 2A are shown in dehydration mode or adsorption mode, such that moisture containing gas 23 enters at the top of the vessels and dehydrated gas 4 exits at the bottom of the vessels. The moisture containing gas 23 may be provided from an acid gas removal unit (AGRU) 9 is fed into the feed gas inlet of the vessel 2A in adsorption mode.”). Regarding claim 3, Tafreshi and White teach the apparatus as applied to claim 2 above. Tafreshi further teaches wherein the apparatus is configured to supply a regeneration gas to the other one of the first and second supplemental adsorption units to regenerate the adsorbent disposed therein (¶0018 “The adsorbent is regenerated in vessel 2R at high temperature by flowing a regeneration gas 3 over the bed of molecular sieve adsorbent material in vessel 2R.” ; ¶0013 “As shown, those vessels in adsorption mode also referred to as dehydration mode are labeled 2A while those vessels in regeneration mode are labeled 2R.”). Regarding claim 4, Tafreshi and White teach the apparatus as applied to claim 3 above. Tafreshi further teaches wherein the regeneration gas comprises at least a portion of the dry process gas discharged from the selected one of the first and second supplemental adsorption units (¶0018 “The regeneration gas 3 is typically initiated by taking a slip stream of filtered dried process gas 4 using valve 15 in a conduit in communication with the dried gas outlet(s) 22, 20 of the vessel(s) in adsorption mode 2A.”). Regarding claim 6, Tafreshi and White teach the apparatus as applied to claim 3 above. Tafreshi further teaches a heater for heating the regeneration gas (¶0018 “The regeneration gas 3 is heated in heater 10 to a temperature sufficient to desorb water”); wherein, during a regeneration process, the heater is activated for a first time period to heat the regeneration gas (¶0008 “A heater heats the regeneration gas prior to passing the regeneration gas to the vessel in regeneration mode to a temperature sufficient to desorb the water from the molecular sieve material.”), the regeneration gas being supplied throughout the regeneration process (¶0009 “The vessel in regeneration mode remains in regeneration mode until the water has been sufficiently desorbed”). Although Tafreshi does not explicitly teach wherein the heater is then deactivated for a second time period, when the structure recited in the reference is substantially identical to that of the claimed invention, claimed properties or functions are presumed to be inherent. That is to say the apparatus as taught by Tafreshi is capable of performing such a function. See MPEP § 2112.01(I). Regarding claim 9, Tafreshi and White teach the apparatus as applied to claim 3 above. Tafreshi further teaches wherein the apparatus is configured to introduce the regeneration gas into the principal adsorption unit after being supplied to the other one of the first and second supplemental adsorption units (¶0023 “In one embodiment, system 100 further includes a conduit 30 for passing the regeneration gas stream from the compressor to a location upstream of the AGRU 9.” ; Fig. 2, regeneration gas 3 passes through vessel 2R in regeneration mode before being cycled through compressor 8 and upstream of AGRU 9). Although Tafreshi does not explicitly teach wherein the regeneration gas is supplied to the principal adsorption unit for regeneration of the adsorbent, when the structure recited in the reference is substantially identical to that of the claimed invention, claimed properties or functions are presumed to be inherent. That is to say the apparatus as taught by Tafreshi is capable of performing such a function. See MPEP § 2112.01(I). Regarding claim 10, Tafreshi and White teach the apparatus as applied to claim 9 above. Tafreshi further teaches a cooler for cooling the regeneration gas prior to introduction into the principal adsorption unit (Fig. 2, regeneration gas cooler 5 is located between the supplemental adsorption vessel 2R and the AGRU 9). Regarding claim 11, Tafreshi and White teach the apparatus as applied to claim 9 above. Tafreshi further teaches a compressor for compressing the regeneration gas prior to introduction into the principal adsorption unit (Fig. 2, compressor 8 is located between the supplemental adsorption unit 2R and the AGRU 9). Regarding claim 12, Tafreshi and White teach the apparatus as applied to claim 2 above. Tafreshi further teaches wherein the apparatus is configured to change the selection of one of the first and second supplemental adsorption units such that the other one of the first and second supplemental adsorption units is operative to dry the process gas and discharging a dry process gas (¶0013 “At any given time, one of the at least two vessels is in regeneration mode and the other(s) of the at least two vessels is (are) in adsorption mode. The vessel in regeneration mode alternates among each of the at least two vessels in a complete cycle.”). Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Naito (US 2018/0236395 A1) teaches a carbon dioxide recovery apparatus that has a principal adsorption unit and two dehydration adsorbent beds. Bresler (US 8337593 B2) teaches a purification system that has multiple adsorbent beds and multiple dryers. Sethna (US 2011/0185896 A1) teaches a method for removing contaminants from a gas stream wherein the feed stream is fed to a first adsorption unit comprising multiple adsorbent beds before passing to a second adsorption unit also comprising multiple adsorbent beds. Any inquiry concerning this communication or earlier communications from the examiner should be directed to RACHEL MARIE SLAUGOVSKY whose telephone number is (571)272-0188. The examiner can normally be reached Monday - Friday 8:30 am - 5:30 pm EST. 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. /RACHEL MARIE SLAUGOVSKY/Examiner, Art Unit 1776 /Jennifer Dieterle/Supervisory Patent Examiner, Art Unit 1776
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Prosecution Timeline

Aug 17, 2023
Application Filed
Jan 20, 2026
Non-Final Rejection — §103, §112 (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
62%
Grant Probability
89%
With Interview (+27.2%)
2y 10m
Median Time to Grant
Low
PTA Risk
Based on 21 resolved cases by this examiner. Grant probability derived from career allow rate.

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