Prosecution Insights
Last updated: April 19, 2026
Application No. 18/250,500

PROCESSING OF TORREFACTION GAS

Non-Final OA §102§103
Filed
Apr 25, 2023
Examiner
SPEER, JOSHUA MAXWELL
Art Unit
1736
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Rwe Generation Nl B V
OA Round
1 (Non-Final)
87%
Grant Probability
Favorable
1-2
OA Rounds
3y 3m
To Grant
79%
With Interview

Examiner Intelligence

Grants 87% — above average
87%
Career Allow Rate
53 granted / 61 resolved
+21.9% vs TC avg
Minimal -8% lift
Without
With
+-8.2%
Interview Lift
resolved cases with interview
Typical timeline
3y 3m
Avg Prosecution
32 currently pending
Career history
93
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
39.7%
-0.3% vs TC avg
§102
29.0%
-11.0% vs TC avg
§112
29.3%
-10.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 61 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 Election/Restrictions Claims 8-14 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Group II, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 2/3/2026. Claim Rejections - 35 USC § 102/103 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. 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. Claim(s) 1 is rejected under 35 U.S.C. 102(a)(1) as anticipated by or, in the alternative, under 35 U.S.C. 103 as unpatentable over US 20130247448 A1 Ampulski et al. Claim 1 requires “A method for processing a torrefaction gas (202), in which the torrefaction gas (202) is substoichiometrically oxidized in a burning chamber (402) with an oxygen rich gas (404) comprising at least 95 Vol.-% oxygen and a fuel gas”. Ampulski et al. discloses “The torrefaction unit 112 has two or more areas to segregate out and then route the non-condensable gases including the C1 to C4 olefins, as well as other gases including CO, CH4, CO2 and H2, through a supply line to the catalytic converter 116 that catalytically transform portions of the non-condensable gases to the syngas components of CO, H2, CO2 in small amounts, and potentially CH4 that are sent in parallel with the portion of syngas components from the biomass gasifier 114 to a combined input to the methanol synthesis reactor 110. The catalytic converter 116 has a control system to regulate a supply of an oxygenated gas and steam along with the non-condensable gases to the catalytic converter 116, which produces at least H2, and CO as exit gases.” [0020]. It is understood that the gasses proceeding from a torrefaction unit are torrefaction gasses, CH4 is a fuel gas, the O2 stream is substantially pure (i.e. above 95%), and that the reaction is substoichiometric as to O2 because the products are partially oxidized (H2 and CO) instead of fully oxidized (H2O and CO2). Claim 1 further requires “by which larger hydrocarbon molecules which originate from the torrefaction gases (202) and/or the fuel gas (403) are thermally cracked generating a syngas”. Ampulski et al. discloses C1-C4 olefins are converted to H2 and CO, this is understood to be large hydrocarbons from the torrefaction gas being thermally cracked. Or alternatively, to the extent that the O2 of Ampulski et al. is not substantially pure O2, but rather any gas mixture that comprises O2 (no such concession is given) the selection of substantially pure O2 in the method of Ampulski et al. would have been obvious to one of ordinary skill in the art. This is because using substantially pure O2 would reduce side-product formation and therefore beneficially and predictably result in a purer resulting syngas. Claim Rejections - 35 USC § 103 Claim(s) 2-6 is/are rejected under 35 U.S.C. 103 as being unpatentable over US 20130247448 A1 Ampulski et al., in view of US 20130109765 A1 Jiang et al. Regarding Claim 2, all of the limitations of Claim 1 are taught by, or obvious over Ampulski et al. Claim 2 further requires “the syngas (407) is quenched by bringing the syngas (407) in contact with a recycled syngas (406) stream having a temperature smaller than the syngas (407).”. Ampulski et al. discloses “The quench unit 708” [0075], but does not provide details to how the quenching occurs. Jiang et al. is similarly directed to methods of treating syngas streams which may arise from torrefaction (“The feedstock dryer may be operable to provide an ultra-low level of HO (e.g., 0 weight percent to 30 wt.%, 10 wt.% to 30 wt. %, 15 wt.% to 30 wt.%, or even substantially 0 wt %, for example, with torrefaction) in the synthesis gas, suitable for subsequent downstream conditioning.” [0100]). Jiang et al. discloses “It is also noted herein that, in embodiments, at least a portion of the FT tailgas may be …, and/or may be recycled to a quench apparatus 340 of a synthesis gas conditioning apparatus such as 300' in order to cool the hot gas exiting a syngas conversion apparatus 330 (e.g., to a temperature below which ash particles and/or aerosols present therein will not adhere to heat transfer and/or other downstream apparatus).” [0085]. Because the Fischer-Tropsch (FT) process does not usually have a 100% conversion it is understood that a FT tailgas is a gas stream comprising H2 and CO, in other words a recycled syngas. It would have been obvious for one of ordinary skill in the art to have combined the method of Ampulski et al. with the method of Jiang et al. because they are similarly related to methods of treating syngas originating from a torrefaction process. The motivation for using the recycled syngas to quench the hot syngas as suggested by Jiang et al. would be to protect downstream equipment from ash and aerosols that may be present in the fresh syngas. Regarding Claim 3, all of the limitations of Claims 1 and 2 are taught by the combination of Ampulski et al. in view of Jiang et al. Claim 3 further requires “the quenched syngas (406) is provided to a heat recovery system (410), in which at least one of the following heat transfers is performed: a) heating a thermal carrier (411); b) generating high pressure steam (413) from boiler feed water (412); and c) superheating low-pressure steam (415).”. Jiang et al. discloses “The heat recovery apparatus may comprise one or more selected from the group consisting of air preheaters (e.g., a combustion air preheater), steam superheaters, waste heat recovery units (e.g., boilers), and economizers. In embodiments, heat recovery generates steam.” [0116]. Regarding Claim 4, all of the limitations of Claims 1 and 2 are taught by the combination of Ampulski et al. in view of Jiang et al. Claim 4 further requires “the quenched syngas (409) is cleaned in a wet scrubbing system (417).”. Jiang et al. discloses “In embodiments, ash water (comprising NaOH and/or Ca(OH)2) is utilized to scrub sulfur from the outlet gases. For example, the system may comprise a scrubbing tower for cleaning the process gas.” [0143]. Regarding Claim 5, all of the limitations of Claims 1-2 and 4 are taught by the combination of Ampulski et al. in view of Jiang et al. Claim 5 further requires “a first part of the cleaned syngas (420) is used as the recycled syngas (406).”. Jiang et al. discloses “It is also noted herein that, in embodiments, at least a portion of the FT tailgas may be …, and/or may be recycled to a quench apparatus 340 of a synthesis gas conditioning apparatus such as 300' in order to cool the hot gas exiting a syngas conversion apparatus” [0085]. Furthermore regarding the location of the scrubber Jiang et al. discloses “water, it may be utilized, in embodiments, as scrubbing water. Such scrubbing may be performed upstream of an ESP or other particulate separator configured to remove particulates.” [0143]. In other words the scrubbing would be performed before particulates were removed and the FT process began, therefore the FT tailgas can be considered cleaned syngas. Regarding Claim 6, all of the limitations of Claims 1-2 and 4 are taught by the combination of Ampulski et al. in view of Jiang et al. Claim 6 further requires “a remaining part (424) of the cleaned syngas (420) is brought into contact with water for cooling and washing.”. Jiang et al. discloses “In embodiments, ash water (comprising NaOH and/or Ca(OH)2) is utilized to scrub sulfur from the outlet gases. For example, the system may comprise a scrubbing tower for cleaning the process gas.” [0143]. It is understood that the gas entering the scrubbing tower, having been used for superheating steam in at least one embodiment of Jiang et al. (see Claim 3) would have a temperature greater than 100 °C and therefore would have been simultaneously cleaned and cooled within the scrubbing tower. Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over US 20130247448 A1 Ampulski et al., in view of US 20130109765 A1 Jiang et al., in further view of US 20150080620 A1 Boon et al. Regarding Claim 7, all of the limitations of Claims 1-6 are taught by the combination of Ampulski et al. in view of Jiang et al. Claim 7 further requires “A method for processing a torrefaction gas (202) generated by the torrefaction of solid recovered fuel pellets (117), wherein the torrefaction gas (202) is processed according to one of the preceding claims.”. Neither Ampulski et al. nor Jiang et al. specifically mention pellets as the form of biomass used for making the torrefaction gas, however Jiang et al. does disclose that a wide variety of carbonaceous materials may be used, including bark and wood, “Many feed materials may serve as carbonaceous sources for gasification, including, for example, shredded bark, wood chips, sawdust, sludges (e.g., sewage sludge), municipal solid waste (MSW), refuse-derived fuel (RDF), and a variety of other carbonaceous materials. [0006]. Boon et al. is similarly directed to methods of treating syngas resulting from torrefaction gasses (“Embodiments of the present invention relate to systems and methods supplying hydrogen to a hydrocatalytic reaction through gasification of a biomass material” [0028]). Boon et al. discloses that the biomass may be in the form of pellets “Additionally, biomass pellets made from wood may also be used. Use of hog fuel generated from an outer layer of wood logs intended for the hydrocatalytic reaction can reduce transport costs, improves process efficiency, as well as reduce carbon dioxide amount associated with transportation of raw material used to generated the biofuel” [0032]. It would have been obvious for one of ordinary skill in the art to have combined the method of Ampulski et al. and Jiang et al. with the method of Boon et al. because they are similarly related to methods of treating syngas originating from a torrefaction process. The motivation for using the biomass in the form of pellets as suggested by Boon et al. would be to reduce transport costs. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to JOSHUA MAXWELL SPEER whose telephone number is (703)756-5471. The examiner can normally be reached M-F 9am-5pm 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, Anthony Zimmer can be reached at 571-270-3591. 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. /JOSHUA MAXWELL SPEER/ Examiner Art Unit 1736 /DANIEL BERNS/Primary Examiner, Art Unit 1736
Read full office action

Prosecution Timeline

Apr 25, 2023
Application Filed
Mar 19, 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
87%
Grant Probability
79%
With Interview (-8.2%)
3y 3m
Median Time to Grant
Low
PTA Risk
Based on 61 resolved cases by this examiner. Grant probability derived from career allow rate.

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