Prosecution Insights
Last updated: April 18, 2026
Application No. 18/690,183

METHOD FOR PURIFYING HYDROCARBON FEEDSTOCK IN AN AQUEOUS MEDIUM AND USE THEREOF

Final Rejection §103
Filed
Mar 07, 2024
Examiner
NGUYEN, TAM M
Art Unit
1771
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Totalenergies One Tech
OA Round
2 (Final)
78%
Grant Probability
Favorable
3-4
OA Rounds
2y 9m
To Grant
88%
With Interview

Examiner Intelligence

Grants 78% — above average
78%
Career Allow Rate
746 granted / 963 resolved
+12.5% vs TC avg
Moderate +11% lift
Without
With
+10.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
68 currently pending
Career history
1031
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
51.2%
+11.2% vs TC avg
§102
16.7%
-23.3% vs TC avg
§112
18.7%
-21.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 963 resolved cases

Office Action

§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 . Response to Amendment The rejection of claims 7 and 10 under 35 USC § 112 is withdrawn by the examiner in view of the amendment filed on 2/24/2026. Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. 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. Claims 1–17 are rejected under 35 U.S.C. §103 as being unpatentable over US 2014/0303421 A1 (hereinafter “Bennett”) in view of WO 2021/204817 A1 (hereinafter “Adam”). Bennett teaches a process for treating hydrocarbon oils comprising contacting a hydrocarbon oil with an aqueous caustic solution including strong bases such as NaOH, KOH, and Ca(OH)₂, followed by mixing and phase separation to obtain a treated oil phase.(see Bennett ¶[0045]–[0047]; ¶[0060]–[0063]). Bennett further teaches removal of contaminants including metals, metalloids, and particulates from the hydrocarbon stream via such aqueous treatment (see Bennett ¶[0035]–[0038]). Bennett also teaches that multiple washing and separation steps using different process solutions may be employed depending on the contaminants present in the hydrocarbon stream. (see Bennett ¶[0055]–[0058]) Adam teaches that pyrolysis oils derived from plastic waste contain contaminants including alkali metals, alkaline earth metals, and halogen-containing compounds that must be removed prior to downstream catalytic processing (see Adam ¶[0007]–[0010]). Adam further teaches that such contaminants poison hydrotreating catalysts and therefore must be reduced prior to hydrogenation (see Adam ¶[0025]–[0028]). Adam additionally teaches performing purification steps including washing, adsorption, or other contaminant removal steps prior to hydrotreatment, followed by hydrogenation of the purified oil (see Adam ¶[0030]–[0035]). Accordingly, the use of adsorption or polishing steps does not require reliance on an additional reference such as Brunetti It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to apply the aqueous caustic treatment process of Bennett to pyrolysis oil as taught by Adam, since both references relate to purification of hydrocarbon oils containing contaminants, and such substitution represents a predictable use of known purification techniques. It would have been further obvious to include an additional washing step using neutral or acidic water after the caustic treatment in order to remove residual alkali or alkaline earth metal species, since Bennett expressly teaches that multiple washing steps and different process solutions may be employed depending on contaminants present (¶[0055]–[0058]), and Adam provides motivation to remove such metal contaminants to prevent catalyst poisoning prior to hydrogenation (¶[0025]–[0028]). It would have been further obvious to control the residual metal (cation) concentration to low levels, including ppm levels such as ≤2 ppm, as this represents a result-effective variable dependent on the degree of purification required for downstream catalytic processing, and optimization of such purification levels would have been within the level of ordinary skill in the art (see Adam ¶[0025]–[0028]). It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Bennet by including a hydrogenation step after purification, as expressly taught by Adam (¶[0030]–[0035]) because Bennett teaches that the conditioned oil can further be treated in a refinery process. Claim 2 Bennett expressly teaches that the aqueous caustic solution may include NaOH, KOH, and Ca(OH)₂, which are strong bases in aqueous solution (see Bennett ¶[0045]–[0047]). Therefore, the specific selection of a strong base as recited in claim 2 is explicitly taught by Bennett. Claim 3 Bennett teaches that the amount and concentration of caustic solution may be adjusted depending on the contaminant level and desired purification efficiency (see Bennett ¶[0055]–[0058]). It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to select an appropriate concentration or amount of base, as this is a result-effective variable routinely optimized to achieve desired contaminant removal. Claim 4 Bennett teaches mixing, contacting, and phase separation of aqueous and hydrocarbon phases, with process conditions selected based on treatment requirements (see Bennett ¶[0060]–[0063]). Optimization of contacting conditions such as temperature, residence time, and mixing intensity would have been obvious as routine process optimization. Claim 5 Bennett expressly teaches phase separation of the treated hydrocarbon phase from the aqueous phase after caustic treatment (see Bennett ¶[0060]–[0063]). Claim 6 Bennett teaches that multiple washing steps using different solutions may be employed depending on contaminants present (see Bennett ¶[0055]–[0058]). Adam teaches purification steps including washing prior to hydrotreatment (see Adam ¶[0030]–[0035]). It would have been obvious to include a neutral or acidic water wash following caustic treatment to remove residual basic species. Claim 7 Bennett expressly teaches that multiple washing steps may be performed depending on the purification requirements (see Bennett ¶[0055]–[0058]). Thus, repeating washing steps or employing multi-stage washing is explicitly suggested. Claim 8 Neither reference explicitly discloses a specific value of ≤2 ppm; however: Bennett teaches removal of metals via aqueous treatment Adam teaches that metal contaminants must be reduced to prevent catalyst poisoning (see Bennett ¶[0035]–[0038]; Adam ¶[0025]–[0028]). It would have been obvious to optimize residual metal concentration to very low levels, including ppm levels, as a result-effective variable depending on downstream catalyst sensitivity. Claim 9 Adam expressly teaches that purified pyrolysis oil is subjected to hydrogenation after contaminant removal (see Adam ¶[0030]–[0035]). Claim 10 Adam teaches hydrotreating/hydrogenation of purified pyrolysis oils under conditions suitable for catalyst operation (see Adam ¶[0030]–[0035]). Selection of specific hydrogenation conditions (temperature, pressure, catalyst) is routine optimization. Claim 11 Adam explicitly teaches that pyrolysis oils contain halogen-containing compounds that must be removed prior to catalytic processing (see Adam ¶[0007]–[0010]). Bennett’s caustic washing process removes contaminants including ionic and polar species, which would include halogen-derived species. Claim 12 Adam teaches removal of sulfur-containing contaminants prior to hydrogenation(see Adam ¶[0007]–[0010]; ¶[0025]–[0028]). Bennett’s aqueous caustic treatment removes polar contaminants, including sulfur-containing species. Claim 13 Adam teaches removal of nitrogen-containing compounds prior to hydrotreatment.(see Adam ¶[0007]–[0010]; ¶[0025]–[0028]) Claim 14 Adam explicitly teaches that pyrolysis oils may contain alkali and alkaline earth metals that must be removed (see Adam ¶[0007]–[0010]). Bennett teaches removal of metals via aqueous treatment (see Bennett ¶[0035]–[0038]). Claim 15 Adam teaches that purified pyrolysis oil is subsequently subjected to hydrotreatment and catalytic processing (see Adam ¶[0030]–[0035]). Claim 16 Adam explicitly teaches a sequence of purification followed by hydrogenation.(see Adam ¶[0030]–[0035]) Bennett provides the purification step, and Adam provides the process sequence, making the claimed sequence obvious. Claim 17 The combination of: caustic treatment (Bennett) washing steps (Bennett + Adam) hydrogenation (Adam) represents a predictable combination of known process steps used in hydrocarbon refining. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to combine these steps to achieve improved purification and downstream processing performance. Response to Arguments Applicant argues that US 2014/0303421 A1 does not teach a basic treatment followed by neutral/acidic washing, and that reversing the order would render Bennett unsatisfactory (citing In re Gordon). This argument is not persuasive. Bennett expressly teaches that multiple washing steps and different process solutions may be employed depending on contaminants present (¶[0055]–[0058]), indicating flexibility in treatment sequence. The rejection relies on the combination with WO 2021/204817 A1, which teaches removal of alkali metals prior to hydrogenation to prevent catalyst poisoning (¶[0025]–[0028]). The addition of a post-caustic wash addresses residual metal removal, not TAN reduction, and therefore does not render Bennett unsatisfactory for its intended purpose. Applicant argues Bennett does not disclose washing after caustic treatment. This argument is not persuasive. Bennett teaches phase separation and multiple washing steps using different solutions (¶[0055]–[0058]; ¶[0060]–[0063]). It would have been obvious to include a neutral or acidic wash to remove residual caustic species, especially in view of Adam’s teaching of purification prior to hydrotreatment (¶[0030]–[0035]). Applicant argues Bennett does not disclose the claimed base concentration or that the base is in solution. This argument is not persuasive. Bennett teaches aqueous caustic solutions of strong bases (NaOH, KOH, Ca(OH)₂) (¶[0045]–[0047]). An aqueous caustic solution inherently requires the base to be dissolved in water. The claimed concentration range represents a routine optimization of a result-effective variable. Applicant argues the claimed pH (>10) differs from Bennett. This argument is not persuasive. The strong bases disclosed by Bennett inherently produce high pH solutions, and the specific pH or concentration is a design choice dependent on contaminant removal requirements. Applicant argues the prior art does not disclose ≤2 ppm cation.This argument is not persuasive. Bennett teaches removal of metal contaminants (¶[0035]–[0038]), and Adam teaches the necessity of reducing such contaminants to prevent catalyst poisoning (¶[0025]–[0028]). The claimed value represents a degree of purification (result-effective variable) that would have been optimized by one of ordinary skill in the art. Applicant argues Bennett does not disclose hydrogenation. This argument is not persuasive. Adam expressly teaches hydrogenation following purification (¶[0030]–[0035]), providing clear motivation to include this step. Applicant’s examples showing reduction of sodium content are not persuasive. The observed reduction is an expected result of water washing of ionic species and does not demonstrate unexpected results or criticality. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to TAM M NGUYEN whose telephone number is (571)272-1452. The examiner can normally be reached Mon - Frid. 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, Prem C Singh can be reached at 571-273-6381. 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. /TAM M NGUYEN/Primary Examiner, Art Unit 1771
Read full office action

Prosecution Timeline

Mar 07, 2024
Application Filed
Nov 20, 2025
Non-Final Rejection — §103
Feb 24, 2026
Response Filed
Mar 30, 2026
Final Rejection — §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

3-4
Expected OA Rounds
78%
Grant Probability
88%
With Interview (+10.9%)
2y 9m
Median Time to Grant
Moderate
PTA Risk
Based on 963 resolved cases by this examiner. Grant probability derived from career allow rate.

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