Prosecution Insights
Last updated: April 19, 2026
Application No. 18/842,383

DUAL FUEL ENGINE SYSTEM

Non-Final OA §103
Filed
Aug 28, 2024
Examiner
VILAKAZI, SIZO BINDA
Art Unit
3747
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Shell Usa Inc.
OA Round
1 (Non-Final)
74%
Grant Probability
Favorable
1-2
OA Rounds
2y 11m
To Grant
86%
With Interview

Examiner Intelligence

Grants 74% — above average
74%
Career Allow Rate
529 granted / 715 resolved
+4.0% vs TC avg
Moderate +12% lift
Without
With
+11.7%
Interview Lift
resolved cases with interview
Typical timeline
2y 11m
Avg Prosecution
12 currently pending
Career history
727
Total Applications
across all art units

Statute-Specific Performance

§101
4.1%
-35.9% vs TC avg
§103
43.9%
+3.9% vs TC avg
§102
36.4%
-3.6% vs TC avg
§112
11.8%
-28.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 715 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 . 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. Claim(s) 1-8 are rejected under 35 U.S.C. 103 as being unpatentable over Tanev et al (US 2021/0283581) in view of Yu et al. (US 2021/0363440). Claim 1 Tanev discloses a process for improving the sustainability of a dual-fuel engine system operated with a first liquid fuel and a second gaseous fuel, said process comprising providing to the engine system a first liquid diesel fuel and a methane based gas as the second gaseous fuel, and combusting said fuels in an internal combustion engine system, wherein exhaust gases from combusting said fuels are contacted with a methane oxidation catalyst provided in the exhaust system of said internal combustion engine system, wherein the exhaust gases are contacted with the methane oxidation catalyst such that methane present in the exhaust gases and oxygen are present in an O2:CH4 ratio of at least 2:1 (see paragraphs [0010], [0011] and [0067]-[0070]). While Tanev discloses providing a diesel fuel, Tanev does not explicitly disclose that the diesel fuel is an EN15940 compliant paraffinic gasoil liquid fuel. However Yu discloses the process of producing high paraffinic EN15940 compliant diesel fuels (see paragraphs [0069] and [0070]). It would have been obvious to one having ordinary skill in the art to modify the process disclosed by Tanev with the specific use of a high paraffinic EN15940 compliant diesel fuel as disclosed by Yu in order to meet environmental regulations. Claim 2 Tanev/Yu disclose a process as claimed in claim 1, wherein said EN15940 compliant paraffinic gasoil comprises a Fischer-Tropsch derived paraffinic gasoil, a renewable paraffinic gasoil, or mixtures thereof (see Yu paragraphs [0069] and [0070]). Claim 3 Tanev/Yu disclose a process as claimed in claim 2, wherein the EN15940 compliant paraffinic gasoil comprises a hydrotreated vegetable oil derived paraffinic gasoil (see Yu, paragraph [0004]). Claim 4 Tanev/Yu disclose a process as claimed in claim 3, wherein the EN15940 compliant paraffinic gasoil consists essentially of one or more hydrotreated vegetable oil derived paraffinic gas oils (see Yu, paragraph [0004]). Claim 5 Tanev/Yu do not explicitly disclose a process as claimed in claim 1, wherein the methane-based gas is provided by methane from biogas production or from a power-to-gas plant. However the use of bio-methane is well known to one having ordinary skill in the art and would have been obvious to implement in order to replace natural gas and provide a fully renewable dual fuel system. Claim 6 Tanev/Yu disclose a process as claimed in claim 1, wherein the first liquid fuel comprises an hydrotreated vegetable oil derived paraffinic gasoil (see Yu, paragraph [0004]), and Tanev/Yu do not explicitly disclose a process wherein the second gaseous fuel comprises a biomass-derived methane. However the use of bio-methane is well known to one having ordinary skill in the art and would have been obvious to implement in order to replace natural gas and provide a fully renewable dual fuel system. Claim 7 Tanev/Yu disclose a process as claimed in claim 1, wherein the methane oxidation catalyst is produced from noble metals and zirconia (see Tanev paragraphs [0011], [0021]-[0027]). Claim 8 A process for reducing the emissions of methane from an engine system, comprising providing one or more hydrotreated vegetable oil derived, EN15940-compliant paraffinic gas oils as a liquid fuel to a dual-fuel engine system, in which a methane-based gas is used as a gaseous fuel, and providing a methane oxidation catalyst to an exhaust system of said engine system (see rejection of Claim 1 above). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to SIZO BINDA VILAKAZI whose telephone number is (571)270-3926. The examiner can normally be reached 10am-6pm. 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, Phutthiwat Wongwian can be reached at 571-270-5426. 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. /SIZO B VILAKAZI/ Primary Examiner, Art Unit 3747
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Prosecution Timeline

Aug 28, 2024
Application Filed
Jan 02, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

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2y 5m to grant Granted Apr 14, 2026
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FUEL REFORMING SYSTEM FOR VEHICLE WITH ENGINE MOUNTED THEREON
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Patent 12594935
PREDICTIVE VARIABLE VELOCITY MODEL-BASED LATERAL CONTROL FOR ROBUST AUTOMATED DRIVING
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Patent 12576907
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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
74%
Grant Probability
86%
With Interview (+11.7%)
2y 11m
Median Time to Grant
Low
PTA Risk
Based on 715 resolved cases by this examiner. Grant probability derived from career allow rate.

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