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The rejection of claims 9 and 11 under 35 USC § 112 is withdrawn by the examiner in view of the amendment filed on 4/29/2026.
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 9 and 11 are rejected under 35 U.S.C. §103(a) as being unpatentable over CN 207973691 in view of CN 104030875.
CN 207973691 discloses a system for treating a hydrocarbon gas stream comprising, connected in sequence, upstream gas-treatment units and downstream separation units (claim 1; Figs. 1-2). CN 207973691 teaches a washing tower, alkali washing tower, oil-gas-water separator, drying unit, high-pressure depropanizer, deethanizer, demethanizer, propylene rectification tower, and debutanizer (claim 1; claims 2-6), thereby separating a gas stream into:
a dry gas mainly containing H2 and C1 (demethanizer overhead fuel gas),
a C2 product,
a C3 product, and
a C4 product,
as recited in claims 9 and 11.
CN 207973691 further teaches gas washing and alkali washing upstream of fractionation,
corresponding to gas-phase and liquid-phase impurity-removal treatment units including water
washing and desulfurization treatment prior to downstream cryogenic/fractionation separation.
However, CN 207973691 does not explicitly teach removal of mercaptans using sweetening units.
CN 104030875 teaches refinery cracked-gas treatment systems including removal of acidic sulfur compounds and mercaptans using desulfurizing and sweetening units, including rich gas desulfurization, rich gas sweetening, liquid hydrocarbon desulfurization, and liquid hydrocarbon sweetening prior to downstream separation.
Regarding claim 9, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the impurity-removal section of CN 207973691 to include mercaptan-removal sweetening units as taught by CN 104030875 B because mercaptans and sulfur-containing acidic compounds are well-known contaminants in refinery and cracked hydrocarbon gas streams, and removal thereof prior to cryogenic/fractionation processing is a routine and predictable design choice to prevent corrosion, fouling, catalyst poisoning, and product contamination.
Regarding claim 11, CN 207973691 expressly teaches a sequential separation train including a demethanizer, deethanizer, depropanizer, and debutanizer, corresponding respectively to the claimed first, second, third, and fourth separation devices for sequential separation of H2/C1, C1, C2, C3, and C4 fractions.
Response to Arguments
Applicant’s arguments have been fully considered but are not persuasive.
Applicant argues that claim 9 requires a “light hydrocarbon extraction unit” that separates gasoline components prior to impurity-removal treatment, and that neither CN 207973691 nor CN 104030875 teaches or suggests such arrangement. However, CN 207973691 expressly teaches upstream phase separation and condensate separation prior to downstream purification and fractionation. In particular, CN 207973691 teaches that the alkali-washed stream is sent to an oil-gas-water three-phase separator, wherein condensate containing heavier hydrocarbons is separated and sent to a condensate cutting tower, which removes C4+ components prior to subsequent downstream separation processing. CN 207973691 further teaches that heavy hydrocarbon components are separated before downstream demethanizer/deethanizer processing in order to reduce downstream load and energy consumption. Thus, CN 207973691 teaches separating heavier gasoline-range hydrocarbons from lighter H2/C1-C4 streams prior to subsequent treatment and recovery operations, as presently claimed.
Applicant further argues that the cited references fail to teach gas-phase and liquid-phase sweetening systems each followed by a water-washing unit. The argument is not persuasive.
While CN 207973691 does not expressly disclose mercaptan-removal sweetening units, CN 104030875 teaches desulfurization and mercaptan-removal treatment for both gas-phase and liquid hydrocarbon streams prior to downstream light hydrocarbon recovery. Further, water washing following alkaline or sweetening treatment to remove entrained alkali and establish acid-base equilibrium constitutes well-known conventional processing in refinery and petrochemical gas-treatment systems. Providing a downstream water-washing step after sweetening treatment would have been an obvious matter of routine engineering optimization to prevent downstream corrosion, fouling, and contamination of separation equipment.
Applicant’s asserted advantages regarding reduced downstream load, reduced energy consumption, and improved product quality merely describe expected results flowing naturally from known upstream contaminant-removal and prefractionation techniques taught by the cited art.
Conclusion
THIS ACTION IS MADE FINAL. 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.
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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.
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/TAM M NGUYEN/Primary Examiner, Art Unit 1771
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