DETAILED ACTION
Response to Amendment
Examiner acknowledges Applicant’s response filed 26 May 2026 containing amendments to the claims and remarks.
Claims 1-20 are pending.
The previous rejection under 35 U.S.C. 112(b) is withdrawn in view of Applicant’s amendments to the claim.
The previous rejections under 35 U.S.C. 103 are maintained. The rejections follow.
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.
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 1-10 and 12-19 are rejected under 35 U.S.C. 103 as being unpatentable over Lilga (US 2016/0194572) in view of Peitz (US 11,254,631).
With respect to claims 1, 2, and 19, Lilga discloses a process for oligomerizing an olefin stream (see Lilga, Abstract) comprising: (a) oligomerizing an olefin feed over a first stage oligomerization catalyst to produce a first-stage oligomerized stream (see Lilga, paragraph [0020]); (b) oligomerizing the first-stage oligomerized stream over a second-stage oligomerization catalyst to provide a second-stage oligomerized stream (see Lilga, paragraph [0021]); and (c) dealkanizing the second-stage oligomerized stream to provide a light alkane (normal paraffin) stream and a dealkanized stream (see Lilga, column 3, lines 61-65). Lilga further discloses wherein alkanes (paraffins) and unreacted (i.e. separated/fractionated) ethylene may be separated/fractionated and recycled back to the first or second oligomerization stages in order to increase carbon number and product yield is the desired distillation range (see Lilga, paragraph [0069]).
Lilga does not explicitly disclose wherein the disclosed fractionation is by way of a “deethanizer column” or “depropanizer column” or the specific bottoms operating temperature of such separator.
However, Lilga clearly discloses wherein such separator may be one that performs “distillation” in order to achieve a light fraction and unreacted ethylene fraction which may be recycled to the first or second reactors (see Lilga, paragraphs [0051], [0067], and [0069]). Thus, the separator/fractionator/distillation of Lilga clearly performs the function of a deethanizer or depropanizer column. Moreover, with regard to bottoms temperature, Peitz (in a related process) (see Peitz, Abstract) explains that the precise conditions of distillation such as temperature and pressure are typically determined by column height, number of trays, type of trays/packing, tray spacing, etc., all of which are known to persons having ordinary skill in the art to achieve the desired separation (see Peitz, column 5, lines 7-17). Thus, the person having ordinary skill in the art could easily adjust column variables to achieve any bottoms temperature desired in order to meet the process objectives of Lilga.
Thus, claims 1, 2, and 19 are unpatentable in view of Lilga and Peitz.
With respect to claims 3-8, 10, 12-18, Lilga discloses wherein the recycle ethylene may be a purified condensate (see Lilga, paragraph [0057]).
With respect to claim 9, Lilga discloses wherein the light recycle fraction may comprise C4 to C8 hydrocarbons (see Lilga, paragraphs [0020], [0064], and [0067]).
Claims 11 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Lilga (US 2016/0194572) in view of Peitz (US 11,254,631) and Chen (US 2017/0088490).
With respect to claims 11 and 20, see discussion above at paragraph 9. Lilga discloses wherein residual liquids from the oligomerization reactor may be removed in a gas/liquid separator (see Lilga, paragraph [0061]), such separated light gases known to be useful as fuels for combustion to provide the necessary heat requirements of the process (see Chen, paragraph [0051]).
Response to Arguments
Applicant’s arguments filed 26 May 2026 have been fully considered but they are not persuasive.
Examiner understands Applicant’s arguments to be:
Lilga does not teach recycling olefins from the light alkane overhead stream and the dealkanized bottoms stream to the first stage oligomerization reaction.
Lilga teaches recycling of an ethylene stream and/or a light fraction stream. Lilga does not teach the composition of the light fraction nor does Lilga directly suggest that the light fraction is devoid of light alkanes.
The recycle strategy of Lilga is that of recycling a purified ethylene stream and/or a light fraction stream comprising lower hydrocarbons including ethylene. Without the teaching provided by Applicant’s disclosure, a person having ordinary skill in the art would not have had sufficient motivation to recycle olefins from a dealkanized bottoms stream to the first-stage oligomerization reaction as recited in claim 1.
Lilga does not teach separating the light alkane stream to provide an off-gas stream and a light alkane condensate stream and taking the recycle olefin stream from the light alkane condensate stream. Lilga only teaches the use of an ethylene recycle stream without any guidance as to the processing steps required to arrive at the recycle feature or from what it is taken. The disclosure of Lilga cannot direct a person of ordinary skill in the art to unambiguously arrive at the steps of separating a light alkane stream from a dealkanizer column to provide an off-gas stream and a light alkane condensate stream and taking a recycle olefin stream from the light alkane condensate stream. Without the technical guidance provided by Applicant’s disclosure, a person having ordinary skill in the art does not have the required suggestion or technical guidance to arrive at the argued recitations of claim 19.
With respect to Applicant’s first, second, third, and fourth arguments, Lilga discloses dealkanizing the second-stage oligomerized stream to provide a light alkane (normal paraffin) stream and a dealkanized stream (see Lilga, column 3, lines 61-65). Lilga further discloses wherein alkanes (paraffins) and unreacted (i.e. separated/fractionated) ethylene may be separated/fractionated and recycled back to the first or second oligomerization stages in order to increase carbon number and product yield is the desired distillation range (see Lilga, paragraph [0069]). Obviousness does not require absolute predictability, only a reasonable expectation of success. In re O’Farrell, 853 F.2d 894, 903 (Fed. Cir. 1988). The person of ordinary skill is a person of ordinary creativity, not an automaton. KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 421 (2007).
With respect to Applicant’s fourth argument, Lilga discloses wherein residual liquids from the oligomerization reactor may be removed in a gas/liquid separator (see Lilga, paragraph [0061]), such separated light gases known to be useful as fuels for combustion to provide the necessary heat requirements of the process (see Chen, paragraph [0051]).
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 Randy Boyer whose telephone number is (571) 272-7113. The examiner can normally be reached Monday through Friday from 10:00 A.M. to 7:00 P.M. (EST).
If attempts to reach the examiner by telephone are unsuccessful, the examiner's supervisor, Prem C. Singh, can be reached at (571) 272-6381. The fax number for the organization where this application or proceeding is assigned is 571-273-8300.
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/Randy Boyer/
Primary Examiner, Art Unit 1771
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