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
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 1–33 are rejected under 35 U.S.C. §103 as being unpatentable over Kurukchi et al. (US 6,576,132 B2) in view of Stephens et al. (US 2022/0081623 A1).
Kurukchi is directed to an ethylene plant quench water treatment and recycle process associated with steam cracking furnaces, and teaches:
Steam cracking furnace effluent being cooled and contacted with quench water in a quench water tower.
Formation of a quench tower overhead vapor stream and a quench tower liquid effluent stream containing water, oil, tar, and coke fines.
Oil/water separation of quench tower bottoms to produce oil and aqueous streams, with removal of solids (coke fines) by straining and filtration.
Liquid–liquid extraction of quench water using an aromatic-rich solvent (C6–C8, BTX, toluene) to remove polymer precursors and heavy hydrocarbons.
Steam stripping of the extracted quench water to remove residual organics.
Recycling stripper overhead vapor (steam and hydrocarbons) back to the quench water tower.
Using stripper bottoms water to generate dilution steam in a dilution steam generator without fouling (see Summary; Detailed Description, quench water tower discussion).
Thus, Kurukchi teaches a closed-loop quench water handling system integrated with a steam cracking process.
Kurukchi does not teach an elevated coil outlet pressures as claimed.
Stephens teaches
Performing ethane steam cracking at an elevated coil outlet pressure (COP) of 200–520 kPa-g.
Using an ethane-containing feed comprising 50 vol % or more ethane.
That operating at elevated COP raises the inlet pressure to downstream equipment, thereby reducing the number of required compression stages, including configurations having two or three compression stages rather than four or more (¶¶ [0013], [0023]).
Conventional quench towers and downstream processing of cracked gas following the radiant section.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to operate the steam cracking and quench water recycle system of Kurukchi at the elevated coil outlet pressures taught by Stephens in order to reduce downstream compression requirements, equipment size, and energy consumption.
Regarding Claims 2–4, these claims specify locations of quench tower liquid withdrawal and optional tar solvent mixing. Such variations are explicitly disclosed or inherently present in Kurukchi quench water tower and separation schemes.
Regarding claims 5–6, Kurukchi teaches removal of coke fines and solids associated with furnace effluent and quench water handling; locating such solids removal upstream of the quench tower represents an obvious placement of a known solids-removal function to reduce fouling.
Regarding claims 7–9 and 11–12, Kurukchi discloses steam stripping of quench water and recycling stripper overhead vapor to the quench water tower. Claimed pressure and temperature ranges represent result-effective variables.
Regarding claim 10, Kurukchi explicitly teaches using aromatic-rich C6–C8 solvents (BTX, toluene) for extraction and tar handling.
Regarding claims 13 and 29, Stephens teaches use of coke-resistant radiant coils and barrier layers in high-COP ethane steam cracking furnaces (¶ [0021]), rendering these features obvious when operating the Kurukchi system under the conditions taught by Stephens.
Regarding claims 14–15 and 30–31, Stephens teaches elevated crossover temperatures (760–775 °C) and recognizes cracking onset in the crossover region.
Regarding claims 16 and 32, Stephens teaches ethane concentration of at least 50 mol %.
Regarding claim claims 17 and 33, Stephens teaches operation with two or three stages of compression at elevated inlet pressures; the claimed ranges represent obvious design choices within the compressor art.
Regarding claims 18–21, These claims recite substantially the same process as claim 1 with rearranged steps and explicit inclusion of stripping, recycle, coke separation, and tar solvent use.For the same reasons set forth above with respect to claim 1, claims 18–21 are unpatentable over Kurukchi in view of Stephens.
Regarding claims 22–28, these claims further limit claims 21 with coke removal, stripper operation conditions, recycle mechanisms, and dilution steam generation. All such features are explicitly taught by Kurukchi.
Conclusion
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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/TAM M NGUYEN/Primary Examiner, Art Unit 1771