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The rejections of claims 1-33 are under 35 USC § 103 over Kurukchi and Sphephens are withdrawn by the examiner in view of the amendment filed on 4/29/2029.
Since a new Non-Final Office Action is follows, Applicant’s arguments will not be addressed.
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 1-3, 8-18, and 21-33 are rejected under 35 U.S.C. 103 as being unpatentable over Kurukchi et al. (US 6,576,132) in view of Stephens et al. (US 2022/0081623 A1).
Kurukchi teaches a steam cracking process including cooling steam cracking furnace effluent and feeding the cooled effluent to a quench water tower where the effluent is contacted with quench water, obtaining quench tower overhead vapor and bottom liquid streams, separating the quench tower liquid into oil-containing streams and aqueous streams, removing coke fines and solids from aqueous streams, steam stripping extracted quench water to produce stripper overhead vapor and stripped bottoms water, recycling stripper overhead vapor back to the quench water tower, and generating dilution steam from stripped bottoms water (col. 8, line 16-col. 11, line 15).
Kurukchi further teaches stripper operation at temperatures of about 125-145°C and pressures of about 2-3 barg (col. 10, lines 18-50), which substantially overlap the claimed stripping column bottom temperature of no greater than 280°F and stripping column overhead pressure of no greater than 250 kPa-gauge. Optimization of overlapping operating conditions would have been obvious to one having ordinary skill in the art.
Kurukchi does not expressly teach operating the steam cracking furnace at a coil outlet pressure (“COP”) of from 200 kPa-gauge to 700 kPa-gauge and recovering olefin product using no more than three stages of compression.
Stephens teaches steam cracking an ethane-containing feed mixed with dilution steam at elevated COP conditions of from 200 kPa-g to 520 kPa-g, including pressures greater than 520 kPa-g, and further teaches that elevated COP operation reduces downstream compression requirements and permits operation using as few as two or three compression stages (¶¶ [0013], [0017], [0023], [0024]).
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 COP conditions taught by Stephens in order to reduce downstream compression stages, reduce compressor power requirements, and reduce downstream equipment size, as expressly taught by Stephens.
Regarding claims 2-3, the claimed quench tower withdrawal locations represent obvious variations of the quench tower liquid withdrawal arrangements taught by Kurukchi (col. 8, lines 52-67).
Regarding claims 8-9, Kurukchi teaches stripping operation at pressures overlapping the claimed ranges and further teaches using stripped bottoms water to generate dilution steam (col. 10, lines 18-67; col. 11, lines 1-15).
Regarding claims 11-12 and 21-24, Kurukchi teaches generating dilution steam from stripped bottoms water (col. 10, lines 51-67; col. 11, lines 1-15) and teaches maintaining sufficient pressure to recycle stripper overhead vapor back to the quench tower (col. 10, lines 39-43). Compressing the stripper overhead vapor to form a recycle stream would have been an obvious engineering expedient for transporting recycle vapor to the quench tower.
Regarding claims 13 and 29, Stephens teaches coke-resistant radiant coils and barrier layers suitable for elevated COP ethane steam cracking systems (¶ [0021]), rendering the claimed radiant tube alloy compositions and barrier layers obvious.
Regarding claims 14-15 and 30, Stephens teaches elevated crossover temperatures of from 760-775°C (¶ [0026]) and recognizes onset of cracking in crossover regions (¶¶ [0020], [0026]).
Regarding claims 16 and 32, Stephens expressly teaches hydrocarbon feeds comprising at least 50 vol % ethane (¶ [0024]).
Regarding claims 17-18 and 33, Stephens teaches operation at elevated COP conditions including pressures greater than 520 kPa-g (¶ [0017]) and further teaches downstream compression using as few as two or three compression stages (¶ [0023]). The claimed compressor outlet pressure ranges represent obvious engineering design parameters for implementing the disclosed multistage compression system.
Claims 10 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Kurukchi in view of Stephens and further in view of McCoy et al. (US 8,025,774 B2).
The processes of Kurukchi and Stephens are as discussed above.
McCoy teaches controlling tar in cracked furnace effluent systems using aromatic-rich hydrocarbon solvent streams, including pyrolysis gasoline streams, and teaches introducing aromatic solvent streams into quench-system liquid streams to maintain tar solvency and reduce fouling (col. 3, lines 15-67; col. 5, lines 1-45). McCoy further teaches separating hydrocarbon solvent-containing streams and recycling aromatic-rich streams within the quench/tar handling system (col. 6, lines 1-67).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to utilize aromatic-rich hydrocarbon streams recovered from the quench/oil system of Kurukchi as tar solvents as taught by McCoy in order to improve tar solvency, reduce fouling, and improve separation efficiency within the quench-water and tar handling system.
Claims 4-6, 19, and 27 are rejected under 35 U.S.C. 103 as being unpatentable over Kurukchi in view of Stephens and further in view of Aslaner et al. (WO 2021/016301 A1).
Aslaner teaches furnace systems including a vessel configured to receive coke-containing effluent, separate the effluent into coke particles and fluid, and remove coke particles through a coke outlet while passing fluid through a fluid outlet (¶¶ [0012]-[0015]). Aslaner further teaches a cyclone separator including an effluent inlet, fluid outlet, and coke outlet for separating coke particles from cracker effluent streams (¶¶ [0065]-[0073]; claims 6-7).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to incorporate the coke-particle separation vessel/cyclone arrangement taught by Aslaner into the steam cracking and quench-water handling system of Kurukchi in order to reduce coke-fouling and solids carryover into downstream quench equipment, because Aslaner expressly teaches separation of coke particles from cracker effluent streams using a vessel having an effluent inlet, fluid outlet, and coke collection/deposition section.
Regarding claims 4 and 27, Aslaner teaches mixing tar solvent with coke-rich streams, aqueous streams, and quench liquid streams represents obvious process integration and solvent handling optimization in view of the combined teachings of Kurukchi and the solids-handling teachings of Aslaner.
Regarding claims 5-6 and 19, Aslaner teaches:
a separation device comprising an effluent inlet, fluid outlet, and coke outlet/deposition section (¶ [0012]);
separating coke-containing effluent into coke particles and fluid (¶ [0015]);
cyclone separators configured to separate coke particles from effluent streams (¶¶ [0065]-[0073]; claims 6-7).
Accordingly, the claimed coke-abatement separation device and associated coke-depleted vapor stream/deposited coke limitations would have been obvious in view of the combined teachings of the references.
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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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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