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.
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.
Claim(s) 1-5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Koselek (WO 2021/148942) in view of Kivlen et al (US 3,557,241).
With respect to claim 1, Koselek discloses a process for steam cracking, comprising:
(B) operating the olefins production plant by:
(B1) introducing a first hydrocarbon feed comprising at least one of ethane and propane into a plurality of radiant coils disposed within the steam cracking furnace under first steam cracking conditions that produce a first steam cracker effluent and deposit coke on an inner surface of the radiant coils, wherein a conversion of ethane, if present at a molar concentration in the first hydrocarbon feed equal to or greater than that of propane, to one or more other compounds is
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75%, or a conversion of propane, if present at a molar concentration in the first hydrocarbon feed higher than that of ethane, to one or more other compounds is > 93% (see page 12-13, example);
(B2) periodically stopping introduction of the first hydrocarbon feed into at least one of the radiant coils in the plurality of radiant coils (see page 8, lines 1-35); and
(B3) introducing a decoking feed comprising steam and optionally air into the at least one of the radiant coils under decoking process conditions, wherein the decoking process conditions comprise at least one of:
introducing the decoking feed into the at least one of the radiant coils to produce a decoking effluent having a coil outlet temperature of about 900°C (see page 8, lines 15-20).
Koselek does not disclose wherein the temperature is greater than 900°C, providing an olefins production plant comprising a steam cracking furnace and an olefins product recovery section; introducing the decoking feed into the at least one of the radiant coils while maintaining introduction of the hydrocarbon feed into one or more of the radiant coils in the plurality of radiant coils.
However, in a related-on stream decoking of a thermal cracker, Kivlen discloses wherein a conventional thermal cracking refinery includes a cracking furnace and a product recovery section (see figure 1), wherein utilizing temperatures greater than 900°C (such as 1900°F, see figure 4) provides an improvement in decoking efficiency with respect to the decoking feed (see figure 4, higher temp leads to a greater production of CO/sec) and decoking feed is introduced into the at least one of the radiant coils while maintaining introduction of the hydrocarbon feed into one or more of the radiant coils in the plurality of radiant coils (see col 6 lines 1-20 and 25-35).
Thus, it would have been obvious to one with ordinary skill in the art, before the effective filling date of the claimed invention to modify the Koselek process in view of Kivlen with the claimed limitations, as said temperature above 900°C provides greater carbon removal and said product recovery section is conventional within the art.
With respect to claim 2-4, the prior combination teaches the limitation of claim 1.
The prior combination further discloses wherein the decoking mixture is steam and air (see Koselek, page 8 lines 10-25).
With respect to claim 5, the prior combination teaches the limitation of claim 1.
Kivlen further discloses wherein the steam cracking conditions comprise a residence time of the hydrocarbon feed within the radiant coils of 0.01 second to 5 seconds, heating the hydrocarbon feed within the radiant coils sufficiently to produce a steam cracker effluent having a coil outlet temperature of from 648 °C to 929 °C (1200°F to about 1700°F) (see col 5 lines 20-40).
Claim Rejections - 35 USC § 103
Claim(s) 6-7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Koselek and Kivlen as applied to claim 1 above, and further in view of Rooney et al (WO 2020/191253).
With respect to claim 6, the prior combination teaches the limitation of claim 1.
The prior combination does not disclose wherein the hydrocarbon feed comprises ethane and propane at a total concentration of no less than 75 wt%, based on the total volume of the hydrocarbon feed.
However, in a related process for on stream decoking, Rooney discloses wherein conventional feedstock for ethylene production includes ethane and propane at a total concentration of no less than 75 wt%, based on the total volume of the hydrocarbon feed (see paragraph 0026).
Thus, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention to modify the prior combination in view of Rooney with the claimed feedstock, as said feedstock is conventional in the production of ethylene.
With respect to claim 7, the prior combination teaches the limitation of claim 1.
The prior combination does not disclose wherein the hydrocarbon feed comprises ethane at a concentration of no less than 75 wt%, based on the total volume of the hydrocarbon feed.
However, in a related process for on stream decoking, Rooney discloses wherein conventional feedstock for ethylene production includes ethane at a total concentration of no less than 75 wt%, based on the total volume of the hydrocarbon feed (see paragraph 0026).
Thus, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention to modify the prior combination in view of Rooney with the claimed feedstock, as said feedstock is conventional in the production of ethylene.
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.
Claim(s) 13-14 and 18-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Rooney et al (WO 2020/191253).
With respect to claim 13, Rooney discloses 13. (Original) A process for steam cracking hydrocarbons, comprising:
introducing a first hydrocarbon feed comprising ethane, propane, or a mixture thereof into a plurality of radiant coils disposed within a steam cracking furnace under steam cracking conditions that produce a steam cracker effluent and deposit coke on an inner surface of the radiant coils, wherein a conversion of at least one of ethane, if present at a molar concentration in the first hydrocarbon feed equal to or greater than that of propane, to one or more other compounds is 75%, or a conversion of propane, if present at a molar concentration in the first hydrocarbon feed higher than that of ethane , to one or more other compounds is > 93% (see paragraph 0019-0020, 0023, 0026 and 0039).
Rooney does not disclose wherein an inner surface of the radiant coils in the plurality of radiant coils comprises a material that is non-catalytic to coke generation.
However, in a related steam cracking process Koselek discloses wherein radiant coils are typically made of stainless steel (see page 9, lines 10-30).
Thus, it would have been obvious to one with ordinary skill in the art, before the effective filing date to modify Rooney with a material that is non-catalytic to coke generation, as Koselek discloses that the coil material is typically stainless steel (a non-catalytic material).
With respect to claim 14, the prior combination teaches the limitation of claim 13.
Koselek further discloses wherein the radiant coils are alumina former tubes made of an alloy comprising > 1.5 wt.% of aluminum that have an aluminum oxide layer disposed on the inner surfaces thereof (see page 10, lines 1-10).
With respect to claim 18, the prior combination teaches the limitation of 13.
Rooney further discloses periodically stopping introduction of the first hydrocarbon feed into at least one of the radiant coils in the plurality of radiant coils; and
introducing a decoking feed comprising a steam and optionally air into the at least one of the radiant coils to remove at least a portion of any coke deposited on an inner surface of the at least one of the radiant coils (see paragraph 0034).
With respect to claim 19, the prior combination teaches the limitation of claim 13.
Rooney further discloses wherein he first hydrocarbon feed comprises ethylene and/or propylene (see paragraph 0026).
With respect to claim 20, the prior combination teaches the limitation of claim 1.
Rooney further discloses wherein the steam cracking conditions comprise a residence time of the first hydrocarbon feed within the radiant coils of 0.01 second to 5 seconds, heating the first hydrocarbon feed within the radiant coils sufficiently to produce a steam cracker effluent having a coil outlet temperature of 815 °C to 900°C or a combination thereof (see paragraph 0028).
Claim Rejections - 35 USC § 103
Claim(s) 15-16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Koselek and Rooney as applied to claim 13 above, and further in view of Spicer et al (US 2016/0168480).
With respect to claim 15-16, the prior combination teaches the limitation of claim 13.
Koselek discloses wherein radiant coils are typically made of stainless steel, an alloy (see page 9, lines 10-30).
The prior combination does not disclose wherein allow is made up a spinel oxide type, as claimed.
However, in a related pyrolysis furnace process, Spicer discloses wherein allows include spinel oxide type (see abstract and paragraph 0069).
Thus, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention to modify the prior combination with the claimed spinel oxide type furnace tubed, as said spinel type are more resistant to carburization (coking).
Allowable Subject Matter
Claims 8-12 and 17 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
With respect to claims 8-12, the prior combination teaches the limitation of claim 1.
Koselek further discloses a start up procedure for the steam cracking furnace (see page 11, lines 15-30, page 12 lines 1-15).
The prior combination fails to teach or suggest to one with ordinary skill in the art, to modify the process such that the process further comprising, before step (B):
(C) operating the olefins production plant by:
(C1) introducing a reference hydrocarbon feed into the plurality of radiant coils under reference steam cracking conditions that produce a reference steam cracker effluent, wherein a conversion of at least one of ethane, if present at an equal or higher molar concentration than propane in the reference hydrocarbon feed, to one or more other compounds is <75%, and propane, if present at a higher molar concentration than ethane in the reference hydrocarbon feed, to one or more other compounds is < 93%; and(D) adjusting step (C) to carry out step (B).
Allowable Subject Matter
Claims 21-25 are allowed.
The following is an examiner’s statement of reasons for allowance:
With respect to claims 21-25, the closest prior Rooney et al (WO 2020/191253) discloses a process for steam cracking hydrocarbons (see abstract), comprising:
(2) operating the olefins production plant by:
(2a) in a cracking interval, introducing a first hydrocarbon feed comprising at least one of ethane and propane into a plurality of radiant coils disposed within the steam cracking furnace under first steam cracking conditions that produce a first steam cracker effluent and deposit coke on an inner surface of the radiant coils, wherein a conversion of ethane, if present at a molar concentration in the first hydrocarbon feed equal to or greater than that of propane, to one or more other compounds is > 75%, or a conversion of propane, if present at a molar concentration in the first hydrocarbon feed higher than that of ethane , to one or more other compounds is > 93% (see paragraph 0019-0020, 0023, 0026 and 0039); and
(2c) periodically stopping introduction of the first hydrocarbon feed into at least one of the radiant coils in the plurality of radiant coils (see paragraph 0034).
However, Rooney does not teach or suggest to one with ordinary skill in the art, before the effective filing date to modify the process with the step of (3) providing a reference process comprising:
(3a) in a reference cracking interval, introducing a reference hydrocarbon feed into the plurality of radiant coils under reference steam cracking conditions that produce a reference steam cracker effluent and deposit coke on the inner surface of the radiant coils, having a reference conversion of ethane, if present, to one or more other compounds of
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75%, and a reference conversion of propane, if present, to one or more other compounds of < 93%;
(3b) periodically stopping introduction of the reference hydrocarbon feed into at least one of the radiant coils in the plurality of radiant coils; and
(3c) in a reference offline decoking interval, introducing the decoking feed into the at least one of the radiant coils under reference decoking conditions; (4) introducing a decoking feed comprising steam and optionally air into the at least one of the radiant coils under decoking process conditions such that -2 mm
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AA < 2 mm, where AA = R1(ref)*D1(ref) + R(ref)*delta(D1) + delta(R1)*(D1(ref) + delta(D1)) - P1 - (P2 - P2(ref)); delta(R1) = R1 - R1(ref),
where R1 is average coke deposition rate in the radiant coils in the process during the cracking interval, in mm-day-1, and
R1(ref) is average coke deposition rate in the radiant coils in the reference process during the reference cracking interval, in mm-day-1;
D1(ref) is the duration of the reference cracking interval, in days;
delta(D 1) = D1 - D1(ref), where D1 is duration of the cracking interval, in days;
P1 is coke removed during the online decoking interval, if any, in mm; P2 is coke removed during the offline decoking interval, in mm; and
P2(ref) is coke removed during the reference offline decoking interval, in mm.
Consequently, it is the Examiner position that the claimed invention is patentable over the prior art.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JUAN C VALENCIA whose telephone number is (571)270-7709. The examiner can normally be reached Monday-Friday 10am - 6pm.
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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 571 272-6381. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JUAN C VALENCIA/Examiner, Art Unit 1771
/PREM C SINGH/Supervisory Patent Examiner, Art Unit 1771