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
This action is responsive to correspondence filed on 04/14/2026.
Claims 1-13 and 18-25 are pending. Claims 14-17 are canceled. Claims 1 and 13 are amended.
The previous rejection of claims 1-7 under 35 U.S.C. 103, are maintained.
The previous rejections of claims 13 and 18-19 under 35 U.S.C. 103 are withdrawn, necessitated by the Applicant amendment.
New rejection of claim 20 under 35 U.S.C. 103 is entered.
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 and 20 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 claims 5 and 20, 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.
Response to Arguments
Applicant’s arguments, see page 2-3, filed 04/14/2026, with respect to Claims 1-8 have been considered, but they are not persuasive
Examiner understands Applicant argument to be:
“The Office concedes that 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." Office Action at page 3, lines 17- 21. However, the Office asserts that Kivlen discloses a process that includes these features. Office Action at page 3, line 22 to page 4, line 6. In particular, the Office states that Kivlen discloses "utilizing temperatures greater than 900°C (such as 1900°F, see figure 4)." Office Action at page 4, lines 1-2. The Applicant respectfully disagrees.
Kivlen is directed to a process that includes the use of a decoking feed that includes steam/water and hydrogen. Kivlen describes FIG. 2 (referred to as FIG. 4 in the Office Action) as showing the temperature "where the effect of hydrogen in the decoking feed begs to drop off' as well as the relationship between temperature and an optimum steam to hydrogen mole ratio. Accordingly, the process conditions taught in Kivlen are not relevant to the presently claimed process that includes introducing a steam (and optionally air) decoking feed into at least one of the radiant coils. Claim 1 is amended to further clarify that "the decoking feed essentially of steam or a mixture of steam and air." As a result, neither Koselek nor Kivlen teach or suggest a process that includes "introducing the decoking feed into the at least one of the radiant coils to produce a decoking effluent having a coil outlet temperature of > 900°C," for a "decoking feed consisting essentially of steam or a mixture of steam and air," as recited in amended claim 1.
With respect to the remarks above, the Examiner disagrees, in particular the Amendment made to claim 1 is the "consisting essentially of" limitation which is construed the same as "comprising."
Moreover, regarding the >900C limitation, the primary reference already discloses "about 900C." It is noted that a temperature of 901°C or 902°C are both "about 900C" and "> 900C," thus the rejection could be maintained on the teachings of the primary reference alone.
With respect to claims 13 and 18-19, the rejection under 35 U.S.C. is withdrawn, necessitated by the Applicant amendment.
Allowable Subject Matter
Claims 8-12 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 startup 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 13, 18-19 and 21-25 are allowed.
The following is an examiner’s statement of reasons for allowance:
With respect to claims 13 and 18-19, the closest prior art Rooney (WO 2020/191253) discloses 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 (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, wherein the radiant coils comprise a layer comprising a spinel-type oxide layer disposed on the inner surfaces thereof, the spinel-type oxide layer comprising 40 wt.% to 60 wt.% of compounds having the chemical formula: MnxCr3-xO4, wherein x is from 0.5 to 2, and from 60 wt.% to 40 wt.% of oxides of Mn and Si selected from the group consisting of MnO, MnSiO3, Mn2SiO4 and mixtures thereof provided that the surface contains less than 5 wt.% of Cr203.
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 ≤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 ≤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 inventions are 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
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/JUAN C VALENCIA/ Examiner, Art Unit 1771
/Randy Boyer/
Primary Examiner, Art Unit 1771
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