DETAILED ACTION
Response to Amendment
Examiner acknowledges Applicant’s response filed 10 April 2026 containing amendments to the claims and remarks.
Claims 1, 4-10, and 12-16 are pending.
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, 4-9, 12-14, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Brewer (US 7,718,052) in view of Ward (US 2022/0127209), Hirst (US 2023/0013408), and Van der Ploeg (US 2021/0113980).
With respect to claims 1 and 16, Brewer discloses a multizone pyrolysis furnace (2) comprising fired radiant chambers (6, 8), each chamber comprising an independent radiant zone (12); a coil (40) disposed within the independent radiant zone (12), wherein the coil is provided with a quenching apparatus for rapid quenching of effluent product gases; and radiant burners (32, 34) along the walls and floor of the independent radiant zone (12), wherein the coil (40) is heated by radiant heat supplied from the radiant burners (32, 34) (see Brewer, column 2, lines 45-52; column 4, lines 20-22 and 51-54; and Fig. 1). The furnace can be used in an apparatus for cracking hydrocarbons (see Brewer, Abstract). Brewer discloses that the coil (40) is preheated in exchanger (42), wherein a feedstock and steam flow through the coil (see Brewer, column 1, lines 47-48; column 3, lines 58-60; column 4, lines 47-48; and Fig. 1). Brewer discloses that the coil (40) is heated by radiant heat supplied from the radiant burners (32, 34) and provided with the quenching apparatus for rapid quenching of the effluent product gases (see Brewer, column 4, lines 20-22 and 51-54; and Fig. 1).
Brewer does not explicitly disclose wherein the furnace additionally comprises one or more electrical heating elements.
However, in a related furnace apparatus, Ward discloses wherein such furnace may comprise electrical heating elements, such electrical based heating providing a more energy efficient system, improved reliability and operability, decreased emission of pollutant gases, and decreased production costs (see Ward, paragraph [0050]). Van der Ploeg notes that such electrical heating elements may comprise materials such as NiCr, SiC, MoSi2, or FeCrAl (see Van der Ploeg, paragraph [0020]).
Therefore, the person having ordinary skill in the art would have been motivated to modify the furnace of Brewer to incorporate electrical heating elements as disclosed by Ward in order to achieve the same benefits noted by Ward. Moreover, the person having ordinary skill in the art would have had a reasonable expectation of success in modifying the furnace of Brewer as described above as evidenced by Hirst which discloses a hybrid steam cracking process making use of both combustion and electrical heating in the radiant section of a furnace (see Hirst, Abstract; and paragraph [0030]), such design providing reduced heat duty in the furnace, thereby curtailing the amount of hydrocarbon-based fuel that would otherwise be used in a combustion only design (see Hirst, paragraph [0035]).
With respect to claims 4 and 5, Brewer discloses that burners (32) are arranged in an array along outer walls (22) and centrally disposed walls (24) (see Brewer, column 3, lines 36-38; and Fig. 1); and Ward discloses an electrified furnace (see Ward, claim 1).
With respect to claims 6 and 7, Ward discloses a supply of electrical energy from any electrical source (e.g., electrical grid) (see Ward, paragraph [0025], [0053])
With respect to claims 8 and 9, the person having ordinary skill in the art could readily ascertain the appropriate materials necessary to carry out the electrified heating of Ward (see Ward, paragraphs [0081] and [0188]) (noting electrical flow through a wire). 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 claim 12, Brewer discloses the coil (40) and the radiant burners (32, 34) along the walls, outer walls (22), centrally disposed walls (24) and the floor of the independent radiant zone (12) and the floors (28) (see Brewer, column 4, lines 51-54; and Fig. 1). Recitation of relative dimensions as well as the mere rearrangement of parts of a prior art device is prima facie obvious in the absence of new or unexpected results. MPEP § 2144.04.
With respect to claims 13 and 14, Brewer discloses wherein the feedstock flows through the coil (see Brewer, column 1, lines 47-48); and the coil is provided with the quenching apparatus for rapid quenching of the effluent product gases (see Brewer, column 4, lines 20-22).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Brewer (US 7,718,052) in view of Ward (US 2022/0127209), Hirst (US 2023/0013408), Van der Ploeg (US 2021/0113980), and Stell (US 2006/0089519).
With respect to claim 10, see discussion supra at paragraph 8.
Neither Brewer nor Ward explicitly discloses wherein the furnace additionally comprises an oxygen controller.
However, in a related apparatus, Stell discloses use of an oxygen controller for maintaining an oxygen concentration within a preferred operating range (see Stell, paragraphs [0356] and [0362]); which provides for temperature control of the convection section (see Stell, paragraph [0356]).
Therefore, the person having ordinary skill in the art would have been motivated to modify the furnace of Brewer to incorporate use of an oxygen controller as disclosed by Stell, such modification providing a means by which to achieve temperature control in the furnace convection section.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Brewer (US 7,718,052) in view of Ward (US 2022/0127209), Hirst (US 2023/0013408), Van der Ploeg (US 2021/0113980), and Zhao (US 2009/0022635).
With respect to claim 15, see discussion supra at paragraph 8. Brewer discloses wherein separate radiant zones may be left idle by use of hot steam through the coil without cracking (see Brewer, column 5, lines 51-56). In this regard, Zhao discloses similar selective operation of radiant coils wherein some coils in some radiant sectors operate in a cracking mode while others in other sectors undergo decoking in the presence of hot steam and air (see Zhao, paragraph [0036]).
Response to Arguments
Applicant’s arguments filed 10 April 2026 have been fully considered but they are not persuasive.
Examiner understands Applicant’s arguments to be:
Brewer does not teach or suggest that the exchanger is an inlet heat exchanger as in amened claim 1.
Brewer does not teach or suggest that the quenching apparatus is a feed-effluent heat exchanger configured for indirectly exchanging heat between the quenched reaction product and the preheated reaction feedstock.
Ward does not teach or suggest that the quenching apparatus is a feed-effluent heat exchanger configured for indirectly exchanging heat between the quenched reaction product and the preheated reaction feedstock.
Examiner’s reliance on Hirst is misplaced. One of ordinary skill in the art would not expect a furnace as taught by Brewer and modified by Hirst to include external electrical heaters to perform the same. The placement of the electrical heating elements outside the radiant zone would not result in reducing the temperature of the element required to dissipate a given amount of heat.
Hirst does not teach or suggest the combination of an inlet heat exchanger and a feed-effluent heat exchanger configured for indirectly exchanging heat between the quenched reaction product and the preheated reaction feedstock.
A person of ordinary skill in the art would not expect a furnace as taught by Brewer and modified based on Van der Ploeg to perform the same as the electrically heated furnace of amended claim 1.
Van der Ploeg does not describe quenching at all. Thus, Van der Ploeg does not teach or suggest the combination of an inlet heat exchanger and a feed-effluent heat exchanger configured for indirectly exchanging heat between the quenched reaction product and the preheated reaction feedstock as in amended claim 1.
One of ordinary skill in the art would not possess a reasonable expectation of success when combining the generic teachings of various exchangers across different types of reactors and heat inputs as taught in Brewer, Ward, Hirst, and Van der Ploeg to arrive at the system of amended claim 1.
With respect to Applicant’s first, second, third, fifth, and seventh arguments, Brewer notes that a feed stream of ethane (inlet feedstock) may be preheated in coil 40 in exchanger 42 in convection section 4. Likewise, a propane feedstock (inlet feedstock) is preheated in coil 44 of convection zone 4 in exchanger 50. The process coils 40 and 44 then proceed to respective radiant zones 12 and 14 the coils being heated by indirect heat transfer with radiant heat supplied by radiant burners 32 and 34 (see Brewer, column 4, lines 51-67). Furthermore, Brewer explains that in each of the process coils, differing amounts of steam (i.e. diluent) may be added to each of the coils depending upon the desired cracking to be performed in the process coils, i.e., the type of feedstock and the product slate (see Brewer, column 4, lines 47-50).
With respect to Applicant’s fourth argument, the person having ordinary skill in the art would have had a reasonable expectation of success in modifying the furnace of Brewer as described above as evidenced by Hirst which discloses a hybrid steam cracking process making use of both combustion and electrical heating in the radiant section of a furnace (see Hirst, Abstract; and paragraph [0030]), such design providing reduced heat duty in the furnace, thereby curtailing the amount of hydrocarbon-based fuel that would otherwise be used in a combustion only design (see Hirst, paragraph [0035]).
With respect to Applicant’s sixth and seventh arguments, Brewer (not Van der Ploeg) is cited as teaching the heat exchange limitations (see discussion supra at paragraphs 8 and 20). Van der Ploeg is merely an evidentiary reference cited as teaching suitable electrical heating elements for use in furnaces such as those disclosed by Ward (see discussion supra at paragraph 8).
With respect to Applicant’s eighth argument, Examiner does not agree. Rather, Examiner submits that the person having ordinary skill in the art would have had a reasonable expectation of success in modifying the furnace of Brewer as described above as evidenced by Hirst which discloses a hybrid steam cracking process making use of both combustion and electrical heating in the radiant section of a furnace (see Hirst, Abstract; and paragraph [0030]), such design providing reduced heat duty in the furnace, thereby curtailing the amount of hydrocarbon-based fuel that would otherwise be used in a combustion only design (see Hirst, paragraph [0035]).
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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