DETAILED ACTION
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office Action has been withdrawn pursuant to 37 CFR 1.114. Applicant’s submission filed on 6 October 2025 has been entered.
Response to Amendment
Examiner acknowledges Applicant’s response filed 6 October 2025 containing amendments to the claims and remarks.
Claims 1-16 are pending.
The previous grounds for rejection under 35 U.S.C. 103 are modified with two additional newly cited references: Hirst (US 2023/0013408) and Van der Ploeg (US 2021/0113980). Because the rejections herein are not identical to those of the previous Office Action mailed 9 July 2025, they are deemed to be new grounds for rejection. The rejections follow.
Claim Interpretation
With respect to amended claim 1, Examiner construes the “consisting essentially of” preamble to have the same effect as “comprising.” For the purposes of searching for and applying prior art under 35 U.S.C. 102 and 103, absent a clear indication in the specification or claims of what the basic and novel characteristics actually are, “consisting essentially of” will be construed as equivalent to “comprising.” See, e.g., PPG Industries v. Guardian Industries, 156 F.3d 1351, 1354-1355 (Fed. Cir. 1998) (“PPG could have defined the scope of the phrase ‘consisting essentially of’ for purposes of its patent by making clear in its specification what it regarded as constituting a material change in the basic and novel characteristics of the invention.”).
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 1-9, 11-14, 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 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 stream 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 claim 2, 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).
With respect to claim 3, 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).
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 claims 11 and 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 10.
Neither Brewer nor Ward explicitly disclose 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 10. 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 6 October 2025 have been fully considered but they are not persuasive.
Examiner understands Applicant’s arguments to be:
Unlike in the disclosure of Brewer, the claimed furnace does not require use of any radiant burners.
There is no mention at all of electrical heating elements in the disclosure of Brewer.
The headers, manifolds, or individual pipes leading to each burner as described in Brewer is specific infrastructure which is explicitly set up to provide fuel to radiant burners in the furnace of Brewer. One of ordinary skill in the art would therefore not be motivated to add electrical heating elements to the furnace of Brewer because Brewer’s furnace is not equipped to supply electrical energy to an electrical heating element. Adding electrical heating elements to Brewer’s furnace such that “the furnace additionally comprises one or more heating elements” as suggested by Examiner renders Brewer’s furnace inoperable as electrical heating elements cannot accept combustion fuel as a power source.
As the Examiner is mapping different prior art references to various aspects of the claims, and thus, performing a piece-wise examination of individual claim limitations, it appears the Examiner is using the present application as a road map for selecting and combining prior art teachings. This is hindsight reconstruction which is improper.
Even if a person of ordinary skill in the art would seek to modify Brewer using the teachings of Ward, the person would be led by Ward to include at least one electrical heater in addition to the fired burners of Brewer. Amended claim 1 precludes the use of radiant fired burners in the claimed furnace. Therefore, one of ordinary skill in the art would not be motivated to combine teachings of Ward and Brewer to arrive at the claimed furnace consisting essentially of electrical heating elements.
With respect to Applicant’s first and fifth arguments, Examiner does not agree that the claims preclude the use of radiant fired burners. To be clear, for the purposes of searching for and applying prior art under 35 U.S.C. 102 and 103, absent a clear indication in the specification or claims of what the basic and novel characteristics actually are, “consisting essentially of” will be construed as equivalent to “comprising.” See MPEP § 2111.03(III) (citing PPG Industries v. Guardian Industries, 156 F.3d 1351, 1354-1355 (Fed. Cir. 1998) (“PPG could have defined the scope of the phrase ‘consisting essentially of’ for purposes of its patent by making clear in its specification what it regarded as constituting a material change in the basic and novel characteristics of the invention.”)).
With respect to Applicant’s second argument, the rejection at issue does not allege that Brewer discloses electrical heating elements. Rather, the rejection is clear that Ward, Van der Ploeg, and Hirst (not Brewer) disclose the use of electricity or electrical heating elements (see discussion supra at paragraph 10).
With respect to Applicant’s third argument, such argument is not found persuasive in view of Hirst which discloses a furnace design making use of both burners and electrical heating elements (see Hirst, Abstract; and entire disclosure).
With respect to Applicant’s fourth argument, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
The remainder of Applicant’s arguments is considered moot in view of the new grounds for rejection.
Conclusion
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