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 .
Applicant amended Claims 11 and 14.Applicant added Claims 18 and 19. Support for the amendments and new claim are found in the original filing. No new matter is presented.
Election/Restrictions
Claims 1-8 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected method, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 10/10/2025.
Information Disclosure Statements
The information disclosure statements (IDS) submitted on 10/10/2025 and 02/11/2026 have been considered by the examiner.
Response to Amendment
Responsive to communications filed on 02/11/2026, amendments to the claims have been acknowledged.
The rejections over NPL Viitasaari are maintained under additional grounds as necessitated by amendment and new rejections in view of Dong et al. CN 117431079 A have been made necessitated by amendment.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 9-10, 12-16, and 18 are rejected under 35 U.S.C. 102(a)(1) and (a)(2) as being anticipated by Viitasaari, "Utilisation possibilities of biochar produced by pyrolysis." (2021).
Regarding Claims 9-10 and 12-13, NPL Viitasaari discloses a system for producing a gas feed containing bio-oil and/or fast pyrolysis biochar and feeding the stream as fuel to a blast furnace for iron ore reduction to produce metallic iron (Abstract) (Figs. 1, 9, Pages 7, 31), meeting the limitations of the instant Claims.
Regarding Applicant’s Arguments, The instantly claimed blast furnace is part of a system that need only be capable of gasifying a source of fuel comprising at least one of bio-oil or fast pyrolysis biochar. The claims are drawn to a system, and not to a method. Therefore, the teachings of NPL Viitasaari meet the limitations of the instant Claims.
Regarding Claim 14, NPL Viitasaari discloses blending biochar with coal for use as fuel in blast furnace injection at (Page 33), meeting the limitations of the instant Claim.
Regarding Claim 15, NPL Viitasaari discloses the use of liquid bio-oil as fuel (Page 11), meeting the limitations of the instant Claim.
Regarding Claim 16, NPL Viitasaari discloses feeding fuel through inputs (meeting the limitation for a plurality of lines) configured to feed the fuel through hot blast through a plurality of tuyeres in the blast furnace (Page 30), meeting the limitations of the instant Claim.
Regarding Claim 19, NPL Viitasaari discloses the use of slow pyrolysis biochar as fuel (Page35), meeting the limitations of the instant Claim.
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.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over NPL Viitasaari.
Regarding Claim 11, NPL Viitasaari teaches the use of bio-oil as blast furnace fuel wherein the bio-oil has a water content of up to 20% water (Page 12), overlapping and meeting the limitation of the instantly claimed range of a water content less than about 10% by mass.
It would have been obvious to one having ordinary skill in the art at the time of filing the invention to utilize as fuel a bio-oil with a water content in the claimed range of less than about 10% by mass based on the teachings of NPL Viitasaari at (Pages 5, 11-12) that such oils with a water content of up to 20% by mass, overlapping the claimed range of water content, are useful as feedstock to a blast furnace.
See MPEP 2144.05. In cases where claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over NPL Viitasaari as applied to Claims 9-10, 12-16, and 19 above further in view of NPL Dimofte, Eugen, Popescu Fl, and V. I. Ion. "Hot air distribution through main bustle pipe on the tuyeres of a blast furnace." Proceedings of the 3rd International Conference of Thermal Equipment, Renewable Energy and Rural Development-TE-RE-RD. 2014.
Regarding Claim 17, NPL Viitasaari discloses the limitations set forth above and further teaches hot blast injection e.g. at (Page 30) but NPL Viitasaari does not expressly teach a ring-shaped manifold disposed around the blast furnace and configured to feed the fuel to a plurality of tuyeres in the blast furnace.
However, NPL Dimofte et al. teaches that the use of a ring-shaped bustle pipe (meeting the limitation for a manifold) disposed around a blast furnace and configured to feed fuel to a plurality of tuyeres in the blast furnace is beneficial for controlling the blast volume within the furnace.
It would have been obvious to one having ordinary skill in the art at the time of filing the invention to dispose the ring-shaped bustle pipe (meeting the limitation for a manifold) configured to feed fuel to a plurality of tuyeres in the blast furnace of NPL Viitasaari in order to control the hot blast volume. One of ordinary skill in the art would have been motivated by desire to increase uniformity of fuel distribution to utilize the ring-shaped manifold of NPL Dimofte et al., meeting the limitations of the instant Claim.
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over NPL Viitasaari as applied to Claims 9-10, 12-16, and 19 above further in view of Dong et al. CN 117431079 A.
Regarding Claim 18, NPL Viitasaari discloses the limitations set forth above and further teaches achieving a 100% coal replacement ratio with biochar e.g. at (Page 31) but NPL Viitasaari does not expressly teach a replacement ratio of bio-oil.
However, Dong et al. ’079 expressly teaches gasified bio-oil as blast furnace fuel with a 1:1 replacement ratio [0012, 0023]. Insofar as the system disclosed by NPL Viitasaari reads on the system of Claim 15, it would have been obvious to one having ordinary skill in the art at the time of filing the invention to achieve a 100% coal replacement ratio of bio-oil fuel based on the teachings of Dong et al. ‘079 at [0012, 0023].
Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
It would have been obvious to one having ordinary skill in the art at the time of filing the invention to achieve a 1:1 replacement of bio-oil in the blast furnace of NPL Viitasaari in order to reduce costs and save energy, based on the teachings of NPL Dong et al. ‘079 at [0026] meeting the limitations of the instant Claim. See MPEP 2141.01(a) I. “[A] reference need not be from the same field of endeavor as the claimed invention in order to be analogous art.” Bigio, 381 F.3d at 1325, 72 USPQ2d at 1212.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
CN 116855267 A teaches producing biomass pyrolysis oil as clean fuel.
Response to Arguments
Applicant's arguments filed 02/11/2026 have been fully considered but they are not persuasive.
Applicant argues the cited references do not teach the gasification of fast pyrolysis biochar.
However, the teachings of NPL Viitasaari are not limited to the gasification of slow pyrolysis char. Where NPL Viitasaari teaches “long residence time is optimal for great biochar yield due to longer residence time of volatiles.” At (Page 21), this teaching is not limited to fast or slow pyrolysis. Even if differences are described between fast and slow pyrolysis char this would not amount to a teaching away of utilizing either type of char. See MPEP 2141.01(a) I. “[A] reference need not be from the same field of endeavor as the claimed invention in order to be analogous art.” Bigio, 381 F.3d at 1325, 72 USPQ2d at 1212. NPL Viitasaari further describes at (Page 46) “Use of fast pyrolysis as a production method for biochar introduces energy efficiency and better control of pollutants to the production process.”
The claims are drawn to a system, not a method of ironmaking or gasifying fuel. Therefore, the system of the prior art is capable of gasifying fast pyrolysis biochar and consequently reads on, or otherwise overlaps and encompasses the instantly claimed subject matter.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 extension fee 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 date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MORIAH S. SMOOT whose telephone number is (571)272-2634. The examiner can normally be reached M-F 8:30am - 5pm EDT.
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/Keith D. Hendricks/Supervisory Patent Examiner, Art Unit 1733
/M.S.S./Examiner, Art Unit 1733