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 .
DETAILED ACTION
This Office action is based on the 18/683388 application originally filed February 13, 2024.
Amended claims 1, 4, and 5, filed January 15, 2025, are pending and have been fully considered. Claims 2, 3, 6 and 7 have been canceled.
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 January 15, 2026 has been entered.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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(s) 1, 4 and 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Phan (US 2018/0079965) in view of Grassi (US 2011/0179701) and further in view of Pekarec (WO 2019/156593 A1) hereinafter cited under “US 2021/0054289”.
Regarding Claims 1, 4 and 5
Phan discloses in the abstract, a process and apparatus for treatment of biomass.
Phan discloses in paragraph 0064 and FIG. 2A, shows the process for treating biomass with a continuous or batch biomass treatment system which comprises a densification/pelletization stage (500), a first treatment stage (800) and a second treatment stage (900), and a cooling treatment stage (600). In FIG. 2B, besides the stages that are illustrated in FIG. 2A, an additional control system (300) having sensors and control devices is incorporated into the process for real-time monitoring and controlling the actual moisture content, the actual oxygen content, the actual temperature, the flow rate of gas, and the residence time, etc. to ensure that all parameters are conformed with the predetermined densification and torrefaction conditions.
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Phan further discloses in paragraph 0064, the process comprises: feeding substantially dried and size-reduced biomass (10) which contains an amount of moisture, preferably between 8 wt. % to 12 wt. %, into the densification stage (500) to produce densified biomass in the form of pellets or briquettes; discharging the densified biomass out of the densification stage (500) to the first treatment stage (800), which comprises heating the densified biomass containing moisture to a pre-torrefaction temperature, preferably ranging from 260 to 300° C., and for a first residence time, wherein the densified biomass containing moisture is substantially and completely dried by evaporating the moisture in the first treatment stage (800) and the densified biomass is at least partially torrefied to form the pre-torrefied biomass after said first treatment stage (800). After that, the pre-torrefied biomass is discharged out of the first treatment stage (800) to the second treatment stage (900), which comprises heating the pre-torrefied biomass supplied to the second treatment stage (900) at a temperature preferably ranging from 240 to 280° C and for a second residence time in order to form a torrefied biomass (20); discharging the torrefied biomass (20) out of the second treatment stage (900) via a biomass discharge device (70) and a gas sealed valve outlet (25) to the cooling treatment stage (600). There is also a heat exchange step (700) carried out by a heat exchange using the flue gas (12) from the combustion burner for heating up a portion of recuperated hot gas after being subjected to the first and second treatment stages in order to re-introduce those recuperated hot gas into the first and second treatment stages. The flue gas (12) out of the heat exchange could also provide heat to other stages (701) such as prior to said densification stage (500), the flue gas heat from the heat exchange step (700) can be used for reducing the moisture content of the biomass to a range of 8 wt. % to 12 wt. % before the introducing to the densification step of pelletizing or briquetting.
It is to be noted, Phan discloses a manufacturing system of a biomass solid fuel but fails to teach the system comprises a preheating step through a preheater in order to heat biomass pellets.
However, it is known in the art to use a preheater before torrefaction of biomass pellets in order to dry the biomass pellets to a desired moisture content, as taught by Grassi.
Grassi discloses in paragraph 0036, a process for manufacturing a “solid torrefied bio-fuel” from ligno-cellulose biomass pellets using a preheating step which heats the biomass in a range of 80° C. to 100° C. The biomass material is dried in a second step to obtain a maximum water content of 3% and torrefaction of the dried material is accomplished in a third step without affecting the cellulose and lignin components of the biomass. The torrefied pellets are then cooled.
Grassi discloses in paragraph 0065, depending on the material to be processed (and particularly its initial water content), these two first steps 10 and 20 constitute a pre-treatment unit to improve the productivity. Such pre-treatment is thus used to achieve standard water content in the material of no more than 3% before processing it in step 3. Alternately as shown in FIG. 2 super-heated steam can be recycled from step 2 (block 20) back to stage 1 (block 10) for pre-drying the biomass. Alternately or dually the heated air from the cooling stage 4 (block 40) can be recycled back into the stage 1 (block 10) pre-drying stage. This can be accomplished by a heat exchanger, or chamber atmosphere blowers venting the heated air from the cooling chamber back to the pre-drying chamber.
Grassi discloses in paragraph 0074, in operation the biomass pellets are fed into a hopper 22 in the pre-drying area onto a conveyor 24 which runs through chamber 21 where the pellets are heated and dried by a gas burner 26 which is used during startup of the process or to supplement heat returned from the cooling chamber 41. The supplemental heat circulates forced heated air through the pellet mass to dry the individual pellets. The temperature in the chamber is preferably 80° C to 100° C. If desired the conveyor can be a screw type of conveyer so that the pellets are constantly moved and brought into contact with the heated air.
It would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to add the preheater and heat generator (heat exchanger) of Grassi to the pretreatment stage of Phan. The motivation to do so is to use a preheater and heat exchanger before torrefaction of biomass pellets in order to dry the biomass pellets to a desired moisture content while using gas or air to heat.
Phan modified by Grassi discloses the manufacturing facility of biomass solid fuel according to independent claim 1 of the present invention but fails to specifically teach a fine powder separator provided between the gas outlet of the reactor and the first heat exchanger.
However, it is known in the art to use a powder separator in a system of preheating and torrefying a solid biomass fuel product, as taught by Pekarec.
Pekarec discloses in paragraph 0038, according to FIG. 1, the complex comprises a crushed wood waste preparation section (1) provided with storage, crushing and grinding, and dosing equipment; a gaseous heating agent preparation section (2) equipped with a multipurpose heat generator; a wood drying section (3) equipped with a loop-type drying device; a device for controlling the target moisture content of the wood particles (4), the structural implementation of which may vary (several embodiments are described in the dependent claims 2 and 3 of the invention); a mixed flow separation section (5) equipped with at least one cyclone; a storage hopper (6); an extrusion briquetting section (7); a low-temperature pyrolysis section (8) equipped with at least two low-temperature pyrolysis furnaces; a packaging section (9), which utilizes the original packaging easily distinguishable for a consumer; and a finished product warehouse (10).
Therefore, through the teachings of Pekarec it would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to add a powder separator in a system of preheating and torrefying a solid biomass fuel product to the pretreatment stage of Phan. The motivation to do so is to use a powder separator in a system of pretreatment before torrefaction of biomass pellets in order to dry the biomass pellets to a desired moisture content while using gas or air to heat.
Response to Arguments
Applicant's arguments filed January 15, 2026 have been fully considered but they are not persuasive.
Applicants argued: “Thus, Grassi teaches only pre-heating of the biomass with microwave heating. Grassi's pre-heating of the biomass with microwave heating is useful only because Grassi performs other phases of its process: the second phase drying and the third phase torrefaction, also with microwave heating. One of ordinary skill in the art would not have any reason or motivation to use Grassi's pre-heating of the biomass with microwave heating because Phan does not use microwave heating in its first treatment stage (800) and second treatment stage (900) performed in the same treatment chamber. Phan teaches that the advantages of its specific process using first treatment stage (800) and second treatment stage (900) performed in the same treatment chamber lowers the energy, time and temperature required for torrefaction. Using Grassi's pre-heating of the biomass with microwave heating in Phan's process would negate the inventive advantages of Phan's process using first treatment stage (800) and second treatment stage (900) performed in the same treatment chamber. Thus, one of ordinary skill in the art would not have any reason or motivation to combine Phan and Grassi as suggested by the Office. For this reason alone, the rejection should be withdrawn.
Applicants arguments are not deemed persuasive. As stated in the above rejection, Grassi discloses a pre-treatment before torrefaction, wherein the system comprises a pre-heater before a torrefaction reactor (see paragraphs 0065 and 0074 of Grassi). Grassi further discloses the pre-heater is heated by a heat exchanger, or chamber atmosphere blowers venting the heated air from the cooling chamber back to the pre-drying chamber. Grassi does not disclose the pre-heater is heated by microwave heat. Therefore, it is maintained that Phan modified by Grassi has met the presently claimed invention of a preheater before torrefaction of biomass pellets.
Applicants argued: “Neither of Pekarec's wood drying section (3) equipped with a loop-type drying device and Pekarec's mixed flow separation section (5) equipped with at least one cyclone would be able to separate fine powder contained in the torrefaction gas generated in Pekarec's semi-carbonization reactor (Pekarec's low-temperature pyrolysis section (8) equipped with at least two low-temperature pyrolysis furnaces) because each of Pekarec's wood drying section (3) equipped with a loop-type drying device and Pekarec's mixed flow separation section (5) equipped with at least one cyclone is positioned before Pekarec's low-temperature pyrolysis section (8) equipped with at least two low-temperature pyrolysis furnaces. Moreover, the "fine powder separator" of amended claim 1 cannot be equated with the "mixed flow separation section (5) equipped with at least one cyclone" described in item (5) of Pekarec. This is because the cyclone of Pekarec is used as a device for separating a gas phase (gas and vapor) from a solid phase (wood particles) after controlling the moisture content of the wood particles prior to pellet forming (i.e., prior to semi-carbonization). In addition, as described above, by providing the fine powder separator, the present application is capable of separating fine powders contained in the semi-carbonized gas generated in the reactor, thereby preventing adhesion of fine powders to the piping surface of the first heat exchanger 14. As a result, efficient heat exchange of the semi-carbonized gas can be achieved (see, for example, Fig. 2).”.
Applicants arguments are not deemed persuasive. As stated in the above rejection, it is maintained Pekarec discloses the addition of at least one cyclone after torrefaction (pyrolysis reactor) in order to aid in separation the crushed/powder wood from the gas-steam mixture (see paragraph 0021 of Pekarec). Therefore, Phan modified by Grassi and Pekarec have met the limitation of the presently claimed invention. It is to be noted, the features upon which applicant relies (i.e., the fine powder separator, the present application is capable of separating fine powders contained in the semi-carbonized gas generated in the reactor, thereby preventing adhesion of fine powders to the piping surface of the first heat exchanger 14). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Grassi et al. (US 2012/0192485) discloses in the abstract, a method and apparatus for treating a biomass material to produce a torrefied fuel comprising the steps of preheating the biomass material with a hot liquid flowing counter to the direction of travel of the biomass material at a temperature up to 200° C., superheating the preheated biomass material with a liquid flowing counter-current to the direction of travel of the biomass material to a temperature ranging up to 300° C. for a period sufficient to obtain full torrefaction of the biomass material, and cooling the torrefied biomass material with liquid flowing counter to the direction of travel of the torrefied biomass material.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to LATOSHA D HINES whose telephone number is (571)270-5551. The examiner can normally be reached Monday thru Friday 9:00 AM - 6:00 PM.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Prem Singh can be reached on 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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/Latosha Hines/Primary Examiner, Art Unit 1771