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
Claims 21-23, 29-30, 35, 37 and 40 are under examination herein.
Election/Restrictions
Applicant’s election without traverse of Group II: claims 21-23, 29-30, 35, 37 and 40 in the reply filed on June 10, 2026 is acknowledged.
Claims 1-5, 9-10, 12-14, 16-17 and 19 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on June 10, 2026.
Priority
This application, filed on 5/10/2024, is a 371 of PCT/US2022/409582 filed on 11/10/2022, which claims benefit of 63/277,962 filed on 11/10/2021. The effective filing date of the current application is November 10, 2021.
Information Disclosure Statement
The information disclosure statement filed on 5/10/2024 complies with 37 CFR 1.98(a)(2), which requires a legible copy of each cited foreign patent document; each non-patent literature publication or that portion which caused it to be listed; and all other information or that portion which caused it to be listed. All references were considered.
Claim Objections
Claims 21 and 40 are objected to because of the following informalities:
Claims 21 and 40 each recite “contacting the feedstock mixture with effective amount” in step b, which is missing an article in front of effective and should be amended to recite “contacting the feedstock mixture with an effective amount”.
Claim 21 recites “contacting the first digestate with effective amount” in step e, which is missing an article in front of “effective” and should be amended to recite “contacting the first digestate with an effective amount”.
Claims 21 and 40 recite “a.” “b.” “c.” “d.” “e.” “f.” and “g.” to identify method steps, which contain periods. It is suggested that the identifiers be amended to remove the periods, such as “a)” or “(a)”. It is noted that claim 22 refers to the steps as “(c)” and “(f)”. See MPEP 608.01(m), first paragraph.
Appropriate correction is required.
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 21-22, 30, 35, and 37 are rejected under 35 U.S.C. 103 as being unpatentable over Ludtke et al. (US2016/0230134A1, published on August 11, 2016) in view of Srisowmeya et al. (“Critical considerations in two-stage anaerobic digestion of food waste – A review”, Renewable and Sustainable Energy Reviews, 2020, Vol. 119, Article 109587, 14 pages).
Regarding claim 21 step a, Ludtke teaches anaerobic fermentation of the heat-treated lignocellulose-containing biomass by means of microorganisms and recovery of the biogas formed (p.3-4, [0037]).
Regarding claim 21 step b, Ludtke teaches the formation of biogas is considerably improved especially through adjustment of the sodium content, if desired by introduction of sodium hydroxide solution (p.3, [0033]). Ludtke teaches the enzymatic digestion is at a pH 8-10 (p.5, [0050]).
Regarding claim 21 step c, Ludtke teaches the residence time of the anaerobic fermentation is selected such that a stable microorganism population is established in the fermented, and with mesophilic or thermophilic operation, a residence time from 10 to 50 days is advantageous; the biogas generated is collected and taken off for further processing (p.6, [0057]). Ludtke teaches the thermal digestion takes place in the aqueous phase at a temperature from 130°C to 200°C (i.e. at least 45°C) (p.9, [0094]).
Regarding claim 21 step d, Ludtke teaches the biogas generated is collected and taken off for further processing (i.e. collecting a first biogas) (p.6, [0057]).
Regarding claim 21 step e, Ludtke teaches the formation of biogas is considerably improved especially through adjustment of the sodium content, if desired by introduction of sodium hydroxide solution (p.3, [0033]). Ludtke further teaches that the technical implementation of the second fermentation can be effected in the same manner as with the first fermentation (p.6, [0062]).
Ludtke does not teach contacting the first digestate with an effective amount of a second pH adjusting agent.
However, Srisowmeya teaches fermentative bacteria can perform efficiently in a wide pH range of 4.0-8.0, whereas methanogenic bacteria are functionally active within a pH range of 6.5-7.5 (i.e. decrease a pH to a substantially neutral pH) (p.7, 2nd column – 4.3. pH).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Ludtke to adjust the pH of the first digestate using a second pH adjusting agent, because Srisowmeya teaches methanogenic bacteria are functionally active within a pH range of 6.5-7.5. One of ordinary skill in the art would have found it beneficial to adjust the pH of the first digestate using sodium hydroxide taught by Ludtke to a more neutral pH as taught by Srisowmeya.
Regarding claim 21 step f, Ludtke further teaches the anaerobic degradation of the heat-treated outflow is effected by feeding into a further, second fermentation (i.e. forming a second biogas) (p.6, [0062]).
Regarding claim 21 step g, Ludtke further teaches collecting biogas from the second fermentation (i.e. collecting the second biogas) (Fig. 2).
Regarding claim 22, Ludtke teaches a fermentation of the organic waste in a first reactor, followed by a hydrolysis of the thus fermented organic waste in an anaerobic hydrolysis tank, followed by a further fermentation in a second reactor (p.3, [0023]).
Regarding claim 30, Ludtke teaches in the fermentation process, about 40% of the organic starting mass should be degraded and converted into biogas by the first fermentation process with an average duration of 25 days (p.1, [0010]).
Regarding claim 35, Ludtke teaches a pH of 8-10 (p.6, [0050]).
Regarding claim 37, Ludtke teaches that it can be useful further to shred the lignocellulose-containing biomass mixed in the suspension, especially if the average substrate particle size is greater than 2 mm, which can for example be achieved with a wet shredding by means of a wet mill or cutting wheels in the pipe transport system or disperser (p.5, [0052]). Ludtke further teaches that the wet shredding can also be performed in several stages, including directly after the mixing, but also after the heat exchanger directly before the anaerobic fermentation (p.5, [0052]).
Claim 23 is rejected under 35 U.S.C. 103 as being unpatentable over Ludtke et al. (US 2016/0230134 A1, published on August 11, 2016) in view of Srisowmeya et al. (“Critical considerations in two-stage anaerobic digestion of food waste – A review”, Renewable and Sustainable Energy Reviews, 2020, Vol. 119, Article 109587, 14 pages) as applied to claim 21 above, and further in view of Stepany et al. (US 11,168,339 B1, issued on November 9, 2021).
The teachings of Ludtke et al. and Srisowmeya et al. are discussed above.
Regarding claim 23, Ludtke and Srisowmeya do not teach a biogas comprising at least 85% methane by volume.
However, Stepany teaches methane-containing biogas can be purified to generate an upgraded biogas with higher methane content by removing non-methane components (col. 23, lines 62-67). Stepany teaches the upgraded biogas can contain 85, 90, 91, 92, 93, 94,. 95, 96, 97, 98 or 99 vol% methane (col.24, lines 17-19).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Ludtke and Srisowmeya, by adding a step to remove non-methane components as taught by Stepany, in order to obtain a biogas comprising at least 85% methane by volume, because Stepany teaches that removing non-methane components can yield biogas containing up to 99 vol% of methane.
Claim 29 is rejected under 35 U.S.C. 103 as being unpatentable over Ludtke et al. (US 2016/0230134 A1, published on August 11, 2016) in view of Srisowmeya et al. (“Critical considerations in two-stage anaerobic digestion of food waste – A review”, Renewable and Sustainable Energy Reviews, 2020, Vol. 119, Article 109587, 14 pages) as applied to claim 1 above, and further in view of Nguyen et al. (“Application of rumen and anaerobic sludge microbes for bio harvesting from lignocellulosic biomass”, Chemosphere, 2019, Vol. 228, pp.702-708).
The teachings of Ludtke et al. and Srisowmeya et al. are discussed above.
Regarding claim 29, Ludtke teaches the outflow from the second fermenter can be separated by a solid-liquid separation into a liquid and a solids-containing phase (p.6, [0064]).
Ludtke does not teach wherein incubation of the feedstock mixture produces a digestate comprising volatile fatty acids and wherein the volatile fatty acid net production is at least 50 mg VFA/g lignocellulosic biomass fed.
Srisowmeya teaches volatile fatty acids in an anaerobic digester mainly includes acetic acid, propionic acid, butyric acid, isobutyric acid, isovaleric acid and valeric acid (p.10, 2nd column – 4.8. Volatile fatty acids). Srisowmeya further teaches that in single stage or two stage anaerobic digestion, volatile fatty acids are formed (p.3, Fig. 1).
Srisowmeya does not teach wherein the volatile fatty acid net production is at least 50 mg VFA/ g lignocellulosic biomass fed.
However, Nguyen teaches the production of biogas, volatile fatty acids (VFAs) and other soluble organic from lignocellulosic biomass by two microbial communities (abstract). Nguyen teaches VFA production from lignocellulosic biomass is the building block chemical for biofuel (abstract). Nguyen teaches an average 100 mg VFA per g of lignocellulosic biomass was produced after two days of inoculation with rumen fluid (i.e. at least 50 mg VFA / g lignocellulosic biomass) (p.705, 1st column – 2.1. Volatile fatty acid production).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to replace the microorganism community taught by Ludtke with rumen fluid microorganism community taught by Nguyen in the method of Ludtke and Srisowmeya to obtain an average 100 mg VFA / g lignocellulosic biomass. Each of Ludtke, Srisowmeya and Nguyen teach fermentation of biomass using microbial communities. One of ordinary skill in the art would reasonably expect that fermenting lignocellulosic biomass with a microbial community would predictably result in the production of volatile fatty acids as a desired level, because it was known in the art at the time of invention that fermenting lignocellulosic biomass material resulted in the production of volatile fatty acids and biogas.
Claim 40 is rejected under 35 U.S.C. 103 as being unpatentable over Ludtke et al. (US 2016/0230134 A1, published on August 11, 2016) in view of Nguyen et al. (“Application of rumen and anaerobic sludge microbes for bio harvesting from lignocellulosic biomass”, Chemosphere, 2019, Vol. 228, pp.702-708).
Regarding claim 40 step a, Ludtke teaches anaerobic fermentation of the heat-treated lignocellulose-containing biomass by means of microorganisms and recovery of the biogas formed (p.3-4, [0037]).
Regarding claim 40 step b, Ludtke teaches the formation of biogas is considerably improved especially through adjustment of the sodium content, if desired by introduction of sodium hydroxide solution (p.3, [0033]). Ludtke teaches the enzymatic digestion is at a pH from 8-10 (p.5, [0050]).
Regarding claim 40 step c, Ludtke teaches the residence time of the anaerobic fermentation is selected such that a stable microorganisms population is established in the fermented, and with mesophilic or thermophilic operation, a residence time from 10 to 50 days is advantageous; the biogas generated is collected and taken off for further processing (p.6, [0057]). Ludtke teaches the thermal digestion takes place in the aqueous phase at a temperature from 130°C to 200°C (i.e. at least 45°C) (p.9, [0094]).
Ludtke teaches the anaerobic degradation of the heat-treated outflow is effected by feeding into a further, second fermentation (p.6, [0062]).
Ludtke does not teach forming a digestate comprising a volatile fatty acid.
However, Nguyen teaches the production of biogas, volatile fatty acids (VFAs) and other soluble organic from lignocellulosic biomass by two microbial communities (abstract). Nguyen teaches VFAs are building blocks for biodegradable plastics and biofuels (p.705, 1st column – 3.1. Volatile fatty acid production).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to obtain a digestate containing a volatile fatty acid taught by Nguyen using the method of Ludtke, because Nguyen teaches that VFA production from lignocellulosic biomass is the building block chemical for biodegradable plastics and biofuel. One of ordinary skill in the art would have found it beneficial to produce VFAs as an important building block in producing biogas.
Claim 40 is rejected under 35 U.S.C. 103 as being unpatentable over Spahr et al. (US 2019/0382700 A1, published on December 19, 2019), in view of Alriksson et al. (“Optimal conditions for alkaline detoxification of dilute-acid lignocellulose hydrolysates”, Applied Biochemistry and Biotechnology, 2006, Vol. 130, pp.599-611).
Regarding claim 40 step a and step c, Spahr teaches a cellulose-containing and/or lignocellulose-containing substrate is at least partially fermented with mesophilic bacteria in a first reactor during a first residence time. The first reactor is preferably closed off in an airtight manner, so that an anaerobic fermentation can be ensured (p.1, [0008]). Spahr teaches transferring of part of the at least partly fermented substrate out of the first reactor into a second, heatable reactor with hyperthermophilic bacteria, wherein the hyperthermophilic bacteria are suitable for breaking down the at least partly fermented substrate (forming a digestate) (p.1, [0010]). Spahr teaches incubating the partly fermented substrate for a second residence time at a temperature in the region of at least 55°C (which is at least 45°C) (p.1, [0011]). Spahr further teaches the at least partly fermented substrate is incubated for a second residence time and acetic acid is at least partly formed (acetic acid is considered a volatile fatty acid (VFA), as it is a short-chain carboxylic acid with 1–6 carbon atoms that is biologically and chemically classified as volatile) (p.1-2, [0011]).
Regarding claim 40 step b, Spahr teaches a pH value in the first reactor lies in the neutral to slightly alkaline range, so that mesophilic bacteria can live under as favourable living conditions as possible to encourage a formation of methane, between pH 6.6 to 8.3 (p. 3, [0025]).
Spahr does not disclose contacting the feedstock mixture with a pH adjusting agent.
However, Alriksson teaches the pH of dilute-acid lignocellulose hydrolysate can be adjusted using ammonium hydroxide, sodium hydroxide, and calcium hydroxide (p.600, last paragraph).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to adjust the pH of the first reactor in Spahr using ammonium hydroxide, sodium hydroxide, or calcium hydroxide as taught by Alriksson to obtain a pH value in the slightly alkaline range. One of ordinary skill in the art would reasonably expect that adding a base taught by Alriksson to the feedstock mixture taught by Spahr would predictably result in an alkaline solution, because it was known in the art at the time of invention that pH could be adjusted by adding ammonium hydroxide, sodium hydroxide or calcium hydroxide.
Conclusion
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/LOUISE W HUMPHREY/Supervisory Patent Examiner, Art Unit 1657
/DEEPA MISHRA/Examiner, Art Unit 1657
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