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 .
Claim Status
Claims 1-14 are pending.
No claims have been amended.
No claims have been cancelled.
Thus, claims 1-14 represent all claims currently under consideration.
Priority
Foreign Applications:
REPUBLIC OF KOREA 10-2019-0160692 (12/05/2019)
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Objections
Claim 1 is objected to because of the following informalities:
In line 2, “comprises of:” should read “comprising of:”.
In line 3, “i.heating” should read “i. heating”.
In line 3, “into” should read “inside”.
In line 14, “of amine extractant-acid complex” should read “of an amine extractant-acid complex”.
Claim 3 is objected to because of the following informalities:
In line 4, “form” should read “from”.
In line 7, “form” should read “from”.
In line 9, “form” should read “from”.
Claim 9 is objected to because of the following informalities:
In line 2, “comprises of” should read “comprises”.
Claim 13 is objected to because of the following informalities:
In line 2, “comprises of:” should read “comprising of:”.
In line 9, “to the temperature of” should read “to a temperature of”.
In line 12, “in range of” should read “in a range of”.
Claim 14 is objected to because of the following informalities:
In line 3, “saccharomyces” should read “Saccharomyces”.
Appropriate correction is required.
Claim Interpretation
Claims 1-2, 4, and 13 recite the term “technical lignin”. Absent a strict definition in the written description, this term will be interpreted as a bulk feedstock generated as byproducts from industrial processes including but not limited to pulping or cellulosic ethanol production, as taught by Li et al. (see Abstract in: Biofuels Bioprod. Biorefin. 2018, 12, 756-787; published 07-10-2018).
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-14 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 recites the phrase “A novel integrated process…” in line 1. However, the use of the word “novel” is subjective, does not add any substance to the claim, and renders the scope of the claim unclear. This ambiguity renders the instant claim indefinite.
Regarding claims 2-14, these dependent claims do not resolve the indefiniteness of claim 1 described above.
Claim 8 recites the limitation “wherein components of fusel oil are…” in line 1. There is insufficient antecedent basis for this limitation in the claim. The term “fusel oil” is not introduced until claim 7.
Claim 9 recites the limitation “the synthetic blend of fusel oil…” in line 1. There is insufficient antecedent basis for this limitation in the claim. The term “synthetic blend of fusel oil” is not introduced until claim 7.
A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claim 9 recites the broad recitation “iso amyl alcohol (55 - 60 %), iso butyl alcohol (18 - 20 %), active amyl alcohol (10 - 15 %), butyl alcohol (5 - 8 %), propyl alcohol (5 - 8 %), and hexanol (2 - 5 %)”, and the claim also recites parenthetical percentage ranges of each of the components, which is the narrower statement of the range/limitation. The claim is considered indefinite because there is a question or doubt as to whether the feature introduced by such parenthetical narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claim.
Claim 13 recites the limitation “the enzymatic hydrolysis and fermentation” in lines 9-10. There is insufficient antecedent basis for this limitation in the claim.
Claim 13 recites “iii. distilling the fermented broth by standard distillation and molecular sieve methods…” in line 13. However, it is unclear as written whether “molecular sieve methods” are a part of the “distilling” method step or a separate purification process, and this ambiguity renders the instant claim indefinite.
Regarding claim 14, this dependent claim does not resolve the indefiniteness of claim 13 detailed above.
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.
Claims 1, 4, 6-7, and 11 are rejected under 35 U.S.C. 103 as being unpatentable over P. L. Woestenborghs (WO 2015/063033 A1; published 05-07-2015), in view of Eda et al. (“Recovery of levulinic acid by reactive extraction using tri-n-octylamine in methyl isobutyl ketone: Equilibrium and thermodynamic studies and optimization using Taguchi multivariate approach; Sep. Purif. Technol. 2018, 197, 314-324; published 05-31-2018”).
Regarding claim 1, Woestenborghs teaches a process for the separation of levulinic acid from a biomass hydrolysate. Suitable carbohydrates to be converted to levulinic acid in the process include wood, sawdust, wood chippings, wood shavings, cellulosic material e.g. from lignocellulosic feedstock, and the carbohydrates may be bound to a component, such as lignin (Title; Abstract; page 5, lines 34-36 and page 6, lines 1-6).
The biomass hydrolysate is obtained by acid hydrolysis of biomass under conditions that results in the formation of levulinic acid and optionally in the formation of tar and/or humins, preferably with diluted sulphuric acid at a temperature that may range between 150-250 ºC. The Example of Woestenborghs teaches that a reaction mixture was obtained via acid hydrolysis of wood in an aqueous environment (H2SO4, 4% w/w; 195 ºC) (page 5, lines 7-15; Example on p. 14-15).
The process of Woestenborghs comprises subjecting the biomass hydrolysate to a solid-liquid separation to yield a solid fraction and a liquid fraction. The solid fraction will contain solids and preferably char, and the liquid fraction will comprise levulinic acid and may also comprise humins and/or colour. Examples of suitable solid-liquid separation techniques are filtration and centrifugation. The process further comprises subjecting the liquid fraction to a solvent-solvent extraction with a suitable organic solvent in order to extract the levulinic acid from the acidic water phase to yield an organic comprising levulinic acid, and an aqueous phase, and recovering said organic phase. The aqueous phase is also referred to as raffinate. The recovered organic phase is subjected to a distillation to yield a distillate comprising levulinic acid, and a distillation residue. The solvent that is used in the extraction step can be recovered as the top fraction and re-used for extraction (claim 1; page 6, lines 33-35; page 7, lines 1-34; page 8, lines 18-20; page 9, lines 11-12; page 14, lines 26-28).
Woestenborghs does not explicitly recycling the acidic aqueous liquid waste or raffinate generated after organic solvent extraction for the next batch of producing levulinic acid (LA), as recited in step v of claim 1. Instead, Woestenborghs teaches that the aqueous phase is separated and can be discarded. However, the skilled artisan would recognize that the recovered aqueous phase could be recycled for the next batch of producing LA to improve the overall sustainability and efficiency of the process with a reasonable expectation of success.
Woestenborghs does not teach mixing of the supernatant containing LA with an organic solvent and an amine extractant and purifying LA by a reactive extraction, as recited in steps iii-iv of claim 1.
However, Eda teaches the recovery of levulinic acid from an aqueous solution using a tertiary amine, tri-n-octylamine (TOA), as an extractant in methyl isobutyl ketone (MIBK). Chemical equilibrium studies showed the formation of 2:1 complex as the main mechanism in the reactive extraction. The chemical extraction is based on the interaction of levulinic acid with TOA through (1) hydrogen bonding or (2) ion pair formation, and the chemical equilibrium processes can be expressed by the following equations and figure:
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265
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30
271
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446
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Eda further teaches that recent research in the carboxylic acid recovery process is targeted towards the selection of a separation process that takes less time, requires less energy, and generates less waste. An intensified process such as reactive extraction meets most of these requirements. The main advantage of using reactive extraction for the recovery of carboxylic acids is that it offers significant improvement in both the reaction and separation stages. The tertiary amine extractants with long chain carbon atoms have benefits over the other extractants because they are cheaper and have higher distribution coefficient KD values. The lower values of distribution coefficients in physical extraction (solvent) indicate that extractants need to be used to improve the extraction efficiency, and reactive (chemical) extraction is more suitable than the solvent (physical) extraction to recover levulinic acid from the aqueous solution because it leads to higher KD and %E values (Abstract; page 314, Col. 2, paragraph 1; page 315, Col. 1, paragraph 1; page 318, Col. 1, Section 3.1.2. Chemical extraction; equations 16-18; page 319, Col. 1, paragraph 1; Col. 2, paragraph 1; Fig. 3; page 322, Col. 1, paragraph 1).
The process of Eda and Woestenborghs are analogous because they both teach the extraction of levulinic acid from aqueous solutions in the presence of an organic solvent, in a manner consistent with steps iii. and iv. of instant claim 1. Furthermore, Eda teaches methyl isobutyl ketone (MIBK) as a preferred organic solvent (Eda; Abstract), and Woestenborghs also teaches that methyl isobutyl ketone is a suitable organic solvent for the extraction method step (Woestenborghs; page 8, line 34). In addition, Eda teaches that levulinic acid can be produced using acid-catalyzed chemical processes such as dehydration of glucose, and is attractive because a number of low-cost ligno-cellulosic feeds can be utilized (page 314, Col. 1, paragraph 1). Therefore, Eda teaches a directed use for the reactive extraction towards processes utilizing the acid hydrolysis of lignocellulosic biomass, such as the method of Woestenborghs.
Thus, the skilled artisan would be sufficiently motivated to modify the extraction step in the process of Woestenborghs to incorporate the TOA extractant of Eda to predictably pursue a reactive extraction method with improved efficiency with a reasonable expectation of success. See MPEP § 2143(I)(A).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Woestenborghs to incorporate the TOA extractant of Eda to arrive at the claimed invention. The motivation to do so would permit the skilled artisan to pursue, with a reasonable expectation of success, a reactive extraction method with improved efficiency compared to a physical extraction that utilizes solvent alone, as described above.
Regarding claim 4, Woestenborghs teaches that the temperature in the acid hydrolysis process may range between 150-250 ºC, preferably between 170-240°C, more preferably between 190-230°C, even more preferably between 200 and 220°C. The reaction time may vary between one second and one day, preferably between 10 seconds and one hour, more preferably between 1 minute and 2 hours, more preferably between 10 and 60 minutes (page 5, lines 14-17 and 30-33). The reaction temperatures and times of Woestenborghs overlap with the ranges recited in the instant claim. MPEP § 2144.05(I) states that “[i]n the case where the claimed ranges ‘overlap or lie inside ranges disclosed by the prior art’ a prima facie case of obviousness exists.”
Regarding claim 6, Eda teaches extraction temperatures ranging from 293-333 K, and extraction times of up to 5 hours (page 317; Fig. 1; page 319; Table 4; page 320, Fig. 4). These ranges correspond to an extraction temperature range of 20-60 C and an extraction time of up to 300 min, and overlap with the instantly claimed ranges. MPEP § 2144.05(I) states that “[i]n the case where the claimed ranges ‘overlap or lie inside ranges disclosed by the prior art’ a prima facie case of obviousness exists.” Furthermore, when considering Woestenborghs in view of Eda, the skilled artisan would recognize that extraction temperatures and times could be optimized accordingly to arrive at the claimed invention through means of routine optimization that is non-inventive in nature. See MPEP § 2144.05(II)
Regarding claim 7, Woestenborghs teaches that the extraction phase, which is an organic phase comprising levulinic acid, can comprise suitable solvents including dichloromethane, diethyl ether, butanol, ethyl acetate, benzene, and toluene (page 8, lines 18-35).
Regarding claim 11, Eda teaches an optimal TOA concentration of 0.678 kmol/m3 (Asbtract). This corresponds to 0.678 M and resides within the range recited in the instant claim. MPEP § 2144.05(I) states that “[i]n the case where the claimed ranges ‘overlap or lie inside ranges disclosed by the prior art’ a prima facie case of obviousness exists.”
Claims 2-3 and 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over P. L. Woestenborghs (WO 2015/063033 A1; published 05-07-2015), in view of Eda et al. (“Recovery of levulinic acid by reactive extraction using tri-n-octylamine in methyl isobutyl ketone: Equilibrium and thermodynamic studies and optimization using Taguchi multivariate approach; Sep. Purif. Technol. 2018, 197, 314-324; published 05-31-2018”) as applied to claims 1, 4, 6-7, and 11 above, and further in view of Satlewal et al. (US 2022/0064199 A1; published 03-03-2022).
Regarding claims 2 and 7-9, claim 1 is rendered obvious over Woestenborghs and Eda, as detailed above.
Further regarding claim 7, although Woestenborghs teaches several of the organic solvents recited in the instant claim, as detailed in the rejection above, Woestenborghs does not teach the use of fusel oil or a synthetic blend of fusel oil as the organic solvent.
Woestenborghs and Eda do not teach wherein the technical lignin is bioethanol residue generated from a lignocellulosic biomass after 2G bioethanol processing as recited in claim 2; wherein the organic solvent is selected from fusel oil or a synthetic blend of fusel oil as recited in claim 7; or wherein the selected fusel oil or a synthetic blend of fusel oil comprises the components as recited in claims 8-9.
However, Satlewal teaches a method to valorize 2G bioethanol waste streams using an integrated approach for utilizing waste products of 2G bio-refineries to fractionate lignin of high purity. At present, lignin is mostly burned as low-quality solid fuel to supply heat and electricity in a biorefinery. As lignin is the most abundant renewable feedstock, its valorization will enable new uses as value-added chemicals and fuels. The availability of lignocellulosic bioethanol residue generated from bio-refineries will be huge (biomass estimated at 62 million tons annually), creating a need for 2G bioethanol residue valorization. The process of Satlewal provides a method to valorize waste streams, including bioethanol residue, to develop high value products (Title; Abstract; claim 1; 00020003, 0011-0012).
Further regarding claims 2 and 7, The method of Satlewal uses includes a method of recycling two waste products, 2-G ethanol residue as the substrate and waste fusel oil/synthetic fusel oil as useful solvents to generate lignin that can be upgraded to value-added compounds through emerging lignin valorization processes. The use of fusel oil/synthetic fusel oil combined with formic acid at a ratio of 1:1 gave highest lignin solubilization (Abstract; claim 1; 0010, 0024, 0026, 0032; 0064; Table 5). Thus, the skilled artisan would recognize that lignin obtained from lignocellulosic bioethanol residue represents a sustainable and renewable source of lignin, and the utilization of fusel oil/synthetic fusel oil derived from biorefinery waste streams is a cost-effective and sustainable extractant to generate lignin useful for the downstream production of value-added compounds.
Further regarding claim 8, Satlewal teaches that the chemical composition of fusel oil obtained from an ethanol production unit contains iso-amyl alcohol, iso-butyl alcohol, active amyl alcohol, butyl alcohol, propyl alcohol, hexanol, and a mixture of methanol, ethanol, acids, water, and metal salts (0062; Table 4).
Further regarding claim 9, Satlewal teaches the use of a synthetic fusel oil or blend that was prepared in laboratory by mixing its individual components, i.e., iso-amyl alcohol (55%), iso-butyl alcohol (18%), active amyl alcohol (10%), butyl alcohol (5%), propyl alcohol (5%), and hexanol (2%) (0062, 0064, Tables 4-5; percentages are v/v). The respective amounts of these individual components reside within the range recited in the instant claim. MPEP § 2144.05(I) states that “[i]n the case where the claimed ranges ‘overlap or lie inside ranges disclosed by the prior art’ a prima facie case of obviousness exists.”
The method of Satlewal and the process of Woestenborghs are analogous because they both teach extraction processes of lignocellulosic biomass derived from renewable feedstocks, in a manner consistent with the instantly claimed invention. As such, the skilled artisan would be sufficiently motivated to modify the process of Woestenborghs and Eda to incorporate with the teachings of Satlewal to predictably implement the use of lignocellulosic biomass generated from 2G bioethanol residue and the use of fusel oil and/or synthetic fusel oil as an organic extraction solvent to pursue a method with improved sustainability through the use of two separate waste streams (2G bioethanol residue and fusel oil) with a reasonable expectation of success. See MPEP2143 § (I)(A). For the same reason, the skilled artisan would also be motivated to predictably substitute the extractant (i.e., methyl butyl isoketone) of Woestenborghs and Eda with fusel oil and/or synthetic fusel oil as an organic extraction solvent with a reasonable expectation of success. See MPEP2143 § (I)(B).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Woestenborghs and Eda to incorporate with the teachings of Satlewal to arrive at the claimed invention. The motivation to do so would permit the skilled artisan to pursue, with a reasonable expectation of success, a method with improved cost-effectiveness and sustainability through the use of two separate waste streams (2G bioethanol residue and fusel oil), as described above.
Regarding claim 3, Woestenborghs teaches that the biomass may comprise lignocellulosic feedstock, agricultural waste products, grass, lignocellulosic (bran) fibers and corn fiber, wood, sawdust, fibre crops, and paper pulp (page 2, lines 8-10 and page 5, lines 34-36 and page 6, lines 1-8).
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over P. L. Woestenborghs (WO 2015/063033 A1; published 05-07-2015), in view of Eda et al. (“Recovery of levulinic acid by reactive extraction using tri-n-octylamine in methyl isobutyl ketone: Equilibrium and thermodynamic studies and optimization using Taguchi multivariate approach; Sep. Purif. Technol. 2018, 197, 314-324; published 05-31-2018”) as applied to claims 1, 4, 6-7, and 11 above, and further in view of Yang et al. (“Synergy of Lewis and Brønsted Acids on Catalytic Hydrothermal Decomposition of Hexose to Levulinic Acid”; Energy Fuels 2013, 27, 6973-6978; published 10-15-2013).
Regarding claim 5, claim 1 is rendered obvious over Woestenborghs and Eda, as detailed above.
The acid hydrolysis Example of Woestenborghs teaches the use of 4% w/w H2SO4 (page 14, line 23, Example). This corresponds to a concentration of about 2.2% v/v H2SO4 and resides within the range recited in the instant claim. See MPEP § 2144.05(I).
Woestenborghs and Eda do not teach wherein the catalyst comprises a combination of 0.5% – 4% of concentrated H2SO4 and 0.5% – 4% of FeCl3, as recited in claim 5.
However, Yang teaches that levulinic acid (LA) is commonly decomposed from biomass such as lignin via the decomposition of cellulose or carbohydrates catalyzed by Brønsted acids, but industrialization is limited by the relatively low yield of LA and formation of human. Yang further teaches that the combination of Lewis acid and Brønsted acid might selectively catalyze the hydrolysis of cellulose, isomerization of glucose, dehydration of fructose, and decomposition of 5-hydroxymethylfurfural (5-HMF) and finally improve the yield and selectivity of LA. To test this hypothesis, Yang investigated the use of mixed-acid systems wherein four Lewis acids (FeCl3, CrCl3, ZnCl2, and CuCl2) were combined with three Brønsted acids for the decomposition of glucose to LA. Of particular note, in systems comprising H2SO4 (0.02 mol/L) and the aforementioned Lewis acids, the use of FeCl3 (0.02 mol/L) resulted in the highest yield and selectivity of LA and superior to the use of H2SO4 alone (Abstract; page 6973, Col. 1, paragraph 1; page 6975, Table 1, entries 1 and 10 and Table footnote).
The concentration of 0.02 mol/L H2SO4 and 0.02 mol/L FeCl3 taught by Yang correspond to about 0.2% v/v H2SO4 and 0.3% w/v FeCl3, respectively. MPEP § 2144.05(I) states that “a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close.” In other an embodiment, Yang teaches that the conversions of glucose and 5-HMF to LA can be increased until 100% as the ratio of Lewis acid (e.g., CrCl3) increased (page 6974, Col. 2, paragraphs 3-4; page 6976, Figure 3). Therefore, the skilled artisan would recognize that the concentration of Lewis acid can be adjusted accordingly to effect the conversion and selectivity of LA production, such that a range of 0.5%-4% w/v of FeCl3 could be achieved through means of routine optimization that is non-inventive in nature. See MPEP § 2144.05(II). Furthermore, when considering the combined teachings of Woestenborghs and Eda, the skilled artisan could arrive at a concentration of H2SO4 within the instantly claimed range based on the Example of Woestenborghs, See MPEP § 2144.05(I).
The process of Yang and Woestenborghs are analogous because they reside in the overlapping technical field of acidic hydrolysis of cellulose components that are derived from lignin, in a manner consistent with the instantly claimed invention. As such, the skilled artisan would be sufficiently motivated to modify the process of Woestenborghs are Eda to incorporate the teachings of Yang to implement a H2SO4/FeCl3 mixed-acid catalyst system to predictably pursue an acidic hydrolysis method with improved yield and selectivity of LA with a reasonable expectation of success. See MPEP § 2143(I)(A).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Woestenborghs and Eda to incorporate with the teachings of Yang to arrive at the claimed invention. The motivation to do so would permit the skilled artisan to pursue, with a reasonable expectation of success, an acidic hydrolysis method with improved yield and selectivity of levulinic acid, as described above.
Claims 10 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over P. L. Woestenborghs (WO 2015/063033 A1; published 05-07-2015), in view of Eda et al. (“Recovery of levulinic acid by reactive extraction using tri-n-octylamine in methyl isobutyl ketone: Equilibrium and thermodynamic studies and optimization using Taguchi multivariate approach; Sep. Purif. Technol. 2018, 197, 314-324; published 05-31-2018”) as applied to claims 1, 4, 6-7, and 11 above, and further in view of Kaur et al. (“Development of reactive extraction systems for itaconic acid: a step towards in situ product recovery for itaconic acid fermentation”; RSC Adv. 2014, 4, 45029-45039; published 09-22-2014).
Regarding claims 10 and 12, Eda teaches the use of tri-n-octylamine as an efficient extractant for the recovery of levulinic acid, as detailed above (Abstract).
Woestenborghs and Eda do not explicitly teach wherein the amine extractant is selected from octylamine and N-methyldioctylamine as recited in claim 10, or wherein the amine extractant-acid complex is selected from octylamine-LA complex and N-methyldioctylamine-LA complex as recited in claim 12.
However, Eda does teach the use of tri-n-octylamine in a reactive extraction comprising the formation of an amine-levulinic acid complex, as detailed above (Abstract). Furthermore, the tri-n-octylamine taught by Eda is a structural homolog of N-methyldioctylamine, differing by seven methylene units (-CH2- groups) on one of the carbon chains, and is therefore expected to have similar properties. MPEP 2144.09(II) states that “Compounds which are position isomers (compounds having the same radicals in physically different positions on the same nucleus) or homologs (compounds differing regularly by the successive addition of the same chemical group, e.g., by -CH2- groups) are generally of sufficiently close structural similarity that there is a presumed expectation that such compounds possess similar properties.”
Further regarding claims 10 and 12, Kaur teaches the development of a reactive extraction system for itaconic acid, a small organic acid compound, from aqueous solutions comprising the formation of extractant-acid complexes having a high affinity for the organic phase. After investigating 136 types of amine-diluent combinations as reactive extraction systems, Kaur found that 3 amines (trioctylamine, dioctylamine, and N-methyldioctylamine) were found to be the most suitable for efficient extraction of itaconic acid from aqueous solutions (Title; Abstract; page 45030, Col. 1, paragraph 1 and Col. 2, paragraph 1; page 45038, Col. 1, paragraph 3). The skilled artisan would recognize that itaconic acid (C5H6O4) and levulinic acid (C5H8O3) are both small chain carboxylic acids containing 5 carbon atoms, and would therefore be expected to possess similar properties. See MPEP § 2144.09(I).
The process of Eda and Kaur are analogous because they both teach the reactive extraction of organic acid compounds (i.e., levulinic acid or itaconic acid) from aqueous solutions with amines, in a manner consistent with the claimed invention. In addition, both Eda and Kaur teach that trioctylamine is an efficient organic extract, and Kaur further teaches that N-methyldioctylamine possesses comparable efficiency to trioctylamine for the extraction of carboxylic acids from aqueous systems. As such, the skilled artisan would be sufficiently motivated to substitute the trioctylamine of Eda with the N-methyldioctylamine of Kaur to pursue an optimized reactive extraction method using an amine of known comparable efficiency to trioctylamine with a reasonable expectation of success. See MPEP § 2143(I)(B).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Woestenborghs and Eda to incorporate with the teachings of Kaur to arrive at the claimed invention. The motivation to do so would permit the skilled artisan to pursue, with a reasonable expectation of success, an optimized reactive extraction method using an amine of known comparable efficiency to trioctylamine, as described above.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over P. L. Woestenborghs (WO 2015/063033 A1; published 05-07-2015), in view of Eda et al. (“Recovery of levulinic acid by reactive extraction using tri-n-octylamine in methyl isobutyl ketone: Equilibrium and thermodynamic studies and optimization using Taguchi multivariate approach; Sep. Purif. Technol. 2018, 197, 314-324; published 05-31-2018”) and Satlewal et al. (US 2022/0064199 A1; published 03-03-2022) as applied to claims 2-3 and 8-9 above, and further in view of Satlewal et al. (US 2019/0248962 A1; published 08-15-2019; hereinafter “Satlewal-2”) and Bušić et al. (“Bioethanol Production from Renewable Raw Materials and Its Separation and Purification: A Review”; Food Technol. Biotechnol. 2018, 56, 289-311; published 2018).
Regarding claim 13, Woestenborghs, Eda, and Satlewal do not teach wherein the technical lignin is obtained from pre-treatment of lignocellulose biomass, comprising the method steps i.-iii. as recited in claim 13.
However, Satlewal-2 teaches an additive composition useful for improved production of fermentable sugars from lignocellulosic biomass during enzymatic hydrolysis. Pretreatment, enzymatic hydrolysis, and fermentation are three integral parts of the process. Pretreatment is required to open up the biomass structure so that the cellulolytic enzymes can access the holocellulose and convert it into monomeric sugars. Following this fermentation is carried out to produce ethanol by using fermenting yeast or bacteria (Abstract; 0002).
The method comprises a dilute acid pretreatment, wherein the concentration of the acid added to the lignocellulosic feedstock may be between 0.02 to about 3% w/w of biomass and the acid treatment may be carried out for about 5-60 min and at room temperature or a temperature ranging from 50 ºC to 100 ºC, followed by heating to between 120 ºC and about 200 ºC for conversion into biomass slurry (containing cellulose, hemicelluloses, and lignin). The acid used in the pretreatment step is selected from the group consisting of sulphuric acid, hydrochloric acid, acetic acid, and phosphoric acid. The pretreatment conditions are applied so as to hydrolyze 40%-90% hemicellulose (xylan, arabinan etc.) in to sugars and to obtain minimum amount of inhibitors like furfurals, hydroxy methyl furfural, levulinic, acetic acids, formic acid etc. (Abstract; claims 1-2; 0019-0020, 0043, 0047). The concentration of acid, reaction time, and reaction temperatures of the method of Satlewal-2 are identical with or overlap with the ranges recited in step i. of claim 13. See MPEP § 2144.05(I).
After pretreatment, the slurry is cooled prior to enzymatic hydrolysis so that the enzymatic hydrolysis could be carried out at a desired temperature range of 45 ºC-55 ºC to obtain fermentable sugars (claim 1; 0019, 0044). The skilled artisan would recognize that the method of Satlewal-2 comprises carrying out enzymatic hydrolysis and fermentation in the same method step, and is therefore simultaneous saccharification and fermentation (SSCF), as recited in step ii. of claim 13.
Does not explicitly teach obtaining a fermented broth and distilling is by standard distillation and molecular sieve methods to produce ethanol and technical lignin, as recited in step iii. of claim 13.
However, Bušić teaches in bioethanol production, saccharification and fermentation often occur simultaneously (simultaneous saccharification and fermentation, SSF), thus reducing the enzyme levels and yeast cell inhibition by ethanol or substrates to a minimum. The fermented broth is then distilled to produce a 95% by volume ethanol. Dehydration of the 95% by volume ethanol requires molecular sieves in order to obtain 99.5% by volume ethanol (page 297; paragraph 3). Thus, the skilled artisan would recognize based on the teachings of Bušić that distillation of the fermentation broth and use of molecular sieve methods could be predictably applied to the method of Satlewal-2 in order to purify the produced bioethanol and separate it from the lignin present in the slurry with a reasonable of success.
Further regarding claim 13, Satlewal teaches that bioethanol residues derived from 2G bioethanol waste streams obtained after fermentation contained extractives including lignocellulosic biomass and enzymes and is a highly renewable feedstock (Title; Abstract; 0002, 0056). Thus, the skilled artisan could reasonably ascertain that the process of Woestenborghs, Eda, and Satlewal could be integrated with the method of Satlewal-2 and Bušić with a reasonable expectation of success, because Satlewal teaches that technical lignin can be derived from bioethanol fermentation for further use for the production of value-added chemicals such as levulinic acid, as taught by Woestenborghs. Such an integrated process would couple 2G bioethanol production from lignocellulosic biomass (as taught by Satlewal-2 and Bušić), wherein the technical lignin waste (from the 2G bioethanol waste stream, as taught by Satlewal) would be further subjected to an extraction and purification method (as taught by Woestenborghs and Eda) to produce levulinic acid to arrive at the invention of claim 13. See MPEP § 2143(I)(A).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Woestenborghs, Eda, and Satlewal to incorporate with the teachings of Satlewal-2 and Bušić to arrive at the claimed invention. The motivation to do so would permit the skilled artisan to pursue, with a reasonable expectation of success, an integrated process using a renewable feedstock that couples 2G bioethanol production from lignocellulosic biomass to levulinic acid production, wherein the lignin from the bioethanol waste stream is further utilized for levulinic acid production, as described above.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over P. L. Woestenborghs (WO 2015/063033 A1; published 05-07-2015), in view of Eda et al. (“Recovery of levulinic acid by reactive extraction using tri-n-octylamine in methyl isobutyl ketone: Equilibrium and thermodynamic studies and optimization using Taguchi multivariate approach; Sep. Purif. Technol. 2018, 197, 314-324; published 05-31-2018”), Satlewal et al. (US 2022/0064199 A1; published 03-03-2022), Satlewal et al. (US 2019/0248962 A1; published 08-15-2019; hereinafter “Satlewal-2”) and Bušić et al. (“Bioethanol Production from Renewable Raw Materials and Its Separation and Purification: A Review”; Food Technol. Biotechnol. 2018, 56, 289-311; published 2018) as applied to claim 13 above, and further in view of Becker et al. (“A Modified Saccharomyces cerevisiae Strain That Consumes L-Arabinose and Produces Ethanol”; Appl. Environ. Microbiol. 2003, 69, 4144-4150; published 07-01-2003).
Regarding claim 14, claim 13 is rendered obvious over Woestenborghs, Eda, Satlewal, Satlewal-2, and Bušić, as detailed above.
Woestenborghs, Eda, Satlewal, Satlewal-2, and Bušić do not teach wherein the enzymatic hydrolysis and fermentation of lignocellulosic biomass is done with genetically modified yeast saccharomyces cerevisiae, as recited in claim 14. Instead, Satlewal-2 teaches the use of a complex of secreted enzymes from filamentous fungi (particularly Trichoderma sp.) for pretreated biomass hydrolysis (0044).
However, Becker teaches a modified S. cerevisiae strain genetically engineered to utilize the pentose D-xylose, the most abundant hemicellulosic sugar, and to ferment it to ethanol. This yeast strain exhibits high ethanol yields and should be useful for efficient fermentation of hexoses and pentoses in cellulosic biomass hydrolysates (Title; Abstract; page 4144, Col. 1, paragraph3 and Col. 2, paragraph 1).
The method of Becker is analogous to the method of Satlewal-2, because they both reside in the closely overlapping technical field of bioethanol production from cellulosic biomass. In addition, the pretreatment conditions of Satlewal-2 are applied so as to hydrolyze 40%-90% hemicellulose (xylan, arabinan etc.) in to sugars, as detailed above (0043). As such, the skilled artisan would be sufficiently motivated to predictably substitute the fungal strain used in the method of Satlewal-2 with the genetically engineered Saccharomyces cerevisiae strain of Becker to pursue an improved method for bioethanol production using a microorganism optimized for the fermentation of hexoses and pentoses with a reasonable expectation of success. See MPEP 2143 § (I)(B).
Therefore, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Woestenborghs, Eda, Satlewal, Satlewal-2, and Bušić to substitute the fungal strain of Satlewal-2 with the modified S. cerevisiae of Becker to arrive at the claimed invention. The motivation to do so would permit the skilled artisan to pursue, with a reasonable expectation of success, an improved bioethanol fermentation method that utilizes a modified fungal strain optimized for the fermentation of hexoses and pentoses such as D-xylose (the most abundant hemicellulosic sugar), as described above.
Based on the combined teachings of the references, the Examiner submits that a person of ordinary skill in the art would have had a reasonable expectation of success of arriving at the instantly claimed process. Therefore, the invention as a whole would have been prima facie obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, and absent a clear showing of evidence to the contrary.
Conclusion
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/D.R./Examiner, Art Unit 1692
/AMY C BONAPARTE/Primary Examiner, Art Unit 1692
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