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 .
This application is the national stage entry of PCT/IB2021/060561, filed 15 Nov 2021; and claims benefit of foreign priority document ITALY 102020000027840, filed 19 Nov 2020. This foreign priority document is not in English.
Claims 1-19 are pending in the current application and are examined on the merits herein.
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 9 and 14-16 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 9 at line 3 recites “which the cellulose is washed and the washing water is added in stage B.” (emphasis added) The phrase “the washing water” lacks antecedent basis because it is unclear whether this means the stage I wash is required to be with water, or whether this refers to the water that is already added in stage B recited in claim 1 and that this phrase is redundant.
Claim 16 at line 1 recites “the DES from step E”. Claim 16 depends from claims 2 which depends from claim 1. Claim 1 recites one alternative for the process solvent is a eutectic solvent, defined at paragraph 32 of the published application as deep eutectic solvent or DES. However, none of claims 1-2 require the process solvent to be a DES. The phrase “the DES” lacks antecedent basis because it is unclear whether this means the process solvent is required to be a DES or whether this is a contingent limitation that only applies when the process solvent is the DES alternative.
Claim 14 recites “washing the precipitate with ethanol and cation exchange resin.” Claim 15 recites “washing the hemicellulose with water and ion exchange resin.” The phrase “washing … with … exchange resin” renders the claims indefinite because it is unclear what is required by this process. The term “washing” as understood by one of skill in the art implies applying a liquid or fluid to a subject, while a resin is understood to be a solid material. For the purpose of examination, claims 14 and 15 are interpreted to mean treating the material with the ion exchange resin in a separation or purification process.
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 1-5, 7-13, and 16-19 are rejected under 35 U.S.C. 103 as being unpatentable over Brandt et al. (US 2014/0073016, published 13 March 2014, provided by Applicant in IDS filed 18 May 2023) in view of Hou et al. (Industrial Crops & Products, 2018, 120, p322–329, provided by Applicant in IDS filed 18 May 2023).
Brandt et al. teaches a method for treating a lignocellulose biomass in order to dissolve the lignin therein, while the cellulose does not dissolve (abstract). Generally pretreatment involves one or more of the following: removing the hemicellulose; modifying and solubilizing the lignin; hydrolysing the hemicellulose-lignin linkages; and reducing the crystallinity of the cellulose fibres (page 1, paragraph 3). The method comprises contacting the lignocellulose biomass with a composition comprising an ionic liquid (IL) to produce a cellulose pulp, wherein the ionic liquid comprises a cation and an anion selected from C1-20 alkylsulfate [Alkyl SO4]−, C1-20 alkylsulfonate [Alkyl SO3]−, hydrogensulfate [HSO4]−, hydrogen sulphite [HSO3]−, dihydrogen phosphate [H2PO4] hydrogen phosphate [HPO4]2− and acetate, with the proviso that if the anion is acetate then the composition further comprises 10-40% v/v water. The IL is preferably heated with the biomass at 100-160° C. The reaction is carried out for 1-22 hours (page 1, paragraph 13-15), addressing limitations of claims 1 and 11-12. It has been surprisingly found that the yield in the saccharification step can be improved if the pretreatment composition comprises water. Therefore in one preferred embodiment the composition comprises the IL and 10-40% v/v water. Preferably the composition comprises 20-30% v/v water (page 3, paragraph 37), addressing limitations of claim 1, step A. The biomass may be agricultural residues, crop residues such as rice straw, and wood pulp (page 1, paragraph 16), addressing limitations of claims 7. The lignin in the lignocellulosic biomass is soluble in the ionic liquid at the treatment temperature, but the cellulose is not, so that a pulp comprising the cellulose is produced. Other components such as hemicellulose may preferably also dissolve in the ionic liquid (page 2, paragraph 19). Brandt et al. teaches the working example 1 in which the lignocellulosic biomass was treated with the ionic liquid, treated with methanol and filtered, and the supernatant was washed with 10 mL water to precipitate the lignin, which was washed and dried (page 6, paragraph 112 to page 7, paragraph 115), addressing limitations of claim 1 steps A and B. Brandt et al. teaches the IL can be recycled (page 1, paragraph 12; page 4, paragraph 44), addressing limitations of claim 16.
Brandt et al. does not specifically disclose the method comprising step C separating the hemicellulose from the process solvent mixture by addition of an organic solvent soluble in the process solvent mixture (claim 1).
Hou et al. teaches obtaining fermentable sugars and other platform chemicals from rice straw mediated by the deep eutectic solvent choline chloride-oxalic acid dihydrate (CO) (page 322, abstract). Hou et al. teaches lignocellulosic biomass from agriculture wastes such as rice straw is a promising feed stock for economic and sustainable production of liquid biofuels and derivative chemicals in large scale. Efficient fractionation of the lignocellulosic biomass for comprehensive utilization of its main constituents avoiding lots of waste of resources is a challenge (page 322, left column). Hou et al. teaches the working example of rice straw pretreatment and fractionation of the cellulose-rich materials (CRM), lignin-rich materials (LRM), and hemicellulose-rich materials (HRM) in which the rice straw was mixed with CO in a biomass loading of 5 wt%. The mixture was thoroughly separated by centrifugation. The solid fraction of the pretreatment mixture was washed with ethanol and then water, then lyophilized and recovered as cellulose-rich materials (CRMs). The washings were condensed by evaporation and combined with the liquid fraction of the pretreatment mixture for recovery of extracted lignin. Two volumes of water were added into the solution to regenerate lignin. The remaining supernatant together with condensed washings was adjusted to the pH value of 6.8 and precipitated with three volume of 96% ethanol under continuous stirring, then the precipitate was obtained as hemicellulose-rich materials (HRMs) after centrifugating. The remaining supernatant combined with the condensed washings of HRMs was collected and used for xylose and furfural determination as well as DES recovery (page 323, paragraph spanning left and right columns, and figure 1). Hou et al. teaches Kraft lignin was purchased for use as a standard for comparison (page 323, left column, paragraph 3).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine Brandt et al. in view of Hou et al. in order modify the method of Brandt et al. by adding the step to separate the hemicellulose from the process solvent or supernatant, and to optimize the process through routine experimentation. One of ordinary skill in the art would have be motivated to combine Brandt et al. in view of Hou et al. with a reasonable expectation of success because both Brandt et al. and Hou et al. are drawn to separating cellulose, hemicellulose and lignin from lignocellulosic biomass, and Hou et al. teaches the steps to obtain the HRMs are known in the prior art, suggesting it would have been obvious to combine Brandt et al. in view of Hou et al. in order modify the method of Brandt et al. by adding the step to separate the hemicellulose from the process solvent or supernatant. Regarding claims 2-3, 9, and 16 and the recycling of the solvents, both Brandt et al. and Hou et al. teach recycling of the ionic liquids, Hou et al. teaches the working example including combining washings condensed by evaporation with the supernatant in the recovery, and Hou et al. teaches avoiding waste of resources is desired, suggesting it would have been obvious to recycle the solvents used in the process. Regarding claim 7-10 and the selection of the lignocellulose biomass, Brandt et al. teaches the wide variety of lignocellulose biomass used which includes cellulose pulp and rice straw, and Hou et al. teaches Kraft lignin is a comparison for the lignin isolated from rice straw, suggesting it would have been obvious to select either rice straw or Kraft cellulose as the lignocellulose biomass. Regarding the concentrations, temperature, and reaction time of claims 10-12, Brandt et al. in view of Hou et al. teaches overlapping ranges for these values, and it would have been obvious to one of ordinary skill in the art to determine the optimum or workable ranges through routine experimentation because Brandt et al. or Hou et al. taken as a whole suggest performing such routine experimentation to provide the optimal result.
Regarding claim 8, Brandt et al. in view of Hou et al. is silent as to the presence of silica in the rice straw. However, the application as published provides evidence that the background art acknowledges rice straw contains a significant amount of silica at paragraph 3. Hou et al. teaches the mixture was thoroughly separated by centrifugation to produce the cellulose-rich materials, suggesting that one of ordinary skill in the art would have expected the separation of the silica from rice straw.
Regarding claims 4-5 and 17-19, the claims recite further limitations of the hydrogen bond acceptor and donor of the deep eutectic solvent, however the claims do not require the process solvent to be said deep eutectic solvent. Therefore claims 5 and 18-19 are interpreted to encompass the method wherein the process solvent is an ionic liquid such as those taught in Brandt et al. and made obvious by the combined teachings of Brandt et al. in view of Hou et al.
Claims 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over Brandt et al. (US 2014/0073016, published 13 March 2014, provided by Applicant in IDS filed 18 May 2023) in view of Hou et al. (Industrial Crops & Products, 2018, 120, p322–329, provided by Applicant in IDS filed 18 May 2023) as applied to claims 1-3, 5, 7-16, and 18-19, further in view of Walton et al. (Ind. Eng. Chem. Res., 2010, 49, p12638–12645, cited in PTO-892) and Dugoni et al. (Green Chem., 2020, 22, p8680-8691, published 11 Nov 2020, cited in PTO-892).
The claim of foreign priority has not been perfected, and the effective filing date is deemed to be 15 Nov 2021. Dugoni et al. published 11 Nov 2020 is deemed to be published more than 1 year before the effective filing date. Additionally, while Dugoni et al. has inventors in common with the claimed invention, the authorship of Dugoni et al. includes others than the inventors of the claimed invention and Dugoni et al. is deemed to be the disclosure by another. Therefore Dugoni et al. is deemed to qualify as prior art under 35 USC 102(a)(1).
Brandt et al. in view of Hou et al. teach as above.
Brandt et al. in view of Hou et al. does not specifically teach the step of glass filtration and washing the precipitate with ethanol and cation exchange resin (claim 14) or washing the hemicellulose with water and ion exchange resin (claim 15).
Walton et al. teaches extraction of hemicellulose and lignin from wood chips (page 12638, abstract). After hydrolysis, the extraction solutions were filtered through a glass microfiber filter to remove Klason or acid-insoluble lignin. The solution pH was then raised to neutral conditions by careful addition of solid calcium hydroxide and then filtered through glass microfiber filters to remove the precipitated gypsum (page 12640, right column, paragraph 4). Walton et al. teaches acid soluble lignin can be removed by ion exchange methods if it would inhibit fermentation but would of course add to the complexity and capital and operating cost of the process (page 12643, right column, paragraph 1).
Dugoni et al. teaches three novel deep eutectic solvents (DESs) were prepared with choline acetate (ChOAc) as the hydrogen bond acceptor (HBA) and three hydrogen bond donors (HBD): glycolic acid (GlyA), levulinic acid (LevA) and imidazole (Im) to dissolve lignin and hemicellulose. The solubility was first tested on commercially available hemicellulose in neat DES and in DES aqueous solution (page 8680, abstract). Dugoni et al. teaches a glass microfiber filter was used to filter the reaction mixture (page 8689, left column, paragraph 5, and right column, paragraph 2). Dugoni et al. teaches the hemicellulose fraction was recovered from the solution by adding a mixture of water and ethanol 1 : 5 v/v. In order to remove the residual DES, the precipitate was washed 4 times with ethanol and treated in batches with the cation exchange resin Amberlite IR-120 (page 8684, left column, paragraph 3).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine Brandt et al. in view of Hou et al. further in view of Walton et al. and Dugoni et al. in order to combine the method of Brandt et al. in view of Hou et al. with the filtration methods taught by Walton et al. and Dugoni et al. to yield predictable results. One of ordinary skill in the art would have combined Brandt et al. in view of Hou et al. further in view of Walton et al. and Dugoni et al. with a reasonable expectation of success because all of Brandt et al., Hou et al., Walton et al. and Dugoni et al. are drawn to separation of lignin and hemicellulose from cellulosic biomass, and Walton et al. and Dugoni et al. teach the known use of glass microfiber filtration and ion exchange resins in processes to separate of lignin and hemicellulose from cellulosic biomass. Regarding the solvents used, Brandt et al. in view of Hou et al. teach the selection of ethanol and water as the appropriate solvents.
Allowable Subject Matter
Claim 6 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: The closest prior art is Brandt et al. (US 2014/0073016, published 13 March 2014, provided by Applicant in IDS filed 18 May 2023) in view of Hou et al. (Industrial Crops & Products, 2018, 120, p322–329, provided by Applicant in IDS filed 18 May 2023) further in view of Dugoni et al. (Green Chem., 2020, 22, p8680-8691, published 11 Nov 2020, cited in PTO-892).
Brandt et al. in view of Hou et al. teach as above. Brandt et al. further teaches many of the prior art processes require the ionic liquid to be substantially water free so that the biomass dissolves. Therefore the IL and the biomass have to be dried before use which adds to the processing costs. A tolerance of up to 15% water by weight in ILs has been reported, but higher levels produced unwanted results, such as precipitation of dissolved cellulose and reduced saccharification yields (page 1, paragraph 9).
For the reasons detailed above, Dugoni et al. is deemed to qualify as prior art under 35 USC 102(a)(1).
Dugoni et al. teaches three novel deep eutectic solvents (DESs) were prepared with choline acetate (ChOAc) as the hydrogen bond acceptor (HBA) and three hydrogen bond donors (HBD): glycolic acid (GlyA), levulinic acid (LevA) and imidazole (Im) to dissolve lignin and hemicellulose. The solubility was first tested on commercially available hemicellulose in neat DES and in DES aqueous solution (page 8680, abstract). The solubility of hemicellulose plateaued at 5 wt% of water for ChOAc : LevA and ChOAc : GlyA. The maximum solubility value within the explored DES–water composition range was 45 wt% of hemicellulose dissolved in 15 wt% water containing DES (page 8683, paragraph spanning left and right columns, and figure 3).
It would not have been obvious to one of ordinary skill in the art before the effective filing date to combine Brandt et al. in view of Hou et al. further in view of Dugoni et al. in a manner that arrives at the claimed invention. Brandt et al. teaches away from methods having higher levels than 15% water, and Dugoni et al. for DES aqueous solutions the solubility of hemicellulose plateaued at 5 wt% of water. Therefore the closest prior art does not teach or fairly suggest the claimed invention.
Conclusion
No claim is currently in condition for allowance.
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/JONATHAN S LAU/ Primary Examiner, Art Unit 1693