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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 05/12/2026 has been entered.
Status of the Claims
The amendment filed on 05/12/2026 has been entered. Claims 12-13 have been newly added. Thus claims 1-10 and 12-13 are currently pending and are under examination.
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 1-10 and 12-13 are newly rejected under 35 U.S.C. 103 as being unpatentable over Patent application publication number US2019/0062244A1 (US’244; cited in PTO-892 10/10/2025) in view of Patent number CN104098439A (CN’439).
Regarding claims 1-3, US’244 teaches a process for the separation of a diol from a product stream, said process comprising the steps of: (i) separating the product stream comprising three or more C2 to C7 diols, C3 to C6 sugar alcohols, and C4 to C6 polyhydric alcohols with at least 3 hydroxyl groups in the molecule, and a catalyst, by a first distillation column to produce a first stream comprising the three or more C2 to C6 diols; (ii) separating the first stream comprising the three or more C2 to C7 diols by a second distillation column using an extractant into a) a second stream comprising a first diol and b) a third stream comprising two or more diols ([0014], [0016]-[0017], [0025], Figs. 1-2, Tables 5-6).
Regarding claims 5-6, US’244 teaches that the extractant is selected from the group of C3 to C6 sugar alcohols and mixtures thereof, wherein sugar alcohols have the general formula HOCH2(CHOH)nCH2OH and include glycerol, erythritol, threitol, arabitol, xylitol, ribitol, mannitol, sorbitol, galacticol and iditol ([0034]).
Regarding claim 7, the distillation in the second distillation column of US’244 is carried out at a temperature in the range of from 50 to 250° C and a pressure of at least 1 kPa ([0037]).
Regarding claim 8, the extractant is added in an amount such that the weight ratio of the feed comprising extractant to the mixture comprising the two or more C2 to C7 diols is at least 0.05:1, more preferably at least 0.1:1, even more preferably at least 0.25:1, based on the overall weight of the feed/mixture ([0036]).
Regarding claim 9, wherein the separating of the first stream of step (ii) comprises distilling the first stream to produce the second stream and the third stream at a temperature and pressure as follows (Table 5):
PNG
media_image1.png
200
400
media_image1.png
Greyscale
Regarding claim 10, US’244 is silent that the third stream comprises an azeotrope of MEG and 1,2-BDO or an azeotrope of MPG and 2,3 BDO, however, there is a prima facie case of anticipation or obviousness for the third stream of US’244 to comprise an azeotrope of MEG and 1,2-BDO or an azeotrope of MPG and 2,3 BDO since the reference teaches the same process as claimed to obtain the third stream. See MPEP § 2112.01.
Regarding claims 1, 7 and 12-13, US’244 further teaches that the product stream is obtained by the saccharide hydrogenolysis, and that in addition to C2 to C7 diols, the reaction product streams comprise oxygenates and hydrocarbons ([0025). However, US’244 fails to teach the presence of unsaturated hydrocarbons and/or one or more compounds with a carbonyl group in the second stream, and (iii) hydrogenating the second stream comprising a first diol and unsaturated hydrocarbons and/or one or more compounds with a carbonyl group to provide a purified diol stream, wherein the hydrogenating of step (iii) comprises a hydrogenation reaction carried out at a temperature within a range of about 20° C to about 300° C and a pressure within a range of about 0.5 bara to about 250 bara, about 3 bara to about 140 bara, or 10 bara to about 70 bara, in the presence of a hydrogenation catalyst.
The deficiency is however cured by CN’439.
Regarding claims 1, 7 and 12-13, CN’439 teaches a method for refining biomass ethylene glycol obtained by catalytic conversion of biomass, wherein the biomass is cellulose, starch, hemicellulose, sucrose, glucose, fructose, fructan, xylose, soluble xylooligosaccharides, sorbitol, xylitol, and glycerol ([0002] and [0015]). The reference teaches that impurities are introduced during the catalytic conversion and distillation processes, especially trace substances such as aldehydes, ketones, and other substances with unsaturated chemical functional groups, making it difficult for the ultraviolet transmittance of ethylene glycol products to meet polymerization grade requirements ([0007]). Thus, CN’439 teaches catalytically hydrogenating biomass ethylene glycol as raw material under the action of a transition metal catalyst thereby increasing the UV transmittance of the ethylene glycol product to the polymerization level ([0011]).
CN’439 teaches that the catalytic hydrogenation is conducted at a temperature of ≥40°C and at hydrogen pressure of ≥0.1 MPa or above ([0020]) (≥1 bar). In view of MPEP § 2144.05, a prima facie case of obviousness exists where the claimed ranges or amounts "overlap or lie inside ranges disclosed by the prior art".
Hence, since US’244 teaches that the reaction product streams comprises oxygenates and hydrocarbons, and CN’439 teaches that these impurities make it difficult for the ultraviolet transmittance of ethylene glycol products to meet polymerization grade requirements, a skilled artisan would have been motivated in using the methods of CN’439 by hydrogenating the impurities recognized by both references with a reasonable expectation of success in improving the UV transmittance of the ethylene glycol product to reach polymerization grade.
It would thus have been prima facie obvious to a skilled artisan before the effective filing date of the instant invention to conduct a process for the separation of a diol from a product stream, said process comprising the steps of: (i) separating the product stream comprising three or more C2 to C6 diols, C3 to C6 sugar alcohols, and C4 to C6 polyhydric alcohols with at least 3 hydroxyl groups in the molecule, and a catalyst, to produce a first stream comprising the three or more C2 to C6 diols; (ii) separating the first stream comprising the three or more C2 to C6 diols into (a) a second stream comprising a first diol and unsaturated hydrocarbons and/or one or more compounds with a carbonyl group, and b) a third stream comprising two or more diols; (iii) hydrogenating the second stream comprising a first diol and unsaturated hydrocarbons and/or one or more compounds with a carbonyl group to provide a purified diol stream, wherein the hydrogenating of step (iii) comprises a hydrogenation reaction carried out at a temperature within a range of about 20° C to about 300° C and a pressure within a range of about 0.5 bara to about 250 bara in the presence of a hydrogenation catalyst in view of the combination of US’244 and CN’439.
Claims 1-10 stand rejected and 12-13 are newly rejected under 35 U.S.C. 103 as being unpatentable over Patent application publication number US2019/0062244A1 (US’244; cited in PTO-892 10/10/2025) in view of Patent number CN106866373A (CN’373; cited in PTO-892 10/10/2025).
Regarding claims 1-3, US’244 teaches a process for the separation of a diol from a product stream, said process comprising the steps of: (i) separating the product stream comprising three or more C2 to C7 diols, C3 to C6 sugar alcohols, and C4 to C6 polyhydric alcohols with at least 3 hydroxyl groups in the molecule, and a catalyst, by a first distillation column to produce a first stream comprising the three or more C2 to C6 diols; (ii) separating the first stream comprising the three or more C2 to C7 diols by a second distillation column using an extractant into a) a second stream comprising a first diol and b) a third stream comprising two or more diols ([0014], [0016]-[0017], [0025], Figs. 1-2, Tables 5-6).
Regarding claims 5-6, US’244 teaches that the extractant is selected from the group of C3 to C6 sugar alcohols and mixtures thereof, wherein sugar alcohols have the general formula HOCH2(CHOH)nCH2OH and include glycerol, erythritol, threitol, arabitol, xylitol, ribitol, mannitol, sorbitol, galacticol and iditol ([0034]).
Regarding claim 7, the distillation in the second distillation column of US’244 is carried out at a temperature in the range of from 50 to 250° C and a pressure of at least 1 kPa ([0037]).
Regarding claim 8, the extractant is added in an amount such that the weight ratio of the feed comprising extractant to the mixture comprising the two or more C2 to C7 diols is at least 0.05:1, more preferably at least 0.1:1, even more preferably at least 0.25:1, based on the overall weight of the feed/mixture ([0036]).
Regarding claim 9, wherein the separating of the first stream of step (ii) comprises distilling the first stream to produce the second stream and the third stream at a temperature and pressure as follows (Table 5):
PNG
media_image1.png
200
400
media_image1.png
Greyscale
Regarding claim 10, US’244 is silent that the third stream comprises an azeotrope of MEG and 1,2-BDO or an azeotrope of MPG and 2,3 BDO, however, there is a prima facie case of anticipation or obviousness for the third stream of US’244 to comprise an azeotrope of MEG and 1,2-BDO or an azeotrope of MPG and 2,3 BDO since the reference teaches the same process as claimed to obtain the third stream. See MPEP § 2112.01.
Regarding claims 1, 7 and 12-13, US’244 further teaches that the product stream is obtained by the saccharide hydrogenolysis, and that in addition to C2 to C7 diols, the reaction product streams comprise oxygenates and hydrocarbons ([0025). However, US’244 fails to teach the presence of unsaturated hydrocarbons and/or one or more compounds with a carbonyl group in the second stream, and (iii) hydrogenating the second stream comprising a first diol and unsaturated hydrocarbons and/or one or more compounds with a carbonyl group to provide a purified diol stream, wherein the hydrogenating of step (iii) comprises a hydrogenation reaction carried out at a temperature within a range of about 20° C to about 300° C and a pressure within a range of about 0.5 bara to about 250 bara, about 3 bara to about 140 bara, or 10 bara to about 70 bara, in the presence of a hydrogenation catalyst.
The deficiency is however cured by CN’373.
Regarding claims 1, 7 and 12-13, CN’373 teaches a method for refining ethylene glycol obtained by catalytic hydrogenation degradation of biomass, wherein the biomass is one or more of cellulose, hemicellulose, glucose, xylose, xylooligosaccharides, fructose, fructooligosaccharides, starch, arabinose, erythrose, chitosan, chitooligosaccharides, glycerol, sorbitol, mannitol and xylitol ([0017]). The reference teaches that impurities are introduced during the catalytic conversion and distillation processes, especially trace substances such as carboxylic acids, aldehydes, and ketones with unsaturated chemical functional groups, making it difficult for the ultraviolet transmittance of ethylene glycol products to meet polymerization grade requirements ([0006]). Thus, CN’373 teaches catalytically hydrogenating a small amount of impurity compounds containing unsaturated chemical bonds in crude ethylene glycol during the distillation under the action of a metal catalyst to reduce them to saturated compounds without UV absorption, thereby improving the UV transmittance of the ethylene glycol product to reach polymerization grade ([0019]).
CN’373 teaches that the catalytic hydrogenation is conducted at vacuum distillation ([0019]), in which the top condenser temperature is 20°C, the distillation section temperature is controlled at 110-130°C, the reaction section temperature is 120-140°C, the stripping section temperature is 130-160°C, the bottom reboiler temperature is 145°C, and the top pressure is 5 kPa ([0029] and [0035]). In other embodiment, the reaction the top pressure is 1-20 kPa ([0014]) (0.01-0.2 bar). In view of MPEP § 2144.05, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close absent any showing of unexpected results or criticality.
Hence, since US’244 teaches that the reaction product streams comprises oxygenates and hydrocarbons, and CN’373 teaches that these impurities make it difficult for the ultraviolet transmittance of ethylene glycol products to meet polymerization grade requirements, a skilled artisan would have been motivated in using the methods of CN’373 by hydrogenating the impurities recognized by both references with a reasonable expectation of success in improving the UV transmittance of the ethylene glycol product to reach polymerization grade.
It would thus have been prima facie obvious to a skilled artisan before the effective filing date of the instant invention to conduct a process for the separation of a diol from a product stream, said process comprising the steps of: (i) separating the product stream comprising three or more C2 to C6 diols, C3 to C6 sugar alcohols, and C4 to C6 polyhydric alcohols with at least 3 hydroxyl groups in the molecule, and a catalyst, to produce a first stream comprising the three or more C2 to C6 diols; (ii) separating the first stream comprising the three or more C2 to C6 diols into (a) a second stream comprising a first diol and unsaturated hydrocarbons and/or one or more compounds with a carbonyl group, and b) a third stream comprising two or more diols; (iii) hydrogenating the second stream comprising a first diol and unsaturated hydrocarbons and/or one or more compounds with a carbonyl group to provide a purified diol stream, wherein the hydrogenating of step (iii) comprises a hydrogenation reaction carried out at a temperature within a range of about 20° C to about 300° C and a pressure within a range of about 0.5 bara to about 250 bara in the presence of a hydrogenation catalyst in view of the combination of US’244 and CN’373.
Response to Arguments
The arguments presented on 05/12/2026 have been considered and have been addressed in the Advisory Action 05/26/2026. Reiterated herein:
Applicant argues that the claimed pressure and the pressure of CN'373 by order of magnitude, wherein 0.5 bar is 2.5 times higher than the maximum pressure of the reference of 0.2 bar. The examiner disagrees and maintains that the pressure values are merely close between the lower claimed pressure and the maximum pressure of CN'373, both under vacuum, that a prima facie case of obviousness exists unless Applicant shows the criticality of conducting the hydrogenation step at the claimed pressure over that of CN'373.
Applicant argues that CN'373 teaches a different process in which formic acid decomposition is used as the hydrogen source, with no introduction of external hydrogen gas. Furthermore, Applicant argues that the reference teaches away from the claimed process, i.e. away from using pressurized external hydrogen. The arguments are not persuasive because the introduction of external hydrogen gas is not a limitation that is recited in the claim. The only limitations recited in hydrogenation step iii is that it is carried out at a temperature range of about 20-300 C and a pressure between 0.5-250 bar, with no recitation of external introduction of hydrogen. As such, contrary to the Applicant's argument, the source of hydrogen is not given patentable in step iii. In this instance, the in situ formation of hydrogen by the decomposition of formic acid as disclosed in CN'373 would still read on the claimed hydrogenation step.
Applicant further discusses that the instant specification presents the criticality of the claimed pressure range, in which Example 2 with a pressure of 77 barg and external hydrogen converts MEG to fiber-grade MEG, whereas comparative example 1 that has no hydrogenation step produces MEG below the fiber grade. Applicant argues that CN'373 is a different approach and would not achieve the same results when applied to the second stream of US'244.
The examiner disagrees. Firstly, the comparative example is not the same as the closest prior art CN'373. Specifically, in the comparative example of the specification there is no hydrogenation step, whereas in CN'373, there is a hydrogenation step. In fact, CN'373 discusses the importance of refining ethylene glycol obtained from biomass by conducting a hydrogenation step, wherein hydrogen is produced in situ by the decomposition of formic acid, and that such step hydrogenates the impurity compounds present with ethylene glycol improves the UV transmittance of the glycol to reach polymerization grade. The same improvement of UV transmittance is observed in Example 2 of the specification. Moreover, it has already been established above that the external source of hydrogen that Applicant argues as being one of the key differences from the reference is not a limitation that is claimed. As such, since the same outcome is demonstrated by conducting the hydrogenation step in both Example 2 of the specification and CN'373, instant claims remain obvious over US'244 in view of CN'373.
Conclusion
Claims 1-10 and 12-13 are rejected and no claims are allowed.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MEDHANIT W BAHTA whose telephone number is (571)270-7658. The examiner can normally be reached Monday-Friday 8am-5pm.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Scarlett Goon can be reached at 571-270-5241. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/MEDHANIT W BAHTA/Primary Examiner, Art Unit 1692
Prosecution Insights