Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Detailed Action
This office action is in response to applicant’s communication filed on 3/6/26.
Claims 1-18 are pending in this application and are being examined in this Office Action.
Priority
The applicant claims benefit as follows:
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Objections
Claims 9 and 11 are objected to because of the following informalities:
Claim 9 is objected to because of informal wording. Claim 9 recites “the tallest peak value at 59 m/z.” The phrase “tallest peak value” is not standard technical wording in the context of GC-MS mass spectral characterization. Suggested corrected wording: “a base peak at m/z 59” or “the most intense mass spectral peak at m/z 59.”
Claim 11 is objected to because of informal wording. Claim 11 recites “at a point, which is below the point, wherein the distillation solvent is fed into the first distillation column.” This wording is awkward and should be corrected for clarity. Suggested corrected wording: “at a point below the point at which the distillation solvent is fed into the first distillation column.”
Appropriate correction is required.
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.
Claim 8 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112, second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Claim 8 recites that “the organic impurity is characterized by a retention time of 6.5 - 6.7 minutes when determined by gas-chromatography-flame ionization detector (GC-FID).”
However, the claim does not recite the GC-FID method conditions used to determine the retention time. Retention time in GC-FID analysis is dependent on test conditions such as column type, column dimensions, carrier gas, flow rate, injection temperature, oven temperature program, heating rate and total run time. The specification provides such conditions, including a DB-HeavyWax column, helium carrier gas flow rate, injection temperature, starting oven temperature, heating rate, final temperature and total operation time. However, these conditions are not recited in claim 8. Thus, one of ordinary skill in the art would not know the metes and bounds of the organic impurity required by claim 8.
Appropriate correction is required.
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 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 of this title, 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 1-18 are rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (“Energy-Saving Designs for Separation of a Close-Boiling 1,2-Propanediol and Ethylene Glycol Mixture,” Industrial & Engineering Chemistry Research, 2015, 54, 3828-3843, published March 31, 2015, in applicant’s IDS filed 1/30/24), in view of Perez Golf et al. (US 2019/0062244 A1, published February 28, 2019).
Determination of the Scope and Content of the Prior Art
(MPEP §2141.01)
Chen et al. teaches a process for separating a close-boiling 1,2-propanediol and ethylene glycol mixture. Chen et al. teaches that 1,2-propanediol and ethylene glycol can be produced by hydrogenolysis of glycerol and that the separation of 1,2-propanediol and ethylene glycol is difficult because of the close boiling points. Chen et al. teaches using extractive distillation with triethylene glycol as a heavy entrainer to enhance the relative volatility between 1,2-propanediol and ethylene glycol. Chen et al. teaches that 1,2-propanediol can be drawn out of the extractive distillation column as distillate, while entrainer and ethylene glycol go out from the bottom stream. Chen et al. further teaches that the heavy entrainer can be purified in an entrainer recovery column and recycled back to the extractive distillation column. Chen et al. teaches that the extractive distillation system using triethylene glycol reduces steam cost and total annual cost. (Chen, Abstract, pages 3828, 3835, Fig. 8, and page 3842)
Perez Golf et al. teaches a process for separating glycols from product streams derived from renewable sugar-based materials and saccharide hydrogenolysis. Perez Golf et al. teaches that when glycols are produced by hydrogenolysis of saccharides, the product stream may contain mono-ethylene glycol (MEG), mono-propylene glycol (MPG), 1, 2-butanediol (1,2-BDO), 2,3-butanediol (2,3-BDO), pentanediols, hexanediols and heptanediols. Perez Golf et al. teaches that separating these diols by distillation is complicated because of the similarity in boiling points, and expressly teaches that MPG and 2,3-pentanediol are a close-boiling, azeotrope-forming glycol pair. (Perez Golf, paragraphs 2-7)
Perez Golf et al. further teaches an extractive distillation process using an extractant to separate close-boiling diols. Perez Golf et al. teaches feeding a mixture comprising C2 to C7 diols to a distillation column and feeding an extractant above the diol mixture feed. Perez Golf et al. teaches that the first diol may be MPG and the product stream may comprise MPG and 2,3-pentanediol. Perez Golf et al. teaches that the extractant may be a C3 to C6 sugar alcohol, including glycerol. Perez Golf et al. teaches that the number of theoretical stages may be 3 to 140 and may be determined by simple economic optimization experiments. Perez Golf et al. also teaches an extractant/feed ratio up to 10:1, operating temperatures of 50-250°C, operating pressures of 0.1-400 kPa, recovery of high purity diol, and recycle of the used extractant stream. (Perez Golf, paragraphs 31-37, 51, 56-60)
Perez Golf et al. specifically exemplifies separation and purification of MPG from close boilers such as 2,3-pentanediol species. Perez Golf et al. teaches using glycerol as the extractant, an MPG initial concentration of 71.8 wt%, a glycerol/MPG mixture weight ratio of 8.6, overall MPG recovery of 98%, and final MPG product purity of 99.96 wt%. Perez Golf et al. further teaches a top temperature of 107.6°C and pressure of 0.05 bar in the extractive distillation column. (Perez Golf, paragraphs 69-72, Tables 5-7)
Ascertainment of the Difference Between Scope the Prior Art and the Claims
(MPEP §2141.012)
Chen et al. is deficient in the sense that it does not specifically teach applicant’s claimed bio-derived diol mixture comprising an organic impurity, and does not specifically teach the claimed distillation solvent/feed ratio of 2.5:1 to 10:1.
However, Perez Golf et al. cures this deficiency because Perez Golf et al. teaches a bio-derived saccharide hydrogenolysis glycol product stream containing MPG and other diols, including pentanediols, and expressly teaches that MPG and 2,3-pentanediol are a close-boiling, azeotrope-forming glycol pair. Perez Golf et al. also teaches using a glycerol extractant/feed ratio up to 10:1 and specifically exemplifies a glycerol/MPG mixture weight ratio of 8.6, which is within applicant’s claimed range. (Perez Golf, paragraphs 7, 31-37, 69-72, Tables 5-7)
Chen et al. is also deficient in the sense that it does not specifically teach the claimed bio-derived MPG feed comprising MPG in the recited amount and recovered MPG purity.
However, Perez Golf et al. cures this deficiency because Perez Golf et al. teaches an MPG-containing saccharide hydrogenolysis product stream and specifically exemplifies an MPG initial concentration of 71.8 wt%, overall MPG recovery of 98%, and final MPG product purity of 99.96 wt%. (Perez Golf, paragraphs 69-72, Tables 5-7)
Perez Golf et al. is deficient in the sense that it does not specifically teach using triethylene glycol or tripropylene glycol as the distillation solvent for applicant’s claimed separation.
However, Chen et al. cures this deficiency because Chen et al. expressly teaches triethylene glycol as a heavy entrainer for extractive distillation separation of 1,2-propanediol from a close-boiling glycol mixture. Chen et al. teaches that adding triethylene glycol enhances the relative volatility between 1,2-propanediol and ethylene glycol and permits 1,2-propanediol to be recovered as distillate. (Chen, Abstract, page 3835)
Perez Golf et al. is further deficient in the sense that its example removes MPG with the extractant in a bottom stream and then recovers high purity MPG in a later column, rather than expressly teaching applicant’s claimed removal of MPG in the first top stream and organic impurity/distillation solvent in the first bottom stream.
However, Chen et al. cures this deficiency because Chen et al. teaches the same stream direction recited by applicant: 1,2-propanediol is drawn out of the extractive distillation column as distillate, while entrainer and ethylene glycol go out from the bottom stream. Therefore, Chen et al. teaches removing mono-propylene glycol in a first top stream and removing impurity/entrainer components in a first bottom stream. (Chen, page 3835)
Finding of Prima Facie Obviousness Rationale and Motivation
(MPEP §2142-2143)
Therefore, it would be prima facie obvious to one of ordinary skill in the art at the time of the invention to modify Chen et al.’s extractive distillation process by applying it to the bio-derived MPG-containing glycol mixture taught by Perez Golf et al. because both references are directed to separating close-boiling glycol mixtures by distillation using an entrainer or extractant. Chen et al. teaches that triethylene glycol is useful for separating 1,2-propanediol from a close-boiling glycol mixture by extractive distillation. Perez Golf et al. teaches that bio-derived saccharide hydrogenolysis streams contain MPG and close-boiling/azeotrope-forming pentanediol impurities. Thus, one of ordinary skill in the art would have been motivated to use Chen et al.’s triethylene glycol extractive distillation process to separate MPG from the close-boiling bio-derived diol mixture taught by Perez Golf et al., with a reasonable expectation of success.
With regard to claims 1, 6 and 7, Chen et al. teaches providing a mixture comprising 1,2-propanediol and ethylene glycol to an extractive distillation column, providing triethylene glycol as a heavy entrainer, separating 1,2-propanediol as a distillate/top stream, removing entrainer and ethylene glycol as a bottom stream, recovering the heavy entrainer and recycling the heavy entrainer. Perez Golf et al. teaches applying extractive distillation to a bio-derived MPG-containing saccharide hydrogenolysis stream containing close-boiling organic impurities such as 2,3-pentanediol. Therefore, the combined teachings render obvious the claimed process of recovering mono-propylene glycol from a bio-derived diol mixture using triethylene glycol as the distillation solvent and recovering MPG in the first top stream while the organic impurity and distillation solvent are removed in the first bottom stream.
With regard to claims 2-5, Perez Golf et al. teaches MPG-containing product streams derived from saccharide hydrogenolysis, including mixtures containing MPG, MEG, butanediols, pentanediols, hexanediols and heptanediols. Perez Golf et al. specifically exemplifies an MPG initial concentration of 71.8 wt%, a glycerol/MPG mixture weight ratio of 8.6, overall MPG recovery of 98%, and final MPG product purity of 99.96 wt%. Applicant’s claimed MPG amount, solvent/feed ratio and recovered MPG concentration therefore would have been obvious from the teachings of Perez Golf et al. and Chen et al.
With regard to claims 8-9, Perez Golf et al. teaches that the MPG separation is from close boilers such as 2,3-pentanediol species, which are a challenge because such glycols form close-boiling point azeotropes. The instant specification identifies the claimed organic impurity by GC-FID and GC-MS analytical characterization and models the organic impurity as a pentanediol compound having a close boiling point with MPG and forming an azeotrope with MPG. Thus, to the extent claims 8-9 are definite, the analytical characterization of the same or substantially similar pentanediol impurity would have been an inherent property or an obvious analytical characterization of the impurity separated from MPG.
With regard to claims 10-11, Perez Golf et al. teaches that the number of theoretical stages may vary from 3 to 140 and may easily be determined by the skilled person on the basis of simple economic optimization experiments. Perez Golf et al. also teaches feeding the extractant above the diol mixture feed. Therefore, the claimed 40-120 theoretical stages and the claimed feed point relationship would have been obvious from Perez Golf et al.
With regard to claims 12-16, Chen et al. teaches optimization of extractive distillation conditions to reduce steam cost and total annual cost. Perez Golf et al. teaches operating temperatures and pressures overlapping the claimed ranges and specifically exemplifies an extractive distillation column top temperature of 107.6°C and pressure of 0.05 bar. Therefore, applicant’s claimed top temperature, top pressure, pressure drop and reflux ratio would have been obvious as routine optimization of known extractive distillation variables.
With regard to claim 17, Chen et al. teaches that the heavy entrainer can be purified and recycled back to the extractive distillation column. Perez Golf et al. also teaches recycling at least a portion of the used extractant stream to the distillation column as at least a portion of the extractant feed. Therefore, recycling the distillation solvent would have been obvious.
With regard to claim 18, Chen et al. teaches an entrainer recovery column after the extractive distillation column. Perez Golf et al. teaches further distillation to recover high purity MPG and specifically teaches final MPG product purity of 99.96 wt%. Therefore, providing the mono-propylene glycol top stream to a second distillation column to recover mono-propylene glycol at a concentration of at least 98 wt% would have been obvious.
Thus the combination is merely the use of a known extractive distillation solvent and known extractive distillation conditions to separate a known close-boiling glycol mixture, with predictable results. Chen et al. supplies triethylene glycol and the claimed top/bottom stream direction, while Perez Golf et al. supplies the bio-derived MPG/pentanediol impurity mixture, solvent/feed ratio, theoretical stage range, feed location, temperature/pressure conditions, recycle and high purity MPG recovery.
Note that an express suggestion to substitute one equivalent component or process for another is not necessary to render such substitution obvious. In re Fout, 675 F.2d 297, 213 USPQ 532 (CCPA 1982).
Furthermore, where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. Applicant has not shown any unusual and/or unexpected results for the claimed distillation solvent amount, theoretical stage number, temperature, pressure, pressure drop or reflux ratio. The prior art provides the same effect desired by applicant, namely the use of an entrainer or extractant in distillation to separate close-boiling glycol mixtures and recover high purity mono-propylene glycol.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the "right to exclude" granted by a patent and to prevent possible harassment by multiple assignees. See In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d438, 164 USPQ 619 (CCPA 1970); and In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) may be used to overcome an actual or provisional rejection based on a nonstatutory double patenting ground provided the conflicting application or patent is shown to be commonly owned with this application. See 37 CFR 1.130(b).
Effective January 1, 1994, a registered attorney or agent of record may sign a terminal disclaimer. A terminal disclaimer signed by the assignee must fully comply with 37 CFR 3.73(b).
The USPTO internet Web site contains terminal disclaimer forms which may be used. Please visit http://www.uspto.gov/forms/. The filing date of the application will determine what form should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to http://www.uspto.gov/patents/process/file/efs/guidance/eTD-info-I.jsp.
Claims 1-18 are provisionally rejected on the ground of nonstatutory obviousness-type double patenting as being unpatentable over claims 1-2, 4-17 of copending Application No. 17916157, in view of Chen et al. (“Energy-Saving Designs for Separation of a Close-Boiling 1,2-Propanediol and Ethylene Glycol Mixture,” Industrial & Engineering Chemistry Research, 2015, 54, 3828-3843, published March 31, 2015, in applicant’s IDS filed 1/30/24), in view of Perez Golf et al. (US 2019/0062244 A1, published February 28, 2019).
Although the claims at issue are not identical, they are not patentably distinct from each other.
Copending Application No. 17916157 is directed to recovering mono-propylene glycol from a mixture comprising bio-derived diols and an organic impurity. Claim 1 recites recovering mono-propylene glycol from a mixture comprising bio-derived diols and an organic impurity, wherein the mixture comprises mono-propylene glycol in an amount of at least 50 weight-% of the total weight of the mixture, and wherein the organic impurity is characterized by a retention time of 6.5 - 6.7 minutes when determined by GC-FID and by a tallest peak value at 59 m/z when determined by GC-MS. Claim 1 further recites separating the organic impurity from mono-propylene glycol in a first distillation process, removing the organic impurity in a first bottom stream from the first distillation process, and removing mono-propylene glycol in a first top stream from the first distillation process.
The instant claims are directed to recovering mono-propylene glycol from a mixture feed comprising bio-derived diols and an organic impurity. The instant claims further recite providing the mixture feed into a first distillation column, providing a distillation solvent into the first distillation column, separating the organic impurity from mono-propylene glycol with the aid of the distillation solvent, and recovering mono-propylene glycol. The instant claims merely further recite carrying out the same recovery of mono-propylene glycol from the same type of bio-derived diol mixture and organic impurity by using a known distillation solvent/entrainer system and known extractive distillation conditions.
The teachings of Chen et al. and Perez Golf et al. have been discussed previously within this office action.
To summarize, Chen et al. teaches using triethylene glycol as a heavy entrainer in extractive distillation to separate 1,2-propanediol from a close-boiling glycol mixture, with 1,2-propanediol recovered as distillate and entrainer/ethylene glycol recovered in the bottom stream. Perez Golf et al. teaches applying extractive distillation to bio-derived saccharide hydrogenolysis streams containing MPG and close-boiling pentanediol impurities, using sugar alcohol extractants, solvent/feed ratios, theoretical stages, feed locations, temperature/pressure ranges, recycle, and high purity MPG recovery.
Therefore, it would have been obvious to one of ordinary skill in the art to modify the MPG recovery method claimed in copending Application No. 17916157 by using the known extractive distillation solvent/entrainer system and known process conditions taught by Chen et al. and Perez Golf et al. to separate the same MPG/organic impurity mixture with predictable results.
This is a provisional obviousness-type double patenting rejection, because the conflicting claims have not in fact been patented.
Conclusion
No claim is allowed.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Jennifer Cho Sawyer whose telephone number is (571) 270 1690. The examiner can normally be reached on Monday-Friday 9 AM - 6 PM PST.
If attempts to reach the examiner by telephone are unsuccessful, the examiner's supervisor, Renee Claytor can be reached on (571) 272-8394. The fax phone number for the organization where this application or proceeding is assigned is 571-274-1690.
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Jennifer Cho Sawyer
Patent Examiner
Art Unit: 1691
/RENEE CLAYTOR/Supervisory Patent Examiner, Art Unit 1691
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