DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claims 1-3, 5-7, 9-10, 12, 14-16, 18-25, 28-29 and 55 are pending as amended on 9/15/2026.
The new grounds of rejection set forth below were necessitated by the incorporation of the limitation from dependent claim 56 into claim 1, as well as the addition of new limitations (h) regarding trapping, filtering and recycling residual solvent vapor. Because the new grounds of rejection were necessitated by amendment, this action is properly made final.
Any rejections and/or objections made in the previous Office action and not repeated below are hereby withdrawn. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office Action.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-3, 5-7, 9-10, 12, 14-16, 18-25, 28-29 and 55 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 1 has been amended to recite a step (h) of trapping, filtering and recycling residual solvent vapor.
The specification as filed describes residual solvent which is released (in vapor form) from PHA-reduced biomass during drying [00012], and, which is released during drying of the substantially isolated PHA [00016].
In contrast, claim 1 as presently amended does not limit the way the “residual solvent vapor” recited in claim (h) was initially produced, and therefore, encompasses process wherein residual solvent vapor was produced in steps other than from drying isolated PHA or from drying PHA-reduced biomass. Furthermore, because there is no step in claim 1 which recites generation of “residual solvent” or vapor thereof (and because step (h) does not refer to any previously recited residual solvent vapor), claim 1 even encompasses processes wherein “residual solvent vapor” as utilized in step (h) was generated in a step or process unrelated to those recited in steps (a) through (g) of claim 1. Because the claims (i.e., claim 1, and claims which depend from claim 1) as presently drafted are not commensurate in scope with the limited support provided in the specification, the written description requirement of 35 USC 112(a) has not been complied with.
Additionally:
Claim 9 has been amended to recite dissolution of PHA and PHA containing biomass by subjecting PHA and PHA containing biomass to elevated temperatures between about 110 to about 130 C. The range of temperatures is newly recited.
The specification as originally filed describes heating solvent to a temperature between about 110 C and 130 C, which is then fed into a dissolution vessel with PHA-containing biomass [00057]. In contrast, claim 9 does not limit how the elevated temperatures are achieved, is not necessarily further limiting the temperature in the dissolution vessel, and is therefore not limited to a process as described in [00057] wherein step (b) is performed by combining an external solvent at a temperature within the presently claimed range with PHA-containing biomass.
Claims 1-3, 5-7, 9-10, 12, 14-16, 18-25, 28-29 and 55 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 has been amended to include a new step (h) reciting trapping, filtering and recycling residual solvent vapor for reuse…” However, there is no prior step in claim 1 which includes a recitation of generating or producing residual solvent vapor. It is therefore not clear whether “residual solvent vapor” as recited in step (h) refers to (and further limits) any, but not necessarily all, vaporized residual solvent which may be generated, OR, whether “residual solvent vapor” as recited in step (h) refers to all vaporized residual solvent which is generated throughout a process according to claim 1. For examination purposes, a process will be considered within the scope of claim 1 as long as some (but not necessarily all) generated vapor of residual solvent is trapped, filtered and recycled as recited in step (h). Claims which depend from claim 1 are unclear for the same reason, due to their dependence from claim 1.
Additionally:
Claim 9 depends from claim 1 and further limits the “dissolution of PHA and PHA containing biomass” by reciting “subjecting… to elevated temperatures, wherein the elevated temperatures comprise temperatures between about 110 C and 130 C. The use of the open-ended term “comprise” to define the recited “elevated temperatures” renders the scope of the claim unclear, because it is not clear whether an elevated temperatures must be between the range of about 110 to 130 C in order to meet claim 9, or, whether the elevated temperatures which meet claim 9 could include unrecited temperatures outside the disclosed range. Applicant may wish to consider further amending claim 9 to recite, e.g., “wherein the temperature of the external solvent recited in step (b) is within a range of about 110 C to about 130 C.”
Claim 19 depends from claim 16 and further limits the pore sizes of “the filter.” However, it is not clear whether “the filter” refers to the filter used to perform filtration as recited in claim 16, or, refers to the internal filter recited in claim 14. Because the term lacks antecedent basis, the scope of the claim is unclear. For examination purposes, the claim has been interpreted as limiting the internal filter recited in claim 14, as “internal filter” was originally recited in claim 19. Applicant should consider replacing the word “internal” in claim 19.
Claims 23 and 24 recite filtration of the residual solvent vapor. Claim 22, from which claims 23 and 24 depend, recites residual solvent vapor released from PHA-reduced biomass. However, claims 22-24 ultimately depend from claim 1, which recites a step of filtering residual solvent vapor (step h). It is not clear whether “the residual solvent vapor” recited in claims 23 and 24 is referring to the residual solvent vapor specifically recited in claim 22, or, whether claim 23 is referring to residual solvent vapor in claim 1 (which is not necessarily limited to solvent released from PHA-reduced biomass). Due to a lack of antecedent basis, the scope of the claims is unclear.
Claim Rejections - 35 USC § 103
Claim(s) 1-3, 5, 6, 7, 9, 10, 12, 18, 25 and 55 is/are rejected under 35 U.S.C. 103 as being unpatentable over Van Walsem (US 20100197885) in view Sorrels et al (Chapter 1, Carbon Adsorbers, October 2018, pp 1-47; https://www.epa.gov/sites/default/files/2018-10/documents/final_carbonadsorberschapter_7thedition.pdf) and Herrema (US 2020/0115724).
As to claims 1, 2, 7, 10, 25 and 55, Van Walsem discloses a process wherein a microbial biomass containing PHA [0035] in the form of a slurry [0036] is contacted with a solvent system [0044] which includes a solvent for PHA [0045-7]. The mixture is heated [0067] and agitated [0068-9] to allow the PHA to be removed from the biomass [0067] and to generate a PHA-rich solvent phase [0071] and a PHA-reduced biomass [0072]. Van Walsem does not explicitly teach “a dissolution vessel” as recited in step “a.” However, it would have been obvious to the person having ordinary skill in the art to have performed a process of heating and agitating a mixture, as taught by Van Walsem, in a vessel in order to contain the materials and perform the steps of heating and agitating in a conventional manner. Therefore, Van Walsem suggests a process which comprises steps according to instant “a” and “b” recited in claim 1.
Van Walsem discloses separation of the PHA phase (PHA-rich solvent) from the residual biomass phase (PHA-reduced biomass) [0073], using centrifugation [0075], which corresponds to instant step (c).
Van Walsem further discloses adding a precipitant to the PHA phase to form a mixture [0080] to generate precipitated PHA [0082], meeting instant step (d), and separating precipitated PHA from the liquid [0083-4], meeting instant step (e). The PHA is then dried [0085], meeting instant (f), and pelletized [0085], meeting instant (g) (and meeting instant claim 55).
As to instant step (h) (and relevant to limitations found in instant claims 20-24):
Van Walsem further teaches that the components of the solvent system can be stripped from the remaining (PHA-reduced) biomass phase using standard techniques such as in a vacuum drier, and the solvent contained in the biomass can be recovered, such as by “solvent condensation” [0090]. Van Walsem discloses that at least 97 vol% of the initially used solvent is recovered for re-use [0088]. Van Walsem also teaches distilling the solvent system/precipitant mixture so that the components (solvent and precipitant) can be re-used [0105]. However, Van Walsem fails to teach filtering residual solvent vapor by passing the vapor through an activated carbon filter.
Sorrels teaches that adsorption is used when recovery of a volatile organic compound (VOC) is desired, and that carbon adsorbers are used in a wide range of applications, including chemical manufacturing (p 1). Sorrels teaches an adsorber system wherein VOC-laden gas is collected by hoods or pipeline collection and passes through a filter to remove particulates, and then passes through a carbon bed. In a desorption cycle, steam flows through the carbon bed, VOC is removed, and the VOC is conveyed to storage (recovered), and may receive additional purification by distillation (p 3). Sorrels teaches that activated carbon remains the most commonly used adsorbent today (p 5), and that recovered VOC can be re-used onsite as a solvent (p 33).
When carrying out the steps of stripping and recovering solvent for re-use, as taught by Van Walsem in [0088-90, 0105], one having ordinary skill in the art would have been motivated to utilize a technique which is known and commonly used in a wide range of applications in order to effectively recover solvent as desired by Van Walsem. It would have been obvious to the person having ordinary skill in the art, therefore, to have recovered residual solvent, as taught by Van Walsem, using a system as taught by Sorrels, i.e., by collecting solvent-laden gas, collecting in a hood or pipeline (corresponding to a step of trapping solvent vapor as presently recited), passing through an activated carbon bed (corresponding to filtration of solvent vapor by passing residual solvent vapor through an activated carbon filter), and then removing the solvent from the carbon for re-use on site (corresponding to recycling as presently recited). It would have been further obvious to the person having ordinary skill in the art to have re-used the recovered solvent in any part of Van Walsem’s process in which solvent was initially used, including, e.g., the dissolution vessel, in order to reduce waste and environmental impact.
Van Walsem teaches biomass of microbial origin [0035], however, Van Walsem fails to teach that the biomass is derived from methanotrophic microorganisms. However, Herrema teaches a methanotrophic microorganism that is capable of generating PHA at high efficiency levels, resulting in increased PHA yield [0010, 0028-29]. It would have been obvious to the person having ordinary skill in the art, therefore, to have utilized a methanotrophic microorganism, as taught by Herrema, to derive the biomass in Van Walsem, in order to increase PHA yield at high efficiency levels.
As to claim 3, Van Walsem teaches using a non-halogenated solvent for the PHA because this can reduce negative environmental impact, reduce health risks and reduce storage/handling costs [0055].
As to claim 9, Van Walsem teaches that the temperature of the solvent system and slurry mixture during agitation can be varied as desired and teaches a range of less than about 160 C [0068]. It would have been obvious to the person having ordinary skill in the art, therefore, to have selected any appropriate temperature within Van Walsem’s range in order to effectively dissolve the PHA, including within the presently claimed range of 110-130 C. Case law has established that a prima facie case of obviousness is established where the claimed ranges overlap the ranges disclosed by the prior art. See MPEP 2144.05.
As to claims 5 and 6, the recited solvents are found in [0050-53] of Van Walsem, and butyl acetate, as recited in instant claim 6, is recited in [0051]. Butyl acetate is further exemplified as the solvent in [0111].
As to claim 12, Van Walsem discloses agitation (dissolution) for less than about three hours [0070], which meets a range of 0 to 5 hours as recited in claim 12.
As to claim 18, Van Walsem fails to teach the PHA content which remains in the PHA-reduced biomass. However, Van Walsem teaches agitation of the solvent system and slurry mixture until the PHA phase has a desired PHA solids content [0070], and teaches decreasing the viscosity of the PHA phase results in improved separation of the phases [0073]. The goal of the process taught by Van Walsem is a reduction in the amount of PHA remaining in the residual biomass [0003] (because PHA is the desired product to be extracted from the biomass). It would have been obvious to the person having ordinary skill in the art, therefore, to have reduced the amount of PHA remaining in the biomass when carrying out the process in Van Walsem in order to increase the yield of the desired product (PHA), including reducing the PHA remaining in the biomass to an amount within the claimed range.
Claim(s) 14-16, 19-24 and 29 is/are rejected under 35 U.S.C. 103 as being unpatentable over Van Walsem (US 20100197885) in view Sorrels et al (Chapter 1, Carbon Adsorbers, October 2018, pp 1-47; https://www.epa.gov/sites/default/files/2018-10/documents/final_carbonadsorberschapter_7thedition.pdf) and Herrema (US 2020/0115724), and further in view of Narasimhan et al (US 2005/0287653).
The rejection over Van Walsem, Sorrels and Herrema is incorporated here by reference.
As to claims 14-16, as established above, modified Van Walsem suggests a method comprising a step according to step (a) recited in instant claim 1, and, discloses separation of the PHA phase (PHA-rich solvent) from the residual biomass phase (PHA-reduced biomass) [0073] using centrifugation [0075].
Van Walsem fails to teach “a dissolution vessel” as recited in step “a” which comprises an internal filter, as recited in claim 14.
Like Van Walsem, Narasimhan discloses a process for extracting PHA from biomass [0017] by stirring [0048] and heating [0051-4] the biomass in a solvent [0044], and then separating biomass from PHA-enriched liquor [0055]. Narasimhan discloses that methods of separation include centrifugation, but that a preferred method of filtration is high temperature filtration before the PHA liquor cools significantly, and that preferred filtration devices include Nutsche filters with mixing, heating and washing capabilities [0056]. Considering Narasimhan’s disclosure, the person having ordinary skill in the art would have been motivated to utilize a Nutsche filter to perform a solvent extraction of PHA from biomass in order to carry out the steps of mixing, heating and filtering the biomass, PHA and solvent in a single vessel, and in order to carry out the filtration before the PHA liquor cools. It would have been obvious to the person having ordinary skill in the art, therefore, to have carried out Van Walsem’s steps of contacting biomass slurry with solvent, heating and agitating, followed by separation of PHA-rich solvent from residual biomass, in a Nutsche filter (as taught by Narasimhan), thereby arriving at a process comprising steps (a) through (c) as recited in claims 14-16.
As to claim 19, modified Van Walsem suggests a method according to claim 16, as set forth above, wherein PHA is extracted in solvent and separated from biomass in a Nutsche style filter. One having ordinary skill in the art would have recognized that the pore size of a filter is a result effective variable - as filter pore size increases, the content of solid impurities which are able to pass through the filter with the desired solution increases. As pore size decreases, the rate at which desired solution passes through the filter decreases. It would have been obvious to the person having ordinary skill in the art, therefore, to have selected any appropriate filter pore size in order to achieve a desired balance between purity (smaller pore size) and filtration efficiency (larger pore size), including a pore size within the presently claimed range.
As to claims 20-24, modified Van Walsem suggests a method according to instant claim 16 as set forth in this rejection above. The further limitations recited in claims 20-24 are met, as set forth in the discussion of step (h) in the rejection above over Van Walsem, Sorrels and Herrema.
As to claim 29, modified Van Walsem suggests a method according to claim 20, as set forth above. Van Walsem teaches that the biomass can be dried to recover and/or eliminate residual solvent, and can be reused as a nutrient for fermentation after removing residual solvent [0090]. It would have been obvious to the person having ordinary skill in the art, therefore, to have re-fed the biomass into the fermentation broth to form a slurry, as taught by Van Walsem in [0034], which is subsequently extracted with solvent [0044], thereby arriving at a process as presently recited wherein PHA-reduced biomass is re-fed into the renewable and sustainable process for further extraction of PHA.
Claim(s) 28 is/are rejected under 35 U.S.C. 103 as being unpatentable over Van Walsem (US 20100197885) in view Sorrels et al (Chapter 1, Carbon Adsorbers, October 2018, pp 1-47; https://www.epa.gov/sites/default/files/2018-10/documents/final_carbonadsorberschapter_7thedition.pdf), Herrema (US 2020/0115724), and Narasimhan et al (US 2005/0287653), and further in view of Stelte et al (Recent Developments in Biomass pelletization - A review; BioRes. 7(3), 4451-4490 (2012)).
The rejection of claim 20 over Van Walsem in view of Sorrels, Herrema and Narasimhan is incorporated here by reference.
As to claim 28, modified Van Walsem suggests a method according to claim 20, as set forth above. Van Walsem teaches that the biomass can be dried to recover and/or eliminate residual solvent, and can be reused as a nutrient for fermentation after removing residual solvent [0090]. Van Walsem fails to teach milling and/or pelleting of the dried/recovered biomass.
Stelte teaches that attempts to overcome the poor handling properties of biomass (low bulk density, inhomogeneous) have resulted in an increase in interest in biomass densification, such as pelletization (abstract). Compaction of biomass into pellets is an old process that has been known for more than 130 years (p 4453, first full paragraph) and pelletization offers density increase, and homogenous shape and structure (p 4452, second paragraph). In view of Stelte’s disclosure, it would have been obvious to the person having ordinary skill in the art to have pelletized the dried recovered biomass in the process of modified Van Walsem in order to provide the biomass in a more convenient form (increased density and homogeneity) for subsequent use.
Response to Arguments
Applicant's arguments filed 9/15/2026 have been fully considered.
The rejections as previously set forth in the action mailed on 6/23/2026 have been overcome by the amendments to the claims. However, new rejections have been set forth. Van Walsem remains cited as a primary reference in the new rejections, and therefore, any arguments which are pertinent to the new grounds of rejection have been addressed below.
Applicant argues (p 10) that there is no teaching in the cited references of methanotropic biomass limitation previously recited in claim 56 and now recited in claim 1. However, Applicant has not addressed the art utilized previously to reject claim 56 (Herrema, see paragraphs 38-40). Therefore, the argument is not persuasive.
Applicant argues (pp 11-12) that amended claim 1 now recites a closed loop solvent recovery system with activated carbon filtration which is not recited in the previously cited prior art. The examiner agrees that the limitations added to claim 1 were not met by the previously cited art. However, the new rejections rely on Sorrels (newly cited art) to meet these limitations. Therefore, Applicant’s arguments regarding the failure of the previously cited art to teach the new limitations are not sufficient to establish non-obviousness.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to RACHEL KAHN whose telephone number is (571)270-7346. The examiner can normally be reached Monday to Friday, 8-5.
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/RACHEL KAHN/ Primary Examiner, Art Unit 1766
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