DETAILED ACTION
Notice of Pre-AIA or AIA Status
This Office action is based on the 18/258,118 application filed 23 June 2023, which is being examined under the first inventor to file provisions of the AIA .
Claims 1-20 are pending and have been fully considered.
Claim Rejections - 35 USC § 102
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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 1-2, 4, 8-10, and 12-13 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Wascheck et al (US 2004/0103782 A1).
With respect to claims 1-2, 4, 8-10, and 12-13, Wascheck et al discloses “[e]xhaust gas 3 from a solid waste landfill 2 is conveyed into the suction of a compressor 6 with a blower 4…The compressor pressurizes the raw exhaust gas to a high pressure suitable for removing the VOC's in the pressure swing adsorption unit ("PSA") 9, downstream. Immediately downstream of compressor 6 is a set of coalescing filters 8 which strip liquid contaminants from the gas. The coalescing filters remove such substances as compressor lubrication oil, condensed water vapor and some higher boiling VOC's…The substantially liquid-free and pressurized feed mixture 7 of methane, carbon dioxide, VOC's and other possible contaminants, such as hydrogen sulfide and siloxanes is charged into the PSA unit 9…As represented in FIG. 1, the feed mixture enters the PSA unit and a major fraction of the VOC's are adsorbed by beds of particles of suitably chosen adsorbent material within the PSA elements…Any adsorbent material that is selective to volatile organic compounds can be used. Representative adsorbent particle compositions are activated alumina, silica gel, activated carbon and mixtures thereof. The gas mixture from the PSA unit preferably is further processed through an activated carbon bed 10 to remove most of the small residual amounts of VOC's that survived PSA treatment…Next the intermediate mixture of gases is introduced into at least one (hereinafter the "primary") gas separation module 12. This is a device that can be generally described as having a membrane 13 within a case such that the membrane defines to compartments, namely a feed-retentate chamber 16, and a permeate chamber 17 inside the module. The membrane comprises a gas permeable substance that exhibits a selectivity for methane relative to other components of the intermediate mixture. Usually, the selectively gas permeable substance is less preferentially permeable to methane than the other components. The intermediate gas mixture should be at an elevated pressure in the feed retentate chamber. This pressure is determined by the discharge pressure of compressor 6 and the pressure drop experienced by the gas as it flows through the coalescing filters, PSA unit and activated carbon filter. Thus there is a driving force sufficient to cause the intermediate mixture to selectively permeate the membrane 13. Consequently, a permeate gas 25 having a composition that is depleted in methane relative to the intermediate mixture composition is provided in the permeate chamber 17. Similarly, a retentate gas 20 forms in the feed-retentate chamber 16. Because the membrane tends to rejects methane, the concentration of methane in the retentate gas is enriched relative to the intermediate mixture composition. Depending on the intended use of the product methane gas, the retentate gas 20 from the primary module may be of sufficient purity that it can be used directly without further purification…In an important aspect of the present invention, the permeate gas 25 from the primary separation module is returned to the PSA unit 9 to regenerate the beds of adsorbent particles therein. This permeate gas is at a satisfactorily low pressure to facilitate the desorption of the VOC's from the particles. Consequently the energy invested in compressing the gas 3 by compressor 6 is conserved by blowing the permeate gas through the PSA unit as compared to venting the permeate and having to pressurize another regeneration gas. The permeate gas is suitably
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conditioned as having been filtered and dried. It is also cleaned of VOC's. Moreover, it has a low concentration of methane, and therefore, little of the useful methane in the initial feedstock is wasted by regenerating the PSA unit with the permeate gas. Thus the permeate gas 25 is ideal for regenerating the PSA unit. When the PSA unit status is switched from active (i.e., available to, or in process of adsorbing VOC from the feed mixture to deactivate (i.e., ready to be, or in process of being regenerated), the particles have VOC adsorbed on them. Until these adsorbed VOC's are removed, the particles are unable to adsorb more and the separation of the VOC's from the feed mixture ceases to occur. The VOC's are removed from the particles by providing a driving force to desorb the VOC'S. The regeneration step of the pressure swing adsorption process involves exposing the adsorbent particles in the bed to a low pressure atmosphere having a low concentration of VOC's. This invention provides that the regenerating atmosphere is provided by the returning permeate gas 25, as mentioned above. During regeneration the VOC's leave the adsorbent particles and enter the regenerating gas stream 22, sometimes referred to herein as spent regeneration gas. The waste VOC's in the regeneration gas can be destroyed to avoid pollution to the environment. Destruction of the VOC's can be achieved by any of many well known methods in the art. Preferably, the spent regeneration gas 22 is processed in a high efficiency incinerator 24…In a typical installation of the present invention at a solid waste landfill site, the landfill can be expected to generate about 5 million standard (i.e., at 0o C. temperature and 1 atmosphere pressure) cubic feet ("SCF") per day of exhaust gas 3. This landfill exhaust gas can have a composition about as follows: 50% methane, 44% carbon dioxide, 5% nitrogen, 1% oxygen, 50 parts per million ("ppm") hydrogen sulfide, 200 ppm VOC's and a saturated amount of water vapor. Gas mixture composition percentages herein are on a volume basis unless specified otherwise…Substantially all of the VOC's are adsorbed by the PSA unit and the activated carbon bed. Thus the retentate gas product of the primary membrane separation stage 20 should have a composition of approximately the following concentrations: 75% methane, 20% carbon dioxide, 4% nitrogen, 1% oxygen, 50 parts per million ("ppm") hydrogen sulfide. The primary permeate gas will thus be about 2.3 million SCF per day and have a composition of approximately the following concentrations: 90% carbon dioxide, 8% methane and 2% nitrogen and oxygen combined” [paragraphs 0031-0036, 0038-0040, and 0042]. The intermediate mixture of gases (7A or 11) corresponds to the source gas stream of the instant application; the primary permeate gas corresponds to the carbon-dioxide rich gas stream; and the retentate gas product corresponds to the substantially carbon dioxide-free gas stream. The PSA corresponds to the regeneration vessel containing an adsorption medium, which adsorbents are the aforementioned activated alumina, silica gel, or activated carbon. The PSA may correspond to the adsorption vessel in instant claim 12; alternatively, the activated carbon bed 10 may correspond to the same. In such a case, intermediate mixture of gases 7a [paragraph 0043] corresponds to the source gas stream.
Claim Rejections - 35 USC § 103
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.
Claim(s) 3, 5-7, 11, and 14-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wascheck et al (US 2004/0103782 A1).
With respect to claim 3, note that the instant application discloses “[i]n some embodiments, the adsorption medium in the regeneration vessel comprises polymer beads, alumina, silica gel, activated carbon” [paragraph 0013 of the published application]. Since the adsorbents in the PSA unit 9 of Wascheck et al is the same as the adsorption media the instant application, it is expected, absent evidence to the contrary, that siloxane, in addition to VOCs, are adsorbed onto said adsorbent of PSA unit 9 as an impurity.
With respect to claims 5-7, Wascheck et al discloses “the adsorbent particles ultimately become saturated with the contaminants and lose ability to adsorb beyond a maximum amount. Before more contaminants can be removed from the crude, the adsorbent particles must be regenerated. This normally involves exposing the saturated particles to high temperatures, and fluids that have low concentrations of the contaminants to promote desorption of the contaminants from the particles” [paragraph 0006]. Consequently, heating the primary permeate gas would have been obvious to one of ordinary skill in the art. Additionally, it appears that temperature may be a result effective variable; that is, a variable that achieves a recognized result. In this case, the result is an extent or degree of adsorbent regeneration. Applicant is reminded that “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.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235.
With respect to claims 11 and 15, mixed matrix membranes are well known in the art for CH4/CO2 separations. Applicant is reminded that “[t]he selection of a known material based on its suitability for its intended use [is] prima facie obvious.” Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297.
With respect to claim 14, the reference element 7 [see figure above] corresponds to the inlet gas line and renders the gas inlet obvious. Membrane 13 corresponds to the membrane coupled to the gas inlet line. Reference element 25 corresponds to the carbon dioxide-rich gas stream and reference element 20 corresponds to the substantially carbon dioxide-free gas stream. PSA unit 9 corresponds to the adsorption vessel and the regeneration vessel. Reference element 25 corresponds to the regeneration line. As noted above, “heating the primary permeate gas would have been obvious to one of ordinary skill in the art,” and, consequently, so would the recited heater. With respect to the gas outlet note the lines depicted by reference elements 7A and 22, which renders the gas outlet(s) obvious.
With respect to claim 16, the required gas outlet is obvious in view of the line depicted by reference element 22 [see figure above]. The incinerator 24 corresponds to the flare.
With respect to claim 17, the aforementioned methane corresponds to the impurities of the instant claim. Therefore, a gas outlet associated with the line depicted by reference element 20 would have been obvious to one of ordinary skill in the art.
With respect to claims 18 and 19, recall the reference teaches “[r]epresentative adsorbent particle compositions are activated alumina, silica gel, activated carbon and mixtures thereof” [see prior discussion].
With respect to claim 20, since the PSA unit 9 corresponds to both the adsorption vessel and regeneration vessel of the instant application, the switching configuration would have been obvious to one of ordinary skill in the art. Alternatively, consider discussion of Figure 2 beginning in paragraph 0043.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure: Dzeti et al (MY 190255), which discloses “a method of fabricating membrane for gas separation, more particularly fabrication of ionic liquid mixed matrix membrane (IL3M) for CO2/CH4 separation.”
Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRIAN A MCCAIG whose telephone number is (571)270-5548. The examiner can normally be reached Monday to Friday 8 to 4:30 Mountain Time.
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/BRIAN A MCCAIG/Primary Examiner, Art Unit 1772
9 December 2025