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 .
Claim Status
Claims 1-18 are pending.
No claims have been amended.
No claims have been canceled.
Thus, claims 1-18 represent all claims currently under consideration.
Priority
Domestic Priority data as claimed by Applicant:
This application is a 371 of PCT/KR2022/016625 (10/27/2022)
Foreign Applications:
REPUBLIC OF KOREA 10-2021-0149849 (11/03/2021)
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Objections
Claim 3 is objected to because of the following informalities:
In lines 5-7, the parentheses around the description of Chemical Formula 1 should be deleted.
Appropriate correction is required.
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.
Claims 1 and 12 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by J. E. Klein (EP 0027805 B1; published 06-15-1983; IDS of 06-23-2025).
Regarding claims 1 and 12, Klein discloses an improved process and system for removal and recovery of vinyl chloride monomer (VCM) from vent gas stream in a polyvinyl chloride (PVC) plant. The gas stream going to the monomer recovery system contains the air which was initially left in the PVC plant reactor. The Figure of Klein
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discloses a simplified flow diagram of the solvent absorption/stripping system. A vent gas stream from PVC production containing the VCM and the components of air is fed through line 10 to the bottom section of a packed absorber column 11, while a stream of solvent is fed through line 12 to the top of column 11. The solvent passes downward in the column countercurrent to the vent gas stream flowing upward in the column, where the solvent absorbs the VCM in the gas stream and the air is vented overhead through line 13. These teachings correspond to the limitations of method step (S1) of claim 1 and the absorption tower of claim 12.
The solvent containing absorbed VCM flows from the bottom of the column through line 14 to a heat exchanger 15 where its temperature is elevated by the heat exchange medium and then flows through line 16 to a stripping column having a packed stripping sections 17a and a packed rectification section 17b. The VCM-rich solvent from line 16 is fed to the top of section 17a where it is further heated and vaporized as it flows down the column by means of heat supplied through a reboiler 18 heated with steam. The heat strips the absorbed VCM from the solvent in section 17a converting it to VCM vapor which passes through rectification section 17b and overhead through line 19 where it is condensed to liquids in an overhead condenser and a portion of the liquid VCM returned for reflux through line 20 and the remainder goes to storage and reuse. These teachings correspond to the limitations of method steps (S2) and (S3) of claim 1 and the first recovery line, first heat exchanger, second recovery line, and stripping tower (wherein the supplied heating medium is reboiler steam) of claim 12.
The lean solvent from the bottom of stripper column section 17a is fed through line 21 back to heat exchanger 15 where it is cooled and flows through line 22 to a chiller 23 for further cooling before reentering the absorber through line 12, so that the path of the solvent through the absorber/stripper forms a complete “figure 8” (Abstract; 0007; 0011-0013; 0029; claim 1; Figure). These teachings correspond to the limitations of method steps (S4) and (S5) of claim 1 and the first circulation line, second heat exchanger, and second circulation line of claim 12. Furthermore, the present application also describes a path of the solvent through the absorber/stripper that forms a complete “figure 8” through a central heat exchanger 40/(41) that acts as the first and second heat exchangers (Specification, paragraphs 84-95 and FIG. 1), in a manner consistent with heat exchanger 15 in the Figure of Klein. Therefore, Klein anticipates the method of claim 1 and the device of claim 12.
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.
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 J. E. Klein (EP 0027805 B1; published 06-15-1983; IDS of 06-23-2025), in view of Wang et al. (CN112892158A; published 06-04-2021; English language machine translation obtained from Espacenet on 09-23-2026).
Regarding claims 1 and 12, the teachings of Klein are incorporated herein as detailed in the rejections above.
Regarding claims 2-4 and 13, Klein does not explicitly teach wherein the absorbent contains a plasticizer as recited in claims 2 and 13, wherein the absorbent is derived from the following formula Chemical Formula 1 as recited in claim 3, or wherein the absorbent is dioctyl terephthalate (DOTP) or bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate (DEHCH) as recited in claim 4. Instead, Klein teaches the use of isooctane as an absorbent (0005, 0014, 0019-0021, 0024-0026; Examples 1, 3, and 11).
However, Wang teaches a comprehensive treatment process system for tail gas containing carbon dioxide and chlorine organic matter that includes a primary absorption group, a primary distillation and purification system, a secondary absorption, distillation (or stripping) purification and separation system, and a tertiary PSA+RTO or RCO system connected in sequence. The system of Wang further comprises heat exchangers for temperature control. The primary and secondary systems have recovery efficiencies of over 99% for high-content vinyl chloride and over 95% for low-content vinyl chloride, respectively. As a result of the process of Wang, vinyl chloride and non-methane total hydrocarbons both met national standards. The exhaust gas from the outlet of the secondary absorption contains < 2 mg/Nm3 vinyl chloride. This corresponds to less than about 0.71 ppm. (0002, 0044, 0079, 0082; 0085; claims 1, 3, 7; English language machine translation).
Of particular note, Wang further teaches that the absorbent solvent is one or more of the following: dioctyl phthalate, dioctyl terephthalate, trioctyl trimellitate, siloxanes, or n-methylpyrrolidone (0013, 0067; claim 2; English language machine translation). The absorbent dioctyl terephthalate is a plasticizer for vinyl chloride polymer as described in the present application (Specification; paragraphs 14 and 52), and dioctyl terephthalate corresponds to the limitations of claims 2, 4, and 13 and Chemical Formula 1 of claim 3 when Cy is phenylene and Ak is a C8 alkyl group.
The methods and systems of Klein and Wang are analogous because they both teach treatment processes for exhaust gases comprising vinyl chloride with systems comprising absorption columns, absorbents, stripping columns, and heat exchangers, in a manner consistent with the instantly claimed invention. As such, the skilled artisan would be sufficiently motivated to predictably substitute the isooctane absorbent of the method and system of Klein with dioctyl terephthalate as taught by Wang to arrive at an alternative method for recovering unreacted vinyl chloride monomer with a reasonable expectation of success. Such an endeavor would result in the simple substitution of one known element for another to obtain predictable results, as described in MPEP § 2143(I)(B).
Therefore, it would have been prima facie obvious before the effective filing date of the claimed invention to have substituted the isooctane absorbent of the method and system of Klein with dioctyl terephthalate as taught by Wang to arrive at the invention of claims claims 2-4 and 13. The motivation to do so would permit the skilled artisan to pursue, with a reasonable expectation of success, an alternative method and device for recovering unreacted vinyl chloride monomer using an absorbent with predictable and demonstrated utility.
Regarding claim 5, Example I of Klein teaches that the isooctane absorbed VCM leaving the absorber column is at a temperature of 24 ºC and a pressure of 3.59 bar. In addition, Klein teaches that the usual design pressure and temperature of the monomer recovery system are not greater than 4 atmospheres or lower than 7 ºC (0008 and 0019; Example 1). The skilled artisan would recognize that the pressures within the closed system of the monomer recovery apparatus correspond to gauge pressures, in a manner consistent with the instant claim. The temperatures and pressures of Example I of Klein and the general temperature and pressure ranges of the monomer recovery system of Klein reside within or overlap with the instantly claimed ranges. MPEP § 2144.05(I) states that “[i]n the case where the claimed ranges ‘overlap or lie inside ranges disclosed by the prior art’ a prima facie case of obviousness exists.”
Regarding claim 6, Example I of Klein teaches that the VCM rice isooctane in line 14 is pumped to heat exchanger 15 to produce in line 16 a stream of liquid/vapor at a temperature of 113 ºC and a pressure of 3.87 bar (0021; Example I). This temperature of Example I of Klein resides within the instantly claimed range. See MPEP § 2144.05(I).
Regarding claim 7, Klein teaches that the stripping column is operated efficiently with 186 ºC reboiler steam (0026). This temperature resides within the instantly claimed range. See MPEP § 2144.05(I).
Regarding claims 8 and 17, Wang teaches that the exhaust gas from the secondary absorption tower enters the PSA and RTO or RCO combined system through pipeline. The pressure swing adsorption (PSA) adsorbs the exhaust gas before being discharged. The top outlet of the second-stage absorption tower is connected to the bottom inlet of the pressure swing adsorber via a pipeline (0012, 0035, 0047, and 0051; claims 1 and 10; English language machine translation). Therefore, the skilled artisan would be sufficient
Regarding claim 9, Klein teaches that the solvent passes downward in the column countercurrent to the vent gas stream flowing upward in the column, where the solvent absorbs the VCM in the gas stream and the air is vented overhead through line 13 (0012; Figure).
Regarding claim 10, Klein teaches that the VCM-rich solvent from line 16 is fed to the top of section 17a where it is further heated and vaporized as it flows down the column by means of heat supplied through a reboiler 18 heated with steam (0012; Figure). The skilled artisan would recognize from the Figure of Klein that the steam supplied from reboiler 18 is at the bottom of the stripping column and flows upward and therefore runs counter-current to the downward flow of the absorbent, in a manner consistent with the instant claim.
Regarding claim 11, both Klein and Wang teach methods and systems that include vinyl chloride monomer (VCM) in the exhaust gas (Klein; Abstract; 0006-0007 and 0009; claim 1; Wang; 0068 and 0079; English language machine translation).
Regarding claims 14-15, the heat exchanger 15 of Klein represents an integrated heat exchanger that heats the absorbent after leaving the absorber column 11 though line 14 and cools the absorbent after leaving the stripper column section 17a through line 21 (0013 and 0021; Figure).
Regarding claim 16, Example I and the Figure of Klein describe a system wherein absorber column 11 includes an absorption body that is 45.72 cm in diameter and 6.15 m high. The vent streams from VCM recovery sections of a plant for producing PVC are fed through feed line 10 at the lower portion of absorber column 11. Absorbent (commercial isooctane) flows into the top of column 11 through line 12, and the isooctane containing absorbed VCM leaves the absorber column through line 14 at the bottom of the column. Absorber column 11 further includes a vent stream leaving the top of the column through line 13 that contains less than 1 ppm VCM by volume, 115.65 kg/hour of inters and 3.15 kg/hour of isooctane vapors from the solvent. The skilled artisan would recognize that lines 10-14 of Klein correspond to the first/second supply ports and first/second discharge ports of the absorption tower, in a manner consistent with the instant claim.
Example I and the Figure of Klein further describes a system wherein the stripping column 17 includes a stripping section 17a and a rectification section 17b, wherein reboiler steam 18 is supplied to the bottom of the stripping column. Line 16 supplies a stream of liquid/vapor heated from heat exchanger 15 to the top of stripping column 17a. The lean solvent from the stripping column in line 21 exits from the bottom of stripping column 17 back to the heat exchanger 15 where it is cooled. The heat strips the absorbed VCM from the solvent in section 17a converting it to VCM vapor which passes through rectification section 17b and overhead through line 19 where it is condensed to liquid in an overhead condenser (0012 and 0019-0021; Example I; Figure). The skilled artisan would recognize that lines 16, 18-19, and 21 of Klein correspond to the third/fourth supply ports and third/fourth discharge ports of the stripping tower, in a manner consistent with the instant claim.
Regarding claim 18, Klein teaches that the VCM vapor which passes through rectification section 17b of absorber column 11 and overhead through line 19 where it is condensed to liquid in an overhead condenser and a portion of the liquid VCM returned for reflux through line 20 and the remainder goes to storage and reuse (0012; Figure).
Although Klein does not explicitly teach the use of a third heat exchanger, the skilled artisan would recognize that the process of condensing the discharged VCM to a liquid in an overhead condenser necessarily involves cooling the vapor through heat exchange. Furthermore, Klein does teach that the monomer recovery system consists of compressors and refrigerated condensers to remove some of the VCM from the air stream before it is vented (0008). Therefore, the skilled artisan could arrive at a refrigerated condenser that would act as a third heat exchanger with a reasonable expectation of success based on the teachings of Klein.
Further regarding claim 18, Wang teaches that the top cooling separator of the secondary distillation (or stripping) refining separation tower is a vertical tube heat exchanger, which uses chilled water at a temperature below 7 ºC to condense and recover moisture from the gas (0065; English language machine translation). Therefore, the skilled artisan could also arrive at the claim limitation based on the teachings of Wang.
Based on the combined teachings of the references, the Examiner submits that a person of ordinary skill in the art would have had a reasonable expectation of success of arriving at the instantly claimed method and device. Therefore, the invention as a whole would have been prima facie obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, and absent a clear showing of evidence to the contrary.
Conclusion
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/D.R./Examiner, Art Unit 1692
/AMY C BONAPARTE/Primary Examiner, Art Unit 1692
