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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 4/20/2026 has been entered.
Response to Amendment
Applicant has amended claims 1, 9, and 11 and canceled claim 7. Claims 1-4, 6, and 8-12 are pending.
The amendments to the claims have necessitated new rejections over the prior art previously relied upon. See 103 rejections below for details.
Response to Arguments
Applicant’s arguments, see Remarks, filed 4/10/2026, with respect to the 103 rejections over Lan have been fully considered but they are not persuasive.
Applicant has argued that the independent claims are allowable on account of limitations to “a heat duty of E0 [being] at least 30% less than a heat duty of E1” and “an amount of steam required for E1 [being] less than 1.3 kg/kg of product methanol”. Examiner respectfully disagrees.
First, Examiner now holds that it is implicit in the embodiment of Lan Figure 23 that “an amount of steam required for E1 is less than 1.3 kg/kg of product methanol”.
While Lan does not Lan does not explicitly teach that the amount of steam required for E1 (E203) is less than 1.3 kg/kg of product methanol in the embodiment of Figure 23, Lan teaches that “The process method of methanol distillation using the four-tower triple-effect heat integrated device provided by this invention has a steam consumption of less than 58 tons/hour and a steam consumption of less than 0.7 tons of steam/ton of refined methanol product,” (paragraph [0179] of Espacenet translation; emphasis added). Lan describes the embodiment of Figure 23 “a four-tower triple-effect thermal integration” (paragraphs [0107] and [0247]). Thus, when Lan’s teaching of steam consumption in paragraph [0179] is taken together with the disclosures of paragraphs [0107] and [0247] regarding the embodiment of Figure 23, it amounts to an implicit disclosure that the overall steam consumption in the embodiment of Figure 23 is less than less than 0.7 kg steam/kg of refined methanol product (0.7 tons of steam/ton of refined methanol product). Because the overall steam consumption is less than 0.7 kg steam/kg of refined methanol product, then the steam required for the reboiler E1 (E203) is also less than 0.7 kg steam/kg of refined methanol product. In view of the forgoing, the amount of steam required for E1 is implicitly less than 0.7 kg/kg of product methanol.
If arguendo said steam requirement for E1 is not implicit in Lan, Lan’s teaching of steam consumption in paragraph [0179] is taken together with the disclosures of paragraphs [0107] and [0247], it would at least suggest that the steam requirements for the reboiler E1 (E203) can be made to be less than 0.7 kg steam/kg of refined methanol product. Thus, even if Lan does not implicitly disclose a steam requirement for the embodiment of Figure 23 of less than 0.7 kg steam/kg of refined methanol product, said steam requirement would be obvious over Lan’s disclosure (see 103 rejections below for further discussion of this matter). Though, in the interest of abundant clarity, Examiner holds that the embodiment of Figure 23 has an overall steam requirement, and thus a steam requirement for E1 specifically, of less than 0.7 kg steam/kg of refined methanol product.
Turning now to the requirement that “a heat duty of E0 is at least 30% less than a heat duty of E1”, Inventor (Per Juul Dahl) asserts that “the claimed less than 1.3 kg steam/kg product methanol is only valid provided duty of E0 is at least 30% less than duty of E1,” (paragraph 9 of the 4/10/2026 declaration by Inventor). As discussed above, the embodiment of Lan Figure 23 implicitly has a steam requirement of less than 0.7 kg/kg of refined methanol product for E1, i.e. E203. Thus, if Inventor’s assertion is correct, it is also implicit that the heat duty of E0 is at least 30% less than the heat duty of E1 in Figure 23 of Lan.
Regardless, for the reasons discussed at length in the 103 rejections below, a person having ordinary skill in the art would recognize that the heat duties of the various heat exchangers used in the process of Lan are result effective variables. Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date to modify Lan by optimizing the heat duty of the heat exchangers E0 (E213), E1 (E203), E2 (E204), and/or E3 (E205), e.g. such that a heat duty of E0 is at least 30% less than a heat duty of E1, in order to obtain a process wherein: i) the various distillation columns are each provided with workable amounts of heat, and ii) the energy consumption of the reboilers is optimized.
Applicant has argued that Examiner’s assertion to reboiler heat duties being result effective variables is “conclusory, unsupported, and fails to establish a prima facie case of obviousness.” Examiner respectfully disagrees.
Said assertion was and continues to be supported by sufficient technical reasoning. To elaborate, said assertion has, and continues to be supported by the following technical reasoning: “Namely, a person having ordinary skill in the art would recognize that the heat exchangers E0 (E213), E1 (E203), E2 (E204), and E3 (E205) are reboilers for respective distillation columns. Therefore, if the heat duty of a particular one of said heat exchangers (i.e. the amount of heat provided by a particular one of said heat exchangers) is too high or too low, a respective distillation column will be provided with too little or too much heat.” (rejection of claim 7 at page 22 of the 2/12/2026 Advisory Action).
Furthermore, the 103 rejections set forth below expand on said technical reasoning and point to disclosures by Lan which affirm the fact that reboiler heat duty is a result effective variable as follows:
a person having ordinary skill in the art would recognize that the heat duties of the various heat exchangers used in the process of Lan are result effective variables. Namely, a person having ordinary skill in the art would recognize that the heat exchangers E0 (E213), E1 (E203), E2 (E204), and E3 (E205) are reboilers for respective distillation columns. Therefore, if the heat duty of a particular one of said heat exchangers (i.e. the amount of heat provided by a particular one of said heat exchangers) is too high or too low, a respective distillation column will be provided with too little or too much heat. Thus, a person having ordinary skill in the art would recognize that, if the embodiment of Lan Figure 23 is to function properly, they MUST discover ranges for the heat duties which are at least workable.
Furthermore, Lan’s disclosure speaks of energy and steam savings (paragraphs [0083], [0115], [0179]-[0184], [0260] of Espacenet translation), and provides indication that reduced steam and energy consumption is desirable (paragraph [0179]-[0184] of Espacenet translation). A person having ordinary skill in the art would recognize that the energy consumption of a distillation process is largely determined by the heat duty of the reboilers, i.e. the heat duty of the reboilers corresponds to the energy consumption of the reboilers, which makes up a large part of a distillation process’ overall energy consumption. A review of Lan’s disclosure affirms this principle. Namely, the purpose of Lan’s invention is energy savings in the field of methanol distillation (paragraphs [0002] and [0010]-[0011] of Espacenet translation). Lan achieves the intended energy savings by use of a using four-tower triple-effect thermal integrated distillation systems (paragraphs [0002] and [0010]-[0011], [0107], and [0260] of Espacenet translation). Said energy savings are achieved relative to a system like that of Figure 1 having a lesser degree of thermal integration in the reboilers (paragraph [0005] of Espacenet translation). Thus, it is clear that reboiler heat duty is a result effective variable that plays a significant role in the overall energy consumption of a distillation system.
Accordingly, a person having ordinary skill in the art would be motivated to optimize the heat duty of individual reboilers and thus, the relative heat duties of various reboilers, in order to: 1) attain a system wherein the reboilers provide a workable amount of heat to each distillation column, and 2) wherein energy consumption of the reboilers is optimized.
Further still, a review of Figure 23 would lead one of ordinary skill in the art to expect the heat duty of E0 (E213) to be less than that of E1 (E203). Specifically, a review of Figure 23 shows that the only point for the introduction of external heat in the system of Figure 23 is the reboiler E1 (E203). Thus, it is understood that the heat to fulfill the heat duties for reboilers E0 (E213), E2 (E204), E3 (E205), and E206 must first be supplied into the system via E203. On the other hand, reboiler E0 (E213) is heated by the overhead vapor stream 15-2 from the column T203. All of the heat in stream 15-2 can be traced back to the heat introduced to the system via E203, but it is clear that the heat in stream 15-2 is less than all of the heat introduced to the system via E1 (E203). For example, some of said heat is necessarily contained in stream 15-1 and 15-3, from which stream 15-2 is split, and in stream 19, from which stream 15 is split by distillation in column T203. Therefore, it is understood, or at least expected, that the heat duty of E0 (E213) is less than the heat duty of E1 (E203).
"[When] 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," (see MPEP 2144.05 II A).
In view of the above, Examiner respectfully asserts that the assertion to heat duty being a result-effect variable is made on the basis of sound technical reasoning and supported by the disclosure of Lan. Therefore, said assertion is not unsupported or merely conclusory.
As for the allegation that it fails to establish a prima facie case of obviousness, Examiner respectfully disagrees. MPEP 2144.05(II)A states, ‘“[W]here 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 (CCPA 1955)”. MPEP 2144.05(II)B makes it clear that, if a particular parameter can be shown to be an art-recognized result effective variable, then determination of optimum or workable ranges for said parameter can be characterized as routine experimentation. Therefore, Examiner respectfully asserts that, by showing the reboiler heat duty is a recognized result effective variable which one of ordinary skill in the art would seek to optimize in Lan (see above), the rejections have established a prima facie case of obviousness with respect to the claimed heat relative heat duties of E0 and E1. The burden is now on Applicant to rebut said prima facie case with evidence or arguments (MPEP 2144.08(II)A).
Applicant has argued that “a heat duty of E0 [being] at least 30% less than a heat duty of E1” is entirely absent from Lan because “Lan does not disclose the heat duty of any exchanger corresponding to E0 or E1, any comparison between them, or any numerical relationship from which a >30% differential could be derived,” and because “Lan provides only qualitative descriptions of pressure and heat integration, without any quantitative energy balances or duty relationships.” Examiner finds this argument unpersuasive.
As discussed above, a person having ordinary skill in the art would recognize that reboiler heat duty is a result effective variable, and the disclosure of Lan affirms this. MPEP 2144.05(II)B makes it clear that, if a particular parameter can be shown to be an art-recognized result effective variable, then determination of optimum or workable ranges for said parameter can be characterized as routine experimentation. It is well established that “[W]here 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 (CCPA 1955). Thus, the notion that Lan is silent a heat duty of E0 being at least 30% less than a heat duty of E1 is moot with respect to the present 103 rejections.
Applicant has argued that reliance on optimization is allegedly “misplaced” because routine optimization doctrine allegedly requires “identification of a recognized objective in the art that would have motivated a person of ordinary skill to adjust the system in a manner leading to the claimed result.” Examiner finds this argument unpersuasive.
Examiner does not concede that a rejection on the basis of routine optimization requires “identification of a recognized objective in the art that would have motivated a person of ordinary skill to adjust the system in a manner leading to the claimed result”. MPEP 2144.05(II)B describes appropriate rational for supporting a rejection on the basis of routine optimization. Having reviewed said section of the MPEP, Examiner finds nothing which suggests one would be required to identify “a recognized objective in the art” as alleged by Applicant. Instead, MPEP 2144.05(II)B states that “after KSR, the presence of a known result-effective variable would be one, but not the only, motivation for a person of ordinary skill in the art to experiment to reach another workable product or process.” By this statement, said MPEP section indicates that identifying a recognized result effective variable is sufficient to support a rejection on the basis of routine optimization.
Examiner acknowledges Applicant’s allegation that “the Office has not shown that Lan provides any objective which, when optimized for… would yield a configuration in which the duty of E0 is at least 30% less than that of E1.”
Although identification of such an objective is not necessary to support a rejection on the basis of routine optimization, Examiner nevertheless notes the 103 rejections set forth below provide a showing that reduction of energy and steam consumption are objectives of Lan. As explained in detail said 103 rejections, said objectives would motivate one of ordinary skill in the art to optimize reboiler heat duty.
Examiner acknowledges Applicant’s allegation that “Lan does not identify any target or benefit associated with achieving a quantified reduction in external energy input relative to internally recovered heat.” Examiner respectfully disagrees.
As explained in the 103 rejections set forth below, the purpose of Lan’s invention is energy savings in the field of methanol distillation (paragraphs [0002] and [0010]-[0011] of Espacenet translation). Lan achieves the intended energy savings by use of a using four-tower triple-effect thermal integrated distillation systems (paragraphs [0002] and [0010]-[0011], [0107], and [0260] of Espacenet translation). Said energy savings are achieved relative to a system like that of Figure 1 having a lesser degree of thermal integration in the reboilers (paragraph [0005] of Espacenet translation). Accordingly, Examiner respectfully asserts that Lan does provide indication that a beneficial reduction in heat consumption can be achieved by a reduction in external energy input relative to internal recovered heat. Furthermore, it is frankly self-evident that a reduction in external energy input relative to internal recovered heat can achieve a reduction in energy consumption.
Applicant has argued that “the Office's characterization of heat duty as a "result-effective variable" oversimplifies the claimed system” because “the relative heat duty of E0 and E1 is an emergent property of a coupled thermodynamic system, not the predictable result of adjusting a single parameter.”
With respect, it is not entirely clear what position Applicant is taking here. Nevertheless, Examiner finds this argument unpersuasive.
Insofar as Applicant is arguing that heat duty is not a result effective variable because it is an emergent property which cannot be manipulated or optimized, Examiner respectfully disagrees. As Applciant’s argument admits, heat duty “depends on multiple interdependent factors” including column pressure, split ratios, and feed stream composition. These variables are manipulable an optimizable. Therefore, so too is heat duty.
Insofar as Applicant is arguing that heat duty is not a result effective variable because one cannot manipulate heat duty directly, but would have to manipulate one or more other variables to do so, Examiner respectfully disagrees. There is no requirement that a variable need be directly manipulable to be a result effective variable.
Insofar as Applicant is arguing that heat duty is not a result effective variable because it is affected by multiple other variables, Examiner respectfully disagrees. A parameter can still be result effective even if it itself affected by multiple other variables. Indeed, in a complex distillation process like those of Lan, nearly all of the variables are interconnected to some extent. For instance, the optimal operating temperature of column T202 is affected by, for example, the column pressure, the feed composition, and the number of trays. However, the fact remains that temperature of column T202 is a result effective variable which one of ordinary skill in the art would seek to optimize.
Insofar as Applicant is arguing that heat duty is not a result effective variable because optimization thereof would require manipulation of multiple other variables, Examiner respectfully disagrees. A parameter which can be manipulated to achieve a particular result is result effective even if one must manipulate multiple other variables to optimize said parameter.
Insofar as Applicant is arguing that it would not be obvious to optimize the heat duties of E1 and E0 because such an optimization would require one to manipulate multiple other process variables, Examiner respectfully disagrees. The notion that one would need to manipulate multiple other process variables to perform a particular optimization is insufficient to establish non-obviousness.
Applicant has alleged that “the ability of the presently claimed process to achieve a configuration in which the energy consumption is less than 1.3 kg steam/kg methanol, when the duty of E0 is at least 30% less than that of E1, therefore represents a non-intuitive and unexpected result, not predictable from Lan and not obtainable through routine optimization.” Applicant supports this allegation by arguing that because the final column of Lan (T204; analogous to column V3 of the claims) is a dividing wall column, “Lan's system would be expected to exhibit higher, not lower, heat duties” relative to Applicant’s system. Examiner finds this argument unpersuasive.
As discussed above, it is implicit that the steam required for the reboiler E1 (E203) is less than 0.7 kg steam/kg of refined methanol product in the embodiment of Lan Figure 23. And in the event that said steam requirement is not implicit, Lan at least suggests said steam requirement. This on its own does much to undermine Applicant’s allegation of unexpected results.
Furthermore, Inventor (Per Juul Dahl) asserts that “the claimed less than 1.3 kg steam/kg product methanol is only valid provided duty of E0 is at least 30% less than duty of E1,” (paragraph 9 of the 4/10/2026 declaration by Inventor). As discussed above, Lan Figure 23 implicitly has a steam requirement of less than 0.7 kg/kg of refined methanol product for E1, i.e. E203. Thus, if Inventor’s assertion is correct, it is also implicit that the heat duty of E0 is at least 30% less than the heat duty of E1 in Figure 23 of Lan. Accordingly, Applciant’s allegation of unexpected results appears to have little merit.
Nevertheless, in the event that the claimed relative heat duties are not implicit in Lan, Applciant’s allegation of unexpected results remains unpersuasive.
Applicant bases the assertion that Lan would be expected to have higher heat duties on the fact that Lan has a dividing wall column. However, though Applicant characterizes the dividing wall column of Lan as amounting to a structural difference between Lan and Applicant’s invention, there is nothing in the claims which exclude the claimed column V3 from being a dividing wall column. Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). Therefore, the fact that Lan comprises a dividing wall column does not differentiate Lan from the claimed invention, and there is no basis for asserting that the invention as claimed would have lower heat duty than Lan.
Regardless, Applicant’s assertion is merely that Lan has a higher heat duty on account of the dividing wall column. Said assertion does nothing to establish that it would be unexpected for the heat duty of E0 to at least 30% less than that of E1, nor does it establish that said relative heat duties are absent from Lan. A broadly higher heat duty is by no means incompatible with the heat duty of E0 being at least 30% less than that of E1. In other words, there is no reason to conclude that a broadly higher heat duty would prevent Lan from operating with a heat duty of E213 (corresponding to E0) that is least 30% less than that of E203 (corresponding to E1). Likewise, there is no reason to conclude that such operation is somehow unexpected in light of a broadly higher heat duty.
Furthermore, in the system of Lan, the dividing wall column T204 is analogous to the claimed column V3, the reboilers E213 and E203 are analogous to claimed reboilers E0 and E1 respectively, and said reboilers E213 and E203 belong to columns T201 and T202, which are analogous to claimed columns V0 and V1 respectively. Said reboilers E213 and E203 are heated respectively by overhead vapor 15-2 from column T203 (analogous to claimed column V2) an external heat source (e.g. steam) (Figure 23, paragraphs [0107], [0126]-[0128], and [0245]-[0247] of Espacenet translation; emphasis on Figure 23 and paragraphs [0107] and [0245]-[0247]). Thus, it is clear that the reboilers E213 and E203 are in a completely different portion of the system than the dividing wall column T204. Bearing the forgoing in mind, Examiner sees no reason why an increased heat duty brought about by the dividing wall column would prevent the heat duty of E213 (analogous to E0) from being 30% less than that of E203 (analogous to E1). Likewise, Examiner sees no reason why operation of E213 and E203 at such relative heat duties would be unexpected.
If anything, an increased heat duty brought about by T204 being a dividing wall column would be expected to increase the heat duty of E203 relative to the heat duties of at least E213 and E204. To elaborate, if T204 being a dividing wall column does lead to an increase in heat duty, then the additional heat to fulfill said duty would need to be introduced into the system of Lan somewhere. A review of Figure 23 shows that the only location at which external heat can be supplied to the system of Lan is at E203. Accordingly, an increase in heat duty anywhere in the system of Lan would necessarily require an increase in the heat duty of E203. On the other hand, there is no reason why increased heat duty in the column T204 would necessitate an increase in heat duty at E213. For this reason, Examiner finds that Applciant’s assertion of increased heat duty actually supports a conclusion one would expect the system of Lan to operate with a higher heat duty for E203 than for E213.
In addition, a review of Lan Figure 23 would lead one of ordinary skill in the art to expect the heat duty of E0 (E213) to be less than that of E1 (E203). Specifically, a review of Figure 23 shows that the only point for the introduction of external heat in the system of Figure 23 is the reboiler E1 (E203). Thus, it is understood that the heat to fulfill the heat duties for reboilers E0 (E213), E2 (E204), E3 (E205), and E206 must first be supplied into the system via E203. On the other hand, reboiler E0 (E213) is heated by the overhead vapor stream 15-2 from the column T203. All of the heat in stream 15-2 can be traced back to the heat introduced to the system via E203, but it is clear that the heat in stream 15-2 is less than all of the heat introduced to the system via E1 (E203). For example, some of said heat is necessarily contained in stream 15-1 and 15-3, from which stream 15-2 is split, and in stream 19, from which stream 15 is split by distillation in column T203. Therefore, it is understood, or at least expected, that the heat duty of E0 (E213) is less than the heat duty of E1 (E203). "[When] 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," (see MPEP 2144.05 II A).
For at least the above reasons, Examiner holds that “the ability of the presently claimed process to achieve a configuration in which the energy consumption is less than 1.3 kg steam/kg methanol, when the duty of E0 is at least 30% less than that of E1” does not amount to an unexpected result.
Applicant has argued that “To the extent the rejection relies on inherency, it is likewise deficient. The Office has not demonstrated that Lan's system would necessarily produce the claimed >30% duty differential.” Examiner considers this argument to be rendered moot by the rejections set forth below.
Applicant has argued that “the rejection relies on the claims as a template”, effectively arguing that the rejections rely on impermissible hindsight.
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
Examiner reiterates that: i) a person having ordinary skill in the art would recognize heat duty as a result effective variable, ii) the disclosure of Lan affirms that heat duty is a result effective variable; and iii) a person having ordinary skill in the art would expect the heat duty of E0 (E213) to be less than that of E1 (E203) in Lan Figure 23. With this in mind, a person having ordinary skill in the art would be able to arrive at the claimed relative heat duties by routine optimization and/or experimentation without consulting Applicant’s disclosure. Therefore, the 103 rejections over Lan do not engage in any improper hindsight reasoning.
Applicant argues that “as testified by the Expert [Inventor Per Juul Dahl], achieving an energy consumption of less than 1.3 kg steam/kg methanol product, when the duty of EQ is at least 30% less than the duty of E1, would require deliberate, non-intuitive system-level design and coordination, rather than routine optimization. Expert Declaration, paragraph 13; see also, Expert Declaration, paragraphs 14-15.” Examiner finds this argument unpersuasive.
The cited testimony at paragraphs 13 and 15 of the 4/10/2026 Declaration merely amounts to an opinion as to a legal conclusion. Thus, said testimony at paragraphs 13 and 15 is not entitled to any weight (MPEP 716.01(c)III).
The cited testimony at paragraph 14 asserts that “the structure of Lan’s system is different from the present patent, providing different product streams”. Notably, this assertion does not allege that Lan’s system is structurally different from the invention as claimed, nor does it identify any particular differences. Thus, said assertion is moot.
The following are new rejections, necessitated by amendment and made over the prior art previously relied upon.
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.
Claim(s) 1-4, 6, and 8-12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lan et al. (CN 108101748 A; see Espacenet translation), hereafter referred to as Lan.
Please note that, in making the following rejections, Examiner is relying first and foremost on the process as illustrated in Figure 23 of Lan. However, in making said rejections, Examiner cites portions of Lan’s disclosure which are made with respect to other embodiments. Said disclosures are cited merely for the purpose of providing citations to written descriptions which clarify the identities of various reference characters used within the Figures. Accordingly, it should be understood that any cited disclosure contradicting the details of Figure 23 is superseded by the details of Figure 23 and/or any disclosures made by Lan with specific reference to the embodiment of Figure 23.
With regard to claim 1: Lan teaches a process for distillation of methanol (Figure 23, paragraphs [0002], [0107], and [0245]-[0247] of Espacenet translation; emphasis on Figure 23 and paragraphs [0107] and [0245]-[0247]).
(i) pretreating a crude stream A (i.e. stream 6) of methanol in a stabilizing column V0 (i.e. “de-lightness tower” T201) at a pressure P0, for separation of volatile components, and obtaining a stream of light gases L (i.e. top gas phase 7) from an upper section of V0 (T201) and a liquid stream B0 (i.e. liquid phase material 36) from a lower section of V0 (T201) (Figure 23, paragraphs [0107], [0126]-[0127], and [0245]-[0247] of Espacenet translation; emphasis on Figure 23 and paragraphs [0107] and [0245]-[0247]). Note: Said step of pretreating the crude stream A (6) in the stabilizing column V0 (T201) is necessarily carried out at a first pressure P0.
ii) Directing B0 (36) into a concentration column V1 (i.e. first distillation tower T202) at a pressure P1 (Figure 23, paragraphs [0107], [0126]-[0128], and [0245]-[0247] of Espacenet translation; emphasis on Figure 23 and paragraphs [0107] and [0245]-[0247]). Note: Said step of directing B0 (36) into the concentration column V1 (T202) is necessarily carried out at a second pressure P1, i.e. said concentration column V1 (T202) is necessarily operated at said second pressure P1.
iii) condensing a gaseous stream T1 (i.e. top gas phase 10) recovered from an upper section of V1 in a heat exchanger E2 (i.e. reboiler E204), and supplying energy to a concentration column V2 (i.e. second distillation tower T303) via the heat exchanger E2 (E204) (Figure 23, paragraphs [0107], [0126]-[0128], [0130], [0161], and [0245]-[0247] of Espacenet translation; emphasis on Figure 23 and paragraphs [0107] and [0245]-[0247]).
iv) recovering part of a condensed stream obtained in step (iii) (i.e. condensate 11) as a product C1 (i.e. condensate 13), and supplying a remaining part (i.e. reflux liquid 12) of the condensed stream obtained in step (iii) (11) to the upper section of V1 as a reflux flow (Figure 23, paragraphs [0107], [0128], [0159], and [0245]-[0247] of Espacenet translation; emphasis on Figure 23 and paragraphs [0107] and [0245]-[0247]).
v) recovering a liquid stream B1 (i.e. bottom material 14) comprising methanol from a lower section of V1 and supplying said liquid stream B1 (14) to V2 (T203) at a pressure P2 (Figure 23, paragraphs [0024], [0107], [0128], and [0245]-[0247] of Espacenet translation; emphasis on Figure 23 and paragraphs [0107] and [0245]-[0247]). Note: Said step of supplying B1 (14) to V2 (T203) is necessarily carried out at a third pressure P2, i.e. said concentration column V2 (T203) is necessarily operated at said third pressure P2.
vi) splitting a gaseous stream T2 (i.e. top base phase 15) recovered from an upper section of V2 into a first split stream (15-2) and a second split stream (15-1), condensing the first split stream (15-2) in a heat exchanger E0 (i.e. reboiler E213), thereby supplying energy to V0 (T201) and forming a condensed first split stream (i.e. 16-2), condensing the second split stream (15-1) in a heat exchanger E3 (i.e. reboiler E205), thereby supplying energy to a concentration column V3 (i.e. third distillation tower T204), and forming a condensed second split stream (16-1), and combining the condensed first split stream (16-2) and the condensed second split stream (16-1) into a combined condensed stream 16 (Figure 23, paragraphs [0025], [0058]-[0060], [0104], [0107], [0129], [0166], and [0245]-[0247] of Espacenet translation; emphasis on Figure 23 and paragraphs [0107] and [0245]-[0247]).
vii) recovering part of the combined condensed stream (16) a product C2 (i.e. condensate 18) and supplying a remaining part (reflux liquid) 17 of the combined condensed stream (16) to the upper section of V2 (T203) as a reflux flow (Figure 23, paragraphs [0025], [0058], [0107], [0129], [0166], and [0245]-[0247] of Espacenet translation; emphasis on Figure 23 and paragraphs [0107] and [0245]-[0247]).
viii) recovering a liquid stream B2 (bottom material 19) comprising methanol V2 and supplying said liquid stream B2 (19) to V3 (T204) at a pressure P3 (Figure 23, paragraphs [0025]-[0026], [0107], [0129]-[0130], and [0245]-[0247] of Espacenet translation; emphasis on Figure 23 and paragraphs [0107] and [0245]-[0247]). Note: Said step of supplying B2 (19) to V3 (T204) is necessarily carried out at a fourth pressure P3, i.e. said concentration column V3 (T204) is necessarily operated at said fourth pressure P3.
ix) condensing a gaseous stream T3 (i.e. top gas phase 20) recovered from an upper section of V3 (T204), recovering part of a stream (i.e. condensate 21) condensed from T3 as a product C3 (i.e. condensate 23), and supplying a remaining part (i.e. condensate 22) of the stream (21) condensed from T3 (20) to the upper section of V3 (T204) as reflux flow (Figure 23, paragraphs [0026], [0107], [0130], and [0245]-[0247] of Espacenet translation; emphasis on Figure 23 and paragraphs [0107] and [0245]-[0247]).
x) withdrawing one or more side streams H (i.e. fusel oil 27) comprising higher alcohols and other minor by products from V3 (T204) and drawing a liquid stream B3 (i.e. bottom material 29) from V3 (T204) (Figure 23, paragraphs [0026], [0029], [0107], [0130], and [0245]-[0247] of Espacenet translation; emphasis on Figure 23 and paragraphs [0107] and [0245]-[0247]).
Wherein heat exchangers E0 (E213), E1 (E203), E2 (E204), and E3 (E205) serve as boilers for columns V0 (T201), V1 (T202), V2 (T203), and V3 (T205) respectively (Figure 23 and paragraphs [0107] and [0245]-[0247] of Espacenet translation).
Wherein heat exchangers E0 (E213) and E3 (E205) serve as condensers for V2 (T203) (Figure 23 and paragraphs [0107] and [0245]-[0247] of Espacenet translation).
Wherein heat exchanger E2 (E204) serves as a condenser for V1 (T202).
And wherein E1 (E203) is supplied by an external energy source (Figure 23 and paragraphs [0107] and [0245]-[0247] of Espacenet translation).
Lan does not explicitly teach that the columns V1, V2 and V3 operate at decreasing pressures such that P1>P2>P3. However, careful review of Lan’s disclosure shows that, in the embodiment relied upon (i.e. that of Figure 23), it is implicit that P1>P2>P3.
First, regarding the embodiment of Figure 23 Lan provides the following teaching:
“FIG. 23 is an evolutionary process method of FIG. 20, namely, deformation process method fifteen. The operating pressure and heat integration sequence of the four-tower three-effect heat integration shown in Figure 20 are adjusted, and it is still a four-tower three-effect heat integration. The first distillation tower T202 is operated at high pressure, and the second distillation tower T203 is operated at low pressure,” (paragraph [0107] of Espacenet translation; emphasis added).
Said teaching serves as an express indication that at least columns V1 (T202) and V2 (T203) operate at decreasing pressures such that P1>P2.
Though the relative pressure P3 of column V3 (T204) is not explicitly disclosed in Lan, it can be determined that P3<P2 on the following basis:
In the embodiment of Figure 23, the reboiler E205 of column T204 transfers heat from the overhead stream 15 of column T203 to a bottom stream of the column T204 (Figure 23, paragraph [0107]). Accordingly, it is understood that, in said embodiment, the temperature of the overhead stream 15 is necessarily higher than the temperature of the bottom stream entering reboiler E205, and thus, the top operating temperature of column T203 is necessarily higher than the bottom operating temperature of the column T204.
Because the overhead stream 15 obtained from column T203, the temperature of said overhead stream 15 is necessarily lower than the bottom operating temperature of column T203. Accordingly, if the overhead stream 15 is to heat the reboiler E205 as intended, the bottom operating temperature of column T204 must also be lower than the bottom operating temperature of column T203.
Because the bottom steam fed to the reboiler E205 is removed from a bottom of column T204, said bottom stream necessarily has a higher boiling point and temperature than the feed stream 19 which is fed to the middle of the column. (Note: The matter of the bottom stream fed to reboiler E206 is somewhat more complicated due to the presence of the dividing wall in column T204. Regardless, analysis of only the bottom stream fed to reboiler E205 is sufficient to make Examiner’s point).
The feed stream 19 to column T204 is the bottom product stream from column T203. Therefore, if we are to assume that the operating pressure of T204 is equal to that of T203, the feed point operating temperature in T204 would need to be at least as high (likely higher) than the bottom operating temperature of T203 in order for said feed 19 to boil, and thus be distilled, upon entering the feed point of column T204. If we are to assume that the operating pressure of T204 is higher than that of T203, then the feed point operating temperature in T204 would need to be higher than the bottom operating temperature of column T203. In either case, the bottom operating temperature of the column T204 would necessarily be higher than the bottom operating temperature of column T203. Therefore, if the operating pressure of column T204 were equal to or greater than that of column T203, the overhead stream 15 would be incapable of heating reboiler E205 as intended by Lan, and the embodiment of Figure 23 would be rendered inoperative.
On the other hand, if the operating pressure of T204 is made to be lower than that of T203, then it is possible for the bottom operating temperature of T204, and thus the temperature of the bottom stream entering the reboiler E205, to be lower than the bottom operating temperature of column T203. Therefore, it is clear that column T204 in the embodiment of Figure 23 must operate at a lower pressure than column T203. Thus, it is clear that P2>P3 in the embodiment of Figure 23.
As discussed above, Lan’s teachings expressly indicate that P1>P2. Nevertheless, it should be appreciated that one can verify that P1>P2 in Figure 23 of Lan by applying the technical reasoning set forth above with respect to columns T204 and T203 to columns T202 and T203.
Because P1>P2 and P2>P3 in the embodiment of Figure 23, it is understood that the columns V1 (T202), V2 (T203), and V3 (T204) necessarily operate at decreasing pressures such that P1>P2>P3.
In the unlikely alternative, for at least the reasons discussed above, Lan at least suggests that P1>P2>P3.
In the unlikely event that it is not implicit that P1>P2>P3, it would have been obvious to one of ordinary skill in the art before the effective filing date to modify Lan in view of Lan’s own suggestions by configuring the columns V1 (T202), V2 (T203) and V3 (T204) to operate at decreasing pressures such that P1>P2>P3, in order to obtain a predictably functional process wherein the heat integration sequence depicted in Figure 23 can be successfully implemented.
Lan does not explicitly teach that the amount of steam required for E1 (E203) is less than 1.3 kg/kg of product methanol in the embodiment of Figure 23. However, Lan teaches that “The process method of methanol distillation using the four-tower triple-effect heat integrated device provided by this invention has a steam consumption of less than 58 tons/hour and a steam consumption of less than 0.7 tons of steam/ton of refined methanol product,” (paragraph [0179] of Espacenet translation; emphasis added). Lan describes the embodiment of Figure 23 “a four-tower triple-effect thermal integration” (paragraphs [0107] and [0247]). Thus, when Lan’s teaching of steam consumption in paragraph [0179] is taken together with the disclosures of paragraphs [0107] and [0247] regarding the embodiment of Figure 23, it amounts to an implicit disclosure that the overall steam consumption in the embodiment of Figure 23 is less than less than 0.7 kg steam/kg of refined methanol product (0.7 tons of steam/ton of refined methanol product). Because the overall steam consumption is less than 0.7 kg steam/kg of refined methanol product, then the steam required for the reboiler E1 (E203) is also less than 0.7 kg steam/kg of refined methanol product. In view of the forgoing, the amount of steam required for E1 is implicitly less than 0.7 kg/kg of product methanol.
In the alternative, when Lan’s teaching of steam consumption in paragraph [0179] is taken together with the disclosures of paragraphs [0107] and [0247], it would at least suggest that the steam requirements for the reboiler E1 (E203) can be made to be less than 0.7 kg steam/kg of refined methanol product.
Furthermore, paragraph [0179] of Lan states that “According to the currently widely used four-tower methanol distillation process, the minimum steam consumption for methanol distillation is 1 ton of steam/ton of refined methanol product.” By “the currently widely used four-tower methanol distillation process”, it is understood that Applicant is referring to the system illustrated in Figure 1 of Lan (see paragraphs [0005] and [0085] of Espacenet translation). The system illustrated in Figure 1, contains three reboilers (E102, E103, and E106) which are heated with an external heat source. In comparison the embodiment of Figure 23 has only one heat exchanger (E203) which is heated by an external heat source. If an overall steam consumption of 1 kg/kg of refined methanol product is achievable in the system of Figure 1 despite the fact that it has three reboilers requiring an external heat source (two more than the embodiment of Figure 23), then an even lower steam consumption clearly would be achievable in the embodiment of Figure 23.
Lan’s disclosure speaks of energy and steam savings (paragraphs [0083], [0115], [0179]-[0184], [0260]), and provides indication that reduced steam consumption is desirable (paragraph [0179]-[0184] of Espacenet translation). Thus, a person having ordinary skill in the art would have clear motivation to operate the various embodiments of Lan with a low steam consumption.
In the event that it is not implicit in Lan, it would have been obvious to one of ordinary skill in the art before the effective filing date to further modify Lan by configuring the embodiment of Lan Figure 23 to operate with an overall steam requirement of less than 0.7 kg/kg of refined methanol product (and thus also a steam requirement for E1, i.e. E203, which is also less than 0.7 kg/kg of refined methanol product), in order to obtain energy and steam savings.
Lan does not explicitly teach that a heat duty of E0 is at least 30% less than a heat duty of E1. However, Applicant asserts that “the claimed less than 1.3 kg steam/kg product methanol is only valid provided duty of E0 is at least 30% less than duty of E1,” (paragraph 9 of the 4/10/2026 declaration by Inventor). As discussed above, the embodiment of Lan Figure 23 implicitly has a steam requirement of less than 0.7 kg/kg of refined methanol product for E1, i.e. E203. Thus, if Applicant’s assertion is correct, it is also implicit that the heat duty of E0 is at least 30% less than the heat duty of E1 in Figure 23 of Lan.
Regardless, a person having ordinary skill in the art would recognize that the heat duties of the various heat exchangers used in the process of Lan are result effective variables. Namely, a person having ordinary skill in the art would recognize that the heat exchangers E0 (E213), E1 (E203), E2 (E204), and E3 (E205) are reboilers for respective distillation columns. Therefore, if the heat duty of a particular one of said heat exchangers (i.e. the amount of heat provided by a particular one of said heat exchangers) is too high or too low, a respective distillation column will be provided with too little or too much heat. Thus, a person having ordinary skill in the art would recognize that, if the embodiment of Lan Figure 23 is to function properly, they MUST discover ranges for the heat duties which are at least workable.
Furthermore, Lan’s disclosure speaks of energy and steam savings (paragraphs [0083], [0115], [0179]-[0184], [0260] of Espacenet translation), and provides indication that reduced steam and energy consumption is desirable (paragraph [0179]-[0184] of Espacenet translation). A person having ordinary skill in the art would recognize that the energy consumption of a distillation process is largely determined by the heat duty of the reboilers, i.e. the heat duty of the reboilers corresponds to the energy consumption of the reboilers, which makes up a large part of a distillation process’ overall energy consumption. A review of Lan’s disclosure affirms this principle. Namely, the purpose of Lan’s invention is energy savings in the field of methanol distillation (paragraphs [0002] and [0010]-[0011] of Espacenet translation). Lan achieves the intended energy savings by use of a using four-tower triple-effect thermal integrated distillation systems (paragraphs [0002] and [0010]-[0011], [0107], and [0260] of Espacenet translation). Said energy savings are achieved relative to a system like that of Figure 1 having a lesser degree of thermal integration in the reboilers (paragraph [0005] of Espacenet translation). Thus, it is clear that reboiler heat duty is a result effective variable that plays a significant role in the overall energy consumption of a distillation system.
Accordingly, a person having ordinary skill in the art would be motivated to optimize the heat duty of individual reboilers and thus, the relative heat duties of various reboilers, in order to: 1) attain a system wherein the reboilers provide a workable amount of heat to each distillation column, and 2) wherein energy consumption of the reboilers is optimized.
Further still, a review of Figure 23 would lead one of ordinary skill in the art to expect the heat duty of E0 (E213) to be less than that of E1 (E203). Specifically, a review of Figure 23 shows that the only point for the introduction of external heat in the system of Figure 23 is the reboiler E1 (E203). Thus, it is understood that the heat to fulfill the heat duties for reboilers E0 (E213), E2 (E204), E3 (E205), and E206 must first be supplied into the system via E203. On the other hand, reboiler E0 (E213) is heated by the overhead vapor stream 15-2 from the column T203. All of the heat in stream 15-2 can be traced back to the heat introduced to the system via E203, but it is clear that the heat in stream 15-2 is less than all of the heat introduced to the system via E1 (E203). For example, some of said heat is necessarily contained in stream 15-1 and 15-3, from which stream 15-2 is split, and in stream 19, from which stream 15 is split by distillation in column T203. Therefore, it is understood, or at least expected, that the heat duty of E0 (E213) is less than the heat duty of E1 (E203).
"[When] 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," (see MPEP 2144.05 II A).
In the event that it is not implicit in Lan, it would have been obvious to one of ordinary skill in the art before the effective filing date to modify Lan by optimizing the heat duty of the heat exchangers E0 (E213), E1 (E203), E2 (E204), and/or E3 (E205), e.g. such that a heat duty of E0 is at least 30% less than a heat duty of E1, in order to obtain a process wherein: i) the various distillation columns are each provided with workable amounts of heat, and ii) the energy consumption of the reboilers is optimized.
Lan is silent to: i) P0 being greater than 0 barg, ii) P3 being greater than 0 barg and less than 2 barg, iii) P1 being higher than 9.7 bar(g), and iv) P2 being between 6.9 and 13 bar(g).
However, the teachings of Lan paragraph [0107] (reproduced above) would indicate to one of ordinary skill in the art that the pressures of the various distillation columns in the method of Lan are result effective variables. Furthermore, it is well understood that pressure is a result effective variable in operation of distillation columns, and in vapor-liquid separation processes more generally. Namely, a person having ordinary skill in the art would recognize that if pressure in a distillation column is too high or too low, desired separations will not be achieved. "[When] 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," (see MPEP 2144.05 II A).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify Lan by optimizing the operating pressures within the various columns, i.e. by configuring the process such that i) P0 is greater than 0 barg, ii) P3 is greater than 0 barg and less than 2 barg, iii) P1 is higher than 9.7 bar(g), and iv) P2 is between 6.9 and 13 bar(g), in order to obtain a predictably functional process wherein distillation is successfully carried out within the various columns.
With regard to claim 2: Modified Lan does not explicitly teach that a temperature in a coldest part of V2 is higher than a temperature in a warmest part of V3 and V0 and a temperature in a coldest part of V1 is higher than a temperature in a warmest part of V2. However, it is understood that Lan necessarily operates under such temperature conditions.
To elaborate, it is well understood that the hottest part of a distillation column is at the bottom, and the coldest part is at the top.
In modified Lan, the overhead stream T2 (15) is withdrawn from the top of V2 (T203) and subsequently used to provide heat to the bottom of V3 (T204) and the bottom of V0 (T201) via reboilers E3 (E205) and E0 (E213) respectively (Figure 23). Therefore, in order for overhead stream T2 (15) to successfully transfer heat to the bottoms of V3 (T204) and V0 (T201) via reboilers E3 (E205) and E0 (E213) respectively, said overhead stream T2 (15), and thus the top of V2 (T203) must be at a higher temperature than the bottoms of columns V3 (T204) and V0 (T201). Accordingly, it is understood that the coldest part of V2 (T203), i.e. the top of V2, is operated at a higher temperature than the warmest parts of V3 (T204) and V0 (T201), i.e. the bottoms of V3 and V0.
Likewise, because the overhead stream T1 (10) withdrawn from the top of V1 (T202) is used to provide heat to the bottom of V2 via reboiler E2 (E204) (see Figure 23), it is understood that the coldest part of V1 (T202), i.e. the top of V1, is operated at a higher temperature than the warmest part of V2, i.e. the bottom of V0.
In the exceedingly unlikely event that the temperature profile in modified Lan were not as described above, it would have been obvious to one of ordinary skill in the art to further modify Lan such that a temperature in a coldest part of V2 is higher than a temperature in a warmest part of V3 and V0, and such that and a temperature in a coldest part of V1 is higher than a temperature in a warmest part of V2, in order to obtain a method wherein the heat integration sequence depicted in Figure 23 can be successfully implemented.
With regard to claim 3: Modified Lan does not explicitly teach that a temperature in a coldest part of V2 is higher than a temperature in a warmest part of V3 and V0 and a temperature in a coldest part of V1 is higher than a temperature in a warmest part of V2. However, it is understood that Lan necessarily operates under such temperature conditions.
To elaborate, it is well understood that the hottest part of a distillation column is at the bottom, and the coldest part is at the top.
In modified Lan, the overhead stream T2 (15) is withdrawn from the top of V2 (T203) and subsequently used to provide heat to the bottom of V3 (T204) and the bottom of V0 (T201) via reboilers E3 (E205) and E0 (E213) respectively (Figure 23). Therefore, in order for overhead stream T2 (15) to successfully transfer heat to the bottoms of V3 (T204) and V0 (T201) via reboilers E3 (E205) and E0 (E213) respectively, said overhead stream T2 (15), and thus the top of V2 (T203) must be at a higher temperature than the bottoms of columns V3 (T204) and V0 (T201). Accordingly, it is understood that the coldest part of V2 (T203), i.e. the top of V2, is operated at a higher temperature than the warmest parts of V3 (T204) and V0 (T201), i.e. the bottoms of V3 and V0.
Likewise, because the overhead stream T1 (10) withdrawn from the top of V1 (T202) is used to provide heat to the bottom of V2 via reboiler E2 (E204) (see Figure 23), it is understood that the coldest part of V1 (T202), i.e. the top of V1, is operated at a higher temperature than the warmest part of V2, i.e. the bottom of V0.
In the exceedingly unlikely event that the temperature profile in modified Lan were not as described above, it would have been obvious to one of ordinary skill in the art to further modify Lan such that a temperature in a coldest part of V2 is higher than a temperature in a warmest part of V3 and V0, and such that and a temperature in a coldest part of V1 is higher than a temperature in a warmest part of V2, in order to obtain a method wherein the heat integration sequence depicted in Figure 23 can be successfully implemented.
Modified Lan does not explicitly teach that the temperature in the coldest part of V2 is specifically 4 °C higher than the temperature in the warmest part of V3 and V0 and the temperature in the coldest part of V1 is specifically 4 °C higher than the temperature in the warmest part of V2.
However, as discussed above, in Lan, the temperature in the coldest part of V2 is necessarily higher than the temperature in the warmest part of V3 and V0 and the temperature in the coldest part of V1 is necessarily higher than the temperature in the warmest part of V2. A person having ordinary skill in the art would recognize that the extents by which the temperatures in question differ from one another are result effective variables. Namely, a person having ordinary skill in the art would recognize that the extent by which the temperatures in question differ from one another will affect the rate and efficacy of heat transfer in the various reboilers E0 (E213), E2 (E204), and E3 (E205). "[When] 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," (see MPEP 2144.05 II A).
It would have been obvious to one of ordinary skill in the art before the effective filing date to further modify Lan by optimizing the extent by which the temperatures in question differ from one another, i.e. such that the temperature in the coldest part of V2 is specifically 4 °C higher than the temperature in the warmest part of V3 and V0 and the temperature in the coldest part of V1 is specifically 4 °C higher than the temperature in the warmest part of V2, in order to obtain a predictably functional process wherein heat transfer in the various reboilers E0 (E213), E2 (E204), and E3 (E205) is optimally effective and proceeds at a desirable rate.
With regard to claim 4: Modified Lan does not explicitly teach that the difference between P1 and P0 is greater than or equal to 7.7 bar.
However, as discussed in the rejection of claim 1 above, Lan provides the following teaching:
“FIG. 23 is an evolutionary process method of FIG. 20, namely, deformation process method fifteen. The operating pressure and heat integration sequence of the four-tower three-effect heat integration shown in Figure 20 are adjusted, and it is still a four-tower three-effect heat integration. The first distillation tower T202 is operated at high pressure, and the second distillation tower T203 is operated at low pressure,” (paragraph [0107] of Espacenet translation; emphasis added).
Said teaching serves as an unambiguous indication that the relative pressures of the columns in Lan are result effective variables. "[When] 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," (see MPEP 2144.05 II A).
It would have been obvious to one of ordinary skill in the art before the effective filing date to further modify Lan by optimizing the difference in operating pressure across various columns, e.g. by configuring the system such that the difference between P1 and P0 is greater than or equal to 7.7 bar, in order to obtain a predictably functional process wherein the heat integration sequence depicted in Figure 23 can be successfully implemented.
With regard to claim 6: Modified Lan does not explicitly teach that P1 is 17 bar(g), P2 is 9 bar(g) and P3 is 0.98 bar(g).
However, regarding the embodiment relied upon (i.e. that of Figure 23) Lan provides the following teaching:
“FIG. 23 is an evolutionary process method of FIG. 20, namely, deformation process method fifteen. The operating pressure and heat integration sequence of the four-tower three-effect heat integration shown in Figure 20 are adjusted, and it is still a four-tower three-effect heat integration. The first distillation tower T202 is operated at high pressure, and the second distillation tower T203 is operated at low pressure,” (paragraph [0107] of Espacenet translation; emphasis added).
Said teaching would indicate to one of ordinary skill in the art that the pressures of the various distillation columns in the method of Lan are result effective variables. Furthermore, it is well understood that pressure is a result effective variable in operation of distillation columns, and in vapor-liquid separation processes more generally. Namely, a person having ordinary skill in the art would recognize that if pressure in a distillation column is too high or too low, desired separations will not be achieved. "[When] 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," (see MPEP 2144.05 II A).
It would have been obvious to one of ordinary skill in the art before the effective filing date to further modify Lan by optimizing the operating pressures in the various columns, e.g. by configuring the system to operate such that P1 is 17 bar(g), P2 is 9 bar(g) and P3 is 0.98 bar(g), in order to obtain a predictably functional process wherein distillation is successfully carried out within the various columns.
With regard to claim 8: B3 (29) comprises water removed from circulating streams and is recovered from a lower section of V3 (Figure 3, paragraphs [0026] and [0028] of Espacenet Translation).
With regard to claim 9: As is necessary for a process which satisfies the limitations of claim 1, modified Lan makes use of an apparatus for distillation of methanol, the apparatus comprising stabilizing column V0 (T201) operating at pressure P0, connected in series with at least 3 distillation columns V1 (T202), V2 (T203) and V3 (T204) at correspondingly decreasing pressures P1, P2 and P3 such that P1>P2>P3, wherein each column is associated with a heat exchanger E0 (E213), E1 (E203), E2 (E204) and E3 (E205), said heat exchangers being reboilers for respective columns, wherein: heat exchangers E0 (E213) and E3 (E205) are condensers of column V2 (T203); heat exchanger E2 (E204) is condenser of column V1 (T202); E1 (E203) has an incoming heat stream, external to said apparatus; P3<2 barg; P1>9.7 barg; and 13 barg > P2 > 6.9 barg; a heat duty of E1 is at least 30% less than a heat duty of E1; and h) an amount of steam required for E1 is less than 0.7 kg/kg of product methanol (Figure 23, paragraphs [0107] and [0245]-[0247] of Espacenet translation; see 103 rejection of claim 1 above for further details).
With regard to claim 10: With respect to the embodiment relied upon, i.e. that of Figure 23, modified Lan does not explicitly teach that the external heat stream to E1 is either: i) steam or ii) synthesis gas containing sensible heat.
The “external heat stream” is expressly indicated to be something which is outside of, i.e. external to, the claimed apparatus (see Claim 9, Line 8: “E1 has an incoming heat stream, external to said apparatus”; and claim 10 lines 1-2: “the external heat stream”). Because the external heat stream is something which is outside of, i.e. external to, it is not part of the claimed apparatus. Therefore, the scope of the claimed apparatus is not limited by language to the composition of the heat stream. Thus, modified Lan satisfies the language of claim 10.
In the alternative, the use of steam as the external heat stream in the embodiment relied upon (that of Figure 23 is nevertheless obvious).
Use of steam as a heating fluid for distillation column reboilers is notoriously well known in the art. Furthermore, though Lan does not expressly teach the use of steam in the context of the embodiment relied upon (that of Figure 23), Lan teaches using steam to heat reboilers in various other embodiments (See for example, paragraphs [0034] and [0244]). To one of ordinary skill in the art, said teachings would at least suggest the use of steam as the external heat stream to E1 in the embodiment of Figure 23.
It would have been obvious to one of ordinary skill in the art before the effective filing date to further modify Lan by configuring the system to use steam as the external heat stream supplied to E1, in order to obtain a predictably functional system having a predictably functional reboiler E1.
With regard to claim 11: As is necessary for a process which satisfies the limitations of claim 1, modified Lan makes use of a plant, i.e. an apparatus, for distillation of methanol, the apparatus comprising stabilizing column V0 (T201) operating at pressure P0, connected in series with at least 3 distillation columns V1 (T202), V2 (T203) and V3 (T204) at correspondingly decreasing pressures P1, P2 and P3 such that P1>P2>p3, wherein each column is associated with a heat exchanger E0 (E213), E1 (E203), E2 (E204) and E3 (E205), said heat exchangers being reboilers for respective columns, wherein: heat exchangers E0 (E213) and E3 (E205) are condensers of column V2 (T203); heat exchanger E2 (E204) is condenser of column V1 (T202); E1 (E203) has an incoming heat stream, external to said apparatus; P3<2 barg; P1>9.7 barg; and 13 barg > P2 > 6.9 barg; a heat duty of E1 is at least 30% less than a heat duty of E1; and h) an amount of steam required for E1 is less than 0.7 kg/kg of product methanol (Figure 23, paragraphs [0107] and [0245]-[0247] of Espacenet translation; see 103 rejection of claim 1 above for further details).
With regard to claim 12: In Lan, and thus modified Lan, the plant (apparatus) is used in a method of distilling methanol (Figure 23, paragraphs [0107] and [0245]-[0247] of Espacenet translation; see 103 rejection of claim 1 above for further details).
The following 103 rejections of claims 9-12 are made over Lan on alternative grounds to those set forth above.
With regard to claim 9: Lan teaches apparatus for distillation of methanol, the apparatus comprising stabilizing column V0 (T201) operating at pressure P0, connected in series with at least 3 distillation columns V1 (T202), V2 (T203) and V3 (T204) at corresponding pressures P1, P2 and P3, wherein each column is associated with a heat exchanger E0 (E213), E1 (E203), E2 (E204) and E3 (E205), said heat exchangers being reboilers for respective columns, wherein: heat exchangers E0 (E213) and E3 (E205) are condensers of column V2 (T203); heat exchanger E2 (E204) is condenser of column V1 (T202); and E1 (E203) has an incoming heat stream, external to said apparatus (Figure 23, paragraphs [0107] and [0245]-[0247] of Espacenet translation; see 103 rejection of claim 1 above for further details).
Lan does not explicitly teach that the columns V1, V2 and V3 operate at decreasing pressures such that P1>P2>P3. However, careful review of Lan’s disclosure shows that, in the embodiment relied upon (i.e. that of Figure 23), it is implicit that P1>P2>P3.
First, regarding the embodiment of Figure 23 Lan provides the following teaching:
“FIG. 23 is an evolutionary process method of FIG. 20, namely, deformation process method fifteen. The operating pressure and heat integration sequence of the four-tower three-effect heat integration shown in Figure 20 are adjusted, and it is still a four-tower three-effect heat integration. The first distillation tower T202 is operated at high pressure, and the second distillation tower T203 is operated at low pressure,” (paragraph [0107] of Espacenet translation; emphasis added).
Said teaching serves as an express indication that at least columns V1 (T202) and V2 (T203) operate at decreasing pressures such that P1>P2.
Though the relative pressure P3 of column V3 (T204) is not explicitly disclosed in Lan, it can be determined that P3<P2 on the following basis:
In the embodiment of Figure 23, the reboiler E205 of column T204 transfers heat from the overhead stream 15 of column T203 to a bottom stream of the column T204 (Figure 23, paragraph [0107]). Accordingly, it is understood that, in said embodiment, the temperature of the overhead stream 15 is necessarily higher than the temperature of the bottom stream entering reboiler E205, and thus, the top operating temperature of column T203 is necessarily higher than the bottom operating temperature of the column T204.
Because the overhead stream 15 obtained from column T203, the temperature of said overhead stream 15 is necessarily lower than the bottom operating temperature of column T203. Accordingly, if the overhead stream 15 is to heat the reboiler E205 as intended, the bottom operating temperature of column T204 must also be lower than the bottom operating temperature of column T203.
Because the bottom steam fed to the reboiler E205 is removed from a bottom of column T204, said bottom stream necessarily has a higher boiling point and temperature than the feed stream 19 which is fed to the middle of the column. (Note: The matter of the bottom stream fed to reboiler E206 is somewhat more complicated due to the presence of the dividing wall in column T204. Regardless, analysis of only the bottom stream fed to reboiler E205 is sufficient to make Examiner’s point).
The feed stream 19 to column T204 is the bottom product stream from column T203. Therefore, if we are to assume that the operating pressure of T204 is equal to that of T203, the feed point operating temperature in T204 would need to be at least as high (likely higher) than the bottom operating temperature of T203 in order for said feed 19 to boil, and thus be distilled, upon entering the feed point of column T204. If we are to assume that the operating pressure of T204 is higher than that of T203, then the feed point operating temperature in T204 would need to be higher than the bottom operating temperature of column T203. In either case, the bottom operating temperature of the column T204 would necessarily be higher than the bottom operating temperature of column T203. Therefore, if the operating pressure of column T204 were equal to or greater than that of column T203, the overhead stream 15 would be incapable of heating reboiler E205 as intended by Lan, and the embodiment of Figure 23 would be rendered inoperative.
On the other hand, if the operating pressure of T204 is made to be lower than that of T203, then it is possible for the bottom operating temperature of T204, and thus the temperature of the bottom stream entering the reboiler E205, to be lower than the bottom operating temperature of column T203. Therefore, it is clear that column T204 in the embodiment of Figure 23 must operate at a lower pressure than column T203. Thus, it is clear that P2>P3 in the embodiment of Figure 23.
As discussed above, Lan’s teachings expressly indicate that P1>P2. Nevertheless, it should be appreciated that one can verify that P1>P2 in Figure 23 of Lan by applying the technical reasoning set forth above with respect to columns T204 and T203 to columns T202 and T203.
Because P1>P2 and P2>P3 in the embodiment of Figure 23, it is understood that the columns V1 (T202), V2 (T203), and V3 (T204) necessarily operate at decreasing pressures such that P1>P2>P3.
In the unlikely alternative, for at least the reasons discussed above, Lan at least suggests that P1>P2>P3.
In the unlikely event that it is not implicit that P1>P2>P3, it would have been obvious to one of ordinary skill in the art before the effective filing date to modify Lan in view of Lan’s own suggestions by configuring the columns V1 (T202), V2 (T203) and V3 (T204) to operate at decreasing pressures such that P1>P2>P3, in order to obtain a predictably functional process wherein the heat integration sequence depicted in Figure 23 can be successfully implemented.
Lan does not explicitly teach that the amount of steam required for E1 (E203) is less than 1.3 kg/kg of product methanol in the embodiment of Figure 23. However, Lan teaches that “The process method of methanol distillation using the four-tower triple-effect heat integrated device provided by this invention has a steam consumption of less than 58 tons/hour and a steam consumption of less than 0.7 tons of steam/ton of refined methanol product,” (paragraph [0179] of Espacenet translation; emphasis added). Lan describes the embodiment of Figure 23 “a four-tower triple-effect thermal integration” (paragraphs [0107] and [0247]). Thus, when Lan’s teaching of steam consumption in paragraph [0179] is taken together with the disclosures of paragraphs [0107] and [0247] regarding the embodiment of Figure 23, it amounts to an implicit disclosure that the overall steam consumption in the embodiment of Figure 23 is less than less than 0.7 kg steam/kg of refined methanol product (0.7 tons of steam/ton of refined methanol product). Because the overall steam consumption is less than 0.7 kg steam/kg of refined methanol product, then the steam required for the reboiler E1 (E203) is also less than 0.7 kg steam/kg of refined methanol product. In view of the forgoing, the amount of steam required for E1 is implicitly less than 0.7 kg/kg of product methanol.
In the alternative, when Lan’s teaching of steam consumption in paragraph [0179] is taken together with the disclosures of paragraphs [0107] and [0247], it would at least suggest that the steam requirements for the reboiler E1 (E203) can be made to be less than 0.7 kg steam/kg of refined methanol product.
Furthermore, paragraph [0179] of Lan states that “According to the currently widely used four-tower methanol distillation process, the minimum steam consumption for methanol distillation is 1 ton of steam/ton of refined methanol product.” By “the currently widely used four-tower methanol distillation process”, it is understood that Applicant is referring to the system illustrated in Figure 1 of Lan (see paragraphs [0005] and [0085] of Espacenet translation). The system illustrated in Figure 1, contains three reboilers (E102, E103, and E106) which are heated with an external heat source. In comparison the embodiment of Figure 23 has only one heat exchanger (E203) which is heated by an external heat source. If an overall steam consumption of 1 kg/kg of refined methanol product is achievable in the system of Figure 1 despite the fact that it has three reboilers requiring an external heat source (two more than the embodiment of Figure 23), then an even lower steam consumption clearly would be achievable in the embodiment of Figure 23.
Lan’s disclosure speaks of energy and steam savings (paragraphs [0083], [0115], [0179]-[0184], [0260]), and provides indication that reduced steam consumption is desirable (paragraph [0179]-[0184] of Espacenet translation). Thus, a person having ordinary skill in the art would have clear motivation to operate the various embodiments of Lan with a low steam consumption.
In the event that it is not implicit in Lan, it would have been obvious to one of ordinary skill in the art before the effective filing date to further modify Lan by configuring the embodiment of Lan Figure 23 to operate with an overall steam requirement of less than 0.7 kg/kg of refined methanol product (and thus also a steam requirement for E1, i.e. E203, which is also less than 0.7 kg/kg of refined methanol product), in order to obtain energy and steam savings.
Lan does not explicitly teach that a heat duty of E0 is at least 30% less than a heat duty of E1. However, Applicant asserts that “the claimed less than 1.3 kg steam/kg product methanol is only valid provided duty of E0 is at least 30% less than duty of E1,” (paragraph 9 of the 4/10/2026 declaration by Inventor). As discussed above, the embodiment of Lan Figure 23 implicitly has a steam requirement of less than 0.7 kg/kg of refined methanol product for E1, i.e. E203. Thus, if Applicant’s assertion is correct, it is also implicit that the heat duty of E0 is at least 30% less than the heat duty of E1 in Figure 23 of Lan.
Regardless, a person having ordinary skill in the art would recognize that the heat duties of the various heat exchangers used in the process of Lan are result effective variables. Namely, a person having ordinary skill in the art would recognize that the heat exchangers E0 (E213), E1 (E203), E2 (E204), and E3 (E205) are reboilers for respective distillation columns. Therefore, if the heat duty of a particular one of said heat exchangers (i.e. the amount of heat provided by a particular one of said heat exchangers) is too high or too low, a respective distillation column will be provided with too little or too much heat. Thus, a person having ordinary skill in the art would recognize that, if the embodiment of Lan Figure 23 is to function properly, they MUST discover ranges for the heat duties which are at least workable.
Furthermore, Lan’s disclosure speaks of energy and steam savings (paragraphs [0083], [0115], [0179]-[0184], [0260] of Espacenet translation), and provides indication that reduced steam and energy consumption is desirable (paragraph [0179]-[0184] of Espacenet translation). A person having ordinary skill in the art would recognize that the energy consumption of a distillation process is largely determined by the heat duty of the reboilers, i.e. the heat duty of the reboilers corresponds to the energy consumption of the reboilers, which makes up a large part of a distillation process’ overall energy consumption. A review of Lan’s disclosure affirms this principle. Namely, the purpose of Lan’s invention is energy savings in the field of methanol distillation (paragraphs [0002] and [0010]-[0011] of Espacenet translation). Lan achieves the intended energy savings by use of a using four-tower triple-effect thermal integrated distillation systems (paragraphs [0002] and [0010]-[0011], [0107], and [0260] of Espacenet translation). Said energy savings are achieved relative to a system like that of Figure 1 having a lesser degree of thermal integration in the reboilers (paragraph [0005] of Espacenet translation). Thus, it is clear that reboiler heat duty is a result effective variable that plays a significant role in the overall energy consumption of a distillation system.
Accordingly, a person having ordinary skill in the art would be motivated to optimize the heat duty of individual reboilers and thus, the relative heat duties of various reboilers, in order to: 1) attain a system wherein the reboilers provide a workable amount of heat to each distillation column, and 2) wherein energy consumption of the reboilers is optimized.
Further still, a review of Figure 23 would lead one of ordinary skill in the art to expect the heat duty of E0 (E213) to be less than that of E1 (E203). Specifically, a review of Figure 23 shows that the only point for the introduction of external heat in the system of Figure 23 is the reboiler E1 (E203). Thus, it is understood that the heat to fulfill the heat duties for reboilers E0 (E213), E2 (E204), E3 (E205), and E206 must first be supplied into the system via E203. On the other hand, reboiler E0 (E213) is heated by the overhead vapor stream 15-2 from the column T203. All of the heat in stream 15-2 can be traced back to the heat introduced to the system via E203, but it is clear that the heat in stream 15-2 is less than all of the heat introduced to the system via E1 (E203). For example, some of said heat is necessarily contained in stream 15-1 and 15-3, from which stream 15-2 is split, and in stream 19, from which stream 15 is split by distillation in column T203. Therefore, it is understood, or at least expected, that the heat duty of E0 (E213) is less than the heat duty of E1 (E203).
"[When] 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," (see MPEP 2144.05 II A).
In the event that it is not implicit in Lan, it would have been obvious to one of ordinary skill in the art before the effective filing date to modify Lan by optimizing the heat duty of the heat exchangers E0 (E213), E1 (E203), E2 (E204), and/or E3 (E205), e.g. such that a heat duty of E0 is at least 30% less than a heat duty of E1, in order to obtain a process wherein: i) the various distillation columns are each provided with workable amounts of heat, and ii) the energy consumption of the reboilers is optimized.
Lan is silent to: i) P0 being greater than 0 barg, ii) P3 being greater than 0 barg and less than 2 barg, iii) P1 being higher than 9.7 bar(g), and iv) P2 being between 6.9 and 13 bar(g).
However, the teachings of Lan paragraph [0107] (reproduced above) would indicate to one of ordinary skill in the art that the pressures of the various distillation columns in the method of Lan are result effective variables. Furthermore, it is well understood that pressure is a result effective variable in operation of distillation columns, and in vapor-liquid separation processes more generally. Namely, a person having ordinary skill in the art would recognize that if pressure in a distillation column is too high or too low, desired separations will not be achieved. "[When] 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," (see MPEP 2144.05 II A).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify Lan by optimizing the operating pressures within the various columns, i.e. by configuring the process such that i) P0 is greater than 0 barg, ii) P3 is greater than 0 barg and less than 2 barg, iii) P1 is higher than 9.7 bar(g), and iv) P2 is between 6.9 and 13 bar(g), in order to obtain a predictably functional process wherein distillation is successfully carried out within the various columns.
With regard to claim 10: With respect to the embodiment relied upon, i.e. that of Figure 23, modified Lan does not explicitly teach that the external heat stream to E1 is either: i) steam or ii) synthesis gas containing sensible heat.
The “external heat stream” is expressly indicated to be something which is outside of, i.e. external to, the claimed apparatus (see Claim 9, Line 8: “E1 has an incoming heat stream, external to said apparatus”; and claim 10 lines 1-2: “the external heat stream”). Because the external heat stream is something which is outside of, i.e. external to, it is not part of the claimed apparatus. Therefore, the scope of the claimed apparatus is not limited by language to the composition of the heat stream. Thus, modified Lan satisfies the language of claim 10.
In the alternative, the use of steam as the external heat stream in the embodiment relied upon (that of Figure 23 is nevertheless obvious).
Use of steam as a heating fluid for distillation column reboilers is notoriously well known in the art. Furthermore, though Lan does not expressly teach the use of steam in the context of the embodiment relied upon (that of Figure 23), Lan teaches using steam to heat reboilers in various other embodiments (See for example, paragraphs [0034] and [0244]). To one of ordinary skill in the art, said teachings would at least suggest the use of steam as the external heat stream to E1 in the embodiment of Figure 23.
It would have been obvious to one of ordinary skill in the art before the effective filing date to further modify Lan by configuring the system to use steam as the external heat stream supplied to E1, in order to obtain a predictably functional system having a predictably functional reboiler E1.
With regard to claim 11: Lan teaches plant, i.e. an apparatus, for distillation of methanol, the apparatus comprising stabilizing column V0 (T201) operating at pressure P0, connected in series with at least 3 distillation columns V1 (T202), V2 (T203) and V3 (T204) at corresponding pressures P1, P2 and P3, wherein each column is associated with a heat exchanger E0 (E213), E1 (E203), E2 (E204) and E3 (E205), said heat exchangers being reboilers for respective columns, wherein: heat exchangers E0 (E213) and E3 (E205) are condensers of column V2 (T203); heat exchanger E2 (E204) is condenser of column V1 (T202); and E1 (E203) has an incoming heat stream, external to said apparatus (Figure 23, paragraphs [0107] and [0245]-[0247] of Espacenet translation; see 103 rejection of claim 1 above for further details).
Lan does not explicitly teach that the columns V1, V2 and V3 operate at decreasing pressures such that P1>P2>P3. However, careful review of Lan’s disclosure shows that, in the embodiment relied upon (i.e. that of Figure 23), it is implicit that P1>P2>P3.
First, regarding the embodiment of Figure 23 Lan provides the following teaching:
“FIG. 23 is an evolutionary process method of FIG. 20, namely, deformation process method fifteen. The operating pressure and heat integration sequence of the four-tower three-effect heat integration shown in Figure 20 are adjusted, and it is still a four-tower three-effect heat integration. The first distillation tower T202 is operated at high pressure, and the second distillation tower T203 is operated at low pressure,” (paragraph [0107] of Espacenet translation; emphasis added).
Said teaching serves as an express indication that at least columns V1 (T202) and V2 (T203) operate at decreasing pressures such that P1>P2.
Though the relative pressure P3 of column V3 (T204) is not explicitly disclosed in Lan, it can be determined that P3<P2 on the following basis:
In the embodiment of Figure 23, the reboiler E205 of column T204 transfers heat from the overhead stream 15 of column T203 to a bottom stream of the column T204 (Figure 23, paragraph [0107]). Accordingly, it is understood that, in said embodiment, the temperature of the overhead stream 15 is necessarily higher than the temperature of the bottom stream entering reboiler E205, and thus, the top operating temperature of column T203 is necessarily higher than the bottom operating temperature of the column T204.
Because the overhead stream 15 obtained from column T203, the temperature of said overhead stream 15 is necessarily lower than the bottom operating temperature of column T203. Accordingly, if the overhead stream 15 is to heat the reboiler E205 as intended, the bottom operating temperature of column T204 must also be lower than the bottom operating temperature of column T203.
Because the bottom steam fed to the reboiler E205 is removed from a bottom of column T204, said bottom stream necessarily has a higher boiling point and temperature than the feed stream 19 which is fed to the middle of the column. (Note: The matter of the bottom stream fed to reboiler E206 is somewhat more complicated due to the presence of the dividing wall in column T204. Regardless, analysis of only the bottom stream fed to reboiler E205 is sufficient to make Examiner’s point).
The feed stream 19 to column T204 is the bottom product stream from column T203. Therefore, if we are to assume that the operating pressure of T204 is equal to that of T203, the feed point operating temperature in T204 would need to be at least as high (likely higher) than the bottom operating temperature of T203 in order for said feed 19 to boil, and thus be distilled, upon entering the feed point of column T204. If we are to assume that the operating pressure of T204 is higher than that of T203, then the feed point operating temperature in T204 would need to be higher than the bottom operating temperature of column T203. In either case, the bottom operating temperature of the column T204 would necessarily be higher than the bottom operating temperature of column T203. Therefore, if the operating pressure of column T204 were equal to or greater than that of column T203, the overhead stream 15 would be incapable of heating reboiler E205 as intended by Lan, and the embodiment of Figure 23 would be rendered inoperative.
On the other hand, if the operating pressure of T204 is made to be lower than that of T203, then it is possible for the bottom operating temperature of T204, and thus the temperature of the bottom stream entering the reboiler E205, to be lower than the bottom operating temperature of column T203. Therefore, it is clear that column T204 in the embodiment of Figure 23 must operate at a lower pressure than column T203. Thus, it is clear that P2>P3 in the embodiment of Figure 23.
As discussed above, Lan’s teachings expressly indicate that P1>P2. Nevertheless, it should be appreciated that one can verify that P1>P2 in Figure 23 of Lan by applying the technical reasoning set forth above with respect to columns T204 and T203 to columns T202 and T203.
Because P1>P2 and P2>P3 in the embodiment of Figure 23, it is understood that the columns V1 (T202), V2 (T203), and V3 (T204) necessarily operate at decreasing pressures such that P1>P2>P3.
In the unlikely alternative, for at least the reasons discussed above, Lan at least suggests that P1>P2>P3.
In the unlikely event that it is not implicit that P1>P2>P3, it would have been obvious to one of ordinary skill in the art before the effective filing date to modify Lan in view of Lan’s own suggestions by configuring the columns V1 (T202), V2 (T203) and V3 (T204) to operate at decreasing pressures such that P1>P2>P3, in order to obtain a predictably functional process wherein the heat integration sequence depicted in Figure 23 can be successfully implemented.
Lan does not explicitly teach that the amount of steam required for E1 (E203) is less than 1.3 kg/kg of product methanol in the embodiment of Figure 23. However, Lan teaches that “The process method of methanol distillation using the four-tower triple-effect heat integrated device provided by this invention has a steam consumption of less than 58 tons/hour and a steam consumption of less than 0.7 tons of steam/ton of refined methanol product,” (paragraph [0179] of Espacenet translation; emphasis added). Lan describes the embodiment of Figure 23 “a four-tower triple-effect thermal integration” (paragraphs [0107] and [0247]). Thus, when Lan’s teaching of steam consumption in paragraph [0179] is taken together with the disclosures of paragraphs [0107] and [0247] regarding the embodiment of Figure 23, it amounts to an implicit disclosure that the overall steam consumption in the embodiment of Figure 23 is less than less than 0.7 kg steam/kg of refined methanol product (0.7 tons of steam/ton of refined methanol product). Because the overall steam consumption is less than 0.7 kg steam/kg of refined methanol product, then the steam required for the reboiler E1 (E203) is also less than 0.7 kg steam/kg of refined methanol product. In view of the forgoing, the amount of steam required for E1 is implicitly less than 0.7 kg/kg of product methanol.
In the alternative, when Lan’s teaching of steam consumption in paragraph [0179] is taken together with the disclosures of paragraphs [0107] and [0247], it would at least suggest that the steam requirements for the reboiler E1 (E203) can be made to be less than 0.7 kg steam/kg of refined methanol product.
Furthermore, paragraph [0179] of Lan states that “According to the currently widely used four-tower methanol distillation process, the minimum steam consumption for methanol distillation is 1 ton of steam/ton of refined methanol product.” By “the currently widely used four-tower methanol distillation process”, it is understood that Applicant is referring to the system illustrated in Figure 1 of Lan (see paragraphs [0005] and [0085] of Espacenet translation). The system illustrated in Figure 1, contains three reboilers (E102, E103, and E106) which are heated with an external heat source. In comparison the embodiment of Figure 23 has only one heat exchanger (E203) which is heated by an external heat source. If an overall steam consumption of 1 kg/kg of refined methanol product is achievable in the system of Figure 1 despite the fact that it has three reboilers requiring an external heat source (two more than the embodiment of Figure 23), then an even lower steam consumption clearly would be achievable in the embodiment of Figure 23.
Lan’s disclosure speaks of energy and steam savings (paragraphs [0083], [0115], [0179]-[0184], [0260]), and provides indication that reduced steam consumption is desirable (paragraph [0179]-[0184] of Espacenet translation). Thus, a person having ordinary skill in the art would have clear motivation to operate the various embodiments of Lan with a low steam consumption.
In the event that it is not implicit in Lan, it would have been obvious to one of ordinary skill in the art before the effective filing date to further modify Lan by configuring the embodiment of Lan Figure 23 to operate with an overall steam requirement of less than 0.7 kg/kg of refined methanol product (and thus also a steam requirement for E1, i.e. E203, which is also less than 0.7 kg/kg of refined methanol product), in order to obtain energy and steam savings.
Lan does not explicitly teach that a heat duty of E0 is at least 30% less than a heat duty of E1. However, Applicant asserts that “the claimed less than 1.3 kg steam/kg product methanol is only valid provided duty of E0 is at least 30% less than duty of E1,” (paragraph 9 of the 4/10/2026 declaration by Inventor). As discussed above, the embodiment of Lan Figure 23 implicitly has a steam requirement of less than 0.7 kg/kg of refined methanol product for E1, i.e. E203. Thus, if Applicant’s assertion is correct, it is also implicit that the heat duty of E0 is at least 30% less than the heat duty of E1 in Figure 23 of Lan.
Regardless, a person having ordinary skill in the art would recognize that the heat duties of the various heat exchangers used in the process of Lan are result effective variables. Namely, a person having ordinary skill in the art would recognize that the heat exchangers E0 (E213), E1 (E203), E2 (E204), and E3 (E205) are reboilers for respective distillation columns. Therefore, if the heat duty of a particular one of said heat exchangers (i.e. the amount of heat provided by a particular one of said heat exchangers) is too high or too low, a respective distillation column will be provided with too little or too much heat. Thus, a person having ordinary skill in the art would recognize that, if the embodiment of Lan Figure 23 is to function properly, they MUST discover ranges for the heat duties which are at least workable.
Furthermore, Lan’s disclosure speaks of energy and steam savings (paragraphs [0083], [0115], [0179]-[0184], [0260] of Espacenet translation), and provides indication that reduced steam and energy consumption is desirable (paragraph [0179]-[0184] of Espacenet translation). A person having ordinary skill in the art would recognize that the energy consumption of a distillation process is largely determined by the heat duty of the reboilers, i.e. the heat duty of the reboilers corresponds to the energy consumption of the reboilers, which makes up a large part of a distillation process’ overall energy consumption. A review of Lan’s disclosure affirms this principle. Namely, the purpose of Lan’s invention is energy savings in the field of methanol distillation (paragraphs [0002] and [0010]-[0011] of Espacenet translation). Lan achieves the intended energy savings by use of a using four-tower triple-effect thermal integrated distillation systems (paragraphs [0002] and [0010]-[0011], [0107], and [0260] of Espacenet translation). Said energy savings are achieved relative to a system like that of Figure 1 having a lesser degree of thermal integration in the reboilers (paragraph [0005] of Espacenet translation). Thus, it is clear that reboiler heat duty is a result effective variable that plays a significant role in the overall energy consumption of a distillation system.
Accordingly, a person having ordinary skill in the art would be motivated to optimize the heat duty of individual reboilers and thus, the relative heat duties of various reboilers, in order to: 1) attain a system wherein the reboilers provide a workable amount of heat to each distillation column, and 2) wherein energy consumption of the reboilers is optimized.
Further still, a review of Figure 23 would lead one of ordinary skill in the art to expect the heat duty of E0 (E213) to be less than that of E1 (E203). Specifically, a review of Figure 23 shows that the only point for the introduction of external heat in the system of Figure 23 is the reboiler E1 (E203). Thus, it is understood that the heat to fulfill the heat duties for reboilers E0 (E213), E2 (E204), E3 (E205), and E206 must first be supplied into the system via E203. On the other hand, reboiler E0 (E213) is heated by the overhead vapor stream 15-2 from the column T203. All of the heat in stream 15-2 can be traced back to the heat introduced to the system via E203, but it is clear that the heat in stream 15-2 is less than all of the heat introduced to the system via E1 (E203). For example, some of said heat is necessarily contained in stream 15-1 and 15-3, from which stream 15-2 is split, and in stream 19, from which stream 15 is split by distillation in column T203. Therefore, it is understood, or at least expected, that the heat duty of E0 (E213) is less than the heat duty of E1 (E203).
"[When] 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," (see MPEP 2144.05 II A).
In the event that it is not implicit in Lan, it would have been obvious to one of ordinary skill in the art before the effective filing date to modify Lan by optimizing the heat duty of the heat exchangers E0 (E213), E1 (E203), E2 (E204), and/or E3 (E205), e.g. such that a heat duty of E0 is at least 30% less than a heat duty of E1, in order to obtain a process wherein: i) the various distillation columns are each provided with workable amounts of heat, and ii) the energy consumption of the reboilers is optimized.
Lan is silent to: i) P0 being greater than 0 barg, ii) P3 being greater than 0 barg and less than 2 barg, iii) P1 being higher than 9.7 bar(g), and iv) P2 being between 6.9 and 13 bar(g).
However, the teachings of Lan paragraph [0107] (reproduced above) would indicate to one of ordinary skill in the art that the pressures of the various distillation columns in the method of Lan are result effective variables. Furthermore, it is well understood that pressure is a result effective variable in operation of distillation columns, and in vapor-liquid separation processes more generally. Namely, a person having ordinary skill in the art would recognize that if pressure in a distillation column is too high or too low, desired separations will not be achieved. "[When] 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," (see MPEP 2144.05 II A).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify Lan by optimizing the operating pressures within the various columns, i.e. by configuring the process such that i) P0 is greater than 0 barg, ii) P3 is greater than 0 barg and less than 2 barg, iii) P1 is higher than 9.7 bar(g), and iv) P2 is between 6.9 and 13 bar(g), in order to obtain a predictably functional process wherein distillation is successfully carried out within the various columns.
With regard to claim 12: In Lan, and thus modified Lan, the plant (apparatus) is used in a method of distilling methanol (Figure 23, paragraphs [0107] and [0245]-[0247] of Espacenet translation; see 103 rejection of claim 1 above for further details).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JONATHAN "LUKE" PILCHER whose telephone number is (571)272-2691. The examiner can normally be reached Monday-Friday 9am-5pm.
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/JONATHAN LUKE PILCHER/Examiner, Art Unit 1772
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