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 .
Status of Claims
Claims 1, 3, and 5-15 are pending. Claims 7-15 are withdrawn from consideration.
Response to Arguments
Applicant’s arguments, see Remarks, filed 12/30/2025, with respect to the 103 rejections over Feng in view of Favilli have been fully considered but they are not persuasive.
Applicant has argued that the “the cited references fail to disclose or reasonably suggest a system comprising (1) a dividing wall column having a dividing wall extending from a bottom of the dividing wall column over only a part of a height of the column, (2) a first condenser in fluid communication with the second reboiler, and (3) a second condenser in fluid communication with the dividing wall column and configured to receive a second portion of the overhead product from the column as required by independent Claim 1,” (12/30/2025 Remarks, page 5).
Examiner respectfully disagrees.
The combination of Feng and Favilli suggests the claimed invention including all of the elements recited in claim 1 as described in the 103 rejections below.
Examiner notes that the test for obviousness is not that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981).
Applicant has alleged that Favilli’s design is incompatible with the energy saving principles of Feng because Favilli has a dividing wall extending the full height of the distillation column therein, whereas Feng’s distillation column has a dividing wall that extends from the bottom of said column over only a portion of said column’s height (12/30/2025 Remarks, page 6).
Examiner finds this argument unpersuasive.
Examiner acknowledges that the dividing wall of Favilli extends the whole height of its respective distillation column, whereas the dividing walls of Feng and Applicant’s invention extend from the bottom of their respective distillation columns over only part of the column height. However, this difference is immaterial to the rejections over Feng in view of Favilli, as Favilli is relied upon specifically for its teachings to the dual condenser arrangement of Figure 6 therein (i.e. the specific dual condenser arrangement described in detail above). In other words, Favilli is relied upon in said rejection to show that a dual condenser arrangement like that of the claims is known in the art.
The 103 rejections maintained below propose modifying Feng in view of Favilli by replacing the single condenser configuration of Feng with a two-condenser arrangement like that of Favilli Figure 6. In the interest of utmost clarity, if the system of Feng were modified in the proposed manner, it would result in the system of Feng (pictured below in Exhibit A) having two condensers as is shown below in Exhibit B. Said modification does not involve or otherwise require modifying the system of Feng so as to comprise a dividing wall that extends the entire height of the column. Thus, the matter of whether or not a full height dividing wall would be compatible with Feng’s energy saving principle is moot with respect to the rejections of record. Instead, the relevant question is whether a two-condenser arrangement (like that of Favilli) is compatible with Feng’s energy saving principle.
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Feng’s energy savings are attained through the use of a vapor recompression heat pump arrangement, i.e. by using a compressor to compress a portion of the overhead stream and using the compressed portion to heat one of the reboilers. As evidence, Examiner points to the following disclosures by Feng:
As shown in Fig. 2, the overhead vapor of the LRDWC is condensed by utilities in the CON, and thus the latent heat of the overhead vapor is wasted. The use of the VRHP is an efficient way to solve this problem. The VRHP [vapor recompression heat pump] recirculates the latent heat after compressing the overhead vapor into a higher pressure and temperature, and this saves the energy consumption of the entire process. An LRDWC only possesses one overhead vapor stream, while an URDWC possesses two overhead vapor streams (Feng et al., 2016). Hence, all the overhead vapor of the LRDWC is compressed with only one compressor, and thus the overhead vapor is used more effectively in the integrated LRDWC with the VRHP model, when compared with that of the integrated URDWC with the VRHP configuration.
(Section 4, pg. 207-208).
In this section, the VRHP provides heat in the REB2. Fig. 3 shows the flow diagram of the process. Specifically, IPOH and MEAC are fed into the RD part, at the top and bottom of the reactive section respectively. The overhead vapor of the LRDWC is split into two streams. A stream is compressed at a higher pressure and temperature in the compressor (COMP), and it then gives heat to the boiling-up stream of the RC part in the REB2. After releasing the pressure in the valve, the stream in conjunction with the other overhead vapor stream of the LRDWC, is condensed in the CON. The condensed stream is separated into two streams, a stream is refluxed back to the LRDWC and the other stream is recycled back to the RD part along with the MEAC feed stream.
(Section 4.1, pg. 208).
The vapor recompression heat pump arrangement in Feng comprises a single compressor COMP, a condenser CON, and a reboiler 2
The two-condenser arrangement of Favilli is part of a vapor recompression heat pump arrangement comprising a single compressor 64’, two condensers 34’ and 67’, and a reboiler 70’, wherein the compressor 64’ compresses a portion 65’ of an overhead stream 32’, and the compressed portion is used to heat the reboiler 70’ (Figure 6, paragraph [0204]; see also paragraphs [0180]-[0188], etc. for further description of various reference numerals). The vapor recompression heat pump arrangement of Feng comprises a single compressor COMP; a single condenser CON, and a reboiler REB2, wherein the compressor COMP compresses a portion of an overhead stream, and the compressed portion is used to heat the reboiler REB2 (Figure 3, section 4.1). Critically, both of these heat pump arrangements compress a portion of a single overhead stream using a single compressor in order to heat a single reboiler using the compressed portion. These similarities alone amount to strong evidence that a vapor recompression heat pump arrangement like that of Favilli (i.e. one having two condensers instead of one) would be a suitable alternative to Feng’s arrangement for the purpose of attaining the energy savings desired by Feng.
Furthermore, Feng’s disclosure indicates that the use of a single compressor is important to the energy savings attained by Feng’s system (see Section 4, pg. 207-208). It is reiterated that both the heat pump arrangement of Feng and the heat pump arrangement of Favilli compress a portion of a single overhead stream using a single compressor.
On the other hand, there is nothing in Feng or Favilli which suggests that a two condenser arrangement like that in Favilli would be incapable of attaining the desired energy savings.
Thus, the evidence of record points firmly to a heat pump arrangement like that of Favilli (i.e. one having two condensers instead of one) being suitable for attaining the energy savings desired by Feng. Accordingly, Examiner respectfully asserts that Favilli’s heat pump arrangement and the two condenser arrangement therein are compatible with Feng’s energy saving principle.
Applicant has argued that because the dual condenser arrangement of Favilli is designed for full-height walls and assumes different thermodynamic conditions, “transplanting the condensers of Favilli into the system of Feng would require redesigning flow paths and control schemes, which is far beyond routine optimization,” (12/30/2025 Remarks, page 6). Examiner finds this argument unpersuasive.
Here, it appears Applicant is arguing that it would not be obvious to bodily incorporate Favilli’s condensers into Feng’s system, because doing so would require one to redesign said condensers so as to be suitable for use in Feng. However, the test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981).
The 103 rejections maintained below do not propose transplanting the two condensers of Favilli into Feng’s system. Rather said rejections propose modifying Feng in view of Favilli by replacing the single condenser configuration of Feng with a two-condenser arrangement like that of Favilli Figure 6. Examiner notes that “‘It is well-established that a determination of obviousness based on teachings from multiple references does not require an actual, physical substitution of elements’” (MPEP 2145 III).
Nevertheless, assuming, for the sake of argument, Applciant’s intent was to argue that the proposed modification would require the alleged redesign, Applicant has merely made a general allegation that the proposed modification would require redesign of flow paths and control schemes without providing any evidence that such redesign would be significant. It is well within the level of ordinary skill in the art to design and redesign flow paths and control schemes. Furthermore, any modification to a prior art system would necessarily require some amount of redesign. The notion that a modification would require redesign of flow paths and flow paths and control schemes would not deter one of ordinary skill in the art from making said modification. Thus, Applciant’s allegation is insufficient to support a case for non-obviousness.
Furthermore, as is illustrated in Exhibits A and B above, if Feng is modified to have the two condenser arrangement as proposed, the flow paths in modified Feng (shown in Exhibit B) remain much the same as those in base Feng (shown in Exhibit A). Thus, any flowpath redesign necessary for making the proposed modification would be minimal and well within the level of ordinary skill in the art and would not deter one of ordinary skill from the proposed modification.
As for the alleged need for control scheme redesign, there is nothing in the record which suggests that the proposed modification to Feng would require significant control scheme redesign in a manner which would deter one of ordinary skill from the proposed modification.
Applicant has argued that there is no reasonable expectation of success in making the proposed modification to Feng in view of Favilli (12/30/2025 Remarks, item I, page 6). Examiner respectfully disagrees.
As discussed above, the single condenser arrangement of Feng is part of a vapor recompression heat pump arrangement, as is the two condenser arrangement of Favilli (Feng: Figure 3, section 4.1; Favilli: Figure 6, paragraph [0204]). Both of these heat pump arrangements: i) split a single overhead stream into a first portion and a second portion, ii) compress the first portion using a single compressor while bypassing the second portion around the compressor, iii) heat a single reboiler using the compressed first portion; and iv) condense and recombine the first and second portions after heating the reboiler with the first portion (Feng: Figure 3, section 4.1; Favilli: Figure 6, paragraph [0204]). Critically, both of heat pump arrangements compress a portion of a single overhead stream using a single compressor in order to heat a single reboiler using the compressed portion. Given these similarities, a person having ordinary skill in the art would have every expectation that a heat pump arrangement having two condensers like that of Favilli could successfully perform the function of the heat pump arrangement in Feng.
Applicant further argues that replacing the single condenser arrangement of Feng with two condensers would disrupt Feng’s “integrated heat recovery loop, requiring new control strategies and energy balance calculations” and therefore, one of ordinary skill would allegedly “expect operational instability and loss of efficiency, not predictable success” with the proposed modification. Examiner is unpersuaded by this argument.
Given the similarities between the two condenser heat pump arrangement of Feng and the two condenser heat pump arrangement of Favilli (discussed in detail above), a person having ordinary skill in the art would expect that a heat pump arrangement having two condensers like that of Favilli could successfully perform the function of the heat pump arrangement in Feng. Thus, a person having ordinary skill in the art would expect Feng’s integrated heat recovery loop (i.e. the heat pump arrangement) to remain workable if modified to have a two condenser arrangement.
As to the allegation that the proposed modifications would require “new control strategies and energy balance calculations”, energy balance calculations are well within the level or ordinary skill in the art and are a routine part of process design, as is the design/redesign of control schemes. Furthermore, any modification to a prior art system would necessarily require some amount of redesign. The notion that a modification would require new energy balance calculations and control schemes would not cause one of ordinary skill to doubt success.
Turning to the allegation that one of ordinary skill would allegedly “expect operational instability and loss of efficiency, not predictable success”, Applicant has not provided any compelling evidence or reasoning to support this conclusion. Though Applicant asserts that the proposed modification would require new energy balance calculations and a new control scheme, the notion that a modification would require additional design considerations would not lead one of ordinary skill in the art to expect instability or loss of efficiency. As discussed above, energy balance calculations and design/redesign of control schemes are well within the level or ordinary skill in the art. Thus, there is no reason to expect that instability and/or loss of efficiency would automatically and/or necessarily result from a modification requiring such design considerations.
Additionally, it is noted that “loss of efficiency” does not amount to failure, nor does general “operational instability”.
Applicant has argued that the proposed modification would change the principle of operation in Feng. More specifically, Applicant argues that “if a second condenser were added to [the system of Feng], heat recovery would become fragmented, undermining the core design objective of Feng,” (12/30/2025 Remarks, item II, page 7). Examiner finds this argument unpersuasive.
With respect, Applciant’s argument fails to clearly identify any particular manner in which the proposed modification would change Feng’s principle of operation. Though Applicant alleges that the addition of a second condenser would cause heat recovery in Feng to become fragmented, allegedly “undermining the core design objective of Feng”, it is not clear how fragmented heat recovery amounts to a change in operating principle, nor is it clear how it would undermine “the core design objective of Feng”.
Regardless, Examiner notes that heat recovery in Feng is achieved by heating the reboiler REB2 with heat from the compressed portion of overhead stream (Figure 3, Sections 4 and 4.1). Thus, one would not characterize the condensers as being involved in the heat recovery operation in Feng. Accordingly, Examiner respectfully asserts that replacing the single condenser CON of Feng with a two condenser arrangement would not fragment the heat recovery, and thus, would not change Feng’s operating principle in the alleged manner.
For the sake of argument, even if one were to characterize the condenser CON as being involved in heat recovery, heat recovery in Feng is already fragmented in that it is split between the reboiler REB2 and the condenser CON. Thus, if the condensers are considered to be involved in the heat recovery, further fragmenting the already fragmented heat recovery by using two condensers in place of one cannot be fairly characterized as changing Feng’s principle of operation.
Furthermore, while the embodiment of Feng relied upon in the rejections (The embodiment of Figure 3 “model 1”) achieves heat recovery by heating only REB2, there are other embodiments of Feng which achieve heat recovery by heating both REB1 and REB2 using the compressed overhead stream (Figures 9 and 11). Surely, heat recovery is “fragmented” in these embodiments, as it is split between two different reboilers. In view of Feng’s disclosure to these embodiments, a fragmented heat recovery cannot be fairly characterized as being contrary to Feng’s operating principle.
Examiner acknowledges Applicant’s statement that “Feng is directed to using a system having a single condenser to ensure tight coupling between compression, reboiling, and condensation for energy savings.” Examiner believes the intent behind this statement is to characterize the use of a single condenser as fundamental element of Feng’s operating principle. Examiner respectfully disagrees with any such notion.
Feng’s principle of operation is best characterized as the use of a vapor recompression heat pump to recover heat from an overhead stream to heat a reboiler. More specifically, Feng operates by using a compressor to compress a portion of an overhead stream and then using the compressed overhead stream to heat a reboiler. If Feng is modified in the proposed manner to include two condensers rather than one, modified Feng would still operate by using a compressor to compress a portion of an overhead stream and then using the compressed overhead stream to heat a reboiler. Therefore, the proposed modification to Feng does not change Feng’s principle of operation.
As Applicant points out, Feng does indicate that the use of a single compressor is important in the heat recovery operation of Feng. However, there is nothing in Feng which suggests that the use of only one condenser is critical in Feng.
On the subject of Feng’s use of a single compressor, Examiner notes that there is nothing in the record to suggest that use of a single compressor is incompatible with the use of two condensers. On the contrary, Favilli teaches a heat pump arrangement comprising a single compressor 64’ and two condensers 34’ and 67’ (Figure 6, paragraph [0204]; see also paragraphs [0180]-[0188], etc. for further description of various reference numerals).
Note: Though it is not relevant to the claims of the rejections of record, Examiner does not concede that modifying Feng to use multiple compressors would amount to a change in operating principle. Examiner also does not concede that modifying Feng would as such would be non-obvious on some other basis.
As Applicant has pointed out (see 12/30/2025 Remarks, item II, page 7), Feng states that “all the overhead vapor of the LRDWC is compressed with only one compressor, and thus the overhead vapor is used more effectively in the integrated LRDWC with the VRHP model, when compared with that of the integrated URDWC with the VRHP configuration.”
Though Feng states that “all of the overhead vapor is compressed with one compressor”, this statement is apparently an error on Feng’s part, as none of Feng’s designs compress all of the overhead vapor. While all of Feng’s designs (“Models” 1-4) use a single compressor to compress the overhead vapor, all of said designs also bypass the compressor with a portion of the overhead vapor (Figures 3, 6, 9, and 11). Thus, it would be more accurate to say that all of the compressed overhead vapor in Feng’s systems is compressed using a single compressor. Examiner respectfully asserts that this is the meaning that should be assigned to the quoted statement.
Applicant has alleged that the proposed modification would render Feng unfit for its intended purpose. More specifically, Applicant alleges that the proposed modification would “render Feng inoperable due to technical incompatibilities between the two systems” (12/30/2025 Remarks, item III, pages 7-8). Examiner respectfully disagrees.
As an initial matter, Examiner notes that Applicant’s argument fails to clearly identify the intended purpose of Feng, for which it is allegedly rendered unsuitable. Examiner contends that Feng’s intended purpose is best characterized as reactive distillation, more specifically the reactive distillation of isopropanol (IPOH) and methyl acetate (MEAC) to yield isopropyl acetate (IPAC) and methanol (MEOH) (Feng: Sections 2, 3, 4.1, Figure 3). On the other hand, a review of Applicant’s arguments suggests that Applicant considers energy savings and/or efficient operation to be Feng’s intended purpose(s).
While there are differences between the systems of Feng and Favilli, it remains that both systems use similar heat pump arrangements for heating a column reboiler using compressed overhead stream from the same column. The heat pump arrangement of Feng comprises one condenser, whereas the heat pump arrangement of Favilli comprises two condensers. Nevertheless, the similarities between these heat pump arrangements (discussed at length above) point firmly to Favilli’s heat pump arrangement, and the two condenser arrangement therein, being compatible with Feng’s system, with the use of Feng’s system for reactive distillation, and with Feng’s energy saving principle.
Furthermore, the proposed modification merely replaces the single condenser arrangement used in Feng (illustrated above in Exhibit A) with a two condenser arrangement like that taught by Favilli, such that modified Feng will have the configuration illustrated in Exhibit B above. Functionally, the only difference between base Feng and modified Feng is that base Feng first recombines the overhead stream, which had previously been split into two portions, before condensing the recombined stream in a single condenser, whereas modified Feng uses two condenser to separately condense the two portions of the overhead stream before recombination. There is nothing in the record to suggest that the changes made to Feng by the proposed modification would render it unsuitable for its intended purpose, regardless of whether that intended purpose is reactive distillation or energy savings and/or efficiency.
In view of the above, Examiner maintains that Feng remains suitable for its intended purpose following the proposed modification.
To support the allegation that the modification would render Feng unfit for its intended purpose, Applicant has made the following three supporting arguments:
First, the column internals and flow paths of the two systems are entirely different. Favilli's dual- condenser system assumes specific overhead vapor splits and pressure drops tailored to its full- height wall design. In contrast, Feng's partial-height wall creates different vapor-liquid traffic. As such, the condenser arrangement of Favilli would be unsuitable in the system of Feng without major redesign.
(12/30/2025 Remarks, item III, page 7).
Second, the proposed modification would require additional control loops and safety hazards that need to be addressed. The addition of a second condenser requires additional control loops, surge handling, and pressure balancing. These changes introduce complexity and risk, which would negate the energy savings and efficiency of Feng.
(12/30/2025 Remarks, item III, page 7).
Third, the system of Feng and the proposed modification have entirely different thermodynamic constraints. Energy integration in Feng depends on recombining streams before condensation. Splitting condensation duties between two condensers breaks this loop, requiring new heat exchanger sizing and compressor work calculations. These incompatibilities demonstrate that the proposed combination is not a simple predictable design choice that would have been obvious absent hindsight reconstruction.
(12/30/2025 Remarks, item III, page 7).
Examiner finds these supporting arguments unpersuasive.
Regarding the first supporting argument, said argument does not provide any evidence or compelling reasoning demonstrating that a two condenser arrangement like that of Favilli would be fundamentally unsuitable for use in Feng’s system. Instead, said argument merely points to several broadly stated differences between Feng and Favilli and concludes that, because of said differences a two condenser arrangement would be “unsuitable in the system of Feng without major redesign”. The mere presence of differences between Feng and Favilli is insufficient to support the allegation that a two condenser arrangement like Favilli is unsuitable for use in Feng, especially considering the many similarities between the vapor recompression heat pump arrangements of Feng and Favilli (discussed at length above).
Furthermore, considering that Applicant’s invention comprises a two condenser arrangement like that taught in Favilli, as well as a partial height column wall like that of Feng, it is seems unlikely that Applicant considers a two condenser arrangement to be fundamentally incompatible with a partial height column wall. Indeed, to argue such would be akin to asserting that Applicant’s own invention is inoperable.
In the second supporting argument, Applicant asserts that certain “changes introduce complexity and risk, which would negate the energy savings and efficiency of Feng”. By this assertion, Applicant is arguing either: i) that added complexity and risk introduced by the proposed combination would render Feng incapable of energy savings and efficient operation, or ii) that the added complexity and risk outweighs the benefits of Feng’s energy savings and efficiency. In either scenario, the second supporting argument is not persuasive.
In scenario ii, the second supporting argument does not actually support the broader assertion that the proposed modification would render Feng unsuitable for its intended purpose. Furthermore, the notion that added complexity and risk would outweigh the benefits of energy savings and efficiency is highly subjective and therefore, carries little weight. Especially considering that the assertion of added complexity and risk is a mere allegation, supported only by further mere allegations.
In scenario i, the second supporting argument ostensibly supports the broader assertion that Feng is rendered unsuitable, but does not do so effectively. The allegation that the added complexity and risk would render Feng incapable of energy savings and efficient operation is a mere allegation, supported only by further mere allegations. Ultimately, there is no evidence or compelling reasoning to suggest the alleged added risk and complexity would have any significant negative effect on the energy savings and efficiency of Feng. Furthermore, there is no evidence or compelling reasoning to suggest that the proposed modification would introduce significant added risk and/or complexity.
Lack of evidence aside, increased risk and/or complexity does not necessarily correlate with decreased energy savings and/or efficiency. Thus, Examiner is doubtful that even a significant increase in risk or complexity could be demonstrated to render Feng truly unsuitable for energy savings and/or efficient operation.
Regardless, the second supporting argument is predicated on the notion that Feng’s intended purpose(s) is energy savings and/or efficiency. However, it is at least questionable whether energy savings and/or efficiency can be fairly characterized as being the intended purpose(s) of Feng. Examiner contends that Feng’s intended purpose is best characterized as reactive distillation, more specifically the reactive distillation of isopropanol (IPOH) and methyl acetate (MEAC) to yield isopropyl acetate (IPAC) and methanol (MEOH) (Feng: Sections 2, 3, 4.1, Figure 3). Thus, for the sake of argument, even if the proposed modification were to render Feng incapable of energy savings and/or efficient operation, Examiner holds that Feng would nevertheless remain suitable for its intended purpose, i.e. reactive distillation.
In the third supporting argument, Applicant argues that certain alleged incompatibilities “demonstrate that the proposed combination is not a simple predictable design choice that would have been obvious absent hindsight reconstruction”. This argument does nothing to support the broader assertion that the proposed modification would render Feng unsuitable for its intended purpose. Instead, it is clearly an argument that the rejections of record rely on improper hindsight.
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).
The 103 rejections rely on Feng as the primary reference. As discussed in detail in the 103 rejections maintained below, the system of Feng differs from claim 1 only in that Feng comprises a single condenser where the claimed system comprises two. The 103 rejections rely on Favilli to cure this deficiency in Feng. The condenser of Feng is part of a vapor recompression heat pump arrangement, as are the condensers in claim 1.
As discussed above and in the 103 rejections below, secondary reference Favilli teaches a heat pump arrangement comprising two condensers, and which is substantially identical to the claimed heat pump arrangement. The heat pump arrangement of Favilli is very clearly workable, as is evident from Favilli’s disclosure. Thus, based on the disclosure of Favilli alone, a person having ordinary skill in the art would recognize that it is workable for a heat pump arrangement to have two condensers disposed in the claimed manner.
Furthermore, the similarities between the heat pump arrangements of Feng and Favilli (discussed at length above) point firmly to: i) Favilli’s heat pump arrangement, and the two condenser arrangement therein, being compatible with Feng’s system, and ii) the two condenser arrangement in Favilli being a suitable alternative to the single condenser arrangement of Feng. Thus, based on the combined disclosures of Feng and Favilli, a person having ordinary skill in the art would be able to conceive of the proposed modification described in the 103 rejections below, and thus arrive at the claimed invention.
In view of the forgoing, Examiner respectfully maintains that the 103 rejections of record take into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and do not rely on any knowledge that can only be gleaned from Applicant's disclosure. Accordingly, the 103 rejections of record do not engage in any improper hindsight.
Applicant has argued that the dependent claims are allowable over Feng in view of Favilli for the same reasons as independent claim 1 (12/30/2025 Remarks, pages 8-9). As discussed above, independent claim 1 is not allowable over Feng in view of Favilli. Therefore, this argument is moot.
Applicant has argued that the “dependent Claim 3 is further allowable because it includes additional limitations,” (12/30/2025 Remarks, page 8). This argument amounts to a general allegation that claim 3 defines a patentable invention without specifically pointing out how the language of the claim patentably distinguishes it from the references. Thus, said argument is unpersuasive.
Applicant has argued that the Couper reference, relied upon in the rejections of dependent claims 5 and 6, fails to cure the alleged deficiencies of Feng and Favilli (12/30/2025 Remarks, pages 8-9). As discussed above, the combination of Feng and Favilli is not deficient in the alleged manner(s). Therefore, this argument is moot.
The following rejections are maintained from the previous Office Action.
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 and 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Feng et al. (“Integrating a vapor recompression heat pump into a lower partitioned reactive dividing-wall column for better energy-saving performance”), hereafter referred to as Feng, in view of Favilli.
With regard to claim 1: Feng teaches dividing wall column system (Figure 3, section 4.1), the system comprising:
A dividing wall column
A first reboiler REB1 outside of the dividing wall column and in fluid communication with the first side of the bottom section of the dividing wall column (Figure 3, section 4.1).
A second reboiler REB2 outside of the dividing wall column and in fluid communication with the second side of the bottom section of the dividing wall column (Figure 3, section 4.1).
A first condenser CON in fluid communication with the second reboiler REB2 (Figure 3, section 4.1).
And a heat pump (compressor) COMP in fluid communication with the dividing wall column and the second reboiler REB2 and configured to compress a first portion of an overhead product from the dividing wall column (Figure 3, section 4.1).
Feng is silent to a second condenser in fluid communication with the dividing wall column and configured to receive a second portion of the overhead product from the dividing wall column.
However, in Feng, the overhead product is split into a first portion which is supplied to the heat pump COMP and the second reboiler REB2 and a second portion which bypasses the heat pump and the second reboiler, wherein the second portion is rejoined with the first portion downstream of the heat pump COMP and the reboiler REB, and wherein both the first and second portions are condensed in the first condenser CON (Figure 3, section 4.1; see annotated Figure 3 below).
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A person having ordinary skill in the art would recognize that, with respect to the task of condensing the overhead product in Feng, the use of two separate condensers which separately condense the first and second portions of the overhead product would be an obvious alternative to the use of a single condenser which condenses both of said portions. In other words, a person having ordinary skill in the art would expect that, in order to successfully affect condensation of the overhead product, a configuration having two separate condensers which separately condense the first and second portions of the overhead stream could be used in the alternative to a single condenser which condenses both the first and second portions.
Furthermore, distillation systems having such arrangements comprising two separate condensers are known in the art. For example, Favilli teaches a distillation system (Figure 6, paragraph [0204]) comprising: a distillation column, a reboiler (heat exchanger) 70’ outside of the distillation column and in fluid communication with a bottom section of the distillation column column (Figure 6, paragraph [0204]; see also paragraphs [0180]-[0188], etc. for further description of various reference numerals); a heat pump (compressor) 64’ in fluid communication with the distillation column and the reboiler 70’ and configured to compress a first portion 65’ of an overhead product 32’ from the distillation column (Figure 6, paragraph [0204]; see also paragraphs [0180]-[0188], etc. for further description of various reference numerals); a first condenser 67’ in fluid communication with the reboiler 70’ (Figure 6, paragraph [0204]; see also paragraphs [0180]-[0188], etc. for further description of various reference numerals); and a second condenser 34’ in fluid communication with the distillation column and configured to receive a second portion of the overhead product 32’ from the distillation column (Figure 6, paragraph [0204]; see also paragraphs [0180]-[0188], etc. for further description of various reference numerals).
It is well established that it would be obvious to one of ordinary skill in the art to substitute one known prior art element for another in order to obtain predictable results (MPEP 2143).
It would have been obvious to one of ordinary skill in the art before the effective filing date to modify Feng in view of Favilli by replacing the single condenser configuration of Feng with a two-condenser arrangement like that of Favilli Figure 6, i.e. a configuration having a first condenser and a second condenser, wherein the first condenser is in fluid communication with the second reboiler and is configured to receive and condense the first portion of the overhead product after said first portion leaves the second reboiler, and wherein the second condenser is in fluid communication with the dividing wall column and is configured to receive the second portion of the overhead product from the dividing wall column and to condense said second portion, in order to obtain a system which is predictably able to successfully affect condensation of the overhead product.
With regard to claim 3: The second reboiler 70’ is fluidly coupled to the dividing wall column to feed-reflux to the second side 73’ of the dividing wall column and the first reboiler 70 is fluidly coupled to the dividing wall column to feed-reflux to the first side 73 of the dividing wall column (Figure 6, paragraph [0204]; see also paragraphs [0180]-[0188], etc. for further description of various reference numerals).
Claim(s) 5 and 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Feng in view of Favilli as applied to claim 1 above, and in further view of Couper et al. (“Chemical Process Equipment (Revised Second Edition)”, Chapter 18: “Process Vessels”), hereafter referred to as Couper.
With regard to claims 5 and 6: Modified Feng is silent to an accumulator in fluid communication with the first condenser and the second condenser, wherein said accumulator is in fluid communication with the dividing wall column to feed-reflux the dividing wall column.
However, distillation columns having accumulators so configured are known in the art. For example, the distillation system of Favilli further comprises an accumulator (storage tank) 43’ in fluid communication with the first condenser 67’ and the second condenser 34’ (Figure 6, paragraph [0204]; see also paragraphs [0180]-[0188], etc. for further description of various reference numerals); wherein the accumulator 43’ is in fluid communication with the dividing wall column to feed-reflux to the dividing wall column (Figure 6, paragraph [0204]; see also paragraphs [0180]-[0188], etc. for further description of various reference numerals).
Accumulators are understood to be advantageous at least because they act as a surge tank for condensed overhead product. As evidence, Examiner points to Couper which teaches that “reflux drums provide surge between a condenser and its tower and downstream equipment,” (page 641, left column, second paragraph). Examiner notes that the term “reflux drum” is a synonym for “accumulator”.
It would have been obvious to one of ordinary skill in the art to further modify Feng in view of Favilli and Couper by adding an accumulator in fluid communication with the first condenser and the second condenser, wherein said accumulator is in fluid communication with the dividing wall column to feed-reflux the dividing wall column, in order to provide the system of Feng with a means of accommodating surges in condensed overhead product production.
Conclusion
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/JONATHAN LUKE PILCHER/Examiner, Art Unit 1772