DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1 and 3-11 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 1 recites the limitation “the stripper overhead stream emitted from the stripper has a composition that is unchanged between the stripper and the absorber.” The originally filed specification does not reasonably convey possession of this limitation. The disclosure of the elected embodiment describes the routing and thermal processing of the stripper overhead stream but does not describe or characterize the stream as maintaining an unchanged composition between the stripper and the absorber. For example, paragraph [0039] describes that during ethane rejection, the stripper overhead vapor may be routed through the stripper overhead or separator vapor/liquid core of a multi-pass heat exchanger for chilling prior to introduction into the absorber. Additionally, paragraph [0050] explains that during ethane rejection the stripper overhead may be chilled and partially condensed, forming a two-phase reflux stream to the absorber. Thus, the disclosure describes thermal processing and phase changes of the stripper overhead stream prior to introduction into the absorber. However, the specification does not disclose or characterize the stripper overhead stream as having a composition that remains unchanged between the stripper and the absorber, nor does the specification otherwise describe the stream in terms of compositional constancy. While cooling or temperature changes may not necessarily alter the chemical composition of a stream, the written description requirement is not satisfied by what might theoretically occur during operation of a process. Rather, the specification must reasonably convey that the inventors had possession of the specific limitation now recited in the claims. Here, the specification merely describes chilling and partial condensation of the stripper overhead stream and does not disclose the specific limitation that the stripper overhead stream has a composition that is unchanged between the stripper and the absorber. Accordingly, the originally filed specification does not provide adequate written description support for this limitation. Therefore, claim 1 is rejected under 35 U.S.C. §112(a).
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 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, 7, 9 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Mak (US 2010/0206003) in view of Patel et al. (US 7,069,744 B2).
In regard to claim 1, Mak teaches a natural gas liquids (NGL) plant, the NGL plant comprising:
an absorber (column 58) configured to provide an absorber overhead (18) and an absorber bottoms (28) (See fig. 1);
a Stripper (59) configured to produce a stripper overhead (34) and a stripper bottoms (39) (See fig. 1), wherein the stripper is positioned downstream from the absorber (58) and fluidly connected therewith such that the absorber bottoms (28) can be introduced into the stripper [59] (See fig. 1); and a multi-pass heat exchanger (heat exchanger 55, 54) configured to provide at least one reflux stream (streams 16 and 29) to the absorber (58),
wherein, when the NGL plant is in an ethane recovery configuration, the multi-pass heat exchanger is configured to provide at least two reflux streams (streams 16 and 29) to the absorber (58) (See fig. 1),
wherein, when the NGL plant is in an ethane rejection configuration, the absorber (58) and stripper (59) are configured to provide the stripper overhead (34) emitted from the stripper (59) to a top of the absorber (58: stream 27 via stream 34/30/29/29), and wherein when the NGL plant is in the ethane recovery configuration, the absorber and stripper are configured to provide the stripper overhead (stream 31: via stream 34/30/31) to a bottom of the absorber (See fig. 1; ¶ 0026-0027).
Mak teaches the absorber (58) and stripper (59) are configured to provide the stripper overhead (34) emitted from the stripper (59) to a top of the absorber (58) (stream 27 via stream 34/30/29/29), wherein Mak discloses the stripper overhead stream (34) is routed through intermediate equipment including reflux drum 61, which separates the stream into a vapor stream (30) and a liquid stream (37). The vapor stream is routed toward the absorber while the liquid stream is returned as reflux to the rectification section of the stripper (Fig. 1; ¶0026–0028). but does not explicitly teach the stripper overhead stream has a composition that is unchanged between the stripper and the absorber.
However, Patel hydrocarbon recovery apparatus and process wherein an absorber (32/32’) and stripper (28/28’) are configured to provide the stripper overhead (42/42”) emitted from the stripper (28/28’) to a top of the absorber (32/32’), wherein the stripper overhead stream (42/42”) has a composition that is unchanged between the stripper (28/28’) and the absorber (32/32’) (see fig. 4, 6, 8, 9). Patel teaches the stripper overhead stream is routed from a stripper to an absorber without intermediate compositional modification (see Patel Figs. 4, 6, 8, and 9).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Mak by routing the stripper overhead stream to the absorber in the manner taught by Patel such that the stripper overhead stream is delivered to the absorber without intermediate compositional modification, in order to allow hydrocarbons contained in the overhead stream to participate in further separation within the absorber column, thereby improving hydrocarbon recovery efficiency and reducing unnecessary intermediate separation steps.
In this case, the combination of Mak and Patel represents the application of a known process configuration to a known NGL recovery system to achieve predictable results.
In regard to claim 4, Mak teaches the NGL plant of claim 1, further comprising:
a cold separator (56) configured to separate a two-phase separator feed (14) into a separator vapor (21) and a separator liquid (22) (See fig. 1),
wherein the cold separator (56) is fluidly connected with the absorber (58), wherein the cold separator (56) is configured, in the ethane rejection arrangement, to route the separator vapor (21) to the bottom of the absorber [58] (See fig. 1).
In regard to claim 7, Mak teaches the NGL plant of claim 4, wherein the cold separator is configured to pass at least a portion of the separator liquid (22/15) through a second pass of the multi-pass heat exchanger (see 15 passing through heat exchanger 54) prior to introduction into the stripper [59] (See fig. 1).
In regard to claim 9, Mak teaches the NGL plant of claim 4, wherein the multi-pass heat exchanger (54) comprises a pass (stream 7) configured to chill a first portion of an NGL feed gas (1/7) and provide at least a portion of the two-phase separator feed (14) (See fig. 1).
In regard to claim 11, Mak teaches the NGL plant of claim 1, further comprising: one or more residue gas compressors (65, 67) configured to compress the absorber overhead (18) to produce a compressed residue gas (11), wherein the NGL plant is configured, in the ethane recovery operation, to expand (expander 90) and pass a portion of the compressed residue gas via the multi-pass exchanger (55) into a top (via 25) of the absorber [58] (See fig. 1; ¶ 0023-0024).
Claim(s) 3 is rejected under 35 U.S.C. 103 as being unpatentable over Mak and Patel as applied to claim 1 above, and further in view of Mak (US 2017/0051970), hereinafter “Mak 970’”.
In regard to claim 3, Mak teaches the NGL plant of claim 1, but does not explicitly teach the stripper is configured, in the ethane recovery arrangement, as a demethanizer to provide a stripper bottoms comprising less than 1 vol% methane, and the stripper is configured, in the ethane rejection arrangement, as a deethanizer to provide a stripper bottoms comprising less than 2 mole percent ethane.
However, it is well known to alter the fractionate bottom liquid streams for the purpose of providing the desired product components, as taught by Mak 970’, wherein Mak 970’ teaches hydrocarbon liquids recovery in a gas processing industry for ethane and propane recovery, wherein during ethane recovery, the temperature of demethanizer bottom product 25 is heated to about 104° F. by the heat medium flow in reboiler 65 for controlling the methane component to the ethane component in the bottom liquid at a ratio of 2 volume %. During ethane rejection, the demethanizer bottom temperature stream 25 is lowered to about 64° F. in reboiler 65 such that the ratio of the methane component to the ethane component in the liquid is increased to about 10 volume %. The higher methane content is used in refluxing the demethanizer during the ethane rejection operation, which significantly reduces the power consumption of the residue gas compressor (See ¶ 0032). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention, to modify Mak with the teachings of Mak 970’ to provide a stripper bottoms comprising less than 1 vol% methane or to provide a stripper bottoms comprising less than 2 mole percent ethane by adjusting the heat medium flow in the reboiler for controlling the methane component to the ethane component in the bottom liquid for the purpose of providing flexible product provision, including ethane recovery and/or propane recovery as demanded by the market situation at hand.
Claim(s) 5 and 6 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Mak and Patel as applied to claim 4 above, and further in view of Patel et al. (US 2004/0148964 A1), hereinafter “Patel 2’”.
In regard to claim 5, Mak teaches the NGL plant of claim 4, wherein Mak teaches a cold separator (56) in ethane recovery arrangement, and configured to separate a two-phase separator feed (14) into a separator vapor (21) and a separator liquid (22), wherein it is configured to pass a portion of the separator vapor (21) to the absorber (58), but does not explicitly teach the cold separator comprising two portion, and configured to pass a first portion of the separator vapor to the absorber through a first pass of the multi-pass heat exchanger, and to pass a second portion of the separator vapor to the bottom of the absorber.
However, Patel 2 teaches a hydrocarbon recovery process and apparatus, wherein a cold separator is configured, in the ethane recovery arrangement, to pass a first portion (26b/34) of the separator vapor (26’/26) to an absorber (32”/32) through a multi-pass heat exchanger (40’/40), and to pass a second portion (26a’/20) of the separator vapor (26’/26) to the bottom of the absorber [32”/32] (See fig. 5, 8; ¶ 0060-0062, 0076-0078).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention, to modify the NGL plant of Mak by splitting the separator vapor into two portions, wherein the two portion are configured to pass a first portion of the separator vapor to the absorber through a first pass of the multi-pass heat exchanger, and to pass a second portion of the separator vapor to the bottom of the absorber, based on the teaching of Patel 2, since it has been shown that combining prior art elements to yield predictable results is obvious whereby splitting the separator vapor into two portion would help the NGL plant of Mak to increase the recovery ethane product.
In regard to claim 6, the modified Mak teaches the NGL plant of claim 5, wherein Mak in view of Patel 2, wherein Patel further teaches an expander (30’/30) in fluid communication with a bottom portion of the absorber (32”/32), wherein, when the NGL plant is in ethane rejection configuration, the expander is configured to produce an expander discharge (34’/34) from the separator vapor (26’/26), and wherein, when the NGL plant is in the ethane recovery configuration, the expander (30’/30) is configured to produce the expander discharge from the second portion of the separator vapor (See Patel, fig. 5 and 8).
In regard to claim 10, Mak teaches the NGL plant of claim 9, wherein Mak teaches a heat exchanger (52, 53) configured to chill second portion of the NGL feed gas (2) to provide at least another portion of the two-phase separator feed (See fig. 1), but does not explicitly teach the heat exchanger is propane chiller configured to chill a second portion of the NGL feed gas to provide at least another portion of the two-phase separator feed.
However, fig. 5 and 6 of Patel 2 teaches a side feed stream 12a is taken from inlet gas stream 12, wherein a third exchanger, or tower side reboiler, 29, cools side feed stream 12a. Tower side reboiler 29 can be a single exchanger or a plurality of exchangers, depending upon the required reboiler duty for distillation tower 28. External refrigerants, such as propane or propylene, can be used, if needed (See Patel, fig. 5, 6; ¶ 0079). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention, to modify the NGL feed heat exchanger of Mak by using a propane chiller to chill the second portion of the NGL feed gas, based on the teaching of Patel 2, since it has been shown that combining prior art elements to yield predictable results is obvious whereby implementing a propane chiller to the heat exchanger would help the NGL plant of Mak to have an additional cooling means in addition to the striper reboiler fluid.
Claim(s) 8 is rejected under 35 U.S.C. 103 as being unpatentable over Mak and Patel as applied to claim 4 above, and further in view of Pierce et al. (US 2018/0347898 A1).
In regard to claim 8, Mak teaches the NGL plant of claim 4, wherein, when the NGL plant is in the ethane recovery configuration, the cold separator (56) is configured to pass a first portion of the separator liquid (22/15) through a second pass of the multi-pass heat exchanger (see 15 passing through heat exchanger 54) prior to introduction into the absorber (58), but does not explicitly teach passing a second portion of the separator liquid directly to the stripper.
However, Pierce teaches a process and an apparatus are disclosed for a compact processing assembly to improve the recovery of C.sub.2 (or C.sub.3) and heavier hydrocarbon components from a hydrocarbon gas stream, wherein a separator 11 is used to separate a cooled feed stream into a vapor (stream 32) and a condensed liquid (stream 33). The liquid (stream 33) from separator 11 is optionally divided into two streams, 35 and 38, wherein stream 35 contains about 15% of the total separator liquid and passes through heat exchanger 12 in heat exchange relation with the cold residue gas (stream 39) where it is cooled to substantial condensation and the resulting substantially condensed stream 36a is then flash expanded through expansion valve 13 to the operating pressure of fractionation tower 17 and the expanded stream 36b is supplied to separator section 17a in the upper region of fractionation tower 17. The remaining separator liquid in stream 38 is expanded to the operating pressure of fractionation tower 17 by expansion valve 16, cooling stream 38a before it is supplied to fractionation tower 17 at a lower mid-column feed point (See fig. 3; ¶ 0024-0026). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention, to modify the separator liquid of Mak by splitting the fluid into two portions, based on the teaching of Pierce for purpose of proving an optional fluid flow to the stripper to provide the desired temperature of the liquid from the separator to the stripper depending on the temperature need in the separation process inside the stripper to reach the desired product.
Response to Arguments
Applicant's arguments filed on 03/04/2026 have been fully considered but they are not persuasive, unless otherwise noted below.
Applicant argues (Remark 12-14) that the claimed limitation is supported by the specification because paragraph [0039] and paragraph [0050] describe chilling and partial condensation of the stripper overhead stream prior to introduction into the absorber and that such thermal processing does not change the chemical composition of the stream.
In response, this argument is not persuasive. While chilling or temperature changes may not necessarily alter the chemical composition of a stream, the written description requirement requires that the specification reasonably convey that the inventors had possession of the specific claimed limitation. The specification cited by Applicant merely describes chilling and partial condensation of the stripper overhead stream and does not describe or characterize the stream as having a composition that remains unchanged between the stripper and the absorber. Accordingly, the originally filed specification does not provide written description support for the claimed limitation.
Applicant argued the motivation to combine (remark page 16) wherein applicant asserts that the Office Action provides an unsupported rationale that modifying Mak would enhance absorber performance by delivering a richer stream.
In response, the allegation is not persuasive. In this case, the rejection does not rely solely on Mak for this benefit. Rather, Patel teaches that routing the stripper overhead directly to the absorber without compositional modification improves hydrocarbon recovery performance by delivering a stream suitable for further separation in the absorber column (see Patel, Figs. 4, 6, 8, and 9). A person having ordinary skill in the art would have recognized that incorporating this known configuration into Mak’s NGL recovery system would have predictably improved separation efficiency in the absorber by forwarding heavier hydrocarbons to the absorber rather than removing them upstream. It is well established that a reference may be modified using the teachings of another reference when the combination yields predictable results within the skill of the art. The motivation to combine need not be found in the primary reference alone but may arise from the knowledge and teachings of the secondary reference. Furthermore, the statement in the rejection that many ethane rejection plants operate with minimal reflux reflects the general operational flexibility known in NGL recovery processes, where different operating configurations are used depending on whether ethane recovery or rejection is desired. Patel demonstrates such an alternative configuration in which the stripper overhead is routed directly to the absorber without compositional modification. Accordingly, one of ordinary skill in the art would have been motivated to implement the configuration taught by Patel within the system of Mak in order to achieve the known benefits associated with forwarding heavier hydrocarbons to the absorber and improving overall recovery performance.
Applicant further argues (Remark page 17) that the combination of Mak and Patel is improper because Mak produces an “ethane rich vapor stream” through separation in reflux drum 61 and that eliminating this separation would contradict Mak’s teachings.
This argument is not persuasive. Mak merely describes one embodiment in which the stripper overhead stream is separated in reflux drum 61 to produce a vapor stream and a liquid reflux stream. Mak does not criticize, discredit, or otherwise discourage alternative configurations in which the stripper overhead stream is routed to the absorber without such compositional separation.
Patel explicitly teaches such a configuration, demonstrating that routing the stripper overhead stream directly to the absorber without intermediate compositional modification was known in the art.
Applicant additionally argues (Remark page 17) that modifying Mak in this manner would render Mak unsuitable for its intended purpose because reflux drum 61 provides reflux to the stripper.
This argument is also not persuasive. The rejection does not require eliminating reflux functionality from Mak’s system. Rather, the rejection proposes modifying the routing of the stripper overhead stream in accordance with the configuration taught by Patel. Process engineers routinely modify routing arrangements in hydrocarbon recovery systems while maintaining the necessary reflux conditions for column operation.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to WEBESHET MENGESHA whose telephone number is (571)270-1793. The examiner can normally be reached Mon-Thurs 7-4, alternate Fridays, EST. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Frantz Jules can be reached at 571-272-6681. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/W.M/Examiner, Art Unit 3763
/FRANTZ F JULES/Supervisory Patent Examiner, Art Unit 3763