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 .
Election/Restrictions
Applicant’s election without traverse of invention I and species B (fig. 4), encompassing claims 1-8, 11, 12 and 14 in the reply filed on 01/26/2026 is acknowledged. Claims 15-22, 24 and 26 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention and species, there being no allowable generic or linking claim. In addition, claims 2-5 and 11 are also withdrawn from consideration for being drawn to a nonelected species fig. 3 (e.g., the limitations wherein the split stream is depressurized to a lower pressure to produce a stripping gas, the split stream is depressurized to a lower pressure using at least one Joule-Thomson (JT) valve, the split stream is depressurized to a lower pressure using a reboiler to produce a stripping gas and feeding the second overhead stream to the MCHX to be liquefied under cryogenic conditions to produce a liquefied stream are all disclosed in a withdrawn species (fig. 3)).
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1, 6-8, 12 and 14 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 recites the limitation "the separated natural gas feed stream" in section b) lacks proper antecedent basis. The limitation should read –the separated natural gas stream--.
Claim 6 recites the limitation "the stripping gas” lacks proper antecedent basis. For examination purposes, examiner read the limitation as –the split stream--.
Claim 8 recites the limitation "the heat exchangers” lacks proper antecedent basis.
Claim 8 recites the limitation "the heat exchangers utilize an external refrigerant comprising propane” renders the claim indefinite because it is unclear which “heat exchangers” it referring to. For examination purposes, it is considered to be the first heat exchanger wherein the methane-rich overhead stream is cooled.
Claim 12 recites the limitation "the cooling of at least a portion of the separated natural gas feed stream and a generation of a reflux by the split stream is integrated in one heat exchanger” renders the claim indefinite because it is unclear what it means by “generation of a reflux by the split stream”. From the elected invention (fig. 4), it is unclear how the separating natural gas stream integrate with the split stream in one heat exchanger. Contrary to the recited limitation, the split stream actually introduced into the column without interaction with any heat exchanger. For examination purposes, as long as at least a portion of the separated natural gas feed stream integrate in one heat exchanger, then it meets the claim requirement. Appropriate correction required.
Claim 12 recites the limitation "the cooling of at least a portion of the separated natural gas feed stream and a generation of a reflux by the split stream is integrated in one heat exchanger” renders the claim indefinite because it is unclear if it is referring to any of the heat exchangers that are mentioned in claim 1 or entirely different heat exchanger.
Claims 7 and 14 are also rejected under 35 U.S.C. 112(b) for being dependent upon a rejected claim.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 1, 7, 8 and 12 is/are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Chen et al. (US 2018/0023889 A1).
In regard to claim 1, Chen teaches a method for operating a hydrocarbon removal system, the method comprising the steps of:
(a) separating at least a portion of a natural gas stream (202) to produce a split stream (202b) and a separated natural gas stream (202a) (see fig. 2, 4-6);
(b) cooling at least a portion of the separated natural gas feed stream (202a) in one or more heat exchangers (heat exchanger 232) to form a pre-cooled feed stream (233) (see fig. 2, 4-6);
(c) feeding the pre-cooled feed stream (233) into a column (236), the column comprising an upper section, a mid-section, and a lower section (see fig. 2, 4-6; ¶ 0099);
(d) separating a methane-rich overhead stream (239) and a bottom stream (240) from a C5+ hydrocarbon-rich mixture (the need comprises C5+ hydrocarbons) in the upper section of the column (236) (see fig. 2, 4-6; ¶ 0004, 0084, 0104-0105);
(e) cooling the methane-rich overhead stream (239) in a first heat exchanger (any one of heat exchangers 232, 210 and 252) to produce a first cooled methane-rich stream (246) (see fig. 2, 4-6); and
(f) subsequently,
(i) feeding the first cooled methane-rich stream (246) to a reflux drum (250) to produce a reflux stream (254) (fig. 2); and/or
(ii) feeding the first cooled methane-rich stream to a Main Cryogenic Heat Exchanger (MCHX) to produce a second cooled methane-rich stream, and feeding the second cooled methane-rich stream to the reflux drum to produce a second overhead stream that is essentially free of heavy hydrocarbons (the limitation is drawn from a Non-elected species- Fig. 3. Furthermore, the limitation is an optional limitation).
In regard to claim 7, Chen teaches the method of claim 1, further comprising feeding the reflux stream (254) into the column (236) (see fig. 2; ¶ 0107).
In regard to claim 8, Chen teaches the method of claim 1, wherein the heat exchangers (heat exchanger 210) utilize an external refrigerant (260) comprising propane (see fig. 2; ¶ 0107-0108; see also the 112b rejection above).
In regard to claim 12, Chen teaches the method of claim 1, wherein the cooling of at least a portion of the separated natural gas feed stream (202a) and a generation of a reflux by the split stream (254) is integrated in one heat exchanger (heat exchanger 232) (see fig. 2; see also the 112b rejection and examiner interpretation).
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.
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) 6 is rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (US 2018/0023889 A1).
In regard to claim 6, Chen teaches the method of claim 1, Chen teaches separating a natural gas feed stream into a separated natural gas stream (202a) and a split stream (202b) (see Fig. 2). Chen further teaches feeding the cooled separated natural gas stream (202a) into a middle portion of a distillation column and feeding the split stream (202b) into a bottom portion of the column to separate an overhead methane stream. Chen teaches does not explicitly state that the stripping gas/the split stream regulates methane slippage to the bottom of the column (see the 112b rejection and the examiner interpretation above).
However, Official Notice is taken that, at the time of the invention, it was well known in the art of cryogenic distillation that introducing a feed or split stream into the bottom of a distillation column (as taught by Chen) affects vapor–liquid equilibrium, mass transfer, and component distribution, thereby controlling or regulating the amount of methane that slips toward the bottom of the column. It was further well known that adjusting the flow rate and composition of such a bottom-fed stream is a routine and predictable technique for controlling methane carry-under or slippage in natural gas separation columns. In view of this well-known knowledge, it would have been obvious to a person of ordinary skill in the art that feeding the split stream (202b) to the bottom of the column as taught by Chen would regulate methane slippage to the bottom of the column, as claimed. The claimed limitation therefore represents an intended result of a known process step, rather than a patentably distinct structural or operational feature.
Claim(s) 14 is rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (US 2018/0023889 A1) in view of Buijs et al. (US 20130098103 A1).
In regard to claim 14, Chen teaches the method of claim 1, but Chen does not explicitly teach wherein the method further comprises a CO2 removal step and/or a H2S removal step.
However, Buijs teaches a method of treating a hydrocarbon stream comprising methane, wherein the method comprises a CO2 removal step and/or a H2S removal step (¶ 0041).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the invention, to modify the method of Chen by adding a CO2 and/or a H2S removal step, in view of the teaching of Buijs, for the purpose of reducing and/or removing one or more of undesired components and avoid a downstream freezing, corrosion, hydrates formation and equipment damage.
Conclusion
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