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 .
Response to Amendment
Amendment to specification filed on 9/22/2025 overcomes objections to specification and drawings made in the Office action mailed 4/21/2025.
Amendment to claims 1 and 2 obviates 112(b) rejections.
Claims 1-13 remain pending.
Claims 14-20 remain withdrawn due to a restriction requirement.
Response to Arguments
Applicant’s arguments, see page 8, paragraphs 8-9, filed 9/22/2025, with respect to the rejection of claim1 under 35 USC 103 have been fully considered and are persuasive. Specifically, Applicant argues amendment to claim 1 requires a “single stream of nitrogen passes through the liquefier, then through the second cooler and then through the first cooler” which is not disclosed by the primary reference to Kaminsky. This argument is persuasive.
With respect to the argument that the secondary reference to Nevison does not “teach the sequence that the single stream of nitrogen is used to provide cooling in the system of amended claim 1” is partly persuasive. It is agreed that Nevison does not disclose the system as called for in the amended claim 1. However, Nevison was relied upon for teaching use of nitrogen as a refrigerant in the method of cooling a natural gas stream. This teaching is still relevant and Applicant has not made any argument why one could not nitrogen in the process of Kaminsky.
In conclusion, the rejection has been withdrawn. Upon further consideration, a new ground of rejection is made in view of different embodiment disclosed in Kaminsky reference.
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
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.
Claims 1-3 and 8-13 are rejected under 35 U.S.C. 103 as being unpatentable over US 2020/0158426) to Kaminsky et al. (hereinafter “Kaminsky”) in view of US 20180142949 to Nevison et al. (hereinafter “Nevison”)
With respect to claims 1-3, and 7-13, Kaminsky discloses a system for removing contaminants, such as water and/or carbon dioxide, from a natural gas stream (Abstract), said system comprising (see Fig. 2 and its corresponding description in [0019] through [0021]):
A heat exchanger 120 (equivalent to claimed water condenser) receives a feed gas and cools the feed gas with a coolant 202 forming a cooled gas and removes liquid water;
A first scraped heat exchanger 128 (equivalent to claimed first cooler) receives the cooled gas and additionally cools the cooled gas with the coolant 202 and removes frozen water (equivalent to claimed first contaminants);
A second scraped heat exchanger 104 (equivalent to claimed second cooler) receives the further cooled gas from the first scraped heat exchanger 128 and is cooled with the coolant 202 to a temperature sufficient for contaminants CO2, water, and other contaminants to solidify and is removed; and
An expander (equivalent to claimed liquefier) receives the cooled gas from the second scraped heat exchanger 104 and liquefies the cold treated fluid. See [0019] through [0021].
Scraped heat exchanger type includes heat exchangers with scraped surface using simple mechanical scrapers and/or using dynamic mechanical scrapers. See [0018].
Kaminsky specifically discloses the second coolant 202 cools, in order, the second scraped heat exchanger 104, the first scraped heat exchanger 128, and a heat exchanger 120. The second coolant 202 is a non-ambient temperature coolant, i.e., not ambient air or ambient water. See [0021]. Kaminsky further discloses a coolant used to cool the gas stream in second scraped heat exchanger 104 may be primarily nitrogen (see[0019, lines 20-27]).
Kaminsky fails to disclose the expander (claimed liquefier) includes a liquefier warming passage configured to receive the nitrogen stream, warm the nitrogen stream so that the purified cooled gas stream is liquified and direct the warmed nitrogen stream through a liquefier nitrogen outlet.
Nevison discloses a method for cooling natural gas using cryogenic nitrogen as a cooling medium (see Abstract). Nevison discloses a liquefier heat exchanger 496 (claimed liquefier) having a cooling passage to liquify the natural gas production stream (claimed purified cooled gas stream), further including a warming passage that receives the nitrogen refrigerant stream and warms it in order to cool the natural gas production stream and releases a nitrogen vapor stream. See Fig. 4 and [0052].
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Kaminsky and include a liquefier warming passage configured to receive the nitrogen stream as disclosed by Nevison because Nevison discloses nitrogen exhibits desired temperature and thermodynamic properties to effectively cool all components of a natural gas stream to meet the desire purposes including production of LNG. See [0023].
With respect to claim 2, Kaminsky discloses heat exchanger 120 (equivalent to claimed water condenser) receives the nitrogen vapor stream from the scraped heat exchange 128 (claimed first cooler) but does not disclose venting the warmed vapor. It is known to those skilled in the art, the nitrogen used to cool the system of Kaminsky would be contaminated to some degree. To prevent a contaminant buildup, it would be beneficial to vent at least a portion of the warmed vapor.
With respect to claim 3, Kaminsky disclose a compressor 112 for increasing the pressure of the feed gas prior to entering the heat exchanger 120 (see Fig. 2 and [0020, lines 6-13]).
With respect to claim 7 directed to the water condenser cooling the feed gas stream to about -5oC to 50oC, Kaminsky discloses cooling the feed gas in the heat exchanger 120 to remove water but is silent with respect to the temperature. However, it would have been obvious to one having ordinary skill in the art to have determined optimum cooling temperature to remove water from the feed gas stream.
Claims 4 and 5 are rejected under 35 U.S.C. 103 as being unpatentable over Kaminsky in view Nevison as applied to claims 1, 3, and 7-13 above, and further in view of EP 3719426 to Air Liquide (hereinafter “Air Liquide”).
The teachings of Kaminsky and Nevison are as discussed above.
Kaminsky does not disclose a contaminant separate configured to receive the first contaminants stream from the first cooler and the second contaminants stream from the second cooler.
Air Liquide is directed to a production of liquid methane from a gaseous supply stream. Air Liquide discloses a crystallization system 5 (equivalent to claimed contaminant separator) having a first outlet 7 and a second outlet 11 (see Fig. 1, [0016]) is configured to receive a gas stream 4 (equivalent to claimed first contaminants stream and second contaminants stream) from heat exchangers 3a (equivalent to claimed first cooler) and 3b (equivalent to claimed second cooler) and produce a first separate contaminant product 7 and a second separate contaminant product 11. See Fig. 1, [0012], [0014], and [0016].
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have included a contaminant separator because it would separate and entrain solid CO2 at the bottom of the crystallization system as taught by Air Liquide (see [0010, lines 132-140]).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Kaminsky, Nevison, and Air Liquide as applied to claims 1 and 4 above, and further in view of US 20200284507 to McCool et al. (hereinafter “McCool”).
The teachings of Kaminsky, Nevison, and Air Liquide are as discussed above.
Kaminsky, Nevison, and Air Liquide do not disclose wherein the first cooler is further configured to receive at least a portion of the second contaminants stream from the second cooler.
McCool is directed to a method for providing refrigeration in natural gas liquid recovery plants. McCool discloses the main heat exchanger 2 (equivalent to claimed first cooler) is configured to receive a portion of the residue gas stream (equivalent to claimed second contaminants stream) from the overheat heat exchanger 10 (equivalent to claimed second cooler). See Fig. 2, [0119]. The residue gas stream is sent back to the first cooler to be used as a cooling medium.
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the system of Kaminsky to include a stream from the second cooler to the first cooler because it would act as a cooling medium as disclosed by McCool ([0119].
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.
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/IN SUK C BULLOCK/Supervisory Patent Examiner, Art Unit 1772
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