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 .
Response to Amendment
The amendment filed May 15th, 2026 has been entered. Claims 1-25 remain pending in the application. The amendments to the claims have overcome each and every claim objection previously cited in the Non-Final rejection mailed January 15th, 2026. However, the amendment has raised other issues detailed below.
Claim Objections
Claim 11 is objected to because of the following informalities:
Claim 11, lines 2-3: “a first one of the two enclosures of the liquid-solid-gas separator” should read “a first one of the two enclosures of the first liquid-solid-gas separator”
Appropriate correction is required.
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 1-25 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.
A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claim 1 recites the broad recitation "being less than 200 ppmv" and the claim also recites "advantageously below 100 ppmv" which is the narrower statement of the range/limitation. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims. For purposes of examination, the Examiner will interpret the narrower language as (a) merely exemplary of the remainder of the claim, and therefore not required.
Claim 14 recites the limitation "the second solid-liquid-separator exchanger" in lines 2-3. There is insufficient antecedent basis for this limitation in the claim. The Examiner recommends changing “the second solid-liquid-separator exchanger" in lines 2-3 of claim 14 to “the finned-tube exchanger”. For purposes of examination, the examiner will interpret the second solid-liquid-separator exchanger and the finned-tube exchanger to be the same components.
Claim 24 lines 1-2 recite, “wherein the carbon dioxide content of is about 3000 parts per million by volume (ppmv)” which is unclear to the Examiner as to what fluid the carbon content is to be about 3000 parts per million by volume (ppmv). For purposes of examination, the Examiner will interpret the claim to read “wherein the carbon dioxide content of the liquid methane is about 3000 parts per million by volume (ppmv)”. The Examiner recommends amending the claim as interpreted herein.
Claims 2-6, 12, 19, and 24 are also rejected by virtue of their dependency on claim 1.
Claim 8 is also rejected by virtue of its dependency on claim 7.
Claims 9-11 are also rejected by virtue of their dependency on claim 8.
Claims 13 and 15-16 are also rejected by virtue of their dependency on claim 12.
Claim 14 is also rejected by virtue of its dependency on claim 13.
Claim 17 is also rejected by virtue of its dependency on claim 16.
Claim 18 is also rejected by virtue of its dependency on claim 17.
Claims 20 and 23 are also rejected by virtue of their dependency on claim 19.
Claims 21-22 are also rejected by virtue of their dependency on claim 8.
Claim 25 is also rejected by virtue of its dependency on claim 10.
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.
Claims 1-3, 19-22, and 24 are rejected under 35 U.S.C. 103 as being unpatentable over Y. M. B. Roche et al. (US Patent No. 3,254,496), hereinafter Roche in view of J. A. Davis et al. (Solid-Liquid-Vapor Phase Behavior of the Methane-Carbon Dioxide System), hereinafter Davis.
Regarding claim 1, Roche discloses a method for extracting carbon dioxide contained in
liquid methane (Fig. 6; Col. 2, lines 8-10, FIGS. 5 and 6 are plant diagrams for carrying out the invention comprising a stage for eliminating CO2 in the course of liquefaction; Col. 6, lines 9-10, The current of liquid natural gas issuing from the column V1 at the point 3 is cooled in the exchanger E2), the method comprising:
a step of expansion of a liquid methane, the methane vaporising and the carbon dioxide crystallising during this expansion, to form a three-phase liquid-vapour-solid mixture of methane and carbon dioxide, the resulting liquid methane being supersaturated with carbon dioxide (Fig. 6, expansion orifice 16; Col. 5, lines 24-35, The process of the invention does not concern the formation of this precipitate but its elimination from the liquid current. It comprises eliminating by filtration the precipitate obtained by expansion of preferably the liquid in a flash flask. The formation of the precipitate is continuous from the point of formation of the first crystal when the temperature of the liquid continues to drop. As the precipitate formed has a tendency to agglomerate into a mass which is compact but, however, fragile owing to the presence in the precipitate of heavier hydrocarbons, there can be no question of cooling the liquid in a normal exchanger, owing to stopping up and clogging; Col. 6, lines 9-23, The current of liquid natural gas issuing from the column V1 at the point 3 is cooled in the exchanger E2; at the outlet of the exchanger E2 the liquid is cooled in the bottom of the column V2 and conducted to the flask B3 through the expansion orifice 16. The filtered liquid part is evacuated through the pipe 36 to the flash flask B4 and through the expansion orifice 37, the latter is expanded. The filtered liquid issuing at 38 is the liquefied natural gas. The vapour part of the flash flask B3 issuing at 39 passes through the exchanger E3, then E4a, issues at 40 and a flask B5 permits the separation of non-condensed gas if desired, the liquid of the flask being sent into the flash flask B3 through a pipe 41 directly into the expanding means 16), and
a step of passing the methane gas phase and the solid phase of carbon dioxide into a first liquid-solid-gas separator, with extraction of the solid carbon dioxide by filtration, and separation of the gaseous methane, to obtain a first liquid methane phase, partially decarbonized (Fig. 6, expansion flask B3, filter, line 36, line 39; Col. 5, lines 24-35, The process of the invention does not concern the formation of this precipitate but its elimination from the liquid current. It comprises eliminating by filtration the precipitate obtained by expansion of preferably the liquid in a flash flask. The formation of the precipitate is continuous from the point of formation of the first crystal when the temperature of the liquid continues to drop. As the precipitate formed has a tendency to agglomerate into a mass which is compact but, however, fragile owing to the presence in the precipitate of heavier hydrocarbons, there can be no question of cooling the liquid in a normal exchanger, owing to stopping up and clogging; Col. 6, lines 9-23, The current of liquid natural gas issuing from the column V1 at the point 3 is cooled in the exchanger E2; at the outlet of the exchanger E2 the liquid is cooled in the bottom of the column V2 and conducted to the flask B3 through the expansion orifice 16. The filtered liquid part is evacuated through the pipe 36 to the flash flask B4 and through the expansion orifice 37, the latter is expanded. The filtered liquid issuing at 38 is the liquefied natural gas. The vapour part of the flash flask B3 issuing at 39 passes through the exchanger E3, then E4a, issues at 40 and a flask B5 permits the separation of non-condensed gas if desired, the liquid of the flask being sent into the flash flask B3 through a pipe 41 directly into the expanding means 16),
a step of transferring this first liquid methane phase to a second solid-liquid separator, the carbon dioxide depositing in the second exchanger, to form a second liquid methane phase (Fig. 6, expansion flask B4, filter; Col. 6, lines 14-17 and 23-26, The filtered liquid part is evacuated through the pipe 36 to the flash flask B4 and through the expansion orifice 37, the latter is expanded. The filtered liquid issuing at 38 is the liquefied natural gas…The flash vapour produced in the flask B4 is recondensed through a pipe 42 in the exchanger E4b, reintroduced through a pipe 43 directly into the expanding means 37).
However, Roche does not explicitly disclose the carbon dioxide content of which is greater than
280 parts per million by volume (ppmv), the expansion being carried out from a pressure greater than 6 bar to a pressure of 1 bar, the temperature of the liquid methane thus expanded being about -161.5°C, the first liquid methane phase being at a temperature of -161 °C, the second solid-liquid separator being an exchanger the temperature of which is less than -170°C, the concentration of carbon dioxide in this second liquid methane phase at -170°C being less than 200 ppmv, advantageously below 100 ppmv.
Davis, teaches a known pressure-temperature relationship between carbon dioxide content in liquid natural gas and that decreases in temperature and pressure decrease carbon dioxide content in liquid natural gas and further teaches the desire to reduce carbon dioxide content in liquid natural gas to improve the purity of the liquid natural gas for consumer usage (Fig. 3 Composition along solid-liquid-vapor locus methane-carbon dioxide system; Fig. 4. Composition of liquid phase methane-carbon dioxide system; Pg. 537, Interest in low-temperature processing of natural gas has increased in recent years. In many cases low-temperature processing may provide a more economical method of removing acid components of a gas than is now offered by more conventional methods. Clark and Kurata (1) have suggested such a method for the removal of carbon dioxide from natural gas). Therefore, it would have been obvious to one having ordinary skill in the art at the time of the invention to modify the method of Roche by decreasing the carbon dioxide content in a liquid methane stream from greater than
280 parts per million by volume to less than 200 ppmv, while decreasing pressure from a pressure greater than 6 bar to a pressure of 1 bar, and decreasing temperature from about -161.5°C to -170°C
as a matter of routine optimization since it has been held that “where 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).
Regarding claim 2, Roche as modified discloses the method according to claim 1 (see the combination of references used in the rejection of claim 1 above).
However, Roche as modified does not explicitly disclose wherein the carbon dioxide content of the first liquid methane phase, from the first liquid-solid-gas separator, is about 300 ppmv.
Davis teaches a known pressure-temperature relationship between carbon dioxide content in liquid natural gas and that decreases in temperature and pressure decrease carbon dioxide content in liquid natural gas and further teaches the desire to reduce carbon dioxide content in liquid natural gas to improve the purity of the liquid natural gas for consumer usage (Fig. 3 Composition along solid-liquid-vapor locus methane-carbon dioxide system; Fig. 4. Composition of liquid phase methane-carbon dioxide system; Pg. 537, Interest in low-temperature processing of natural gas has increased in recent years. In many cases low-temperature processing may provide a more economical method of removing acid components of a gas than is now offered by more conventional methods. Clark and Kurata (1) have suggested such a method for the removal of carbon dioxide from natural gas). Therefore, it would have been obvious to one having ordinary skill in the art at the time of the invention to modify the method of Roche by decreasing the carbon dioxide content in a liquid methane stream from greater than
280 parts per million by volume to about 300 ppmv in the first liquid methane phase as a matter of routine optimization since it has been held that “where 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).
Regarding claim 3, Roche as modified discloses the method according to claim 1 (see the combination of references used in the rejection of claim 1 above).
However, Roche as modified does not explicitly disclose wherein the temperature of the second solid-liquid separator is -176°C, the carbon dioxide content of the second liquid methane phase, at the outlet of the second solid-liquid separator, being less than 50 ppmv.
Davis teaches a known pressure-temperature relationship between carbon dioxide content in liquid natural gas and that decreases in temperature and pressure decrease carbon dioxide content in liquid natural gas and further teaches the desire to reduce carbon dioxide content in liquid natural gas to improve the purity of the liquid natural gas for consumer usage (Fig. 3 Composition along solid-liquid-vapor locus methane-carbon dioxide system; Fig. 4. Composition of liquid phase methane-carbon dioxide system; Pg. 537, Interest in low-temperature processing of natural gas has increased in recent years. In many cases low-temperature processing may provide a more economical method of removing acid components of a gas than is now offered by more conventional methods. Clark and Kurata (1) have suggested such a method for the removal of carbon dioxide from natural gas). Therefore, it would have been obvious to one having ordinary skill in the art at the time of the invention to modify the method of Roche by decreasing the temperature of the second solid-liquid separator to -176°C to lower the carbon dioxide content from about 300 at the outlet of the first separator to less than 50 ppmv at the outlet of the second solid-liquid separator as a matter of routine optimization since it has been held that “where 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).
Regarding claim 19, Roche as modified discloses a device for extracting the carbon dioxide contained in the liquid methane (Fig. 6; Col. 2, lines 8-10, FIGS. 5 and 6 are plant diagrams for carrying out the invention comprising a stage for eliminating CO2 in the course of liquefaction; Col. 6, lines 9-10, The current of liquid natural gas issuing from the column V1 at the point 3 is cooled in the exchanger E2), for implementing the method according to claim 1 (see the combination of references used in the rejection of claim 1 above), the device comprising:
a tank of the liquid methane (Fig. 6, column V1; Col. 6, lines 9-10, The current of liquid natural gas issuing from the column V1 at the point 3 is cooled in the exchanger E2);
an expansion valve downstream of the tank, to reduce the pressure of the liquid methane, to form the three-phase liquid-vapour-solid mixture of methane and carbon dioxide, the liquid methane obtained being supersaturated with carbon dioxide (Fig. 6, expansion orifice 16; Col. 5, lines 24-35, The process of the invention does not concern the formation of this precipitate but its elimination from the liquid current. It comprises eliminating by filtration the precipitate obtained by expansion of preferably the liquid in a flash flask. The formation of the precipitate is continuous from the point of formation of the first crystal when the temperature of the liquid continues to drop. As the precipitate formed has a tendency to agglomerate into a mass which is compact but, however, fragile owing to the presence in the precipitate of heavier hydrocarbons, there can be no question of cooling the liquid in a normal exchanger, owing to stopping up and clogging; Col. 6, lines 9-23, The current of liquid natural gas issuing from the column V1 at the point 3 is cooled in the exchanger E2; at the outlet of the exchanger E2 the liquid is cooled in the bottom of the column V2 and conducted to the flask B3 through the expansion orifice 16. The filtered liquid part is evacuated through the pipe 36 to the flash flask B4 and through the expansion orifice 37, the latter is expanded. The filtered liquid issuing at 38 is the liquefied natural gas. The vapour part of the flash flask B3 issuing at 39 passes through the exchanger E3, then E4a, issues at 40 and a flask B5 permits the separation of non-condensed gas if desired, the liquid of the flask being sent into the flash flask B3 through a pipe 41 directly into the expanding means 16);
the first liquid-solid-gas separator, wherein between the three-phase liquid-vapour-solid mixture, with extraction of the solid carbon dioxide by filtration, and separation of the gaseous methane, to obtain the first phase of liquid methane, partially decarbonized (Fig. 6, expansion flask B3, filter, line 36, line 39; Col. 5, lines 24-35, The process of the invention does not concern the formation of this precipitate but its elimination from the liquid current. It comprises eliminating by filtration the precipitate obtained by expansion of preferably the liquid in a flash flask. The formation of the precipitate is continuous from the point of formation of the first crystal when the temperature of the liquid continues to drop. As the precipitate formed has a tendency to agglomerate into a mass which is compact but, however, fragile owing to the presence in the precipitate of heavier hydrocarbons, there can be no question of cooling the liquid in a normal exchanger, owing to stopping up and clogging; Col. 6, lines 9-23, The current of liquid natural gas issuing from the column V1 at the point 3 is cooled in the exchanger E2; at the outlet of the exchanger E2 the liquid is cooled in the bottom of the column V2 and conducted to the flask B3 through the expansion orifice 16. The filtered liquid part is evacuated through the pipe 36 to the flash flask B4 and through the expansion orifice 37, the latter is expanded. The filtered liquid issuing at 38 is the liquefied natural gas. The vapour part of the flash flask B3 issuing at 39 passes through the exchanger E3, then E4a, issues at 40 and a flask B5 permits the separation of non-condensed gas if desired, the liquid of the flask being sent into the flash flask B3 through a pipe 41 directly into the expanding means 16);
the second liquid-solid separator, the second solid-liquid separator being the exchanger, carbon dioxide depositing in the second solid-liquid separator, to form the second liquid methane phase (Fig. 6, expansion flask B4, filter; Col. 6, lines 14-17 and 23-26, The filtered liquid part is evacuated through the pipe 36 to the flash flask B4 and through the expansion orifice 37, the latter is expanded. The filtered liquid issuing at 38 is the liquefied natural gas…The flash vapour produced in the flask B4 is recondensed through a pipe 42 in the exchanger E4b, reintroduced through a pipe 43 directly into the expanding means 37).
However, Roche does not explicitly disclose the carbon dioxide content of which is about 3000 parts per million by volume, the tank having the liquid methane at a pressure greater than 6 bar and reducing the pressure of the liquid methane to a value of 1 bar, the temperature of the liquid methane thus expanded being about -161.5°C, wherein between the first liquid methane phase at a temperature of -161 °C, an exchanger the temperature of which is less than -170°C, the concentration of carbon dioxide in this second phase of liquid methane at -170°C being less than 100 ppmv.
Davis teaches a known pressure-temperature relationship between carbon dioxide content in liquid natural gas and that decreases in temperature and pressure decrease carbon dioxide content in liquid natural gas and further teaches the desire to reduce carbon dioxide content in liquid natural gas to improve the purity of the liquid natural gas for consumer usage (Fig. 3 Composition along solid-liquid-vapor locus methane-carbon dioxide system; Fig. 4. Composition of liquid phase methane-carbon dioxide system; Pg. 537, Interest in low-temperature processing of natural gas has increased in recent years. In many cases low-temperature processing may provide a more economical method of removing acid components of a gas than is now offered by more conventional methods. Clark and Kurata (1) have suggested such a method for the removal of carbon dioxide from natural gas). Therefore, it would have been obvious to one having ordinary skill in the art at the time of the invention to modify the method of Roche by decreasing the carbon dioxide content in a liquid methane stream from greater than
3000 parts per million by volume to less than 100 ppmv, while decreasing pressure from a pressure greater than 6 bar to a pressure of 1 bar, and decreasing temperature from about -161.5°C to -170°C
as a matter of routine optimization since it has been held that “where 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).
Regarding claim 20, Roche as modified discloses the device according to claim 19 (see the combination of references used in the rejection of claim 19 above).
However, Fig. 6 of Roche does not explicitly disclose wherein the first liquid-solid-gas separator comprises two enclosures, each enclosure being provided with a micron filter for recovery of solid carbon dioxide.
Fig. 5 of Roche teaches wherein the first liquid-solid-gas separator comprises two enclosures, each enclosure being provided with a micron filter for recovery of solid carbon dioxide (Fig. 5, flash flask B3a, B3b, filters 18; Col. 5, lines 38-24, This precipitate only decants when the speeds are substantially nil and it is filtered by passing it through a pad of glass wool, a plate of sintered metal or any other filtering material which resists the con templated temperature conditions and stresses; Col. 5, lines 43-49, With reference to FIG. 5 which shows a detail of the plant, it can be seen that two flash flasks or filters B3a and B3b are fed in parallel with liquefied natural gases under pressure through the pipe 15 and expanded in a nozzle 16. Operation of the valves 17, 17a, 20, 28, 22, 25, 27, 29, 26, 35 permits the alternative operation of the flash flask B3a or B3b).
Therefore, it would have been obvious before the effective filing date of the claimed invention to modify the device of Roche as modified wherein the first liquid-solid-gas separator comprises two enclosures, each enclosure being provided with a micron filter for recovery of solid carbon dioxide as taught by Fig. 5 of Roche. One of ordinary skill in the art would have been motivated to make this modification to permit the alternative operation of the two enclosures to improve overall system efficiencies (Roche, Col. 5, lines 47-49).
Regarding claim 21, Roche as modified discloses the device according to claim 20 (see the combination of references used in the rejection of claim 20 above), wherein the two enclosures of the first liquid-solid-gas separator are identical (Fig. 5 of Roche depicts flash flasks B3a and B3b to be identical). Further, the limitations of claim 21 are the result of the modification of references used in the rejection of claim 20 above.
Regarding claim 22, Roche as modified discloses the device according to claim 20 (see the combination of references used in the rejection of claim 20 above).
Roche as modified discloses the claimed invention except for wherein the micron filter has a solid matrix, with a porosity of about 10 micrometers. It would have been obvious to one having ordinary skill in the art at the time the invention was made to modify the micron filter to have a solid matrix with a porosity of about 10 micrometers since it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use or purpose MPEP 2144.07. Further, the limitations of claim 22 are the result of the modification of references used in the rejection of claim 20 above.
Regarding claim 24, Roche as modified discloses the method according to claim 1 (see the combination of references used in the rejection of claim 1 above).
However, Roche as modified does not explicitly disclose wherein the carbon dioxide content of is about 3000 parts per million by volume (ppmv) and the concentration of carbon dioxide in this second liquid methane phase at -170°C is less than 100 ppmv.
Davis teaches a known pressure-temperature relationship between carbon dioxide content in liquid natural gas and that decreases in temperature and pressure decrease carbon dioxide content in liquid natural gas and further teaches the desire to reduce carbon dioxide content in liquid natural gas to improve the purity of the liquid natural gas for consumer usage (Fig. 3 Composition along solid-liquid-vapor locus methane-carbon dioxide system; Fig. 4. Composition of liquid phase methane-carbon dioxide system; Pg. 537, Interest in low-temperature processing of natural gas has increased in recent years. In many cases low-temperature processing may provide a more economical method of removing acid components of a gas than is now offered by more conventional methods. Clark and Kurata (1) have suggested such a method for the removal of carbon dioxide from natural gas). Therefore, it would have been obvious to one having ordinary skill in the art at the time of the invention to modify the method of Roche by decreasing the carbon dioxide content in a liquid methane stream from about 3000 parts per million by volume (ppmv) to less than 100 ppmv at -170 °C in the second liquid methane phase as a matter of routine optimization since it has been held that “where 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).
Furthermore, since applicants have not disclosed that these modifications solve any stated problem or are for any particular purpose and it appears that the device would perform equally well with either designs, these modifications are a matter of design choice. Absent a teaching as to criticality of the carbon dioxide content of is about 3000 parts per million by volume (ppmv) and the concentration of carbon dioxide in this second liquid methane phase at -170°C is less than 100 ppmv, this particular arrangement is deemed to have been known by those skilled in the art since the instant specification and evidence of record fail to attribute any significance (novel or unexpected results) to a particular arrangement. In re Kuhle, 526 F.2d 553,555,188 USPQ 7, 9 (CCPA 1975). MPEP 2144.05.
Claims 4-5 are rejected under 35 U.S.C. 103 as being unpatentable over Roche as modified by Davis as applied to claim 1 above, and further in view of Wilding et al. (US 20020174678), hereinafter Wilding.
Regarding claim 4, Roche as modified discloses the method according to claim 1 (see the combination of references used in the rejection of claim 1 above).
However, Roche as modified does not explicitly disclose comprising a step of extracting the solid carbon dioxide deposited in the second solid-liquid separator, this extraction being carried out in the gas phase at a pressure of about 500 mbar.
Wilding teaches a step of extracting the solid carbon dioxide deposited in the second solid-liquid separator, this extraction being carried out based on pressure conditions throughout the system (Fig. 4, CO2 screen filters 266A, 266B; Pg. 9, paragraph 101, The CO2 screen filters 266A and 266B may, from time to time, become clogged or plugged with solid CO2 captured therein. Thus, as one filter, i.e., 266A, is being used to capture CO2 from the liquid natural gas stream, the other filter, i.e., 266B, may be purged of CO2 by passing a relatively high temperature natural gas therethrough in a counter flowing fashion. For example, gas may be drawn after the water clean-up cycle through a fourth heat exchanger 275 as indicated at interface points 276C and 276B to flow through and clean the CO2 screen filter 266B. Gas may be flowed through one or more pressure regulating valves 277 prior to passing through the heat exchanger 275 and into the CO2 screen filter 266B as may be dictated by pressure and flow conditions within the process).
Therefore, it would have been obvious before the effective filing date of the claimed invention to modify the method of Roche as modified to include the step or limitation of extracting the solid carbon dioxide deposited in the second solid-liquid separator, this extraction being carried out based on pressure conditions throughout the system as taught by Wilding. One of ordinary skill in the art would have been motivated to make this modification to unclog the filters of second separator to improve overall system efficiencies (Wilding, Pg. 9, paragraph 101).
Moreover, Roche as modified teaches the claimed invention except for this extraction being carried out in the gas phase at a pressure of about 500 mbar. It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include his extraction being carried out in the gas phase at a pressure of about 500 mbar, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges [ or optimum value ] involves only routine skill in the art. In re Aller, 105 USPQ 233. MPEP 2144.05-II-A.
Furthermore, since applicants have not disclosed that these modifications solve any stated problem or are for any particular purpose and it appears that the device would perform equally well with either designs, these modifications are a matter of design choice. Absent a teaching as to criticality of this extraction being carried out in the gas phase at a pressure of about 500 mbar, this particular arrangement is deemed to have been known by those skilled in the art since the instant specification and evidence of record fail to attribute any significance (novel or unexpected results) to a particular arrangement. In re Kuhle, 526 F.2d 553,555,188 USPQ 7, 9 (CCPA 1975). MPEP 2144.05.
Regarding claim 5, Roche as modified discloses the method according to claim 1 (see the combination of references used in the rejection of claim 1 above).
However, Roche as modified does not explicitly disclose comprising a step of extracting the solid carbon dioxide deposited in the second solid-liquid separator, this extraction being carried out in the liquid phase at a pressure of about 6 bar.
Wilding teaches a step of extracting the solid carbon dioxide deposited in the second solid-liquid separator, this extraction being carried out based on pressure conditions throughout the system (Fig. 4, CO2 screen filters 266A, 266B; Pg. 9, paragraph 101, The CO2 screen filters 266A and 266B may, from time to time, become clogged or plugged with solid CO2 captured therein. Thus, as one filter, i.e., 266A, is being used to capture CO2 from the liquid natural gas stream, the other filter, i.e., 266B, may be purged of CO2 by passing a relatively high temperature natural gas therethrough in a counter flowing fashion. For example, gas may be drawn after the water clean-up cycle through a fourth heat exchanger 275 as indicated at interface points 276C and 276B to flow through and clean the CO2 screen filter 266B. Gas may be flowed through one or more pressure regulating valves 277 prior to passing through the heat exchanger 275 and into the CO2 screen filter 266B as may be dictated by pressure and flow conditions within the process).
Therefore, it would have been obvious before the effective filing date of the claimed invention to modify the method of Roche as modified to include the step or limitation of extracting the solid carbon dioxide deposited in the second solid-liquid separator, this extraction being carried out based on pressure conditions throughout the system as taught by Wilding. One of ordinary skill in the art would have been motivated to make this modification to unclog the filters of second separator to improve overall system efficiencies (Wilding, Pg. 9, paragraph 101).
Moreover, Roche as modified teaches the claimed invention except for this extraction being carried out in the liquid phase at a pressure of about 6 bar. It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include his extraction being carried out in the liquid phase at a pressure of about 6 bar, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges [ or optimum value ] involves only routine skill in the art. In re Aller, 105 USPQ 233. MPEP 2144.05-II-A.
Furthermore, since applicants have not disclosed that these modifications solve any stated problem or are for any particular purpose and it appears that the device would perform equally well with either designs, these modifications are a matter of design choice. Absent a teaching as to criticality of this extraction being carried out in the liquid phase at a pressure of about 6 bar, this particular arrangement is deemed to have been known by those skilled in the art since the instant specification and evidence of record fail to attribute any significance (novel or unexpected results) to a particular arrangement. In re Kuhle, 526 F.2d 553,555,188 USPQ 7, 9 (CCPA 1975). MPEP 2144.05.
Claims 6-12, 15-18, and 25 are rejected under 35 U.S.C. 103 as being unpatentable over Roche as modified by Davis as applied to claim 1 above, and further in view of Turner et al. (US Patent No. 7,591,150), hereinafter Turner.
Regarding claim 6, Roche as modified discloses the method according to claim 1 (see the combination of references used in the rejection of claim 1 above).
However, Roche as modified does not explicitly disclose comprising a step of measuring the pressure loss on the liquid methane between the inlet and outlet of the first liquid-solid-gas separator.
Turner teaches the importance of maintaining appropriate pressures within a first liquid-solid-gas separator to prevent boiling in the separator due to pressure losses (Fig. 2, separator 180; Col. 12-13, lines 45-67 and 1-8, As the separator 180 is filled, the level may be monitored by appropriate sensors. The level of the liquid/solid within the separator 180 may be desirably monitored and controlled in order to provide desired resident times for the CO2 and thereby ensure that the CO2 particles are subcooled. When a specified maximum level of liquid/solid slurry is reached within the separator 180, the liquid/solid slurry will be transferred to at least one of a plurality of transfer tanks 190A and 190B. In one embodiment, the transfer tanks 190A and 190B are used alternately. The transfer tanks 190A and 190B are utilized to transfer the slurry from the separator 180 to one of a plurality of hydrocyclones 192A and 192B. While it is possible to transfer the slurry from the separator 180 to the hydrocyclones 192A and 192B without the use of the transfer tanks 190A and 190B, it is believed that, in the currently described embodiment, the use of transfer tanks 190A and 190B provides improved control over the transfer of the slurry (including transfer of the slurry to the hydrocyclones 192A and 192B and subsequent transfer of the liquid from the hydrocyclones 192A and 192B to downstream components such as the storage tank 116), and ensures that adequate transfer pressures are maintained during such transfer. If pressures are not properly maintained during transfer of the slurry, the liquid may boil due to pressure losses associated with piping and other components. Additionally, failure to maintain proper pressures during transfer of the slurry may result in inadequate solid-liquid separation. The use of separate, alternating tanks 190A and 190B to effect the transfer of the slurry from the separator 180, is one means that may be used to maintain the pressure integrity of the liquefaction plant 102).
Therefore, it would have been obvious before the effective filing date of the claimed invention to modify the method of Roche as modified to include the step or limitation of measuring the pressure loss on the liquid methane between the inlet and outlet of the first separator as taught by Turner. One of ordinary skill in the art would have been motivated to make this modification to ensure appropriate pressure is maintained within the first separator to provide desired phase separation (Turner, Col. 12-13, lines 67 and 1-4).
Regarding claim 7, Roche as modified discloses the method according to claim 6 (see the combination of references used in the rejection of claim 6 above), wherein when the pressure loss on the liquid methane between the inlet and outlet of the first liquid-solid-gas separator is greater than a predetermined threshold, the extraction of the carbon dioxide deposited in the first liquid-solid-gas separator is interrupted (Col. 12-13, lines 45-67 and 1-8, As the separator 180 is filled, the level may be monitored by appropriate sensors. The level of the liquid/solid within the separator 180 may be desirably monitored and controlled in order to provide desired resident times for the CO2 and thereby ensure that the CO2 particles are subcooled. When a specified maximum level of liquid/solid slurry is reached within the separator 180, the liquid/solid slurry will be transferred to at least one of a plurality of transfer tanks 190A and 190B. In one embodiment, the transfer tanks 190A and 190B are used alternately. The transfer tanks 190A and 190B are utilized to transfer the slurry from the separator 180 to one of a plurality of hydrocyclones 192A and 192B. While it is possible to transfer the slurry from the separator 180 to the hydrocyclones 192A and 192B without the use of the transfer tanks 190A and 190B, it is believed that, in the currently described embodiment, the use of transfer tanks 190A and 190B provides improved control over the transfer of the slurry (including transfer of the slurry to the hydrocyclones 192A and 192B and subsequent transfer of the liquid from the hydrocyclones 192A and 192B to downstream components such as the storage tank 116), and ensures that adequate transfer pressures are maintained during such transfer. If pressures are not properly maintained during transfer of the slurry, the liquid may boil due to pressure losses associated with piping and other components. Additionally, failure to maintain proper pressures during transfer of the slurry may result in inadequate solid-liquid separation. The use of separate, alternating tanks 190A and 190B to effect the transfer of the slurry from the separator 180, is one means that may be used to maintain the pressure integrity of the liquefaction plant 102; Further, the teachings of pressures not being properly maintained in the separator 180 resulting in inadequate solid-liquid separation is at least an implicit teaching of the extraction of the carbon dioxide deposited in the first separator being interrupted since it has been held in considering the disclosure of a reference, it is proper to take into account not only specific teachings of the reference but also the inferences which one skilled in the art would reasonably be expected to draw therefrom (MPEP 2144.01)). Further, the limitations of claim 7 are the result of the modification of references used in the rejection of claim 6 above.
Regarding claim 8, Roche as modified discloses the method according to claim 7 (see the combination of references used in the rejection of claim 7 above).
However, Fig. 6 of Roche does not explicitly disclose wherein the first liquid-solid-gas separator comprises two enclosures, each enclosure being provided with a micron filter for recovery of solid carbon dioxide.
Fig. 5 of Roche teaches wherein the first liquid-solid-gas separator comprises two enclosures, each enclosure being provided with a micron filter for recovery of solid carbon dioxide (Fig. 5, flash flask B3a, B3b, filters 18; Col. 5, lines 38-24, This precipitate only decants when the speeds are substantially nil and it is filtered by passing it through a pad of glass wool, a plate of sintered metal or any other filtering material which resists the con templated temperature conditions and stresses; Col. 5, lines 43-49, With reference to FIG. 5 which shows a detail of the plant, it can be seen that two flash flasks or filters B3a and B3b are fed in parallel with liquefied natural gases under pressure through the pipe 15 and expanded in a nozzle 16. Operation of the valves 17, 17a, 20, 28, 22, 25, 27, 29, 26, 35 permits the alternative operation of the flash flask B3a or B3b).
Therefore, it would have been obvious before the effective filing date of the claimed invention to modify the first separator of the method of Roche as modified wherein the first liquid-solid-gas separator comprises two enclosures, each enclosure being provided with a micron filter for recovery of solid carbon dioxide as taught by Fig. 5 of Roche. One of ordinary skill in the art would have been motivated to make this modification to permit the alternative operation of the two enclosures to improve overall system efficiencies (Roche, Col. 5, lines 47-49).
Regarding claim 9, Roche as modified discloses the method according to claim 8 (see the combination of references used in the rejection of claim 8 above).
However, Roche as modified does not explicitly disclose wherein when the extraction of the carbon dioxide deposited in the first separator is interrupted, the method comprises a step of heating the filters.
Fig. 5 of Roche teaches wherein when the extraction of the carbon dioxide deposited in the first liquid-solid-gas separator is interrupted, the method comprises a step of heating the filters (Col. 5-6, lines 66-75 and 1-2; The flask B3b being in the regenerating condition, the regeneration is effected by a supply of combustible gas heated to around -50° C. coming from the pipe 8 and passing, through an open valve 29, the filter of the flash flask B3b at counter-current. The hot gas sublimates the CO2 deposited on the filter; the mixture gas-combustible CO2 being sent toward the point of utilization through the pipe 31, a valve 35 being open, the end of the regeneration of the filter is effected when the temperature at 34 tends· to reach -50° C).
Therefore, it would have been obvious before the effective filing date of the claimed invention to modify the method of Roche as modified to include the step or limitation of heating the filters when the extraction of the carbon dioxide deposited in the first separator is interrupted as taught by Fig. 5 of Roche. One of ordinary skill in the art would have been motivated to make this modification to permit the alternative operation of the two enclosures to improve overall system efficiencies (Roche, Col. 5, lines 47-49).
Regarding claim 10, Roche as modified discloses the method according to claim 8 (see the combination of references used in the rejection of claim 8 above).
However, Roche as modified does not explicitly disclose comprising a measurement of the temperature of the fluid circulating in the filters, downstream of the filters, the extraction of the carbon dioxide being completed when this temperature exceeds a predetermined threshold value.
Fig. 5 of Roche teaches comprising a measurement of the temperature of the fluid circulating in the filters, downstream of the filters, the extraction of the carbon dioxide being completed when this temperature exceeds a predetermined threshold value (Col. 5-6, lines 66-75 and 1-2; The flask B3b being in the regenerating condition, the regeneration is effected by a supply of combustible gas heated to around -50° C. coming from the pipe 8 and passing, through an open valve 29, the filter of the flash flask B3b at counter-current. The hot gas sublimates the CO2 deposited on the filter; the mixture gas-combustible CO2 being sent toward the point of utilization through the pipe 31, a valve 35 being open, the end of the regeneration of the filter is effected when the temperature at 34 tends to reach -50° C).
Therefore, it would have been obvious before the effective filing date of the claimed invention to modify the method of Roche as modified to include the step or limitation of a measurement of the temperature of the fluid circulating in the filters, downstream of the filters, the extraction of the carbon dioxide being completed when this temperature exceeds a predetermined threshold value as taught by Fig. 5 of Roche. One of ordinary skill in the art would have been motivated to make this modification to permit the alternative operation of the two enclosures to improve overall system efficiencies (Roche, Col. 5, lines 47-49).
Regarding claim 11, Roche as modified discloses the method according to claim 8 (see the combination of references used in the rejection of claim 8 above).
However, Roche as modified does not explicitly disclose wherein when the extraction of carbon dioxide is interrupted, the methane flow is diverted from a first one of the two enclosures of the liquid-solid-gas separator to a second one of the two enclosures of the first liquid-solid-gas separator.
Fig. 5 of Roche teaches comprising disclose wherein when the extraction of carbon dioxide is interrupted, the methane flow is diverted from a first one of the two enclosures of the liquid-solid-gas separator to a second one of the two enclosures of the first liquid-solid-gas separator (Col. 5-6, lines 43-75 and 1-2; With reference to FIG. 5 which shows a detail of the plant, it can be seen that two flash flasks or filters B3a and B3b are fed in parallel with liquefied natural gases under pressure through the pipe 15 and expanded in a nozzle 16. Operation of the valves 17, 17a, 20, 28, 22, 25, 27, 29, 26, 35 permits the alternative operation of the flash flask B3a or B3b. Assuming that the flash flask B3a is operating, the flask B3b regenerating: the valve 17 is open, 17a closed, the liquid expanded in B3a is cooled and separates into a liquid fraction and a gaseous fraction. In the liquid fraction, all the CO2 precipitates, the CO2 being retained inside a filter 18 placed at the lower part of the flash flask. The liquid natural gas is recovered toward the second expansion stage through the collector 19 through the medium of a valve 20 which is open. The gaseous phase issuing from flask B3a at 21 is conducted through an open valve 22 to a condenser 23. The recondensed vapours issuing at 24 from the condenser 23 are re-injected into the expanding means 16 feeding the flash flask B3a through the valve 17. In this operation, the valves 1,7, 20 and 22 are open, the valves 2'5, 26, 27 and 28 being closed. The flask B3b being in the regenerating condition, the regeneration is effected by a supply of combustible gas heated to around -50° C. coming from the pipe 8 and passing, through an open valve 29, the filter of the flash flask B3b at counter-current. The hot gas sublimates the CO2 deposited on the filter; the mixture gas-combustible CO2 being sent toward the point of utilization through the pipe 31, a valve 35 being open, the end of the regeneration of the filter is effected when the temperature at 34 tends to reach -50° C).
Therefore, it would have been obvious before the effective filing date of the claimed invention to modify the method of Roche as modified to include the step or limitation of wherein when the extraction of carbon dioxide is interrupted, the methane flow is diverted a first one of the two enclosures of the liquid-solid-gas separator to a second one of the two enclosures of the first liquid-solid-gas separator as taught by Fig. 5 of Roche. One of ordinary skill in the art would have been motivated to make this modification to permit the alternative operation of the two enclosures to improve overall system efficiencies (Roche, Col. 5, lines 47-49).
Regarding claim 12, Roche as modified discloses the method according to claim 1 (see the combination of references used in the rejection of claim 1 above).
However, Roche as modified does not explicitly disclose comprising a step of measuring the pressure loss on the liquid methane between the inlet and outlet of the second solid-liquid separator.
Turner teaches comprising a step of measuring the pressure loss on the liquid methane between the inlet and outlet of the second solid-liquid separator (Fig. 2, Filters 200A, 200B; Col. 15, lines 26-35 In another embodiment, the filters 200A and 200B may be configured to include a floating bed that traps solid CO2 while permitting fluid to pass therethrough. As the floating bed becomes filled with CO2 the trapped CO2 settles to the bottom. When the filter (e.g., filter 200A) is filled with CO2, an elevated pressure differential develops indicating that the filter 200A needs to be cleaned and flow can be switched to the redundant filter (e.g., filter 200B). The first filter 200A may then be cleaned in a manner similar to that which has been described hereinabove; Further, the teachings of Turner at least imply a step of measuring the pressure loss on the liquid methane between the inlet and outlet of the second separator since it has been held in considering the disclosure of a reference, it is proper to take into account not only specific teachings of the reference but also the inferences which one skilled in the art would reasonably be expected to draw therefrom (MPEP 2144.01)).
Therefore, it would have been obvious before the effective filing date of the claimed invention to modify the method of Roche as modified to include the step or limitation of measuring the pressure loss on the liquid methane between the inlet and outlet of the second solid-liquid separator as taught by Turner. One of ordinary skill in the art would have been motivated to make this modification to ensure proper function of the second separator to improve overall system efficiencies (Col. 15, lines 30-35).
Regarding claim 15, Roche as modified discloses the method according to claim 12 (see the combination of references used in the rejection of claim 12 above), wherein when the pressure loss on the liquid methane between the inlet and outlet of the second solid-liquid separator is greater than a predetermined threshold, the extraction by frosting of the carbon dioxide deposited in the second solid-liquid separator is interrupted (Turner, Col. 15, lines 26-35 In another embodiment, the filters 200A and 200B may be configured to include a floating bed that traps solid CO2 while permitting fluid to pass therethrough. As the floating bed becomes filled with CO2 the trapped CO2 settles to the bottom. When the filter (e.g., filter 200A) is filled with CO2, an elevated pressure differential develops indicating that the filter 200A needs to be cleaned and flow can be switched to the redundant filter (e.g., filter 200B). The first filter 200A may then be cleaned in a manner similar to that which has been described hereinabove; Further, the teachings of Turner at least imply when the pressure loss on the liquid methane between the inlet and outlet of the second separator is greater than a predetermined threshold, the extraction by frosting of the carbon dioxide deposited in the second separator is interrupted since it has been held in considering the disclosure of a reference, it is proper to take into account not only specific teachings of the reference but also the inferences which one skilled in the art would reasonably be expected to draw therefrom (MPEP 2144.01)). Further, the limitations of claim 15 are the result of the modification of references used in the rejection of claim 12 above.
Regarding claim 16, Roche as modified discloses the method according to claim 12 (see the combination of references used in the rejection of claim 12 above).
However, Roche as modified does not explicitly disclose wherein the second solid-liquid separator comprises two enclosures, the method comprises a step of heating a first enclosure of the two enclosures when the frosting of the carbon dioxide deposited in the first enclosure of the two enclosures of the second solid-liquid separator is interrupted.
Turner teaches wherein the second solid-liquid separator comprises two enclosures, the method comprises a step of heating a first enclosure of the two enclosures when the frosting of the carbon dioxide deposited in the first enclosure of the two enclosures of the second solid-liquid separator is interrupted (Fig. 2, Filters 200A, 200B; Col. 15, lines 26-35 In another embodiment, the filters 200A and 200B may be configured to include a floating bed that traps solid CO2 while permitting fluid to pass therethrough. As the floating bed becomes filled with CO2 the trapped CO2 settles to the bottom. When the filter (e.g., filter 200A) is filled with CO2, an elevated pressure differential develops indicating that the filter 200A needs to be cleaned and flow can be switched to the redundant filter (e.g., filter 200B). The first filter 200A may then be cleaned in a manner similar to that which has been described hereinabove).
Therefore, it would have been obvious before the effective filing date of the claimed invention to modify the method of Roche as modified to include the step or limitation of wherein the second solid-liquid separator comprises two enclosures, the method comprises a step of heating a first enclosure of the two enclosures when the frosting of the carbon dioxide deposited in the first enclosure of the two enclosures of the second solid-liquid separator is interrupted as taught by Turner. One of ordinary skill in the art would have been motivated to make this modification to ensure proper function of the second separator to improve overall system efficiencies (Col. 15, lines 30-35).
Regarding claim 17, Roche as modified discloses the method according to claim 16 (see the combination of references used in the rejection of claim 16 above).
However, Roche as modified does not explicitly disclose comprising a measurement of the temperature of the fluid circulating in the enclosures, downstream of the enclosures, the defrosting of the carbon dioxide being completed when this temperature exceeds a predetermined threshold value.
Turner teaches comprising a measurement of the temperature of the fluid circulating in the enclosures, downstream of the enclosures, the defrosting of the carbon dioxide being completed when this temperature exceeds a predetermined threshold value (Fig. 4, steps 256-286; Col. 24-25, lines 33-67 and 1-10, If the first filter 200A is not the current filter, it is then determined if the first filter 200A is available (as it is possible that both filters 200A and 200B may be simultaneously unavailable) as indicated at 258. If the first filter 200A is not available, an error message may be reported to the controller as shown at 260. If the first filter200A is available, then liquid flow is switched to the first filter 200A as indicated at 262 and the second filter 200B is set as being unavailable as indicated at 264. Warming gas is then introduced into the second filter 200B, such as by supplying such warming gas from interface point 202B, through the filter 200B and out interface connection 136E, as indicated at 265. The temperature of the second filter 200B is monitored and compared with a target temperature as indicated at 266. If the temperature of the filter 200B is less than the target temperature, the process continues, as indicated by loop 268. In one embodiment of the present invention, the target temperature may be approximately -70° F. If the temperature of the filter 200B is greater than the target temperature, indicating that all of the CO2 has been sublimed from the filter 200B, then the flow of warming gas is stopped as indicated at 270. The second filter 200B is then set as being available as indicated at 272 and the process continues as indicated by loop 274. Returning back to the decision point at 256, if the first filter 200A is the current filter, then it is determined whether the second filter 200B is available as indicated at 276. If the second filter 200B is not available, an error message may be reported as shown at 260. If the second filter 200B is available, then liquid flow is switched to the second filter 200B as indicated at 278 and the first filter 200A is set as being unavailable as indicated at 280. Warming gas is then introduced into the first filter 200A, such as by supplying such warming gas from interface point 202A, through the filter 200A and out interface connection 136D, as indicated at 282. The temperature of the first filter 200A is monitored and compared with a target temperature as indicated at 284. If the temperature of the filter 200A is less than the target temperature, the process continues, as indicated by loop 286. If the temperature of the filter 200A is greater than the target temperature, indicating that all of the CO2 has been sublimed from the filter 200A, then the flow of warming gas is stopped as indicated at 288. The first filter 200A is then set as being available as indicated at 290 and the process continues as indicated by loop 274).
Therefore, it would have been obvious before the effective filing date of the claimed invention to modify the method of Roche as modified to include the step or limitation of a measurement of the temperature of the fluid circulating in the enclosures, downstream of the enclosures, the defrosting of the carbon dioxide being completed when this temperature exceeds a predetermined threshold value as taught by Turner. One of ordinary skill in the art would have been motivated to make this modification to ensure proper function of the second separator to improve overall system efficiencies (Col. 15, lines 30-35).
Regarding claim 18, Roche as modified discloses the method according to claim 17 (see the combination of references used in the rejection of claim 17 above), wherein when the frosting of the carbon dioxide is completed in a first enclosure of the second solid-liquid separator, the methane flow is diverted to a second enclosure of the second solid-liquid separator, the second solid-liquid separator thus operating alternately, the first enclosure of the second solid-liquid separator being in the frosting phase when the second enclosure of the second solid-liquid separator is in the defrosting phase (Turner, Fig. 4, steps 256-286; Col. 24-25, lines 33-67 and 1-10, If the first filter 200A is not the current filter, it is then determined if the first filter 200A is available (as it is possible that both filters 200A and 200B may be simultaneously unavailable) as indicated at 258. If the first filter 200A is not available, an error message may be reported to the controller as shown at 260. If the first filter200A is available, then liquid flow is switched to the first filter 200A as indicated at 262 and the second filter 200B is set as being unavailable as indicated at 264. Warming gas is then introduced into the second filter 200B, such as by supplying such warming gas from interface point 202B, through the filter 200B and out interface connection 136E, as indicated at 265. The temperature of the second filter 200B is monitored and compared with a target temperature as indicated at 266. If the temperature of the filter 200B is less than the target temperature, the process continues, as indicated by loop 268. In one embodiment of the present invention, the target temperature may be approximately -70° F. If the temperature of the filter 200B is greater than the target temperature, indicating that all of the CO2 has been sublimed from the filter 200B, then the flow of warming gas is stopped as indicated at 270. The second filter 200B is then set as being available as indicated at 272 and the process continues as indicated by loop 274. Returning back to the decision point at 256, if the first filter 200A is the current filter, then it is determined whether the second filter 200B is available as indicated at 276. If the second filter 200B is not available, an error message may be reported as shown at 260. If the second filter 200B is available, then liquid flow is switched to the second filter 200B as indicated at 278 and the first filter 200A is set as being unavailable as indicated at 280. Warming gas is then introduced into the first filter 200A, such as by supplying such warming gas from interface point 202A, through the filter 200A and out interface connection 136D, as indicated at 282. The temperature of the first filter 200A is monitored and compared with a target temperature as indicated at 284. If the temperature of the filter 200A is less than the target temperature, the process continues, as indicated by loop 286. If the temperature of the filter 200A is greater than the target temperature, indicating that all of the CO2 has been sublimed from the filter 200A, then the flow of warming gas is stopped as indicated at 288. The first filter 200A is then set as being available as indicated at 290 and the process continues as indicated by loop 274). Further, the limitations of claim 18 are the result of the modification of references used in the rejection of claim 17 above.
Regarding claim 25, Roche as modified discloses the method according to claim 10 (see the combination of references used in the rejection of claim 10 above).
However, Roche as modified does not explicitly disclose wherein the predetermined threshold value is about 10°C.
Roche as modified teaches the claimed invention except for wherein the predetermined threshold value is about 10°C. It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include wherein the predetermined threshold value is about 10°C, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges [or optimum value] involves only routine skill in the art. In re Aller, 105 USPQ 233. MPEP 2144.05-II-A.
Furthermore, since applicants have not disclosed that these modifications solve any stated problem or are for any particular purpose and it appears that the device would perform equally well with either designs, these modifications are a matter of design choice. Absent a teaching as to criticality of wherein the predetermined threshold value is about 10°C, this particular arrangement is deemed to have been known by those skilled in the art since the instant specification and evidence of record fail to attribute any significance (novel or unexpected results) to a particular arrangement. In re Kuhle, 526 F.2d 553,555,188 USPQ 7, 9 (CCPA 1975). MPEP 2144.05. Further, the limitations of claim 25 are the result of the modification of references used in the rejection of claim 10 above.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Roche as modified by Davis and Turner as applied to claim 12 above, and further in view of Nobel, III (US Patent No. 6,467,300), hereinafter Nobel.
Regarding claim 13, Roche as modified discloses the method according to claim 12 (see the combination of references used in the rejection of claim 12 above).
However, Roche as modified does not disclose wherein the second solid-liquid separator is a finned-tube exchanger.
Nobel teaches a separator that is a finned-tube exchanger (Fig. 1, accumulator 62; Col. 11, lines 3-10, The cold return gas, a cold oily gas, leaves evaporator outlet 2 through tube A into accumulator 62, through accumulator inlet 3 where it bathes the hot liquid container 57, which may be shaped as a tube (e.g. coiled tubing 67), cylinder (not shown), braised plate (not shown), finned tube (not shown), or any other effective liquid-carrying heat exchange device, then leaves accumulator 62 at accumulator outlet 4).
Roche as modified fails to teach a separator that is a finned-tube exchanger, however Nobel teaches that it is a known method in the art of separators to include a separator that is a finned-tube exchanger. This is strong evidence that modifying Roche as modified as claimed would produce predictable results (i.e. providing desired pressure and temperature conditions within a separator). Accordingly, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify Roche as modified by Nobel and arrive at the claimed invention since all claimed elements were known in the art and one having ordinary skill in the art could have combined the elements as claimed by known methods with no changes in their respective functions and the combination would have yielded the predictable result of providing desired pressure and temperature conditions within a separator.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Roche as modified by Davis, Turner, and Nobel as applied to claim 13 above, and further in view of Bhatia et al. (US Patent No. 12,339,066), hereinafter Bhatia.
Regarding claim 14, Roche as modified discloses the method according to claim 13 (see the combination of references used in the rejection of claim 13 above).
However, Roche as modified does not disclose wherein the maximum speed of the liquid methane in the channels formed by the inter-fin spaces of the second solid-liquid separator exchanger is about 0.2 m/s.
Bhatia teaches a known relationship between fluid velocity over a finned tube heat exchanger and desired heat exchange characteristics of the heat exchanger that can be affected by the orientation of the fins (Col. 11, lines 9-32, In certain embodiments, the amount of heat exchanged between the fluid and the refrigerant is based on a distribution of a velocity of the fluid as the fluid is directed across the microchannel tubes 104, 106 of the heat exchanger 100. For example, a speed at which the fluid is directed across each microchannel tube 104, 106 may determine the amount of heat exchanged between the fluid and the refrigerant. In some embodiments, it may be desirable to have an improved
distributed velocity profile of the fluid directed across the heat exchanger 100. That is, the heat exchanger 100 may be designed such that the velocity of the fluid across each microchannel tube 104, 106 along the respective lengths 110 is approximately the same (e.g., uniform) to enable the amount of heat transferred between the fluid and the refrigerant to be approximately the same across each respective length 110. In heat exchangers 100 that include a plurality of microchannel tubes 104, 106, the velocity profile of the fluid at certain portions of the heat exchanger 100 may not be desirable due to an orientation of the microchannel tubes 104, 106 and/or the set of fins 116 relative to a flow of the
fluid. However, selecting a particular position of certain fins may produce an improved distributed velocity profile of the fluid across the heat exchanger 100 to improve heat transfer efficiency of the heat exchanger 100). Therefore, it would have been obvious to one having ordinary skill in the art at the time of the invention to modify the method of Roche by arranging the fins of the finned-tubed exchanger wherein the maximum speed of the liquid methane in the channels formed by the inter-fin spaces of the second solid-liquid separator exchanger is about 0.2 m/s as a matter of routine optimization since it has been held that “where 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).
Claim 23 is rejected under 35 U.S.C. 103 as being unpatentable over Roche as modified by Davis as applied to claim 19 above, and further in view of Turner et al. (US Patent No. 7,591,150), hereinafter Turner and Nobel, III (US Patent No. 6,467,300), hereinafter Nobel.
Regarding claim 23, Roche as modified discloses the device according to claim 19 (see the combination of references used in the rejection of claim 19 above).
However, Roche as modified does not disclose wherein the second solid-liquid separator comprises two enclosures.
Turner teaches wherein the second solid-liquid separator comprises two enclosures (Fig. 2, Filters 200A, 200B; Col. 15, lines 26-35 In another embodiment, the filters 200A and 200B may be configured to include a floating bed that traps solid CO2 while permitting fluid to pass therethrough. As the floating bed becomes filled with CO2 the trapped CO2 settles to the bottom. When the filter (e.g., filter 200A) is filled with CO2, an elevated pressure differential develops indicating that the filter 200A needs to be cleaned and flow can be switched to the redundant filter (e.g., filter 200B). The first filter 200A may then be cleaned in a manner similar to that which has been described hereinabove).
Therefore, it would have been obvious before the effective filing date of the claimed invention to modify the device of Roche as modified wherein the second solid-liquid separator comprises two enclosures as taught by Turner. One of ordinary skill in the art would have been motivated to make this modification to ensure proper function of the second separator to improve overall system efficiencies (Col. 15, lines 30-35).
Further, Roche as modified does not disclose each enclosure being provided with a finned-tube exchanger.
Nobel teaches a separator that is a finned-tube exchanger (Fig. 1, accumulator 62; Col. 11, lines 3-10, The cold return gas, a cold oily gas, leaves evaporator outlet 2 through tube A into accumulator 62, through accumulator inlet 3 where it bathes the hot liquid container 57, which may be shaped as a tube (e.g. coiled tubing 67), cylinder (not shown), braised plate (not shown), finned tube (not shown), or any other effective liquid-carrying heat exchange device, then leaves accumulator 62 at accumulator outlet 4).
Roche as modified fails to teach each enclosure being provided with a finned-tube exchanger, however Nobel teaches that it is a known method in the art of separators to include each enclosure being provided with a finned-tube exchanger. This is strong evidence that modifying Roche as modified as claimed would produce predictable results (i.e. providing desired pressure and temperature conditions within a separator). Accordingly, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify Roche as modified by Nobel and arrive at the claimed invention since all claimed elements were known in the art and one having ordinary skill in the art could have combined the elements as claimed by known methods with no changes in their respective functions and the combination would have yielded the predictable result of providing desired pressure and temperature conditions within a separator.
Response to Arguments
Applicant's arguments filed May 15th, 2026 have been fully considered but they are not persuasive.
Applicant argues on Pg. 11-13 (as numbered by Applicant) of the Remarks, “Applicant respectfully disagrees. In the plants and processes disclosed by Roche, there is no second solid-liquid separator that is an exchanger receiving liquid methane produced by a first solid-liquid-gas separator. Roche does not disclose a second solid-liquid separator and does not disclose a second solid-liquid separator being an exchanger. Roche indicates, with reference to Figs. 5 and 6, that carbon dioxide may be eliminated by filtration during the course of liquefaction of natural gases (see col. 1 lines 57-59, col. 5 lines 1-3). In the plant diagram represented in Fig. 5, Roche discloses two flash flasks or filters B3a, B3b (see col.5 lines 43-col.6 line 2), fed in parallel with liquefied natural gases through pipe 15 and expanded in a nozzle 16. Operation of the valves 17, 17a, 20, 28,22, 25, 27, 29, 26, 35 permits the alternative operation of the flash flask B3a, B3b. Assuming the flash flask B3a is operating, the flask B3b regenerating, the valve 17, is open, 17a is closed, the liquid expanded in B3a is cooled and separates into a liquid fraction and a gaseous fraction. In the liquid fraction, all the CO2 precipitates, the CO2 being retained inside a filter 18 placed at the lower part of the flash flask. The liquid natural gas is recovered towards the second expansion stage through the collector 19, through the medium of a valve 20 which is open. The flash flask B3b being in the regenerating condition, a supply of combustible gas heated to around -50°C passes the filter of the flask B3b at counter-current, the hot gas sublimating the CO2 deposited on the filter. In the plant diagram represented in Fig. 6, each expansion flask or filter B3 and B4 provided with filters is represented by a single flask, whereas the device shown in Fig. 5 is adapted to one and the other (see col.6 lines 3-28). Expansion flasks B3, B4 of Roche are not solid-liquid exchangers. They are identical flash flasks comprising filters, such as flasks B3a, B3b.”
However, this argument is not persuasive as Fig. 6 of Roche, not Fig. 5, is relied upon in the rejection independent claim 1. Further, Fig. 6 of Roche discloses flasks B3a and B3b to be solid-liquid-gas separators that are arranged in a series configuration (Roche, Fig. 6, expansion flask B3, filter, line 36, line 39; Col. 5, lines 24-35, The process of the invention does not concern the formation of this precipitate but its elimination from the liquid current. It comprises eliminating by filtration the precipitate obtained by expansion of preferably the liquid in a flash flask. The formation of the precipitate is continuous from the point of formation of the first crystal when the temperature of the liquid continues to drop. As the precipitate formed has a tendency to agglomerate into a mass which is compact but, however, fragile owing to the presence in the precipitate of heavier hydrocarbons, there can be no question of cooling the liquid in a normal exchanger, owing to stopping up and clogging; Col. 6, lines 9-23, The current of liquid natural gas issuing from the column V1 at the point 3 is cooled in the exchanger E2; at the outlet of the exchanger E2 the liquid is cooled in the bottom of the column V2 and conducted to the flask B3 through the expansion orifice 16. The filtered liquid part is evacuated through the pipe 36 to the flash flask B4 and through the expansion orifice 37, the latter is expanded. The filtered liquid issuing at 38 is the liquefied natural gas. The vapour part of the flash flask B3 issuing at 39 passes through the exchanger E3, then E4a, issues at 40 and a flask B5 permits the separation of non-condensed gas if desired, the liquid of the flask being sent into the flash flask B3 through a pipe 41 directly into the expanding means 16). See the rejection of claim 1 above.
Applicant argues on Pg. 14 (as numbered by Applicant) of the Remarks, “Davis is a scientific publication disclosing results obtained in a lab, using very low amount of materials. Even if, for the sake of argument, one accepts that the person skill in the art could modify the method of Roche by decreasing the carbon dioxide content in a liquid methane stream from greater than 280 parts per million by volume to less than 200 ppmv, while decreasing pressure from a pressure greater than 6 bar to a pressure of I bar, and decreasing temperature from about -161. 5°C to -170°C as a matter of routine optimization, in view of Davis, the resulting method would not be as claimed. Davis does not disclose a plant or process comprising a first liquid-solid-gas separator and a second solid-liquid separator being an exchanger. Moreover, Davis does not teach that these claimed parameters as combined are result effective variables. In order to properly support a rejection on the basis that an invention is the result of "routine optimization," the Office must make findings of relevant facts, and present the underpinning reasoning in sufficient detail. The articulated rationale must include an explanation of why it would have been routine optimization to arrive at the claimed invention and why a person of ordinary skill in the art would have had a reasonable expectation of success to formulate the claimed range. See In re Stepan, 868 F.3d 1342, 1346 (Fed. Cir. 2017) and In re Van Os, 844 F.3d 1359,1361, 121 USPQ2d 1209, 1211 (Fed. Cir. 2017).”
However, this argument is not persuasive as Davis teaches a known pressure-temperature relationship between carbon dioxide content in liquid natural gas and that decreases in temperature and pressure decrease carbon dioxide content in liquid natural gas and further teaches the desire to reduce carbon dioxide content in liquid natural gas to improve the purity of the liquid natural gas for consumer usage (Davis, Fig. 3 Composition along solid-liquid-vapor locus methane-carbon dioxide system; Fig. 4. Composition of liquid phase methane-carbon dioxide system; Pg. 537, Interest in low-temperature processing of natural gas has increased in recent years. In many cases low-temperature processing may provide a more economical method of removing acid components of a gas than is now offered by more conventional methods. Clark and Kurata (1) have suggested such a method for the removal of carbon dioxide from natural gas). These teachings show it is known in the art to decrease the temperature, which has a proportional relationship to pressure, in order to decrease the carbon dioxide content is a methane stream to improve the purity of the liquid natural gas for consumer usage. Further, the teachings of Davis suggest to a PHOSITA that pressure and temperature of the stream must be adjusted to achieve a desired carbon content in the methane stream. With this teaching, the specific values a PHOSITA arrives at to achieve their desired carbon content is as a matter of routine optimization since it has been held that “where 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). Moreover, the Examiner notes applicants have not disclosed that these modifications solve any stated problem or are for any particular purpose and it appears that the device would perform equally well with either designs, these modifications are a matter of design choice. Absent a teaching as to criticality of specific pressure and temperature parameters to achieve desired carbon contents in the output stream, this particular arrangement is deemed to have been known by those skilled in the art since the instant specification and evidence of record fail to attribute any significance (novel or unexpected results) to a particular arrangement. In re Kuhle, 526 F.2d 553,555,188 USPQ 7, 9 (CCPA 1975). MPEP 2144.05.
In response to applicant's argument that Nobel is nonanalogous art, it has been held that a prior art reference must either be in the field of the inventor’s endeavor or, if not, then be reasonably pertinent to the particular problem with which the inventor was concerned, in order to be relied upon as a basis for rejection of the claimed invention. See In re Oetiker, 977 F.2d 1443, 24 USPQ2d 1443 (Fed. Cir. 1992). In this case, Nobel teaches the use of a finned tube heat exchanger in a separator.
In response to applicant's argument that Bhatia is nonanalogous art, it has been held that a prior art reference must either be in the field of the inventor’s endeavor or, if not, then be reasonably pertinent to the particular problem with which the inventor was concerned, in order to be relied upon as a basis for rejection of the claimed invention. See In re Oetiker, 977 F.2d 1443, 24 USPQ2d 1443 (Fed. Cir. 1992). In this case, Bhatia teaches a known relationship between fluid velocity over a finned tube heat exchanger and desired heat exchange characteristics of the heat exchanger that can be affected by the orientation of the fins.
The rejection of independent claim 19 is maintained. The rejections of dependent claims 2-25 are also maintained for at least the reasons described herein.
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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/DEVON MOORE/Examiner, Art Unit 3763 July 21st, 2026
/FRANTZ F JULES/Supervisory Patent Examiner, Art Unit 3763
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