Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Interpretation
In claims 1 and 12, while the term “cryogenic distillation” is recited with respect to the second distillation column, this distillation is not considered to be at a cryogenic temperature as the separation of carbon dioxide as an overhead gas would not happen at cryogenic temperatures, which are considered to start well below -60 C, which is the coldest temperature recited in the specification. This limitation is understood to be distillation that allow for the separation as claimed into carbon dioxide and the liquefying agent.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1-6, 9-11, 13-18, 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Holmes et al. (US Patent No. 4318723), hereinafter referred to as Holmes and further in view of Holmes et al. (US Patent no. 4462814), hereinafter referred to as Ryan and Gnanendran et al. (US PG Pub 20120186296), hereinafter referred to as Gnanendran and O’Brien (US Patent No. 4681612), hereinafter referred to as O’Brien and further in view of Mak et al. (US PG Pub 20080264100), hereinafter referred to as Mak.
With respect to claim 1, Holmes (Figure 1) a method for separating one or more compounds in the a liquid state or in a two-phase liquid/vapor state, containing methane and carbon dioxide (dry feed gas 10 includes methane and carbon dioxide, Column 6, lines 47-48 which is partially condensed in 16, Column 6, lines 55-56), wherein a first separation for separating the methane is carried out by cryogenic distillation in a first column (distillation column 18 distills the cryogenic cooled stream into overhead methane, Column 6, lines 55-63) comprising a column top brought to a temperature at which methane condensed at an operating pressure of the first distillation column (the temperature at the top of the column is -130 F at 600 psia, Column 8, lines 15-17 which is below where methane condenses, which means the top is at a condensation temperature of methane), the first separation being carried out by injecting into the first distillation column in a primary feed, liquefied at an equilibrium temperature making it possible to obtain a two-phase mixture ensuring the separation one or more compounds (partially liquefied feed gas is fed into the column and during that cooling is cooled to an equilibrium temperature at least initially, Column 5, lines 24-27, the column separates at least one component from methane),
in secondary feed, a liquefying agent in the liquid state compose of a hydrocarbon (recycled agent which is NGLs is recycled to the column via 66 or 70, Column 7, lines 12-37), the liquefying agent being injected at the top of the first distillation column, above a gas inlet (recycled agent is fed at the top of the column via 70, Column 7, line 36), at a temperature T1 lower than or equal to the carbon dioxide sublimation temperature at the operating pressure of the first distillation column (the additive is at -100 F before being added to the condenser for entering the column, so it would be either at that temperature when it enters the column at 70 or colder when it enters the column, which is well below the sublimation temperature at 600 psia).
the liquefying agent being added in an amount proportional to the vapor flow rate of the carbon dioxide ascending to the top of the first distillation column (the amount of agent added to the column has a direct relationship with the amount of carbon dioxide in the feed stream, which means it would also have a direct relationship with the carbon dioxide vapor flowing up to the top in the column, Column 8, lines 34-45),
wherein a second separation of the compounds of the liquid mixture recovered at the end of the first separation and comprising carbon dioxide and the liquefying agent is carried out by cryogenic separation (bottoms liquid 28 forms stream 36 which contains the liquid mixture form the first separation and contains carbon dioxide and NGLS is separated in second separation equipment 38 to form a carbon dioxide stream 42 and a recycled agent stream 44, Column 7, lines 15-20) to reach a temperature and an equilibrium pressure allowing the separation of carbon dioxide and the liquefying agent in liquid residue (the recycled agent includes nonpolar liquids such as C3-C6 alkanes including NGLs, Column 7, lines 63-65, Column 8, lines 1-4).
Holmes does not teach the feed gas is a biogas such that the primary feed gas point is a biogas inlet.
Gnanendran teaches that various gas streams contain a mixture of methane, higher hydrocarbons and carbon dioxide including biogas (paragraph 52) which are separated to form a methane overhead and carbon dioxide bottoms stream (paragraphs 66 and 75).
Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to have based on the teaching of Gnanendran to have the dry feed gas stream of Holmes have been a biogas stream containing methane, ethane, higher hydrocarbons (which as they are C3+ would include butane) and carbon dioxide since it has been shown that a simple substitution of one known element (feed gas origin for Holmes) for another (feed gas origin being biogas) to yield predictable results is obvious whereby as they are both known gas sources that require cryogenic distillation to separate the methane from carbon dioxide and both contain similar or the same general main components (CO2, CH4, C2+ hydrocarbons) one of ordinary skill in the art would have been able to carry out such a substitution with the reasonably predictable result of a stream that would be suitable for separation in the system of Holmes to produce a methane stream and a separate carbon dioxide stream.
Holmes as modified does not teach the second separation is in a second distillation column to teach allowing the separation of the carbon dioxide in the form of vapor at the top of the second distillation column and the liquefying agent at the bottom of the second distillation column.
Ryan (Figure 1) teaches that a second separation in a methane starts with a distillation column (34) to separate carbon dioxide from natural gas liquids including one that is eventually recycled back as the liquid agent to the original column such that the liquid from the first column (32) is separate into an overhead carbon dioxide vapor recovered as a gaseous CO2 product (42) with a carbon dioxide reflux and a bottoms liquid (44) which includes ethane and higher hydrocarbons which are later separated into the butane that is reeled as the liquefying agent (Column 4, line 60 – Column 5, line 25).
Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to have based on the teaching of Ryan had the second separation of Holmes as modified include a distillation column to separate the carbon dioxide from the liquefying agent to form a gaseous overhead carbon dioxide recovered at least in part as a gaseous CO2 product with a carbon dioxide reflux and a bottom stream containing the liquid (recycled) agent since it has been shown that combining prior art elements to yield predictable results is obvious whereby it is common knowledge in the art that using distillation column as separation allows the recovery of high purity components of a distilled stream.
Holmes does not teach the cryogenic distillation is carried out at a temperature and equilibrium pressure.
O’Brien teaches that for purification in a low-temperature column the column is operated with pressure and temperature of the column selected to follow the equilibrium pressure and temperature for recovery of a purified carbon dioxide (Column 7, lines 25-29).
Therefore, it would have been obvious to a person having ordinary skill in the art at the time the invention was filed for the second distillation in the column of Holmes as modified based on the teaching of O’Brien to be carried out at an equilibrium pressure and temperature in order to provide a purified carbon dioxide from the column.
Holmes does not teach does not teach expansion of the liquid mixture as it is passed to the second distillation column.
Mak teaches that when a bottoms liquid stream (7) is passed from one column (58) to another (64) then that the stream is let down in pressure in a valve (63) between them (paragraph 34).
Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to have based on the teaching of Mak provide an valve on the liquid bottom stream passing from the first distillation column of Holmes as modified to the second distillation column since it has been shown that combining prior art elements to yield predictable results is obvious whereby providing the valve and an expansion would provide what is common knowledge in the art of being able to reduce the pressure of the stream so that it was at a suitable pressure for a lower pressure distillation in the second stage of distillation.
With respect to claim 2, Holmes as modified teaches wherein the liquefying agent is injected into the first distillation column at a level at which the methane reflux is returned the first distillation column (the liquefying agent can be added via 23 as part of the stream from the condenser and thus is introduced along with the methane reflux at the same level).
With respect to claim 3, Holmes as modified does not teach wherein the liquefying agent is injected into the first distillation column at a temperature T1 on the order of -100°C.
Holmes teaches that the solids-preventing agents should be liquid at the overhead temperature in the distillation column and that the temperature of the overhead column depends upon the pressure of the column (Column 8, lines 8-20). Holmes further teaches different conditions including those at which the additive is added to the condenser including pressure for the column, temperatures for the column and temperature for the additives (Tables I, II, III) with different additive temperatures and different operating pressures and teaches which shows the relationship between solubility of the carbon dioxide and (Figures 6-9). As such, the temperature at which the liquefying agent is injected into the first distillation column is a result effective variable depending on the pressure of the column and the operating temperature of the column. Further, it appears that one of ordinary skill in the art at the time of the invention would have had a reasonable expectation of success in modifying Holmes as modified to have a temperature within the claimed range, as it only involves adjusting the dimension of a component disclose to require adjustment. Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to modify Holmes as modified to have had the liquefying agent injected into the first distillation column at a temperature T1 on the order or -100 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).
With respect to claim 4, Holmes as modified teaches wherein the liquefying agent is subject to cooling in two stages under pressure before it is injected into the top of the first distillation column in order to reach temperature T1 (liquefying agent is cooled in both 40 and 22 and is at the pressure from the second separation, which is what brings it to T1).
With respect to claim 5, Holmes as modified teaches wherein the top of the first distillation column is cooled at least in part by the liquefying agent (the liquefying agent is added at the top of the column and thus provides cooling there).
With respect to claim 6, Holmes as modified teaches further comprising recovering the methane in a gas state at the end of the first separation (purified methane 20 leaving the top of the column would be vapor as it is up flowing out of the column and is being send to be condensed in 22).
With respect to claim 9, Holmes as modified teaches further comprising recovering the liquefying agent at the end of the second separation and redirecting at least sone of the recovered liquefying agent to the first distillation column (the second separation produces the reeled agent which is what is sent back to 18).
With respect to claim 10, Holmes as modified teaches wherein the liquefying agent is a linear or non-linear alkene hydrocarbon of the C3 to C7 family (the liquefying agent as shown in the Table 1, of the example is n-butane which is a linear alkene).
With respect to claim 13, Holmes as modified teaches wherein the biogas further comprises a hydrocarbon (the feed gas can comprise multiple hydrocarbons including butane, column 12-Column 13, line 10, which butane would include n-butane and i-butane) and wherein the liquid mixture recovered at the end of the first separation further comprises the hydrocarbon, and the liquid residue at the bottom of the second distillation column further comprise the hydrocarbon (both separations produce n-butane as a bottom product).
With respect to claim 11, Holmes as modified teaches wherein the liquefying agent comprises the same hydrocarbon present in the biogas (the mixture fed to the column can include nitrogen, ethane and other hydrocarbons (column 12-Column 13, line 10 and as the recycled agent is formed of C3-C7 alkenes, would include a hydrocarbon present in the biogas).
With respect to claim 14, Holmes as modified teaches wherein the liquefying agent exhibits the same physical-chemical properties exhibited by the hydrocarbon (they are both n-butane and would thus do the same thing).
With respect to claim 15, Holmes as modified does not teach wherein the liquefying agent is injected into the first distillation column at a temperature T1 on the order of -100°C.
Holmes teaches that the solids-preventing agents should be liquid at the overhead temperature in the distillation column and that the temperature of the overhead column depends upon the pressure of the column (Column 8, lines 8-20). Holmes further teaches different conditions including those at which the additive is added to the condenser including pressure for the column, temperatures for the column and temperature for the additives (Tables I, II, III) with different additive temperatures and different operating pressures and teaches which shows the relationship between solubility of the carbon dioxide and (Figures 6-9). As such, the temperature at which the liquefying agent is injected into the first distillation column is a result effective variable depending on the pressure of the column and the operating temperature of the column. Further, it appears that one of ordinary skill in the art at the time of the invention would have had a reasonable expectation of success in modifying Holmes as modified to have a temperature within the claimed range, as it only involves adjusting the dimension of a component disclose to require adjustment. Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to modify Holmes as modified to have had the liquefying agent injected into the first distillation column at a temperature T1 on the order or -100 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).
With respect to claim 16, Holmes as modified teaches wherein the liquefying agent is subject to cooling in two stages under pressure before it is injected into the top of the first distillation column in order to reach temperature T1 (liquefying agent is cooled in both 40 and 22 and is at the pressure from the second separation).
With respect to claim 17, Holmes as modified teaches wherein the top of the first distillation column is cooled at least in part by the liquefying agent (the liquefying agent is added at the top of the column and thus provides cooling there).
With respect to claim 18, Holmes as modified teaches further comprising recovering the methane in a gas state at the end of the first separation (purified methane 20 leaving the top of the column would be vapor as it is up flowing out of the column and is being send to be condensed in 22).
With respect to claim 20, Holmes as modified teaches further comprising recovering the carbon dioxide in a gas state at the end of the second separation (the final carbon dioxide product as modified is a gas, which as it leaves the system can be considered recovered).
Claim(s) 7-8 and 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Holmes/Ryan/Gnanendran/O’Brien/Mak and further in view of Fieler et al. (US PG Pub 20080034789), hereinafter referred as Fieler.
With respect to claim 7, Holmes as modified teaches the second separation is carried out by cooling the top of the second distillation column to the condensation temperature of the carbon dioxide (carbon dioxide reflux is sent back to the column which would cool the column top to the same temperature which is a condensation temperature of carbon dioxide).
Holmes as modified does not teach the cooling is to between -50° Celsius and -60° Celsius as a function of the pressure reached after the expansion.
Fieler teaches that the amount of acid gas (which is impurities in Fieler) in the overhead of a column is controlled by multiple factors including operating temperature and operating pressure.
As such, the temperature operating temperature of the column (which would include the temperature of the overhead part of the column and thus the temperature the top of the column is cooled to) is a result effective variable which is set as one of multiple factors including operating pressure of the column (which would be related to the pressure after expansion) which is set to achieve a desired separation of components within the column. Further, it appears one of ordinary skill in the art would have had a reasonable expectation of success in modifying Holmes as modified as it involves only adjusting the dimension of a component (column temperature) known to require adjustment. Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to have modified the operation of Holmes as modified to have had the cooling of the top of the second distillation column to between -50C and -60C as a function of the pressure reached after the expansion Therefore it would have been obvious to a person having ordinary skill in the art at the time the 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).
With respect to claim 8, Holmes as modified teaches further comprising recovering the carbon dioxide in a gas state at the end of the second separation (the final carbon dioxide product as modified is a gas, which as it leaves the system can be considered recovered).
With respect to claim 19, Holmes as modified teaches the second separation is carried out by cooling the top of the second distillation column to the condensation temperature of the carbon dioxide (carbon dioxide reflux is sent back to the column which would cool the column top to the same temperature which is a condensation temperature of carbon dioxide).
Holmes as modified does not teach the cooling is to between -50° Celsius and -60° Celsius as a function of the pressure reached after the expansion.
Fieler teaches that the amount of acid gas (which is impurities in Fieler) in the overhead of a column is controlled by multiple factors including operating temperature and operating pressure.
As such, the temperature operating temperature of the column (which would include the temperature of the overhead part of the column and thus the temperature the top of the column is cooled to) is a result effective variable which is set as one of multiple factors including operating pressure of the column (which would be related to the pressure after expansion) which is set to achieve a desired separation of components within the column. Further, it appears one of ordinary skill in the art would have had a reasonable expectation of success in modifying Holmes as modified as it involves only adjusting the dimension of a component (column temperature) known to require adjustment. Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to have modified the operation of Holmes as modified to have had the cooling of the top of the second distillation column to between -50C and -60C as a function of the pressure reached after the expansion Therefore it would have been obvious to a person having ordinary skill in the art at the time the 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(s) 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Holmes and further in view of Gnanendran and Ryan.
With respect to claim 12, Holmes teaches an installation enabling the separation of at least sone of a gas in a liquid state or in a two-phase liquid/vapor state (Figure 5) containing methane and carbon dioxide (dry feed gas 10 includes methane and carbon dioxide, Column 6, lines 47-48 which is partially condensed in 16, Column 6, lines 55-56), the installation comprising:
a first distillation column configured to separate the methane from the carbon dioxide by cryogenic distillation column 18 distills the cryogenic cooled stream into overhead methane, Column 7, lines 55-63 and a bottom product that contains carbon dioxide, Column 8, lines 1-11) comprising a primary feed for the injection of the gas at an equilibrium temperature making it possible to obtain a two-phase mixture for ensuring the separation of the methane from the carbon dioxide (the feed is cooled in 16 to a cryogenic temperature to liquefy a portion of it before feeding it to column 18, Column 6, lines 54-56 with initial cooling to equilibrium, Column 5, lines 21-25) and a secondary feed for injection of a liquefying agent in the liquid state composed of a hydrocarbon or a mixture of hydrocarbon from the C3 to C7 family (recycled agent which is NGLs is recycled to the column via 66 or 70, Column 7, lines 12-37), the second feed being arranged to inject the liquefying agent at the top of the first distillation column above a gas inlet (recycled agent is fed at the top of the column via 70, Column 7, line 36),
a second separation for the separation of the carbon dioxide from a liquid mixture recovered at the end of the first separation comprising the carbon dioxide and the liquefying agent (bottoms liquid 28 forms stream 36 which contains the liquid mixture form the first separation and contains carbon dioxide and NGLS is separated in second separation equipment 38 to form a carbon dioxide stream 42 and a recycled agent stream 44, Column 7, lines 15-20).
Holmes does not teach the feed gas is a biogas such that the primary feed gas point is a biogas inlet.
Gnanendran teaches that various gas streams contain a mixture of methane, higher hydrocarbons and carbon dioxide including biogas (paragraph 52) which are separated to form a methane overhead and carbon dioxide bottoms stream (paragraphs 66 and 75).
Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to have based on the teaching of Gnanendran to have the dry feed gas stream of Holmes have been a biogas stream containing methane, ethane, higher hydrocarbons (which as they are C3+ would include butane) and carbon dioxide since it has been shown that a simple substitution of one known element (feed gas origin for Holmes) for another (feed gas origin being biogas) to yield predictable results is obvious whereby as they are both known gas sources that require cryogenic distillation to separate the methane from carbon dioxide and both contain similar or the same general main components (CO2, CH4, C2+ hydrocarbons) one of ordinary skill in the art would have been able to carry out such a substitution with the reasonably predictable result of a stream that would be suitable for separation in the system of Holmes to produce a methane stream and a separate carbon dioxide stream.
Holmes as modified does not teach the second separation is a second distillation column.
Ryan (Figure 1) teaches that a second separation in a methane starts with a distillation column (34) to separate carbon dioxide from natural gas liquids including one that is eventually recycled back as the liquid agent to the original column such that the liquid from the first column (32) is separate into an overhead carbon dioxide vapor recovered as a gaseous CO2 product (42) and a bottoms liquid (44) which includes ethane and higher hydrocarbons which are later separated into the butane that is reeled as the liquefying agent (Column 4, line 60 – Column 5, line 25).
Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to have based on the teaching of Ryan had the second separation of Holmes as modified include a distillation column to separate the carbon dioxide from the liquefying agent to form a gaseous overhead carbon dioxide and a bottom stream containing the liquid (recycled) agent since it has been shown that combining prior art elements to yield predictable results is obvious whereby it is common knowledge in the art that using distillation column as separation allows the recovery of high purity components of a distilled stream.
Response to Arguments
Applicant's arguments filed 12/16/2025 have been fully considered but they are not persuasive.
Applicant has amended the claims to overcome the rejections under 35 USC 112(b) and as such those rejections are withdrawn and the arguments in regard to those rejections are moot.
Applicant argues, page 10 that “Holmes does not teach or suggest the recited temperature element ‘the liquefying agent being injected at the top of the first distillation column… at a temperature T1 lower than or equal to the carbon dioxide desublimation temperature at an operating pressure of the first distillation column” because Holmes “-100 F” references is to the additive being added to the condenser at that temperature. This is not persuasive.
As shown in table 1, the known condition is that the additive is added to the condenser at -100 F, which one having ordinary skill in the art would recognize based on the configuration shown in the claims where there are no other cooling or heating, would result in the streaming being at the same rough temperature range and likely also at 100 F for each other streams being added including 70 and 66 as they are all from the same cooled stream formed at 50.
Applicant further argues, that Table II states additive at -115 F added to condenser and at -95 to tray 1 in regards to Table 2 does not teach that the liquefying agent is injected at the top of the column above the biogas inlet at the recited temperature T1. This is not persuasive.
The rejection is not relying on Table 2, but the general teachings of T1 and what would be obvious to a person having ordinary skill in the art. That being said, applicant arguments provide a showing of an additional condition that is taught by the prior art of the additive agent being added “at a temperature T1 lower than or equal to the carbon dioxide desublimation temperature” at -95 F, which is in the same range as -100 F, the T1 would be at a temperature T1 lower than the desublimation temperature of carbon dioxide at 600 psia. As such, one having ordinary skill in the art would recognize that the general teachings provided by Holmes would teach a temperature T1 for the additive being added above the feed stream (of biogas as modified) at temperature less than or equal to the desublimating temperature. It should be noted however, that as described by applicant, and as disclosed, there isn’t a desublimation temperature that exists at the pressure of the column, the only pressure of which is described to be 20 bars or 21 bars in the specification, which are pressures at which carbon dioxide does not desublimates, but melts and the claims are being interpreted in the same way as applicant’s specification in which to have a temperature T1 in the general range of around -100 F, which can be shown based on table 1, and further provided in evidence based on Table 2 as argued by applicant. The claims later require a specific temperature, which is shown to be obvious in the rejection of claim 3.
Applicant argues, pages 10-11 that “Holmes also does not teach or suggest the recited element ‘in an amount proportional to the vapor flow rate of the carbon dioxide ascending to the top of the first distillation column’” as the teaching of Holmes lacks a teaching of identifying “a vapor-flow-rate proportionality nor teaches controlling agent injection as a function of a carbon dioxide vapor flow rate at the top of the column” and lacks a suggestion in Holmes that “an additive amount ‘dependent upon factors such as the composition of the feed’ necessarily result s in an amount proportional to the carbon dioxide vapor flow ate ascending to the top of the first distillation column”. This is not persuasive.
The claims do not require that there are any specific adjustments or control of the flow rate itself in regards to the proportionality, only that the injection is “proportional the vapor flow rate of the carbon dioxide ascending” and do not require anything beyond the casual relationship so as long as any relationship can be drawn between the two, the limitation is met by the prior art. The amount of carbon dioxide ascending in the column would be at least in part related to the composition of the feed, as the amount of carbon dioxide in the feed would have an effect on the amount of carbon dioxide ascending in the column and as such, as the amount of liquefying agent can be provided is related to the composition of the feed they can be said to be proportional. Additionally, as noted by applicant, Holmes also teaches the liquefying agent being related to the desired purity of the overhead methane, which is an additional teaching of the flow rate being proportional to the carbon dioxide vapor rising, as the methane content would be adjusted by removing rising carbon dioxide vapor with the liquefying agent.
Applicant’s remaining arguments page 11 are moot as the rejection of claim 1 is maintained and applicant is only arguing how the limitations which are argued above is not taught by the additional prior art.
Applicant argues, page 12 that Gnanedran’s teaching for biogas “does not teach or suggest modifying Holmes to use a primary feed that is a biogas in a liquid stage or in a liquid/vapor two-phase state” as recited in claim 1. This is not persuasive.
Gnanedran is only used to show that the feed gas itself would be biogas, such that the dry gas of Holmes which Holmes converts to the liquid or two-phase state would have been obvious to have been biogas, which applicant does not argue. Thus, the combination of Gnanendran and Holmes together result in a biogas which is separated in the first distillation column as a two-phase liquid.
Applicant argues, page 12 that O’Brien only teaches the general concept of a purification column operating with a pressure and temperature selected to follow equilibrium conditions but does not teach this being “after expansion of the liquid mixture” and Mak does not provide such a teaching. This is not persuasive.
In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). The claims recite “is carried out by cryogenic distillation in a second distillation column after expansion of the liquid mixture to reach a temperature and equilibrium pressure allowing separation” which limitation can be interpreted differently than applicant argues and does not take into account the combination. The claims can be interpreted that the distillation column is operated such that the liquid mixture is brough to a temperature and an equilibrium pressure in the column to allow for the separation after the expansion occurs which limitation is shown to be obvious by the combination.
Applicant’s arguments in regards to claim 7, 8 and 19 are moot as the rejection of claim 1 is maintained.
Applicant argues, page 13 in regards to claim 12 that Holmes does not teach the feed gas is a biogas and Gnanendran’s cited teaches “does not teach or suggest configuring Holmes such that the relevant inlet becomes a ‘biogas inlet’”. This is not persuasive.
Gnanedran is only used to show that the feed gas itself would be biogas, such that the dry gas of Holmes which Holmes converts to the liquid or two-phase state would have been obvious to have been biogas, which applicant does not argue here, such that when modified, it would result in the inlet for the column be a biogas inlet that receives a liquid or two-phase biogas.
Applicant argues that the substitution of biogas for natural gas would not have been a “simple substitution” as it does not address Gnanendran biogas can contain other components that can cause problems and that “Even if using biogas were considered routine, that rationale still does not teach or suggest ‘the secondary feed being arranged to inject the liquefying agent at the top of the first distillation column, above a biogas inlet” as “Application as-filed explain that injecting the liquefying agent above the biogas inlet I used to dissolve dry ice crystals”. This is not persuasive.
In response to applicant's argument that “biogas can contain other components that cause problems”, the test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). One of ordinary skill in the art would recognize that a feed gas formed of natural gas would contain similar components as that of biogas, including water and other components beyond just methane and carbon dioxide, and would dry the biogas as part of the operations. Further, Gnanendran while it discusses that water can be present in the stream, acknowledges that the gas stream of feed gas can be multiple different types of streams including natural gas and biogas (paragraph 52) and that the gas stream is dehydrated (paragraph 55) as part of processing, which as the feed gas of Holmes is a dry feed gas, one of ordinary skill in the art would recognize is also true when modifying Holmes. Holmes already has the feed gas inlet, below the inlet for the liquefying agent, such that when modified such that the feed gas is biogas, the biogas inlet would be below the liquefying agent as the change is in what the feed gas is, not where the feed gas inlet is located. Further, Gnanendran teaches a general separation system which can be used to separate different gases including and not limited to natural gas and biogas which would provide a suggestion to one of ordinary skill in the art that it would have been obvious to have used a different feed gas in Holmes. Finally, applicant is arguing their reasoning for using the liquefying agent, a liquefying agent that is already present in Holmes; however, this is something that would result natural from the invention of Holmes itself if there was solid CO2 in the same location. In response to applicant's argument that the liquefying agent is used to dissolve dry ice crystals, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
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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/BRIAN M KING/ Primary Examiner, Art Unit 3763