DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Examiner Comment
The applicant is thanked for providing line numbers to the claims.
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.
Claim(s) 23, 33 is/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.
In regard to claim 23, the recitation, “prior to filling of the storage tank with liquefied natural gas, spraying liquefied natural gas into the storage tank using the pump and spray header” is indefinite for not being clear what “prior to filling” encompasses. There is no way to discern if this requires the spraying to be done before any liquid is in the tank or if this is merely prior to some filling operation – not prior to any liquid being in the tank. This creates confusion, since prior to filling, there is no liquid in the tank. The recitation is logically inconsistent and unclear. Further the recitation improperly reintroduces liquefied natural gas and creates ambiguity as to whether the presently recited fluid is the same fluid introduced in claim 22 or not. For present examination, the recited spraying is performed prior to a further filling of the storage tank with the liquefied natural gas.
In regard to claim 33, the recitation, “flashing the first portion” is indefinite for improperly reintroducing flashing and not properly referencing --the flashing of the first portion--.
Claim Interpretation
Claim limitation “compression system” invokes 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. Spec. para. 50 - interpreted as one or more compressors.
Applicant may:
(a) Amend the claim so that the claim limitation will no longer be interpreted as a limitation under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph;
(b) Amend the written description of the specification such that it expressly recites what structure, material, or acts perform the entire claimed function, without introducing any new matter (35 U.S.C. 132(a)); or
(c) Amend the written description of the specification such that it clearly links the structure, material, or acts disclosed therein to the function recited in the claim, without introducing any new matter (35 U.S.C. 132(a)).
If applicant is of the opinion that the written description of the specification already implicitly or inherently discloses the corresponding structure, material, or acts and clearly links them to the function so that one of ordinary skill in the art would recognize what structure, material, or acts perform the claimed function, applicant should clarify the record by either:
(a) Amending the written description of the specification such that it expressly recites the corresponding structure, material, or acts for performing the claimed function and clearly links or associates the structure, material, or acts to the claimed function, without introducing any new matter (35 U.S.C. 132(a)); or
(b) Stating on the record what the corresponding structure, material, or acts, which are implicitly or inherently set forth in the written description of the specification, perform the claimed function. For more information, see 37 CFR 1.75(d) and MPEP §§ 608.01(o) and 2181.
Claim Rejections - 35 USC § 103
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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1, 2, 5, 6, 21, 26, 27, 31-33 is/are rejected under 35 U.S.C. 103 as being unpatentable over Skolaude (DE 2636933) in view of Oka (US 2010/0170297).
In regard to claim 1, Skolaude teaches a liquefying method (see whole disclosure) comprising:
(a) flashing (with 12) a first portion (to 12) of a high pressure cooled refrigerant stream (from 5) to form a two phase refrigerant stream (entering 13; para. 15);
(b) feeding the two phase refrigerant stream (entering 13) to a first structure (13);
(c) forming a gaseous refrigerant stream (14; para. 20), the two phase refrigerant stream (entering 13) comprising no more than 5 mol % hydrocarbons and at least 90 mol % of nitrogen (para. 16; see nitrogen), the two-phase refrigerant stream (entering 13) having a gas phase portion (gas) and a liquid phase portion (liquid) in the first structure (13);
(e) heating the gaseous refrigerant stream (14) in a second heat exchanger (1, 2) against a high pressure refrigerant stream (from 5) to form a warmed refrigerant stream (after 1, toward 6);
(f) compressing the warmed refrigerant stream (after 1 toward 6) in a compression system (one or more compressors, 6, 7, 8) to form a compressed refrigerant stream (to 5);
(g) cooling the compressed refrigerant stream (to 5) in a third heat exchanger (5) to form the high pressure refrigerant stream (from 5);
(h) cooling the high pressure refrigerant stream (from 5) against the gaseous refrigerant stream (14) in the second heat exchanger (1, 2) to form the high pressure cooled refrigerant stream (before split to 15);
(i) separating the high pressure cooled refrigerant stream (before split to 15) into the first portion (toward 12) and a second portion (15); and
(j) expanding (via 11) the second portion (15) of the high pressure cooled refrigerant stream (before split to 15) to form an expanded refrigerant stream (after 11).
Skolaude does not explicitly teach at least partially condensing a boil-off gas stream in the first structure (13) as claimed in the step (c) and the returning the at least partially condensed boil-off gas stream as claimed in the step (d).
However, it is routine and ordinary to recondense boil-off gas from a storage tank as taught by Oka. Oka teaches recondensing a boil-off gas stream (“BOG”, para. 43) from a storage tank (3) by at least partially condensing the boil-off gas stream (BOG) in a first heat exchanger (9; see Fig. 1, 2B) against a nitrogen refrigerant stream (nitrogen refrigerant, para. 49) to form an at least partially condensed boil-off gas stream (16; para. 46) and a gaseous refrigerant stream (nitrogen gas output from 9, para. 58); returning the at least partially condensed boil-off gas stream (16) to the storage tank (3) to prevent release of valuable natural gas product (para. 2). Therefore it would have been obvious to those of ordinary skill in the art at the time the invention was made to apply the liquefaction method of Skoulade to recondense BOG for the purpose of providing all of the liquefaction benefits of Skoulade to the application of boil-off recondensation and to modify the first structure (13) of Skoulade to be a first heat exchanger (9, Fig. 2B) as identified from Oka to provide liquefaction of BOG, for the purpose of maintaining and preserving the liquid natural gas and preventing the release of the natural gas to the outside (para. 2-Oka).
In regard to claim 2, Skoulade teaches (k) combining the expanded refrigerant stream (from 11) with the gaseous refrigerant stream (14) before performing at least a portion of the step (e) (see figures 1-3).
In regard to claim 5, Skoulade, as modified, does not explicitly teach to maintaining the BOG at a pressure 110% of a pressure of the storage tank during the steps (c) and (d). However, the cooling of the BOG with the liquefier of Skoulade, as already describes necessarily reduces the pressure of the BOG and storage tank as portions of the BOG are condensed and therefore it would have been obvious to those of ordinary skill in the art at the time the invention was made to maintain the pressure of the BOG at least below 110% the pressure of the storage tank as a natural result of providing the recondensation of the BOG and for the purpose of reducing the required refrigeration to provide the recondensation.
In regard to claim 6, Skoulade, as modified, teaches that the at least partially condensing the boil-off gas stream (BOG) of the step (c) comprises at least partially condensing the boil-off gas stream (BOG) in a first vessel (Oka-12, 18’) of the first heat exchanger (13 modified by Oka as 9) against the two phase refrigerant stream (after 12) flowing through a second vessel (Oka-shell of 9) to form the at least partially condensed boil-off gas stream (Oka- 16) and the gaseous refrigerant stream (14), the first vessel (Oka-18’) being contained within the second vessel (shell of 9).
In regard to claim 21, Skoulade, as modified, teaches that the step (d) comprises returning the at least partially condensed boil-off gas stream (16) to a vapor space (Oka- Fig. 1; para. 74, 77) of the storage tank (3) and the at least partially condensed boil-off gas stream (16) is only partially condensed during the performance of the step (d) (inherent during initiation of recondensation).
In regard to claim 26, Skoulade, as modified, teaches that the at least partially condensed boil-off gas stream (Oka-16) is returned to the storage tank by gravity (Oka-para. 74, 77).
In regard to claim 27, Skoulade, as modified, teaches that the at least partially condensed boil-off gas stream (Oka-16; further see that during an initiation of cooling only a part will be condensed) is returned to a top (see fig. 1) of the storage tank (3).
In regard to claim 31, Skoulade, as modified, teaches feeding the two-phase refrigerant stream (from 12-Skoulade) to the first heat exchanger (modified by Oka to be 9) comprises feeding the two phase refrigerant stream (from 12-Skoulade) to a shell side (shell around core – see Oka) of the first heat exchanger (modified by Oka to be 9).
In regard to claim 32-33, Skoulade, as modified, teaches that the flashing (via 12) of the first portion of the high pressure cooled refrigerant stream (before split 15) to form the two phase refrigerant stream (from 12) comprises flashing the first portion of the high pressure cooled refrigerant stream across a JT valve (12) to form the two phase refrigerant stream (after 12); and feeding the two phase refrigerant stream (after 12) to the first heat exchanger (Oka-9) comprises feeding the two phase refrigerant stream (from 12) from the JT valve (12) to the first heat exchanger (Oka - 9).
Claim(s) 4, 22, 23 is/are rejected under 35 U.S.C. 103 as being unpatentable over Skolaude (DE 2636933) in view of Oka (US 2010/0170297) and Lee (US 8959930).
In regard to claim 4, Skoulade, as modified, teaches most of the claim limitations, but does not explicitly teach a temperature difference between the boil-off gas stream (BOG) entering the first heat exchanger (modified as 9 from Oka) and the at least partially condensed boil-off gas stream (Oka-16) exiting the first heat exchanger (modified as 9 from Oka) is less than 2 degrees Celsius. However, Lee teaches it is well known to store LNG near atmospheric pressure at a temperature of about -160 C (column 9, line 45-50) and Lee teaches that a heat leak may increase the temperature of the LNG by a small amount of less than 2C (column 9, line 45-55). This underscores that initial BOG is a saturated vapor, therefore, in view of these teachings and those of Oka showing that the recondensation is desirably performed close to and above the tanks (see above), it would have been obvious to those of ordinary skill in the art at the time the invention was made to provide a reliquefaction of the BOG that provides a temperature reduction of less than 2 C via the first heat exchanger (modified as 9 from Oka) for the purpose of reducing the refrigeration required to reliquefy the BOG and for the purpose of improving the efficiency of reliquefaction and for the purpose of maintaining an operational pressure near atmospheric in the storage tanks as desired.
In regard to claim 22, Skoulade, as modified, teaches most of the claim limitations but does not explicitly teach pumping liquefied natural gas from the storage tank through a spray header in the vapor space using a pump, thereby preventing enrichment of nitrogen in the vapor space. However, it is well known to perform such pumping as taught by Lee. Lee teaches (column 11, line 20-30) that by pumping (via 11) the LNG into a spray bar (13) at the top of the tank that a uniform temperature can be maintained in the storage tank (1) thereby reducing generation of boil-off gas (column 11, line 50) and maintaining a uniform temperature distribution in the storage tank (1)(column 11, line 45-50). In view of these teachings, it would have been obvious to those of ordinary skill in the art at the time the invention was made to modify Skoulade with pumping of LNG to a top of the storage tank (3) for the purpose of improving the temperature uniformity of the fluid in the tank (3) and reduce boil-off gas generation therein and provide greater pressure stability thereof. Note that the mixing will reduce nitrogen enrichment in the vapor space.
In regard to claim 23, Skoulade, as modified, does not appear to explicitly teach performing a cooldown of the storage tank using the pump and the spray header used to perform the step (r) prior to a filling of the storage tank. However, Lee explicitly teaches that operating the pump (11) and spray header (13) does provide cooling of the vapor space (column 11, line 20-50) and therefore in a situation when there is not very much LNG in the storage tanks and prior to a filling operation, it would have been obvious to those of ordinary skill in the art at the time the invention was made to operate the pump (11) to the spray header (13) for the purpose of reducing the temperature of the storage tank and reducing how much of the LNG from the filling operation that is boiled off.
Claim(s) 29 is/are rejected under 35 U.S.C. 103 as being unpatentable over Skolaude (DE 2636933) in view of Oka (US 2010/0170297) and Brostow (US 2004/0231359).
Skolaude teaches most of the claim limitations but does not appear to explicitly teach that the refrigerant has hydrocarbons of more than 0% and less than 5%. However, employing nitrogen refrigerant that has a small amount of a hydrocarbon is routine and ordinary. Brostow explicitly teaches that it is routine and ordinary to employ a nitrogen refrigerant that is between having 1% - 5% methane (para. 84, 108, 118) and being 90-99% nitrogen. Therefore it would have been obvious to those of ordinary skill in the art at the time the invention was made to modify employ a nitrogen refrigerant having hydrocarbons for the purpose of using refrigerant that is obtained from natural gas on hand and reduce the need to purchase or procure pure nitrogen from an outside source and reduce the cost and energy of providing the refrigerant by employing refrigerant that is not required to be pure nitrogen only and that has minor amounts of hydrocarbon.
Claim(s) 30 is/are rejected under 35 U.S.C. 103 as being unpatentable over Skolaude (DE 2636933) in view of Oka (US 2010/0170297) and Becker (US 3511058).
Skolaude teaches most of the claim limitations but does not appear to explicitly teach that the refrigerant is argon. However, argon is a well known alternative for refrigerant as taught by Becker (column 2, line 25-26). Therefore it would have been obvious to those of ordinary skill in the art at the time the invention was made to employ argon refrigerant in place of the nitrogen for the purpose of providing an inert refrigerant with the well known thermal performance of argon.
Claim(s) 1, 2, 5, 21, 26, 27, 33 is/are rejected under 35 U.S.C. 103 as being unpatentable over Skolaude (DE 2636933) in view of Hirose (US 2020/0056837).
In regard to claim 1, Skolaude teaches a liquefying method (see whole disclosure) comprising:
(a) flashing (with 12) a first portion (to 12) of a high pressure cooled refrigerant stream (from 5) to form a two phase refrigerant stream (entering 13; para. 15);
(b) feeding the two phase refrigerant stream (entering 13) to a first structure (13);
(c) forming a gaseous refrigerant stream (14; para. 20), the two phase refrigerant stream (entering 13) comprising no more than 5 mol % hydrocarbons and at least 90 mol % of nitrogen (para. 16; see nitrogen), the two-phase refrigerant stream (entering 13) having a gas phase portion (gas) and a liquid phase portion (liquid) in the first structure (13);
(e) heating the gaseous refrigerant stream (14) in a second heat exchanger (1, 2) against a high pressure refrigerant stream (from 5) to form a warmed refrigerant stream (after 1, toward 6);
(f) compressing the warmed refrigerant stream (after 1 toward 6) in a compression system (one or more compressors, 6, 7, 8) to form a compressed refrigerant stream (to 5);
(g) cooling the compressed refrigerant stream (to 5) in a third heat exchanger (5) to form the high pressure refrigerant stream (from 5);
(h) cooling the high pressure refrigerant stream (from 5) against the gaseous refrigerant stream (14) in the second heat exchanger (1, 2) to form the high pressure cooled refrigerant stream (before split to 15);
(i) separating the high pressure cooled refrigerant stream (before split to 15) into the first portion (toward 12) and a second portion (15); and
(j) expanding (via 11) the second portion (15) of the high pressure cooled refrigerant stream (before split to 15) to form an expanded refrigerant stream (after 11).
Skolaude does not explicitly teach at least partially condensing a boil-off gas stream in the first structure (13) as claimed in the step (c) and the returning the at least partially condensed boil-off gas stream as claimed in the step (d). However, it is routine and ordinary to recondense boil-off gas from a storage tank as taught by Hirose. Hirose teaches recondensing a boil-off gas stream (“BOG”, para. 88) from a storage tank (16) by at least partially condensing the boil-off gas stream (BOG) in a first heat exchanger (17) using a liquefaction system (15) having a refrigerant (para. 86) to form an at least partially condensed boil-off gas stream (A4) and a gaseous refrigerant stream (B2); returning the at least partially condensed boil-off gas stream (A4) to the storage tank (16) to prevent release of valuable natural gas product. Therefore it would have been obvious to those of ordinary skill in the art at the time the invention was made to apply the liquefaction method of Skoulade for the liquefier of Hirose to recondense BOG for the purpose of providing all of the system benefits of Skoulade to the application of boil-off recondensation and to modify the first structure (13) of Skoulade to be a first heat exchanger (17) as identified from Hirose to provide recondensing of the BOG, for the purpose of maintaining and preserving the liquid natural gas and preventing the loss of the natural gas to the outside.
In regard to claim 2, Skoulade teaches (k) combining the expanded refrigerant stream (from 11) with the gaseous refrigerant stream (14) before performing at least a portion of the step (e) (see figures 1-3).
In regard to claim 5, Skoulade, as modified, does not explicitly teach to maintaining the BOG at a pressure 110% of a pressure of the storage tank during the steps (c) and (d). However, the cooling of the BOG with the liquefier of Skoulade as already describes necessarily reduces the pressure of the BOG and storage tank as portions of the BOG are condensed and therefore it would have been obvious to those of ordinary skill in the art at the time the invention was made to maintain the pressure of the BOG at least below 110% the pressure of the storage tank as a natural result of providing the recondensation of the BOG and for the purpose of reducing the required refrigeration to provide the recondensation.
In regard to claim 21, Skoulade, as modified, teaches that the step (d) comprises returning the at least partially condensed boil-off gas stream (Hirose-A4) to a vapor space (top space)(Hirose- para. 149) of the storage tank (3) and the at least partially condensed boil-off gas stream (Hirose-A4) is only partially condensed during the performance of the step (d) (inherent during initiation of recondensation).
In regard to claim 26, Skoulade, as modified, teaches that the at least partially condensed boil-off gas stream (Hirose - A4) is returned to the storage tank by gravity (para. 149).
In regard to claim 27, Skoulade, as modified, teaches that the at least partially condensed boil-off gas stream (Hirose - A4, further see that during an initiation of cooling only a part will be condensed) is returned to a top (Hirose - per para. 149) of the storage tank (3).
In regard to claim 33, Skoulade, as modified, teaches that the flashing (via 12) of the first portion of the high pressure cooled refrigerant stream (before split 15) to form the two phase refrigerant stream (from 12) comprises flashing the first portion of the high pressure cooled refrigerant stream across a JT valve (12) to form the two phase refrigerant stream (after 12); and feeding the two phase refrigerant stream (after 12) to the first heat exchanger (Oka-9) comprises feeding the two phase refrigerant stream (from 12) from the JT valve (12) to the first heat exchanger (Oka - 9).
Claim(s) 6, 31, 32 is/are rejected under 35 U.S.C. 103 as being unpatentable over Skolaude (DE 2636933) in view of Hirose (US 2020/0056837) and Oka (US 2010/0170297).
In regard to claim 6, Skoulade, as modified, teaches most of the claim limitations but does not appear to explicitly teach flowing the BOG into a first vessel and the refrigerant into the second vessel as claimed. However, Oka explicitly teaches that providing the refrigerant to the core or the shell are obvious variants of each other (see Fig. 2A and 2B). Therefore it would have been obvious to those of ordinary skill in the art at the time the invention was made to modify the first heat exchanger to have the BOG flow to a first vessel (interior core of the heat exchanger) and the refrigerant to flow into a surrounding second vessel to provide a bath of refrigerant around the first vessel to provide a large cooling capacity for recondensation of the BOG and to provide greater independence from the operations of the liquefier.
In regard to claim 31, Skoulade, as modified immediately above relative to claim 6, teaches feeding the two phase refrigerant stream (from 12) to the first heat exchanger (Hirose - 17) comprises feeding the two phase refrigerant stream (from 12) to a shell side (Oka shell around core) of the first heat exchanger (modified as shown by Oka - see 9 Fig. 2b).
In regard to claim 32, Skoulade, as modified, teaches that the flashing (via 12) of the first portion of the high pressure cooled refrigerant stream (before split 15) to form the two phase refrigerant stream (from 12) comprises flashing the first portion of the high pressure cooled refrigerant stream across a JT valve (12) to form the two phase refrigerant stream (after 12); and feeding the two phase refrigerant stream (after 12) to the first heat exchanger (Oka-9) comprises feeding the two phase refrigerant stream (from 12) from the JT valve (12) to the first heat exchanger (Oka - 9).
Claim(s) 4, 22, 23 is/are rejected under 35 U.S.C. 103 as being unpatentable over Skolaude (DE 2636933) in view of Hirose (US 2020/0056837) and Lee (US 8959930).
In regard to claim 4, Skoulade, as modified, teaches most of the claim limitations, but does not explicitly teach a temperature difference between the boil-off gas stream (BOG) entering the first heat exchanger (modified as 17 from Hirose) and the at least partially condensed boil-off gas stream (Hirose-A4) exiting the first heat exchanger (Hirose-17) is less than 2 degrees Celsius. However, Lee teaches it is well known to store LNG near atmospheric pressure at a temperature of about -160 C (column 9, line 45-50) and Lee teaches that a heat leak may increase the temperature of the LNG by a small amount of less than 2C (column 9, line 45-55). This underscores that initial BOG is a saturated vapor, therefore, in view of these teachings and those of Oka showing that the recondensation is desirably performed close to and above the tanks (see above), it would have been obvious to those of ordinary skill in the art at the time the invention was made to provide a reliquefaction of the BOG that provides a temperature reduction of less than 2 C via the first heat exchanger (Hirose-17) for the purpose of reducing the refrigeration required to reliquefy the BOG and for the purpose of improving the efficiency of reliquefaction and for the purpose of maintaining an operational pressure near atmospheric in the storage tanks as desired.
In regard to claim 22, Skoulade, as modified, teaches most of the claim limitations but does not explicitly teach pumping liquefied natural gas from the storage tank through a spray header in the vapor space using a pump, thereby preventing enrichment of nitrogen in the vapor space. However, it is well known to perform such pumping as taught by Lee. Lee teaches (column 11, line 20-30) that by pumping (via 11) the LNG into a spray bar (13) at the top of the tank that a uniform temperature can be maintained in the storage tank (1) thereby reducing generation of boil-off gas (column 11, line 50) and maintaining a uniform temperature distribution in the storage tank (1)(column 11, line 45-50). In view of these teachings, it would have been obvious to those of ordinary skill in the art at the time the invention was made to modify Skoulade with pumping of LNG to a top of the storage tank (3) for the purpose of improving the temperature uniformity of the fluid in the tank (3) and reduce boil-off gas generation therein and provide greater pressure stability therein. Note that the mixing will reduce nitrogen enrichment in the vapor space.
In regard to claim 23, Skoulade, as modified, does not appear to explicitly teach performing a cooldown of the storage tank using the pump and the spray header used to perform the step (r) prior to a filling of the storage tank. However, Lee explicitly teaches that operating the pump (11) and spray header (13) does provide cooling of the vapor space (column 11, line 20-50) and therefore in a situation when there is not very much LNG in the storage tanks and prior to a filling operation, it would have been obvious to those of ordinary skill in the art at the time the invention was made to operate the pump (11) to the spray header (13) for the purpose of reducing the temperature of the storage tank and reducing how much of the LNG from the filling operation that is boiled off.
Claim(s) 29 is/are rejected under 35 U.S.C. 103 as being unpatentable over Skolaude (DE 2636933) in view of Hirose (US 2020/0056837) and Brostow (US 2004/0231359) and
Claim(s) 29 is/are rejected under 35 U.S.C. 103 as being unpatentable over Skolaude (DE 2636933) in view of Hirose (US 2020/0056837), Oka (US 2010/0170297), and Brostow (US 2004/0231359) and
Skolaude teaches most of the claim limitations but does not appear to explicitly teach that the refrigerant has hydrocarbons of more than 0% and less than 5%. However, employing nitrogen refrigerant that has a small amount of a hydrocarbon is routine and ordinary. Brostow explicitly teaches that it is routine and ordinary to employ a nitrogen refrigerant that is between having 1% - 5% methane (para. 84, 108, 118) and being 90-99% nitrogen. Therefore it would have been obvious to those of ordinary skill in the art at the time the invention was made to modify employ a nitrogen refrigerant having hydrocarbons for the purpose of using refrigerant that is obtained from natural gas on hand and reduce the need to purchase or procure pure nitrogen from an outside source and reduce the cost and energy of providing the refrigerant by employing refrigerant that is not required to be pure nitrogen only and that has minor amounts of hydrocarbon.
Claim(s) 30 is/are rejected under 35 U.S.C. 103 as being unpatentable over Skolaude (DE 2636933) in view of Hirose (US 2020/0056837) and Becker (US 3511058).
and
Claim(s) 30 is/are rejected under 35 U.S.C. 103 as being unpatentable over Skolaude (DE 2636933) in view of Hirose (US 2020/0056837), Oka (US 2010/0170297), and Becker (US 3511058).
Skolaude teaches most of the claim limitations but does not appear to explicitly teach that the refrigerant is argon. However, argon is a well known alternative for refrigerant as taught by Becker (column 2, line 25-26). Therefore it would have been obvious to those of ordinary skill in the art at the time the invention was made to employ argon refrigerant in place of the nitrogen for the purpose of providing an inert refrigerant with the well known thermal performance of argon.
Response to Arguments
Applicant's arguments filed 7/2/2026 have been fully considered but are moot in view of the grounds of rejection above.
Applicant's arguments (page 10) are an allegation that one of ordinary skill in the art would not have been motivated to replace the liquid nitrogen of Oka with a partially liquefied compressed circulating gas.
In response, the allegation is unpersuasive, first since Oka is not being modified. Rather, Skaulade is modified. Therefore the allegation fails to address the grounds of rejection and the modification that is actually made. Further, since the contextual teachings of Oka include that BOG is liquefied using nitrogen refrigerant, such evidence only bolsters the modification position of the rejection Skoulade already teaches the partially liquefied nitrogen and is merely being modified with the first heat exchanger structure of Oka. Further since Oka teaches that BOG is desirably cooled with nitrogen refrigerant, these teachings only bolster the position of the rejection. Lastly, the provision of the nitrogen as taught by Skoulade provides nitrogen refrigerant in a re-occurring fashion as the refrigeration cycle operates and therefore the rejection is maintained.
Applicant's arguments (page 10) are an allegation that one of ordinary skill in the art would not have been motivated to apply the method of Skoulade to Hirose.
In response, the allegation is unpersuasive since Skoulade is modified with the heat exchanger features of Hirose and the rejection does not posit to modify Hirose as alleged.
Conclusion
THIS ACTION IS MADE FINAL. 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.
The prior art made of record on the 892 and not relied upon is considered pertinent to applicant's disclosure. Any inquiry concerning this communication or earlier communications from the examiner should be directed to JOHN F PETTITT whose telephone number is (571) 272-0771. The examiner can normally be reached on M-F, 9-5p. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR): http://www.uspto.gov/interviewpractice. The examiner’s supervisor, Frantz Jules can be reached on 571-272-6681. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/JOHN F PETTITT, III/Primary Examiner, Art Unit 3763
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