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 .
Drawings
The drawings filed 11/5/2025 are unacceptable and not entered, as they do not show the claimed features that led to the previous drawing objection and the line between compressor (101) and turbo expander (202) is a fluid line and the amended label does not show any air cooling just the fluid line.
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the claimed heating, the claimed intermixing, the claimed chilling a stream of NGLs with the heat exchange equipment, must be shown or the feature(s) canceled from the claim(s). No new matter should be entered.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
The drawings are objected to under 37 CFR 1.83(a) because they fail to show the air cooling discussed in pg. pub. para. 79 as described in the specification. Any structural detail that is essential for a proper understanding of the disclosed invention should be shown in the drawing. MPEP § 608.02(d). Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Examiner Comment
The applicant is thanked for providing line numbers to the claims.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claim(s) 1-11, 13, 15, 16 is/are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
In regard to claim 1, the recitation, “delivering the conditioned feedstock to the inlet of the turbo expansion device at the elevated temperature and the elevated pressure directly after compression and/or heating, wherein the conditioned feedstock is not chilled after compression and before expansion” (line 16-19) is new matter as the scope of the recitation includes that there is no cooling between the compression and the turbo expansion device, however the disclosure explicitly states that the compressed fluid is cooled (spec. para. 52) and therefore the recitation is explicitly contrary to the disclosure and introduces new matter.
In regard to claim 16, the recitation, “delivering the conditioned feedstock to the inlet of the turbo expansion device at the elevated temperature and the elevated pressure directly after compression and/or heating, wherein the conditioned feedstock is not chilled after compression and before expansion” (line 1-4, page 7) is new matter as the scope of the recitation includes that there is no cooling between the compression and the turbo expansion device, however the disclosure explicitly states that the compressed fluid is cooled (spec. para. 52) and therefore the recitation is explicitly contrary to the disclosure and introduces new matter.
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) 1-11, 13, 15, 16 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 pre-AIA the applicant regards as the invention.
In regard to claim 1, the recitation, “turbo expansion device” as detailed below in the claim interpretation section.
The recitation, “elevated pressure” and “elevated temperature” are indefinite for being relative and there is no way to determine what the pressure or temperature must be elevated relative to.
The recitation, “that will enable chilling of the conditioned feedstock along a chilling curve offset from a conventional chilling curve such that the offset chilling curve terminates at lower pressure levels of a gaseous region of a phase envelope” (line 12-15) is indefinite for many reasons. The recitation, “the offset chilling curve” lacks proper antecedent basis. Further, there is no way to determine what features, characteristics, or parameters must be true of the recited chilling curve since there is no way to determine how the recited chilling curve must be different from “a conventional chilling curve” and no way to determine what feature the recited conventional chilling curve must have or is excluded from having. There are hundreds or perhaps thousands of cooling processes known and they all have differences with one another and there is no way to discern what would make the presently recited chilling curve “offset” from any conventional chilling curve. Further, what amounts to an offset is undefined and unclear. Further, the recitation qualifies that the curve “terminates at lower pressure levels” and this is indefinite since it is unclear why a pressure of expanded fluid would be a plurality of pressure levels instead of a pressure level. Further, it is unclear since all expansions terminate at a lower pressure level and therefore it is entirely unclear how the curve differs when all expansions terminate at a lower pressure level. Further, it is unclear what steps must be performed to meet the recited “chilling…along” the recited curve as there is no way to discern what features and attributes the recited curve requires, much less what doing so “such that” the curve terminates at a lower pressure, since all expansions terminate in a lower pressure and this appears to provide do distinguishing feature over a mere recitation of expansion.
The recitation, “delivering the conditioned feedstock to the inlet of the turbo expansion device at the elevated temperature and the elevated pressure directly after compression and/or heating, wherein the conditioned feedstock is not chilled after compression and before expansion” is indefinite for being explicitly contrary to the disclosure as the recitation appears to exclude cooling between the compression and the turbo expansion device, however the disclosure explicitly states that the compressed fluid is cooled (spec. para. 52) and therefore the recitation is explicitly contrary to the disclosure and therefore there is no way to discern what is and is not excluded by the recited negative limitation. Further, the recitation of “compression and/or heating” is indefinite for improperly reintroducing what was already previously introduced creating ambiguity as to whether this is the same or other compression and/or heating. Further, the recitation of “and before expansion” is indefinite for improperly reintroducing what was already previously introduced creating ambiguity as to whether this is the same or other expansion of the turbo expansion device or some other expansion.
The recitation, “light NGL gas mixtures” and “rich NGL gas mixtures” is indefinite as there is no way to discern what composition ranges are included and excluded. NGL gas mixtures have a range of values for the components of the mixture and there is no way to discern which gas mixtures would be judged “light” and which would be judged “rich”.
The recitation, “the conditioned feedstock is not further compressed after delivery to the inlet of the turbo expansion device to achieve further chilling in step c)” is indefinite since it is unclear if the recitation requires further chilling or if the recitation excludes further chilling achieved from an additional compressing step after expansion. Further the recitation is indefinite for referencing “step c)” anew improperly rather than referencing -the step c)--. Further the recitation is indefinite since there is no chilling recited in the step c) and so it is unclear how “further chilling” is or is not related to the step c). The recitation “after delivery” is indefinite for improperly reintroducing that which was already previously introduced and this creates un-necessary ambiguity.
In regard to claim 8, the recitation, “the offset chilling curve” lacks proper antecedent basis. Further, the recitation, “the offset chilling curve has a starting condition of 170F at 3400 psi or 190F at 3400 psi” is indefinite since the recitation only concerns some theoretical idea and it is unclear how this abstract representation influences what step actually occurs. Some theoretical curve that has properties of temperature and pressure having some particular starting point does not appear to create any definite limitation on what step must occur. Further there is no way to discern how having such a starting point would limit the operations already recited.
In regard to claim 9, the recitation, “by expansion” is indefinite for improperly reintroducing expansion performed by the turbo expansion device.
In regard to claim 11, the recitation, “by expansion” is indefinite for improperly reintroducing expansion performed by the turbo expansion device.
In regard to claim 15, the recitation, “chilling a stream of NGLs with the heat exchange equipment externally,” is indefinite as there is no way to discern what feature or characteristics make the chilling “externally”. Externally relative to what? There is no way to discern.
In regard to claim 16, the recitation, “turbo expansion device” as detailed below in the claim interpretation section.
The recitation, “elevated pressure” and “elevated temperature” are indefinite for being relative and there is no way to determine what the pressure or temperature must be elevated relative to.
The recitation, “that will enable chilling of the conditioned feedstock along a chilling curve offset from a conventional chilling curve such that the offset chilling curve terminates at lower pressure levels of a gaseous region of a phase envelope” (line 12-15) is indefinite for many reasons. The recitation, “the offset chilling curve” lacks proper antecedent basis. Further, there is no way to determine what features, characteristics, or parameters must be true of the recited chilling curve since there is no way to determine how the recited chilling curve must be different from “a conventional chilling curve” and no way to determine what feature the recited conventional chilling curve must have or is excluded from having. There are hundreds or perhaps thousands of cooling processes known and they all have differences with one another and there is no way to discern what would make the presently recited chilling curve “offset” from any conventional chilling curve. Further, what amounts to an offset is undefined and unclear. Further, the recitation qualifies that the curve “terminates at lower pressure levels” and this is indefinite since it is unclear why a pressure of expanded fluid would be a plurality of pressure levels instead of a pressure level. Further, it is unclear since all expansions terminate at a lower pressure level and therefore it is entirely unclear how the curve differs when all expansions terminate at a lower pressure level. Further, it is unclear what steps must be performed to meet the recited “chilling…along” the recited curve as there is no way to discern what features and attributes the recited curve requires, much less what doing so “such that” the curve terminates at a lower pressure, since all expansions terminate in a lower pressure and this appears to provide do distinguishing feature over a mere recitation of expansion.
The recitation, “delivering the conditioned feedstock to the inlet of the turbo expansion device at the elevated temperature and the elevated pressure directly after compression and/or heating, wherein the conditioned feedstock is not chilled after compression and before expansion” (page 7, line 1-4) is indefinite for being explicitly contrary to the disclosure as the recitation appears to exclude cooling between the compression and the turbo expansion device, however the disclosure explicitly states that the compressed fluid is cooled (spec. para. 52) and therefore the recitation is explicitly contrary to the disclosure and therefore there is no way to discern what is and is not excluded by the recited negative limitation. Further, the recitation of “compression and/or heating” is indefinite for improperly reintroducing what was already previously introduced creating ambiguity as to whether this is the same or other compression and/or heating. Further, the recitation of “and before expansion” is indefinite for improperly reintroducing what was already previously introduced creating ambiguity as to whether this is the same or other expansion of the turbo expansion device or some other expansion.
The recitation, “the conditioned feedstock is not further compressed after delivery to the inlet of the turbo expansion device to achieve further chilling in step c)” is indefinite since it is unclear if the recitation requires further chilling or if the recitation excludes further chilling achieved from an additional compressing step after expansion. Further the recitation is indefinite for referencing “step c)” anew improperly rather than referencing -the step c)--. Further the recitation is indefinite since there is no chilling recited in the step c) and so it is unclear how “further chilling” is or is not related to the step c). The recitation “after delivery” is indefinite for improperly reintroducing that which was already previously introduced and this creates un-necessary ambiguity.
CLAIM INTERPRETATION
The following is a quotation of 35 U.S.C. 112(f):
(f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked.
As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph:
(A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function;
(B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and
(C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function.
Claim limitation “turbo expansion device” invokes 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. However, the written description fails to disclose the corresponding structure, material, or acts for performing the entire claimed function and to clearly link the structure, material, or acts to the function. The disclosure does nothing but recite the term and provides no clarity as to what structure is necessary and sufficient to provide for the term. Therefore, the claim is indefinite and is rejected under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph.
Claim limitation “externally refrigerated heat exchange equipment” invokes 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. However, the written description fails to disclose the corresponding structure, material, or acts for performing the entire claimed function and to clearly link the structure, material, or acts to the function. The disclosure does nothing but recite the term and provides no clarity as to what structure is necessary and sufficient to provide for the term. Therefore, the claim is indefinite and is rejected under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph.
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) 1-5, 7-11, 13, 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mak (US 2018/0058753) in view of Whitesell (US 2006/0213222). See the indefiniteness rejections and note that the prior art teaches the claimed features as far as can be interpreted.
In regard to claim 1, Mak teaches a process (see whole disclosure, including Fig. 1) for producing liquefied natural gas (14, LNG) from a natural gas feedstock (natural gas feed gas in 1) of a pipeline (1) comprising:
a) compressing the natural gas feedstock (from 1) upstream (via 53, 54; para. 47) of an inlet (see input of 55) of a turbo expansion device (55; interpreted as a turbine), to form a conditioned feedstock (10 or 11) with an elevated pressure and elevated temperature (11 has a higher temperature and a pressure than before compression) that will enable chilling of the conditioned feedstock stream (11) along a chilling curve (see Fig. 4; see that the stream 1 is cooled) offset (having at least one difference in at least one parameter) from a conventional chilling curve (from any other known cooling process, see fig. 3, para. 50) such that the chilling curve terminates at a lower pressure level (para. 48) of a gaseous region of a phase envelope (see natural gas is expanded and cooled thereby and still gaseous at 12);
b) delivering the conditioned feedstock (11) to the inlet of the turbo expansion device (55) at the elevated temperature and elevated pressure directly after the compression (with 53, 54), wherein the conditioned feedstock (11) is not chilled after the compression (with 53, 54) and before the expansion with the turbo expansion device (55) (see fluid in line 11 is not further refrigerated); and
c) expanding the conditioned feedstock (11) in the turbo expander (55); and
d) discharging an expanded gas (12) from an outlet of the turbo expander (55) at a lowered temperature and a lowered pressure (due to operation of 55, para. 50),
wherein the conditioned feedstock gas (11) is not further compressed (see figure 1, there is not further compression of 12) after the delivery to the inlet of the turbo expander (55).
Mak teaches most of the claim limitations but does not explicitly teach that the lowered pressure is between about 5 and about 15 psig and the lowered temperature is between about -145F and -175F. However, it is routine and ordinary to expand natural gas to the recited lowered pressure and achieve the recited lowered temperature for the purpose of obtaining the majority of the expansion cooling available in the natural gas feedstock and for preparing the LNG for storage and transportation. Whitesell teaches expansion (see several expansions via 24 and 34) of a compressed natural gas to a lowered pressure of 3 psig to 7 psig (para. 19, 45) to a temperature of -252 F (para. 19, 45) and teaches that the expansion provides a relatively large temperature drop (para. 19). Therefore it would have been obvious to those of ordinary skill in the art at the time the invention was made to modify the process of Mak to discharge the expanded gas (12) at a pressure of between 5 and 15 psig and temperature of -252F for the purpose of obtaining all of the expansion cooling from the compressed natural gas and to prepare the LNG for storage and transportation.
In regard to claim 2, Mak teaches that the turbo expander (55) is a stepped series of turbo expander (para. 40 “multi-stage expander”).
In regard to claim 3, Mak, as modified, teaches that a final temperature of the expanded gas (12 as modified) leaving the turbo expander (55) is above -262°F (see Whitesell -252 F, para. 19), the expanded gas is further subjected to extraction of heat (via cooling in 66) to render a liquid state (LNG) at a temperature of about -262°F (due to modification).
In regard to claim 4, Mak teaches that the conditioned feedstock (11) at the turbo expander inlet (inlet of 55) is a mixture NGLs that has been preconditioned (para. 43.) to remove water vapor (para. 43), acid gas (para. 43), CO2 (para. 43, 46), mercury (para. 43).
In regard to claim 5, Mak teaches that the natural gas feedstock (1) comprises up to: a) 100 mol% methane (para. 46); b) 25 mol% ethane (para. 46); c) 12.5 mol% propane (para. 46); and d) 8.5 mol% i-butane and/or n-butane (para. 46).
In regard to claim 7, Mak, as modified, teaches that the elevated pressure of the conditioned feedstock (11) is between about 3400 psig and about 600 psig (para. 47), the elevated temperature of the conditioned feedstock (11) is between about -20°F and about 210°F (para. 47).
In regard to claim 8, Mak, as modified, teaches that the cooling of the natural gas feedstock (10 or 11) with the expansion of the turbo expansion device (55) has the elevated pressure and the elevated temperature, but does not explicitly teach that the elevated pressure is 3400 psig and the elevated temperature is either 170 F or 190 F. However, the elevated pressure and the elevated temperature are routinely selected depending on the desired pressure ratio and the properties of the natural gas and the compression would ordinarily cause the natural gas feedstock to rise in temperature to such levels. Further, Whitesell teaches an elevated pressure of 3500 psig (para. 17) and it is considered that selecting an elevated temperature to be either 170F or 190F a routine and ordinary result-effective variable, i.e. a variable which achieves a recognized result. In this case, the recognized result is a pressure ratio over the turbo expansion device and a required cooling to liquefy the natural gas. Therefore, since the general conditions of the claim were disclosed in the prior art, it is not inventive to discover the optimum workable range by routine experimentation, and it would have been obvious to one of ordinary skill in the art at the time of the claimed invention to provide the recited elevated pressure and the elevated temperature for the purpose of providing a desired pressure ratio and a cooling load to achieve desired liquefaction efficiently and with low costs.
In regard to claim 9, Mak teaches that the turbo expansion device (55) is coupled to a shaft (see figures and para. 48), to recover energy released by the expansion (para. 48) of the conditioned feedstock (11).
In regard to claim 10, Mak teaches the shaft is a single shaft (at least).
In regard to claim 11, Mak, as modified, teaches most claim limitations, but does not appear to explicitly teach that interrupting the expansion to remove liquid fractions. However, Whitesell teaches that expansion with a turbo expansion device (24) can employ guide vanes (para. 58, radially sliding vanes) with liquid bleed off chambers (para. 59 chambers 306) providing the ability to operate the turbo expansion device (24) with some liquefaction and expanding the flexibility and range of operation of the turbine. Therefore it would have been obvious to those of ordinary skill in the art at the time the invention was made to modify the expansion of Mak to include the guide vanes and chambers of Whitesell for the purpose of increasing a tolerance of the turbo expander to liquid formation without damage or loss of efficiency (Whitesell-para. 58, 59, 60).
In regard to claim 13, Mak teaches that the expanded gas (13) is further cooled using externally refrigerated heat exchange equipment (66) situated downstream of the outlet of the turbo expansion device (55) to extract latent heat (para. 45) for final liquefaction (forming LNG) of the expanded gas (13).
In regard to claim 16, Mak teaches a process (see whole disclosure, including Fig. 1) for producing liquefied natural gas (14, LNG) from a natural gas feedstock (natural gas feed gas in 1) of a pipeline (1) comprising:
a) compressing the natural gas feedstock (from 1) upstream (via 53, 54; para. 47) of an inlet (see input of 55) of a turbo expansion device (55; interpreted as a turbine), to form a conditioned feedstock (10 or 11) with an elevated pressure and elevated temperature (11 has a higher temperature and a pressure than before compression) that will enable chilling of the conditioned feedstock stream (11) along a chilling curve (see Fig. 4; see that the stream 1 is cooled) offset (having at least one difference in at least one parameter) from a conventional chilling curve (from any other known cooling process, see fig. 3, para. 50) such that the chilling curve terminates at a lower pressure level (para. 48) of a gaseous region of a phase envelope (see natural gas is expanded and cooled thereby and still gaseous at 12);
b) delivering the conditioned feedstock (11) to the inlet of the turbo expansion device (55) at the elevated temperature and elevated pressure directly after the compression (with 53, 54), wherein the conditioned feedstock (11) is not chilled after the compression (with 53, 54) and before the expansion with the turbo expansion device (55) (see fluid in line 11 is not further refrigerated); and
c) expanding the conditioned feedstock (11) in the turbo expander (55); and
d) discharging an expanded gas (12) from an outlet of the turbo expander (55) at a lowered temperature and a lowered pressure (due to operation of 55, para. 50),
wherein the conditioned feedstock gas (11) is not further compressed (see figure 1, there is not further compression of 12) after the delivery to the inlet of the turbo expander (55).
Further note that Mak teaches that the cooling of the natural gas feedstock (10 or 11) with the expansion of the turbo expansion device (55) starts at the elevated pressure and the elevated temperature and that the elevated pressure is between 3400 psig and 600 psig (para. 47) and the elevated temperature is between -20F and 210 F (implicit to para. 47, 48).
Mak teaches most of the claim limitations but does not explicitly teach that the lowered pressure is between about 5 and about 15 psig and the lowered temperature is between about -145F and -175F. However, it is routine and ordinary to expand natural gas to the recited lowered pressure and achieve the recited lowered temperature for the purpose of obtaining the majority of the expansion cooling available in the natural gas feedstock and for preparing the LNG for storage and transportation. Whitesell teaches employing a higher elevated pressure (para. 17 see 3400 psig included therein) and teaches expansion (see several expansions via 24 and 34) of a compressed natural gas to a lowered pressure of 3 psig to 7 psig (para. 19, 45) to a temperature of -252 F (para. 19, 45) and teaches that the expansion provides a relatively large temperature drop (para. 19). Therefore it would have been obvious to those of ordinary skill in the art at the time the invention was made to modify the process of Mak to employ an elevated pressure as taught by Whitesell (para. 17) and to discharge the expanded gas (12) at a pressure of between 5 and 15 psig and temperature of -252F for the purpose of obtaining greater expansion cooling and to prepare the LNG for storage and transportation.
Claim(s) 6, 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mak (US 2018/0058753) in view of Whitesell (US 2006/0213222) and Huang (US 20070012071). See the indefiniteness rejections and note that the prior art teaches the claimed features as far as can be interpreted.
In regard to claim 15, Mak does not explicitly teach chilling a stream of NGLs with the heat exchange equipment, to enhance a HHV heat content of produced LNG by intermixing of the stream of NGL and the produced LNG.
However, it is routine and well known to mix LNG with a spiking fluid to adjust the HHV of the LNG to provide LNG to different markets as taught by Huang (see whole disclosure, including para. 10-15). Huang teaches chilling (para. 52-53) a stream of NGLs (spiking fluid, para. 52, 53, 38, 39) with heat exchange equipment (29, Fig. 1-3 cooled by the liquefier), to enhance a HHV heat content (higher heating value content, para. 14) of produced LNG (para. 51 initial LNG) by intermixing (para. 51 mixing LNG with spiking fluid) of the stream of NGL (spiking fluid) and the produced LNG (initial LNG, para. 51). Therefore it would have been obvious to those of ordinary skill in the art at the time the invention was made to modify Mak to chill a stream of NGLs with the heat exchange equipment (66), to enhance a HHV heat content of produced LNG by intermixing of the stream of NGL and the produced LNG as taught by Huang for the purpose of providing the ability to easily customize the compositional specifications of LNG product for different markets without having to modify the complex liquefaction and separation operations of the liquefaction process.
In regard to claim 6, Mak, as modified, does not explicitly teach that the natural gas feedstock (410) has a HHV of less than about 1395 BTU/ft3, molecular weight less than about 23.2, modified Wobbe index of less than 62.20 at 60F. However, natural gas routinely have a range of compositions and all of these parameters are merely a function of composition of the natural gas feedstock and further as evidenced by the teachings of Huang, a natural gas having a HHV of < 1150 BTU/ft3 has a routine composition of at least 80% methane, less than 10% ethane, less than 6% propane, etc. (see table 2) and therefore providing a natural gas having the cited parameters would be routine and ordinary as most natural gas feed streams being liquefied are predominantly methane streams, as illustrated by Huang, and therefore it would have been obvious to those of ordinary skill in the art at the time the invention was made to operate the process of Mak with a natural gas feedstock that has the recited parameters (a molecular weight less than about 23.2, a HHV of the natural gas feedstock is less than about 1395BTU/ft3, a modified Wobbe Index as calculated for 60°F is less than about 62.20) for the purpose of liquefying natural gases having routine compositions to profit from the their sale and distribution to market.
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.
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
JFPIII
January 27, 2026