DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Objections
In claim 1, the recitation "a proportion of liquid between 5 and 20 mol% of liquid" repeats the words "of liquid." It is suggested that the phrase be amended to read "a proportion of liquid between 5 and 20 mol%."
In claims 5 and 6, the recitation "the first exchanger" is inconsistent with the term "first heat exchanger" introduced in claim 1. It is suggested that "the first exchanger" be amended to read "the first heat exchanger" in each occurrence.
In claim 11, the recitation "the added gas having a same composition as the nitrogen cycle fluid" should read "the added gas having the same composition as the nitrogen cycle fluid," and the successive phrases "in order to increase an inlet pressure of the compressor in order to increase a proportion of liquid produced by the turbine" are grammatically awkward. It is suggested that the latter phrase be amended to read, for example, "so as to increase an inlet pressure of the compressor and thereby increase a proportion of liquid produced by the turbine."
In claim 13, the recitation "the cooled feed gas" is inconsistent with the term "a cooled hydrogen feed gas" introduced in claim 1 (and with the term "the cooled hydrogen feed gas" used in claim 14). It is suggested that "the cooled feed gas" be amended to read "the cooled hydrogen feed gas." Appropriate corrections is required.
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 7 is 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.
Claim 7, as amended, recites "all of the liquid of the two-phase fluid sent to the phase separator or directly to the second heat exchanger originates from the turbine" (emphasis on "directly to the second heat exchanger"). The specification describes sending the two-phase fluid either to the phase separator or "directly to the heat exchanger" (¶ 0031), and identifies that heat exchanger as the first heat exchanger E1: "It is also possible to send the two-phase fluid 6 or the mixture of fluids 6,7 directly to the heat exchanger E1 in order to be heated, without passing through the phase separator" (¶ 0054). The second heat exchanger E2, by contrast, receives only the liquid fraction 8-1 withdrawn from the phase separator V1, which is vaporized against the cooled feed gas 2 and returned to the separator (¶¶ 0046, 0050; FIG. 1). Original claim 7 likewise recited sending the fluid "directly to the heat exchanger," which, in the context of original claim 1, referred to the "first exchanger" of alternative f). Nothing in the application as filed describes sending the two-phase fluid produced at the turbine outlet directly to the second heat exchanger E2, bypassing the phase separator. The amendment therefore introduces new matter. See MPEP §§ 2163.05 and 2163.06.
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1, 2 and 5-14 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.
Claim 1 recites, in step d), "a heated cycle gas, which is compressed in a compressor and then cooled in the refrigeration cycle according to step a)," and, in step e) line 6-8 "an amount of liquid produced in the turbine is adjusted by adjusting an outlet pressure of a cycle compressor and therefore an inlet pressure of the turbine." Claim 11 further recites "gas is added, from an external source, to the nitrogen cycle fluid downstream of the compressor" and "an inlet pressure of the compressor." Because step e) line 6-8 introduces "a cycle compressor" after step d) has already introduced "a compressor," it is unclear whether the cycle compressor whose outlet pressure is adjusted is the same compressor that compresses the heated cycle gas in step d), or an additional compressor. If an additional compressor is intended, the claim does not set out where in the refrigeration cycle it is located or how its outlet pressure establishes the inlet pressure of the turbine. The specification describes a single cycle compressor C1 that compresses the heated cycle gas 9 and whose outlet pressure sets the turbine inlet pressure (¶¶ 0047, 0050-0051; FIG. 1), but the claim language does not make that identity clear. The same ambiguity carries into claim 11, which recites "the compressor" without indicating which of the two compressors of claim 1 is meant. For purposes of examination, the "cycle compressor" is interpreted as the compressor of step d).
Claim 2 recites "the ratio between an inlet pressure and an outlet pressure in bar absolute of the turbine is equal to or greater than 11." Claim 1, from which claim 2 depends, already recites "an inlet pressure of the turbine" and "an expansion rate of the turbine." Because claim 2 introduces a second "inlet pressure" with the indefinite article, it is unclear whether the inlet pressure of claim 2 is the same as, or different from, the inlet pressure of the turbine recited in claim 1. In addition, "the ratio" lacks antecedent basis, and it is unclear whether "the ratio" of claim 2 is the "expansion rate" of claim 1 or a different quantity. For purposes of examination, "the ratio" of claim 2 is interpreted as the expansion rate of claim 1, determined from the same turbine inlet and outlet pressures.
Claim 5 recites "a second portion of the cooled nitrogen cycle fluid is cooled in the first exchanger until the cooled nitrogen cycle fluid is completely liquefied, forming a liquid," and further recites that "the expanded liquid and the two-phase fluid at the outlet of the turbine are either mixed in the phase separator or mixed before being sent directly to the first heat exchanger in order to be heated.” Claim 6 depends from claim 5 and incorporates both limitations. The limitations renders the claims indefinite because first, the recitation "the cooled nitrogen cycle fluid is completely liquefied" is unclear as to whether it refers to the second portion or to the entire cooled nitrogen cycle fluid. The entire cooled nitrogen cycle fluid cannot be completely liquefied in the first heat exchanger, because claim 1 requires at least one portion of that fluid to be expanded in the turbine. Second, the alternative in which the expanded liquid and the two-phase fluid are "mixed before being sent directly to the first heat exchanger" describes a flow path in which the two-phase fluid produced at the turbine outlet is heated in the first heat exchanger without being separated (see specification ¶ 0054). That alternative conflicts with steps c) through e) of claim 1, which require the two-phase fluid to be separated in the phase separator, the gas produced in the phase separator to be sent to the first heat exchanger, and the liquid of the phase separator to be vaporized in the second heat exchanger. One of ordinary skill in the art therefore could not determine the metes and bounds of claims 5 and 6. For purposes of examination, the phrase "the cooled nitrogen cycle fluid is completely liquefied" is interpreted as the second portion being completely liquefied, and claims 5 and 6 are examined on the alternative in which the expanded liquid and the two-phase fluid are mixed in the phase separator.
Claim 6 recites "a flow of the cooled portion in the first exchanger is variable in order to adjust the level of liquid in the phase separator." Claim 1 recites "at least one portion of the cooled nitrogen cycle fluid" that is expanded in the turbine, and claim 5 recites "a second portion of the cooled nitrogen cycle fluid" that is cooled in the first exchanger. It is therefore unclear which portion is "the cooled portion." In addition, "the level of liquid in the phase separator" lacks antecedent basis. For purposes of examination, "the cooled portion" is interpreted as the second portion of claim 5, and "the level of liquid" is interpreted as "a level of liquid."
Claim 7 recites "all of the liquid of the two-phase fluid sent to the phase separator or directly to the second heat exchanger originates from the turbine." Claim 1, from which claim 7 depends, requires that the two-phase fluid be separated in the phase separator (step c)) and that the second heat exchanger receive "at least one fraction of a liquid of the phase separator" (step e)). It is unclear whether claim 7 requires that at least some of the two-phase fluid bypass the phase separator and be sent directly to the second heat exchanger, which would conflict with the steps of claim 1, or whether the second alternative is merely optional. For purposes of examination, claim 7 is interpreted as reciting the two-phase fluid sent to the phase separator.
Claims 1, 2, 8-10 and 12-14 are also rejected under 35 U.S.C. 112(b) for being dependent upon a rejected claim.
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 7 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
Claim 1 defines "the two-phase fluid" as the fluid produced at the outlet of the turbine by the expansion of step b). The liquid of that two-phase fluid necessarily originates from the turbine. Claim 7, which recites that "all of the liquid of the two-phase fluid ... originates from the turbine," therefore restates a characteristic already required by claim 1 and does not specify a further limitation; the only other added language ("or directly to the second heat exchanger") broadens rather than narrows the flow paths required by claim 1, as discussed in the rejection under 35 U.S.C. 112(b) above. Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1, 2, 5-8, 10 and 12-14 are rejected under 35 U.S.C. § 103 as being unpatentable over Grenier (US 5,579,655 A) in view of Turney (US 2017/0038137 A1) and Prosser (US 2018/0202690 A1).
In regard to claim 1, Grenier teaches a process for cooling a hydrogen feed gas (hydrogen to be liquefied supplied at 20 bars via conduit 26) utilizing a refrigeration cycle (nitrogen refrigeration cycle comprising nitrogen cycle compressor 2, booster 8, expansion turbine 9 and phase separator 13) (col. 2, ll. 22-65; fig. 1), wherein:
a) a nitrogen cycle fluid (high pressure nitrogen from compressor 2, boosted to 50 bars in booster 8) is cooled (in passages 31 of warm exchanger 3) to a temperature lower than –100° C. (intermediate temperature of the order of –120° C.) (col. 2, ll. 47-56; fig. 1);
b) at least one portion of the cooled nitrogen cycle fluid (portion of the high pressure nitrogen leaving passages 31 at about –120° C.) is expanded in a turbine (expansion turbine 9, expanding from 50 bars to 5 bars) in order to cool the at least one portion of the cooled nitrogen cycle fluid, the expanded fluid being discharged at an outlet of the turbine to the phase separator (nitrogen from turbine 9 sent to separator 13) (col. 2, ll. 49-61; fig. 1);
c) the fluid from the turbine outlet is separated in a phase separator (separator 13, providing a vapor phase and a liquid phase) (col. 2, ll. 61-67; fig. 1);
d) at least one portion of a gas produced in the phase separator (vapor phase of separator 13) is sent to a first heat exchanger (warm exchanger 3, passages 32; indirect, countercurrent heat exchange type) in order to exchange heat indirectly with the hydrogen feed gas to be cooled (hydrogen in passages 27 of exchanger 3), which produces a cooled hydrogen feed gas (hydrogen precooled to about –178° C.) and a heated cycle gas (vapor phase reheated from the cold end to the warm end of exchanger 3), which is compressed in a compressor (intermediate stage of nitrogen cycle compressor 2, via conduit 33) and then cooled in the refrigeration cycle according to step a) (refrigerator 16, booster 8, refrigerator 17, passages 31) (col. 2, ll. 22-65; fig. 1); and
e) at least one fraction of a liquid of the phase separator (liquid phase collected in separator 13) is vaporized in a second heat exchanger (cold exchanger 4, passages 35, after expansion in valve 25) by way of indirect heat exchange with the cooled hydrogen feed gas (hydrogen in passages 28 of exchanger 4) in order to further cool the hydrogen feed gas (from about –178° C. to about –192° C.) (col. 2, ll. 22-46; col. 2, l. 66 – col. 3, l. 4; fig. 1).
Grenier does not explicitly teach (a) that the expansion in the turbine produces a two-phase fluid at the outlet of the turbine; (b) wherein the two-phase fluid contains a proportion of liquid between 5 and 20 mol%; and (c) wherein an amount of liquid produced in the turbine is adjusted by adjusting an outlet pressure of a cycle compressor and therefore an inlet pressure of the turbine, thus modifying an expansion rate of the turbine.
However, as to (a), Turney teaches a nitrogen recycle refrigeration cycle in which nitrogen compressed in a recycle compressor and boosters (recycle compressor 40; boosters 50, 53) to about 45 to about 65 bar (fully boosted nitrogen 56) is partially cooled (heat exchanger 10) and expanded in a turbine (second turbine 80) to about 5 to about 6 bar and to a temperature near or below its dew point, forming a two-phase fluid consisting of gas and liquid phases (second expanded nitrogen 82) that is introduced into a liquid/gas separator (separator 60); the gaseous nitrogen from the separator (gaseous nitrogen 68) is warmed in the heat exchanger and recycled to the recycle compressor, and a fully cooled, liquefied nitrogen portion (liquefied nitrogen 58) is flashed through a valve (valve 59) into the same separator (¶ 0037-0040; fig. 1).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the hydrogen cooling process of Grenier to include expanding the cooled nitrogen in the turbine to a temperature near or below its dew point so that the turbine discharge is a two-phase fluid of gas and liquid phases introduced into the separator, the separated gas being rewarmed and recycled to the recycle compressor, as taught by Turney, in order to have the turbine work expansion provide the refrigeration needs of the process (Turney ¶ 0039-0040). One of ordinary skill would have been motivated to make this modification because Grenier's nitrogen cycle already has the same arrangement as Turney's: turbine 9 discharges into separator 13, the separator vapor is rewarmed in passages 32 of exchanger 3 and returned to compressor 2, and a liquefied nitrogen portion is expanded through valve 24 into the same separator (Grenier col. 2, ll. 49-65), so that operating turbine 9 into the two-phase region as Turney does delivers the refrigeration of the turbine directly at the saturation temperature of separator 13.
However, as to (b), Prosser teaches a closed-loop, turbine-based refrigeration cycle (refrigeration circuit 12) in which a compressed refrigerant containing nitrogen (working fluid 16) is cooled (main cooler heat exchanger 20) and expanded across a turbine (turbine 25) to produce a turbine exhaust (exhaust stream 26) that is partially condensed to between about 5 mol% and about 10 mol% liquid, the two-phase exhaust cooling a process stream by indirect heat exchange (oxygen chiller heat exchanger 30) and being returned to the compressor (compressor 15) (¶ 0008, 0011, 0024-0026; fig. 1). The range of about 5 to about 10 mol% lies within the claimed range of 5 to 20 mol%.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Grenier, as modified by Turney, to include a turbine expansion in which the cold, compressed refrigerant is partially condensed so that the turbine exhaust contains about 5 to about 10 mol% liquid as taught by Prosser, in order to provide latent heat of the refrigerant in the downstream heat exchange and thereby reduce the recirculating refrigerant flow and the power consumption of the cycle (Prosser ¶ 0026). One of ordinary skill would have been motivated to make this modification because Grenier relies on the liquid phase collected in separator 13, vaporized in passages 35 of exchanger 4, to provide the coldest cooling of the hydrogen from about –178° C. to about –192° C. (Grenier col. 2, ll. 37-46; col. 2, l. 61 – col. 3, l. 4), and Turney, while discharging the turbine as a two-phase fluid, leaves the liquid fraction of that discharge to the designer (Turney ¶ 0038), so that Prosser supplies a known operating fraction whose liquid adds directly to the latent-heat refrigeration on which Grenier's cold exchanger depends. Where the claimed range lies within or overlaps a range disclosed by the prior art, a prima facie case of obviousness exists. See MPEP § 2143(I)(G).
However, as to (c), Prosser teaches that the pressure ratio at which the compressor is operated establishes the pressure ratio across the turbine (cold compressor 15 operated at a pressure ratio of about 10 allowing the pressure ratio of turbine 25 to approach 10), that the liquid fraction of the turbine exhaust depends on the operating conditions of the turbine (exhaust stream 26 partially condensed to between about 5 mol% and about 10 mol% liquid depending on the working fluid and the operating conditions of turbine 25), and that higher turbine pressure ratios lower the temperature reached at the turbine exhaust (¶ 0024-0025, 0045; fig. 1). Prosser thus teaches that the liquid formed at the turbine outlet is governed by the turbine pressure ratio, which is set by the compressor discharge pressure delivered to the turbine inlet.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the modified process of Grenier, to include setting the pressure ratio across the turbine, and with it the liquid fraction of the turbine exhaust, through the discharge pressure of the cycle compressor as taught by Prosser, in order to operate the turbine at a pressure ratio at which it performs efficiently while producing the targeted liquid fraction at the turbine exhaust (Prosser ¶ 0024-0025). One of ordinary skill would have been motivated to make this modification because in Grenier the inlet pressure of turbine 9 is the 50-bar discharge pressure delivered by compressor 2 and booster 8, and the turbine exhausts at 5 bars into separator 13 (Grenier col. 2, ll. 49-61), so that, once the turbine discharge is operated in the two-phase region with a targeted liquid fraction as taught by Turney and Prosser, the discharge pressure of the cycle compressor is the operating variable that sets the turbine pressure ratio and therefore the amount of liquid made at the turbine outlet. The liquid fraction of the turbine exhaust is thus a result-effective variable whose adjustment would have been a matter of routine optimization. In re Applied Materials, Inc., 692 F.3d 1289, 1295 (Fed. Cir. 2012); MPEP § 2144.05(II), § 2143(I)(D).
In regard to claim 2, the modified Grenier teaches the process of claim 1, wherein Grenier teaches including expansion of the cooled nitrogen cycle fluid in turbine 9 from 50 bars to 5 bars, i.e., at a ratio of 10 (Grenier col. 2, ll. 47-56). Grenier does not teach wherein the ratio between the inlet pressure and the outlet pressure in bar absolute of the turbine is equal to or greater than 11.
However, Turney further teaches the nitrogen recycle refrigeration cycle in which fully boosted nitrogen (stream 56) at a pressure of about 45 to about 65 bar is partially cooled (heat exchanger 10) and expanded in a turbine (second turbine 80) to a pressure of about 5 to about 6 bar, forming a two-phase fluid of gas and liquid phases (second expanded nitrogen 82) that is introduced into a liquid/gas separator (separator 60), the gaseous nitrogen (gaseous nitrogen 68) being warmed and recycled (¶ 0037-0038, 0043; fig. 1). Turney's inlet and outlet pressures correspond to a turbine pressure ratio ranging from about 7.5 to about 13, which overlaps the claimed ratio of equal to or greater than 11.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the modified process of Grenier, to include a nitrogen turbine expansion from an elevated inlet pressure of up to about 65 bar to an outlet pressure of about 5 to 6 bar producing a two-phase gas and liquid discharge as taught by Turney, in order to operate the turbine from an elevated inlet pressure so that the expanded nitrogen reaches a temperature near or below its dew point and is discharged as a two-phase fluid for separation (Turney ¶ 0038, 0043).
In regard to claim 5, the modified Grenier teaches the process of claim 1, and Grenier further teaches wherein a second portion of the cooled nitrogen cycle fluid (the rest of the high pressure nitrogen in passages 31) is cooled in the first heat exchanger (warm exchanger 3) until the second portion is completely liquefied (liquefied and subcooled until the cold end of exchanger 3), forming a liquid, the liquid is then expanded in a valve (expansion valve 24, to 5 bars), and the expanded liquid and the two-phase fluid at the outlet of the turbine (nitrogen from turbine 9) are mixed in the phase separator (both introduced into separator 13) (col. 2, ll. 56-61; fig. 1).
In regard to claim 6, the modified Grenier teaches the process of claim 5, including the second portion of the nitrogen cycle fluid cooled and liquefied in passages 31 of warm exchanger 3, expanded in valve 24 and introduced into separator 13 (Grenier col. 2, ll. 56-61; fig. 1). The modified Grenier does not explicitly teach a flow of the cooled portion in the first heat exchanger is variable in order to adjust a level of liquid in the phase separator.
However, the Examiner takes Official Notice that it was well known in the art, before the effective filing date of the claimed invention, to regulate the flow of a liquefied stream expanded through a control valve into a phase separator of a cryogenic refrigeration or liquefaction cycle in response to the liquid level in that separator, so as to hold the separator liquid level at a set point.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the modified process of Grenier, to include varying the flow of the liquefied second portion through valve 24 in response to the liquid level in separator 13, in order to maintain the liquid inventory of the separator at a set point. One of ordinary skill would have been motivated to make this modification because the liquid phase of separator 13 is continuously withdrawn, subcooled in passages 34 and vaporized in passages 35 to cool the hydrogen feed in exchanger 4 (Grenier col. 2, l. 66 – col. 3, l. 4), so that a stable separator liquid level is required to supply that duty.
In regard to claim 7, the modified Grenier teaches the process of claim 1, wherein all of the liquid of the two-phase fluid sent to the phase separator (separator 13) originates from the turbine (the liquid of the two-phase turbine exhaust formed in turbine 9 as modified per Prosser, the turbine exhaust being partially condensed within the turbine expansion) (Grenier col. 2, ll. 59-61; fig. 1; Prosser ¶ 0025).
In regard to claim 8, the modified Grenier teaches the process of claim 1, and Grenier further teaches wherein the nitrogen cycle fluid contains at least 90 mol% of nitrogen (the cycle fluid of the nitrogen refrigeration cycle is nitrogen, compressed in nitrogen cycle compressor 2 as high pressure nitrogen, no other constituent being disclosed) (col. 2, ll. 22-24, 47-53; fig. 1).
In regard to claim 10, the modified Grenier teaches the process of claim 1, including the liquid phase collected in separator 13 (Grenier col. 2, ll. 66-67). Grenier does not teach one portion of the liquid formed in the phase separator serves as a liquid product of the process.
However, Turney further teaches the nitrogen recycle refrigeration cycle in which liquid nitrogen (recovered liquid nitrogen 62) is withdrawn from the liquid/gas separator (separator 60) that receives the two-phase turbine discharge and is collected as product (¶ 0038; fig. 1).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the modified process of Grenier, to include withdrawing a portion of the liquid nitrogen collected in the turbine-discharge separator as a liquid nitrogen product as taught by Turney, in order to produce liquid nitrogen in addition to providing refrigeration (Turney ¶ 0004, 0038).
In regard to claim 12, the modified Grenier teaches the process of claim 1, and Grenier further teaches wherein the nitrogen cycle fluid is cooled in step a) to a temperature greater than –192° C. (intermediate temperature of the order of –120° C. at which the turbine portion leaves passages 31) (col. 2, ll. 53-56; fig. 1).
In regard to claim 13, the modified Grenier teaches the process of claim 1, and Grenier further teaches wherein the cooled hydrogen feed gas (hydrogen leaving passages 28 at about –192° C.) is then liquefied (sent via conduit 29 to the cold portion of the installation for liquefaction of the treated hydrogen) (col. 2, ll. 16-21, 37-42; fig. 1).
In regard to claim 14, the modified Grenier teaches the process of claim 13, and Grenier further teaches wherein the cooled hydrogen feed gas is then liquefied by a second refrigeration cycle in which hydrogen circulates (hydrogen refrigeration cycle with hydrogen cycle compressor 1, in whose cold portion the precooled cycle hydrogen is cooled, liquefied and expanded to produce the cold for liquefaction of the treated hydrogen, the cycle hydrogen returning through passages 47 and 48) (col. 2, ll. 16-24; col. 4, ll. 5-14; fig. 1).
Claim(s) 9 is rejected under 35 U.S.C. 103 as being unpatentable over Grenier, Turney and Prosser as applied to claim 1 above, and further in view of Agrawal (US 5,141,543 A).
In regard to claim 9, the modified Grenier teaches the process of claim 1, including cooling the nitrogen cycle fluid in step a) in passages 31 of warm exchanger 3 before expansion of the turbine portion in turbine 9 (Grenier col. 2, ll. 47-56; fig. 1). The modified Grenier does not teach during step a), the nitrogen cycle fluid is cooled by an external source of cold in a third heat exchanger, and is sent directly to the turbine without passing through the first heat exchanger.
However, Agrawal teaches a nitrogen refrigeration and liquefaction process in which a compressed nitrogen substream (first highest pressure nitrogen substream 140) is cooled by heat exchange against vaporizing liquefied natural gas (heat exchanger 92, LNG line 88) to a temperature between –100° F. and –250° F. and is then work expanded (expander 142), the expanded nitrogen providing refrigeration in separate downstream exchangers (heat exchangers 100, 102) (col. 4, ll. 50-54; col. 5, ll. 11-14; col. 7, ll. 6-7, 47-48; col. 7, l. 60 – col. 8, l. 3; col. 11, ll. 9-18; fig. 2). The turbine feed is thereby cooled by an external source of cold in a dedicated heat exchanger and passed from that exchanger to the expander without passing through the exchangers in which the expanded nitrogen is warmed.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the modified process of Grenier, to include cooling the nitrogen portion fed to the turbine by heat exchange against vaporizing liquefied natural gas in a separate heat exchanger and passing it from that exchanger directly to the expander as taught by Agrawal, in order to use the refrigeration available from vaporizing LNG as the refrigerant for the nitrogen cycle and to reduce the energy consumed by the process (Agrawal col. 11, ll. 21-27).
Claim(s) 11 is rejected under 35 U.S.C. 103 as being unpatentable over Grenier, Turney and Prosser as applied to claim 1 above, and further in view of Beddome (US 5,231,835 A).
In regard to claim 11, the modified Grenier teaches the process of claim 1, but does not teach wherein gas is added, from an external source, to the nitrogen cycle fluid downstream of the compressor, the added gas having the same composition as the nitrogen cycle fluid, in order to increase an inlet pressure of the compressor in order to increase a proportion of liquid produced by the turbine.
However, Beddome teaches supplying make-up nitrogen from an external source (make-up, external source nitrogen; medium pressure nitrogen feed 12 imported from the air separation plant as make-up) to the nitrogen recycle cycle, the make-up gas stream being introducible at any temperature and pressure of the process at the appropriate location, for example in line 31a or 33a downstream of recycle compressor 2 (col. 5, ll. 12-16; col. 9, ll. 42-46; claim 10; fig.). The make-up nitrogen has the same composition as the recycle nitrogen, and Beddome ties the recycle compressor suction and discharge pressures to the liquid content of the cold turbine exhaust (col. 2, ll. 15-25; col. 3, l. 55 – col. 4, l. 3).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the modified process of Grenier, to include introducing make-up nitrogen from an external source into the nitrogen cycle downstream of the cycle compressor as taught by Beddome, in order to supply the make-up liquefier gas to the process at the appropriate temperature and pressure location (Beddome col. 9, ll. 42-46).
Response to Arguments
Applicant’s arguments with respect to the amended claims have been considered but are moot in view of the new ground(s) of rejection.
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 WEBESHET MENGESHA whose telephone number is (571)270-1793. The examiner can normally be reached Mon-Thurs 7-4, alternate Fridays, EST. 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) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Frantz Jules can be reached at 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 published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/W.M/Examiner, Art Unit 3763
/FRANTZ F JULES/Supervisory Patent Examiner, Art Unit 3763
