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 .
Status of Claims
The Office Action is in response to the remarks and amendments filed on 12/08/2025.
The objections to the Drawings have been withdrawn in light of the amendments filed. The objections to the Specification have been withdrawn in light of the amendments filed. The rejections pursuant to 35 U.S.C. 112(b) have been withdrawn in light of the amendments filed. Accordingly, claims 1-20 are pending for consideration in this Office Action.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim 1 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Bello (US20080302650A1).
Regarding Claim 1, Bello teaches a process for cooling streams [where heat is recovered from a deethanizer using refrigerant; 0008] comprising:
compressing a refrigerant stream to provide a compressed refrigerant stream [where compressor 191 compresses refrigerant, Figure 1;0040]; and
heat exchanging said compressed refrigerant stream [where the refrigerant transfers heat with the deethanizer side reboiler 173, Figure 1; 0040] with a deethanizer reboil stream [line 118, Figure 1] from a deethanizer column [deethanizer column 161, Figure 1] to cool the compressed refrigerant stream and provide a cooled compressed refrigerant stream [where the side stream is partially vaporized using the heat recovered from the deethanizer overhead product, implying the refrigerant is cooled releasing heat to the side stream, Figure 1;0040] and boil up said deethanized reboil stream and provide a boiling deethanizer reboil stream [where the side stream is partially vaporized using the heat recovered from the deethanizer overhead product and the mixed phase stream is reintroduced to deethanizer 161, Figure 1; 0040]
compressing a propylene refrigerant stream [where overhead product of depropanizer 362 is compressed in compressor 391, Figure 3, where the elements cited from Figure 1 above are also present in the embodiment of Figure 3] to provide a compressed propylene refrigerant stream [line 332, Figure 3]; and heating an ethylene product stream by heat exchange [heating line 314 from side of deethanizer 361 via deethanizer reboiler 372, Figure 3] with said compressed propylene refrigerant stream to provide a heated ethylene product stream [where after absorbing heat, vapor is returned to deethanizer 361 via line 316, Figure 1; 0058] and a cooled compressed propylene refrigerant stream [line 33, Figure 3].
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.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Bello (US20080302650A1) in view of Wegerer et al. (US20090120780A1).
Regarding Claim 2, Bello teaches the invention of claim 1 and does not teach where said deethanized reboil stream is a deethanized bottom stream and said compressed refrigerant stream is a first compressed refrigerant stream and further comprising compressing a cooled first compressed refrigerant stream to provide a second compressed refrigerant stream and heat exchanging a deethanizer side stream from said deethanizer column with said second compressed refrigerant stream to cool the second compressed refrigerant stream and provide a cooled second compressed refrigerant stream and boil up said deethanizer side stream to provide a boiling deethanizer side stream.
However, Wegerer teaches a method of processing hydrocarbon-containing materials into two materials [0001] where said reboil stream is a bottom stream [bottoms material loop 187, 188 with reboiler 168, Figure 2] and said compressed refrigerant stream is a first compressed refrigerant stream [where pressurized vapor is delivered via line 171 from compressor 163b to bottom reboiler 168, Figure 2; 0049] and further comprising compressing a cooled first compressed refrigerant stream [where after passing suction drum 167 and 178 fluid is compressed in heat pump compressor 163a, Figure 2; 0051] to provide a second compressed refrigerant stream [line 166, Figure 2] and heat exchanging a side stream [via inter-reboiler heat exchanger 164 of intermediate loops 175 and 176, Figure 2; 0051] from said column with said second compressed refrigerant stream to cool the second compressed refrigerant stream and provide a cooled second compressed refrigerant stream [where pressurized vapor from heat pump compressor 163a condenses through inter-reboiler heat exchanger 164 via line 165; 0054] and boil up said side stream to provide a boiling side stream [where the intermediate loop 175 absorbs heat through inter-reboiler heat exchanger 164; 0054] where one of ordinary skill in the art would have been capable of applying this known technique to a known device, a deethanizer, that was ready for improvement and the results would have been predictable to one of ordinary skill in the art i.e., reducing heat pump compressor power consumption [Wegerer, 0058].
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Bello to have where said deethanized reboil stream is a deethanized bottom stream and said compressed refrigerant stream is a first compressed refrigerant stream and further comprising compressing a cooled first compressed refrigerant stream to provide a second compressed refrigerant stream and heat exchanging a deethanizer side stream from said deethanizer column with said second compressed refrigerant stream to cool the second compressed refrigerant stream and provide a cooled second compressed refrigerant stream and boil up said deethanizer side stream to provide a boiling deethanizer side stream in view of the teachings of Wegerer where this known technique could have been applied to a known device that was ready for improvement and the results would have been predictable i.e., reducing heat pump compressor power consumption [Wegerer, 0058].
Regarding Claim 3, Bello teaches the invention of claim 1 and further teaches where said deethanized reboil stream is a deethanized side stream [deethanizer side reboiler 173 via line 118, Figure 1] but does not teach where said refrigerant stream is a cooled first compressed refrigerant stream and said compressed refrigerant stream is a second compressed refrigerant stream and further comprising compressing a preliminary refrigerant stream to provide a first compressed refrigerant stream and heat exchanging a deethanizer bottoms stream from said deethanizer column with said first compressed refrigerant stream to cool the first compressed refrigerant stream and provide said cooled first compressed refrigerant stream and boil up said deethanizer side bottom to provide a boiling deethanizer bottom stream.
However, Wegerer teaches a method of processing hydrocarbon-containing materials into two materials [0001] where said refrigerant stream is a cooled first compressed refrigerant stream [where pressurized vapor is delivered via line 171 from compressor 163b to bottom reboiler 168, Figure 2; 0049] and said compressed refrigerant stream is a second compressed refrigerant stream [where after passing suction drum 167 and 178 fluid is compressed in heat pump compressor 163a, Figure 2; 0051] and further comprising compressing a preliminary refrigerant stream [line 170, Figure 2] to provide a first compressed refrigerant stream [where pressurized vapor is delivered via line 171 from compressor 163b to bottom reboiler 168, Figure 2; 0049] and heat exchanging a deethanizer bottoms stream from said deethanizer column with said first compressed refrigerant stream [where pressurized vapor is delivered via line 171 from compressor 163b to bottom reboiler 168, Figure 2; 0049] to cool the first compressed refrigerant stream and provide said cooled first compressed refrigerant stream [where liquid condensate from the reboiler heat exchanger 169 returns via line 171 a, Figure 2; 0053] and boil up said deethanizer side bottom to provide a boiling deethanizer bottom stream [where bottoms liquid is heated through reboiler 168, Figure 2; 0057] where one of ordinary skill in the art would have been capable of applying this known technique to a known device, a deethanizer, that was ready for improvement and the results would have been predictable to one of ordinary skill in the art i.e., reducing heat pump compressor power consumption [Wegerer, 0058].
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Bello to have where said refrigerant stream is a cooled first compressed refrigerant stream and said compressed refrigerant stream is a second compressed refrigerant stream and further comprising compressing a preliminary refrigerant stream to provide a first compressed refrigerant stream and heat exchanging a deethanizer bottoms stream from said deethanizer column with said first compressed refrigerant stream to cool the first compressed refrigerant stream and provide said cooled first compressed refrigerant stream and boil up said deethanizer side bottom to provide a boiling deethanizer bottom stream in view of the teachings of Wegerer where this known technique could have been applied to a known device that was ready for improvement and the results would have been predictable i.e., reducing heat pump compressor power consumption [Wegerer, 0058].
Regarding Claim 12, Bello teaches a process for cooling streams [where heat is recovered from a deethanizer using refrigerant; 0008] comprising:
compressing a refrigerant stream to provide a first compressed refrigerant stream [where compressor 291 compresses refrigerant from overhead line 222, Figure 2]; and heat exchanging said first compressed refrigerant stream with a bottoms deethanizer reboil stream [where the compressed refrigerant via line 232 transfers heat in the deethanizer reboiler 272 to bottoms product line 213, Figure 2; 0047] from a deethanizer column [deethanizer column 261, Figure 2] to cool the first compressed refrigerant stream and provide a cooled first compressed refrigerant stream [where heat is transferred from refrigerant in line 232 via reboiler 272, Figure 2;0047] and boil up said deethanized reboil stream and provide a boiling deethanizer reboil stream [where vapor from deethanizer reboiler is directed to deethanizer 261, Figure 2;0047]; compressing a propylene refrigerant stream [where overhead product of depropanizer 362 is compressed in compressor 391, Figure 3, where the elements cited from Figure 1 above are also present in the embodiment of Figure 3] to provide a compressed propylene refrigerant stream [line 332, Figure 3]; and heating an ethylene product stream by heat exchange [heating line 314 from side of deethanizer 361 via deethanizer reboiler 372, Figure 3] with said compressed propylene refrigerant stream to provide a heated ethylene product stream [where after absorbing heat, vapor is returned to deethanizer 361 via line 316, Figure 1; 0058] and a cooled compressed propylene refrigerant stream [line 33, Figure 3].
but Bello does not teach where said cooled first compressed refrigerant stream is compressed in a second compressor to provide a second compressed refrigerant stream and heat exchanging a deethanizer side stream from said deethanizer column with said second compressed refrigerant stream to cool the second compressed refrigerant stream and provide a cooled second compressed refrigerant stream and boil up said deethanizer side stream to provide a boiling deethanizer side stream.
However, Wegerer teaches a method of processing hydrocarbon-containing materials into two materials [0001] where said cooled first compressed refrigerant stream [where after passing suction drum 167 and 178 fluid is compressed in heat pump compressor 163a, Figure 2; 0051] is compressed in a second compressor [where after passing suction drum 167 and 178 fluid is compressed in heat pump compressor 163a, Figure 2; 0051] to provide a second compressed refrigerant stream [line 166, Figure 2] and heat exchanging a deethanizer side stream from said deethanizer column with said second compressed refrigerant stream [via inter-reboiler heat exchanger 164 of intermediate loops 175 and 176, Figure 2; 0051] to cool the second compressed refrigerant stream and provide a cooled second compressed refrigerant stream [where pressurized vapor from heat pump compressor 163a condenses through inter-reboiler heat exchanger 164 via line 165; 0054] and boil up said deethanizer side stream to provide a boiling deethanizer side stream [where the intermediate loop 175 absorbs heat through inter-reboiler heat exchanger 164; 0054] where one of ordinary skill in the art would have been capable of applying this known technique to a known device, a deethanizer, that was ready for improvement and the results would have been predictable to one of ordinary skill in the art i.e., reducing heat pump compressor power consumption [Wegerer, 0058].
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Bello to have where said cooled first compressed refrigerant stream is compressed in a second compressor to provide a second compressed refrigerant stream and heat exchanging a deethanizer side stream from said deethanizer column with said second compressed refrigerant stream to cool the second compressed refrigerant stream and provide a cooled second compressed refrigerant stream and boil up said deethanizer side stream to provide a boiling deethanizer side stream in view of the teachings of Wegerer where this known technique could have been applied to a known device that was ready for improvement and the results would have been predictable i.e., reducing heat pump compressor power consumption [Wegerer, 0058].
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Bello (US20080302650A1) in view of Wegerer et al. (US20090120780A1) and in further view of Purola (US20210171836A1).
Regarding Claim 4, Bello, as modified, teaches the invention of claim 2 and does not teach where the cooled second compressed refrigerant stream exchanges heat with a pyrolyzed stream to provide said refrigerant stream and a cooled pyrolyzed stream.
However, Purola teaches a method of heat integration in hydrocarbon processing [0001] where high pressure refrigerant stream [superheated high pressure steam (HPS) 13, Figure 1A;0162;0117] exchanges heat [via heat recovery unit 302, Figure 1A] with a pyrolyzed stream [effluent 8 from reactor 202, Figure 1A] to provide said refrigerant stream [HPSS 14, Figure 1A] and a cooled pyrolyzed stream [where heat is recovered from effluent 8 in heat recovery unit 302; 0117] where one of ordinary skill in the art could have combined the elements as claimed by known methods and that in combination, each element would perform the same function as it did separately [where the heat recovery unit 302 is for heating or preheating such as a dilution steam mixture or any other stream within the hydrocarbon processing; 0117] and one of ordinary skills would have recognized that the results of the combination were predictable i.e., improving energy efficiency through recovering heat of cracked gaseous effluent.
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Bello to have where the cooled second compressed refrigerant stream exchanges heat with a pyrolyzed stream to provide said refrigerant stream and a cooled pyrolyzed stream in view of the teachings of Purola where the elements could have been combined by known methods with no change in their respective functions, and the combination would have yielded predictable results i.e., improving energy efficiency through recovering heat of cracked gaseous effluent.
Regarding Claim 13, Bello, as modified, teaches the invention of claim 12 and does not teach heat exchanging the cooled second compressed refrigerant stream with a pyrolyzed stream to provide said refrigerant stream and a cooled pyrolyzed stream.
However, Purola teaches a method of heat integration in hydrocarbon processing [0001] where high pressure refrigerant stream [superheated high pressure steam (HPS) 13, Figure 1A;0162;0117] exchanges heat [via heat recovery unit 302, Figure 1A] with a pyrolyzed stream [effluent 8 from reactor 202, Figure 1A] to provide said refrigerant stream [HPSS 14, Figure 1A] and a cooled pyrolyzed stream [where heat is recovered from effluent 8 in heat recovery unit 302; 0117] where one of ordinary skill in the art could have combined the elements as claimed by known methods and that in combination, each element would perform the same function as it did separately [where the heat recovery unit 302 is for heating or preheating streams such as a dilution steam mixture or any other stream within the hydrocarbon processing; 0117] and one of ordinary skills would have recognized that the results of the combination were predictable i.e., improving energy efficiency through recovering heat of cracked gaseous effluent.
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Bello to have where the cooled second compressed refrigerant stream exchanges heat with a pyrolyzed stream to provide said refrigerant stream and a cooled pyrolyzed stream in view of the teachings of Purola where the elements could have been combined by known methods with no change in their respective functions, and the combination would have yielded predictable results i.e., improving energy efficiency through recovering heat of cracked gaseous effluent.
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Bello (US20080302650A1) in view of Lee et al. (US6244070B1).
Regarding Claim 5, Bello teaches the invention of Claim 1 but does not teach demethanized reboil bottoms stream is boiled up by heat exchange with a demethanizer feed stream to provide a demethanized reboiling bottom stream fed back to the demethanizer column and a precooled demethanizer feed stream.
However, Lee teaches a method of recovering ethane, ethylene and heavier hydrocarbons from natural gas [col. 1, lines 5-12] including boiling up a demethanized reboil bottoms stream [bottom reboiler and side reboiler 100, where the bottom reboiler is below the side reboiler, Figure 2] by heat exchange [liquid exchanger 18, Figure 2] with a demethanizer feed stream [where dry feed gas 10 is cooled in liquid exchanger 18 through stream 14, Figure 2; col. 5, lines 43-57] to provide a demethanized reboiling bottom stream fed back to the demethanizer column [line 56a, Figure 2; col. 6, lines 24-27] and a precooled demethanizer feed stream [col. 5, lines 43-57] where one of ordinary skill in the art would have been capable of applying this known technique to a known device that was ready for improvement and the results would have been predictable to one of ordinary skill in the art i.e., maximizing ethane recovery without significantly increasing operating costs [Lee, col.13, lines 5-10].
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Bello to have where the predefined temperature range includes demethanized reboil bottoms stream is boiled up by heat exchange with a demethanizer feed stream to provide a demethanized reboiling bottom stream fed back to the demethanizer column and a precooled demethanizer feed stream in view of the teachings of Lee where this known technique could have been applied to a known device that was ready for improvement and the results would have been predictable i.e., maximizing ethane recovery without significantly increasing operating costs [Lee, col.13, lines 5-10].
Regarding Claim 6, Bello teaches the invention of Claim 1 but does not teach heat exchanging a demethanizer side stream with a demethanizer feed stream to cool a demethanizer feed stream and heating said demethanizer side stream.
However, Lee teaches a method of recovering ethane, ethylene and heavier hydrocarbons from natural gas [col. 1, lines 5-12] including heat exchanging [through liquid heat exchanger 18, Figure 2] a demethanizer side stream [bottom reboiler and side reboiler 100, where the side reboiler is above the side reboiler, Figure 2] with a demethanizer feed stream [stream 14, Figure 2] to cool a demethanizer feed stream [where dry feed gas 10 is cooled in liquid exchanger 18 through stream 14, Figure 2;col.6, lines 30-39 ] and heating said demethanizer side stream [where cooling feed gas 10 in exchanger 18 implies side reboiler and bottom reboiler absorb heat from stream 14, Figure 2; col.6, lines 30-39], where one of ordinary skill in the art would have been capable of applying this known technique to a known device that was ready for improvement and the results would have been predictable to one of ordinary skill in the art i.e., maximizing ethane recovery without significantly increasing operating costs [Lee, col.13, lines 5-10].
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Bello to have exchanging a demethanizer side stream with a demethanizer feed stream to cool a demethanizer feed stream and heating said demethanizer side stream in view of the teachings of Lee where this known technique could have been applied to a known device that was ready for improvement and the results would have been predictable i.e., maximizing ethane recovery without significantly increasing operating costs [Lee, col.13, lines 5-10].
Claim 7 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Bello (US20080302650A1) in view of Hirata (Hirata, K. Energy Saving for Ethylene Process by Advanced Integration, April 2011, Chem Eng Trans 25, [retrieved on 22 Aug 2025]. Retrieved from Internet < https://skoge.folk.ntnu.no/prost/proceedings/pres2011-and-icheap10/PRES11/6Hirata.pdf>).
Regarding Claim 7, Bello teaches the invention of claim 1 and does not teach reboiling a C2 splitter side stream by heat exchange with a deethanizer overhead stream.
However, Hirata teaches a method of heat integration between a deethanizer and C2 splitter including reboiling a C2 splitter side stream [where the side reboiler is heated from -27.2 to -21.4 degrees Celsius, Figure 2(b)] by heat exchange with a deethanizer overhead stream [where side reboiler exchanges heat with the deethanizer overhead at NEW-HX Q = 3.44 ΔTLM=4. 5, Figure 2(b)] where one of ordinary skill in the art would have been capable of applying this known technique to a known device that was ready for improvement and the results would have been predictable to one of ordinary skill in the art i.e., reducing energy costs of low temperature cooling through integrating heat between deethanizer condenser and a C2 splitter [Hirata, Abstract].
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Bello to have reboiling a C2 splitter side stream by heat exchange with a deethanizer overhead stream in view of the teachings of Hirata where this known technique could have been applied to a known device that was ready for improvement and the results would have been predictable i.e., reducing energy costs of low temperature cooling through integrating heat between deethanizer condenser and a C2 splitter [Hirata, Abstract].
Regarding Claim 8, Bello, as modified, teaches the invention of claim 7 and does not teach fractionating said deethanizer overhead stream to provide an C2 splitter overhead stream rich in ethylene, a C2 splitter bottom stream rich in ethane and said C2 splitter side stream.
However, Hirata teaches a C2 splitter [Figure 2(b)] and fractionating said deethanizer overhead stream [where overhead stream feeds into C2 splitter, annotated Figure 2(b)] to provide an C2 splitter overhead stream rich in ethylene [where one of ordinary skill in the art prior to the effective filing date would understand the overhead stream of a C2 splitter to be rich in ethylene, refer to pertinent art] a C2 splitter bottom stream [annotated Figure 2(b)] rich in ethane [where one of ordinary skill in the art prior to the effective filing date would understand the bottom stream of a C2 splitter to be rich in ethane, refer to pertinent art] and said C2 splitter side stream [annotated Figure 2(b)] where one of ordinary skill in the art would have been capable of applying this known technique to a known device that was ready for improvement and the results would have been predictable to one of ordinary skill in the art i.e., improving the purity of ethane product.
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Bello to have fractionating said deethanizer overhead stream to provide an C2 splitter overhead stream rich in ethylene, a C2 splitter bottom stream rich in ethane and said C2 splitter side stream in view of the teachings of Hirata where this known technique could have been applied to a known device that was ready for improvement and the results would have been predictable i.e., improving the purity of ethane product.
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Claim 9 are rejected under 35 U.S.C. 103 as being unpatentable over Bello (US20080302650A1) in view of Mcharg (US3336761A).
Regarding Claim 9, Bello teaches the invention of claim 1 and teaches compressing said propylene refrigerant in a first propylene compressor to provide a first compressed propylene refrigerant stream [where overhead product of depropanizer 362 is compressed in compressor 391, Figure 3, where the elements cited from Figure 1 above are also present in the embodiment of Figure 3] but does not teach compressing said propylene refrigerant in a first propylene compressor to provide a first compressed propylene refrigerant stream and boiling up a reboil C2 splitter bottom stream by heat exchange with said first compressed propylene refrigerant stream to provide a cooled first compressed propylene refrigerant stream and a reboiled C2 splitter reboiled stream.
However, Mcharg teaches an economical ethylene fractionating column [col.1, lines 65-71] including compressing a propylene refrigerant in a first propylene compressor [where low pressure propylene flows through flow conduit 45 into multi-stage compressor 43, Figure 1; col. 4, lines 33-40] to provide a first compressed propylene refrigerant stream [where the pressure of propylene is increased to a high or more intermediate pressure level; col. 4, lines 33-40] and boiling up a reboil C2 splitter bottom stream [where the ethylene column bottom fraction is removed through flow conduit 25 where a portion of said fraction passes through flow conduit 26 through the process side of heat exchange heater 28 and returns to ethylene fractionator 18 by means of flow conduit 29; col. 4, lines 20-25] by heat exchange with said first compressed propylene refrigerant stream [where propylene flows through conduit 30 through the heating side of heat exchange heater 28, Figure 1; col. 4 lines 43-49] to provide a cooled first compressed propylene refrigerant stream and a reboiled C2 splitter reboiled stream [where the propylene is condensed and the process material in conduit 29 is heated ; col. 4 liens 43-49] where one of ordinary skill in the art would have been capable of applying this known technique to a known device that was ready for improvement and the results would have been predictable to one of ordinary skill in the art i.e., improving efficiency of heating and cooling energy by integration with a refrigeration system.
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Mcharg to have where a propylene refrigerant is compressed in a first propylene compressor to provide a first compressed propylene refrigerant stream and boiling up a reboil C2 splitter bottom stream by heat exchange with said first compressed propylene refrigerant stream to provide a cooled first compressed propylene refrigerant stream and a reboiled C2 splitter reboiled stream in view of the teachings of Bello to where this known technique could have been applied to a known device that was ready for improvement and the results would have been predictable i.e., improving efficiency of heating and cooling energy by integration with a refrigeration system.
Claim 14 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Bello (US20080302650A1) in view of Wegerer et al. (US20090120780A1) and in further view of Lee et al. (US6244070B1).
Regarding Claim 14, Bello, as modified, teaches the invention of claim 12 and does not teach where a demethanized reboil bottoms stream is boiled up by heat exchange with a demethanizer feed stream to provide a demethanized reboiling stream that is fed back to the demethanizer column and a precooled demethanizer feed stream.
However, Lee teaches a method of recovering ethane, ethylene and heavier hydrocarbons from natural gas [col. 1, lines 5-12] including boiling up a demethanized reboil bottoms stream [bottom reboiler and side reboiler 100, where the bottom reboiler is below the side reboiler, Figure 2] by heat exchange [liquid exchanger 18, Figure 2] with a demethanizer feed stream [where dry feed gas 10 is cooled in liquid exchanger 18 through stream 14, Figure 2; col. 5, lines 43-57] to provide a demethanized reboiling bottom stream fed back to the demethanizer column [line 56a, Figure 2; col. 6, lines 24-27] and a precooled demethanizer feed stream [col. 5, lines 43-57] where one of ordinary skill in the art would have been capable of applying this known technique to a known device that was ready for improvement and the results would have been predictable to one of ordinary skill in the art i.e., maximizing ethane recovery without significantly increasing operating costs [Lee, col.13, lines 5-10].
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Bello to have where the predefined temperature range includes demethanized reboil bottoms stream is boiled up by heat exchange with a demethanizer feed stream to provide a demethanized reboiling bottom stream fed back to the demethanizer column and a precooled demethanizer feed stream in view of the teachings of Lee where this known technique could have been applied to a known device that was ready for improvement and the results would have been predictable i.e., maximizing ethane recovery without significantly increasing operating costs [Lee, col.13, lines 5-10].
Regarding Claim 15, Bello, as modified, teaches the invention of Claim 12 and does not teach where a demethanizer bottom stream exchanging heat with a demethanizer feed stream to cool a demethanizer feed stream and heating said demethanizer bottom stream.
However, Lee teaches a method of recovering ethane, ethylene and heavier hydrocarbons from natural gas [col. 1, lines 5-12] including a demethanizer bottom stream [bottom reboiler and side reboiler 100, where the bottom reboiler is below the side reboiler, Figure 2] exchanging heat with a demethanizer feed stream to cool a demethanizer feed stream [where dry feed gas 10 is cooled in liquid exchanger 18 through stream 14, Figure 2; col. 5, lines 43-57] and heating said demethanizer bottom stream [where cooling feed gas 10 in exchanger 18 implies side reboiler and bottom reboiler absorb heat from stream 14, Figure 2; col.6, lines 30-39] where one of ordinary skill in the art would have been capable of applying this known technique to a known device that was ready for improvement and the results would have been predictable to one of ordinary skill in the art i.e., maximizing ethane recovery without significantly increasing operating costs [Lee, col.13, lines 5-10].
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Bello to have where a demethanizer bottom stream exchanging heat with a demethanizer feed stream to cool a demethanizer feed stream and heating said demethanizer bottom stream in view of the teachings of Lee where this known technique could have been applied to a known device that was ready for improvement and the results would have been predictable i.e., maximizing ethane recovery without significantly increasing operating costs [Lee, col.13, lines 5-10].
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Bello (US20080302650A1) in view of Wegerer et al. (US20090120780A1) and in further view of Hirata (Hirata, K. Energy Saving for Ethylene Process by Advanced Integration, April 2011, Chem Eng Trans 25, [retrieved on 22 Aug 2025]. Retrieved from Internet < https://skoge.folk.ntnu.no/prost/proceedings/pres2011-and-icheap10/PRES11/6Hirata.pdf>).
Regarding Claim 16, Bello, as modified, teaches the invention of claim 12 and does not teach reboiling a C2 splitter side stream by heat exchange with a deethanizer overhead stream and fractionating said deethanizer overhead stream to provide an C2 splitter overhead stream rich in ethylene, a C2 splitter bottom stream rich in ethane and said C2 splitter side stream.
However, Hirata teaches a method of heat integration between a deethanizer and C2 splitter including reboiling a C2 splitter side stream [where the side reboiler is heated from -27.2 to -21.4 degrees Celsius, Figure 2(b)] by heat exchange with a deethanizer overhead stream [where side reboiler exchanges heat with the deethanizer overhead at NEW-HX Q = 3.44 ΔTLM=4. 5, Figure 2(b)] and fractionating said deethanizer overhead stream [where overhead stream feeds into C2 splitter, annotated Figure 2(b)] to provide an C2 splitter overhead stream rich in ethylene [where one of ordinary skill in the art prior to the effective filing date would understand the overhead stream of a C2 splitter to be rich in ethylene, refer to pertinent art] a C2 splitter bottom stream [annotated Figure 2(b)] rich in ethane [where one of ordinary skill in the art prior to the effective filing date would understand the bottom stream of a C2 splitter to be rich in ethane, refer to pertinent art] and said C2 splitter side stream [annotated Figure 2(b)] where one of ordinary skill in the art would have been capable of applying this known technique to a known device that was ready for improvement and the results would have been predictable to one of ordinary skill in the art i.e., improving the purity of ethane product.
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Bello to reboil a C2 splitter side stream by heat exchange with a deethanizer overhead stream and fractionating said deethanizer overhead stream to provide an C2 splitter overhead stream rich in ethylene, a C2 splitter bottom stream rich in ethane and said C2 splitter side stream in view of the teachings of Hirata where this known technique could have been applied to a known device that was ready for improvement and the results would have been predictable i.e., reducing energy costs of low temperature cooling through integrating heat between deethanizer condenser and a C2 splitter [Hirata, Abstract].
Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over Bello (US20080302650A1) in view of Wegerer et al. (US20090120780A1) and in further view of Mcharg (US3336761A).
Regarding Claim 17, Bello, as modified, teaches the invention of Claim 12 and does not teach compressing a propylene refrigerant in a first propylene compressor to provide a first compressed propylene refrigerant stream and boiling up a reboil C2 splitter bottom stream by heat exchange with said first compressed propylene refrigerant stream to provide a cooled first compressed propylene refrigerant stream and a reboiled C2 splitter reboiled stream.
However, Mcharg teaches an economical ethylene fractionating column [col.1, lines 65-71] including compressing a propylene refrigerant in a first propylene compressor [where low pressure propylene flows through flow conduit 45 into multi-stage compressor 43, Figure 1; col. 4, lines 33-40] to provide a first compressed propylene refrigerant stream [where the pressure of propylene is increased to a high or more intermediate pressure level; col. 4, lines 33-40] and boiling up a reboil C2 splitter bottom stream [where the ethylene column bottom fraction is removed through flow conduit 25 where a portion of said fraction passes through flow conduit 26 through the process side of heat exchange heater 28 and returns to ethylene fractionator 18 by means of flow conduit 29; col. 4, lines 20-25] by heat exchange with said first compressed propylene refrigerant stream [where propylene flows through conduit 30 through the heating side of heat exchange heater 28, Figure 1; col. 4 lines 43-49] to provide a cooled first compressed propylene refrigerant stream and a reboiled C2 splitter reboiled stream [where the propylene is condensed and the process material in conduit 29 is heated ; col. 4 liens 43-49] where one of ordinary skill in the art would have been capable of applying this known technique to a known device that was ready for improvement and the results would have been predictable to one of ordinary skill in the art i.e., improving efficiency of heating and cooling energy by integration with a refrigeration system.
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Mcharg to have where a propylene refrigerant is compressed in a first propylene compressor to provide a first compressed propylene refrigerant stream and boiling up a reboil C2 splitter bottom stream by heat exchange with said first compressed propylene refrigerant stream to provide a cooled first compressed propylene refrigerant stream and a reboiled C2 splitter reboiled stream in view of the teachings of Bello to where this known technique could have been applied to a known device that was ready for improvement and the results would have been predictable i.e., improving efficiency of heating and cooling energy by integration with a refrigeration system.
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Bello (US20080302650A1) in view of Jana (Jana, A. Advances in heat pump assisted distillation column: A review, January 2014, Energy Conversion and Management, Vol 77 [retrieved on 23 August 2025]. Retrieved from Internet <DOI: https://doi.org/10.1016/j.enconman.2013.09.055 >), Yang (CN210569512U)
Regarding Claim 20, Bello teaches an apparatus for cooling streams comprising a deethanizer bottoms reboil exchanger [deethanizer reboiler 272, Figure 2] in downstream communication with a first compressor [overhead compressor 291, Figure 2] and teaches a side reboil exchanger [deethanizer side reboiler 273, Figure 2] and does not teach where a second compressor in downstream communication with said first compressor and a side reboil exchanger in downstream communication with said second compressor.
However, Jana teaches heat pump assisted distillation [Abstract] where a second compressor [Comp-S2, Figure 9, p.293] is downstream communication with a first compressor [Comp-S1, Figure 9, p.293] and a side reboil exchanger [IR1, Figure 9, p.293] in downstream communication with said second compressor [where the double intermediate reboiler IR is downstream the double stage vapor recompression Comp, Figure 9; p.293] where one of ordinary skill in the art would have been capable of applying this known technique, multi-stage vapor recompression, to a known device, a deethanizer, that was ready for improvement and the results would have been predictable to one of ordinary skill in the art i.e., achieving higher thermodynamic efficiency [Jana, p. 292, left col, para 2].
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Bello to have where a second compressor in downstream communication with said first compressor and a side reboil exchanger in downstream communication with said second compressor in view of the teachings of Jana where this known technique could have been applied to a known device that was ready for improvement and the results would have been predictable i.e., achieving higher thermodynamic efficiency [Jana, p. 292, left col, para 2].
The combined teachings do not teach a dehydrogenation cold box in downstream communication with said first compressor, wherein said dehydrogenation cold box is configured to receive a compressed refrigerant stream from said first compressor and to cool a dehydrogenated hydrocarbon stream by heat exchange with said compressed refrigerant stream, and a pyrolysis cold box in downstream communication with said second compressor, wherein said pyrolysis cold box is configured to receive a second compressed refrigerant stream from said second compressor and to cool said second compressed refrigerant stream by heat exchange with a pyrolyzed hydrocarbon stream.
However, Yang teaches a cold box system for ethane cracking [0002] where a dehydrogenation cold box [cold box 29, Figure 2] is configured to receive a compressed refrigerant stream [where the cold box 29 is configured to receive a binary refrigerant, annotated Figure 2] from said first compressor and to cool a dehydrogenated hydrocarbon stream by heat exchange with said compressed refrigerant stream [where the distilled ethylene condensation pipeline 20 exchanges heat to condense in cold box 29; 0030] and a pyrolysis cold box [cold box 19, Figure 2], wherein said pyrolysis cold box is configured to receive a second compressed refrigerant stream from said second compressor [where the cold box 19 is configured to receive cooling recovery pipeline 15, Figure 2] and to cool said second compressed refrigerant stream by heat exchange with a pyrolyzed hydrocarbon stream [where cooling recovery 15 recovers cooling capacity through heat exchange in cold box 19, thus heating the overhead product of ethylene distillation column top fraction condensation pipeline 22 and cooling the cooling recovery pipeline, Figure 2; 0030] where one of ordinary skill in the art could have combined the elements as claimed by known methods, where cold boxes are a key piece of equipment in an ethylene plant for heat exchange [Yang,0005;0006], and that in combination, each element would perform the same function as it did separately and one of ordinary skills would have recognized that the results of the combination were predictable i.e., improving heat exchange efficiency across multiple streams with a compact cold box system [Yang; 0010]
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the assembly of the combined teachings to have a dehydrogenation cold box in downstream communication with said first compressor, wherein said dehydrogenation cold box is configured to receive a compressed refrigerant stream from said first compressor and to cool a dehydrogenated hydrocarbon stream by heat exchange with said compressed refrigerant stream, and a pyrolysis cold box in downstream communication with said second compressor, wherein said pyrolysis cold box is configured to receive a second compressed refrigerant stream from said second compressor and to cool said second compressed refrigerant stream by heat exchange with a pyrolyzed hydrocarbon stream in view of the teachings of Yang where the elements could have been combined by known methods with no change in their respective functions, and the combination would have yielded predictable results i.e., improving heat exchange efficiency across multiple streams with a compact cold box system [Yang; 0010]
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Allowable Subject Matter
Claim 10, 11, 18 and 19 are allowed.
Claims 10, 11, 18 and 19 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is an examiner’s statement of reasons for allowance:
Regarding Claim 10 and 18, the subject matter which is considered to distinguish from the closest prior art of record, Bello (US20080302650A1) in view of Mcharg (US3336761A), where Mcharg teaches compressing said cooled first compressed propylene refrigerant stream [from first stage of compressor 43, col. 5 lines 10-20] in a second propylene compressor [second stage of compressor 43, col.5, lines 5-10] to provide a second compressed propylene refrigerant stream [high pressure refrigerant via line 32, Figure 1] and cooling an ethylene product stream [where the propylene refrigerant vaporizes in cooler 20 with ethylene vapor; col. 5, lines 50-59] by heat exchange with said first compressed propylene refrigerant stream to provide a cooled ethylene product stream [line 24, Figure 1] and a heated second compressed propylene refrigerant stream [where vaporized propylene leaves cooler 20; col. 5 lines 10-15] contrasting the claimed feature of and heating an ethylene product stream by heat exchange with said second compressed propylene refrigerant stream to provide a heated ethylene product stream and a cooled second compressed propylene refrigerant stream.
Therefore, it would not be obvious to modify the technique of the prior art structures to have the apparatus as claimed without improper hindsight and claim 10 with dependent claim 11, and claim 18, with dependent claim 19, therefrom are considered allowable.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
Response to Arguments
On page 13 and 14 of the remarks filed 12/08/2025, Applicant argues that claims 1 and 12 incorporate features indicated in the Examiner reasons for allowance such that claims 1-19 are in condition for allowance. Please refer to the rejections of claim 1 and claim 12 above. To clarify from the Examiner reasons for allowance further, the recitation of “…heating an ethylene product stream by heat exchange with said second compressed propylene refrigerant stream to provide a heated ethylene product stream and a cooled second compressed propylene refrigerant stream” distinguishes from the prior art of Bello in process claims 1 and 12. Applicant does not separately argue the rejection of claims 2-11 except for their dependence upon claim 1 and Applicant does not separately argue the rejection of claims 11-19 except for their dependence upon claim 12. Accordingly, the rejections of record are considered proper and remain.
On page 14 and 15 of the remarks filed 12/08/2025, Applicant argues that none of the cited references disclose claim 20 as amended. Applicant’s arguments have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Accordingly, the rejections of record are considered proper and remain.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Verma (US 20080141712 A1) describes an olefin recovery process where known prior art includes the separation of ethylene and ethane from one or more C2-rich hydrocarbon streams, producing an ethylene rich overhead vapor 108, a mixed ethylene-ethane side stream 112, and a bottoms stream comprising C3 and heavier compounds 110. Refer to 0004 and Figure 2.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/KEONA LAUREN BANKS/Examiner, Art Unit 3763
/ELIZABETH J MARTIN/Primary Examiner, Art Unit 3763