Flare Recovery with Carbon Capture

Abstract

A flare recovery method includes receiving a flare gas inlet stream that has C 1 -C 8 hydrocarbons. The flare gas inlet stream is separated in a recovery column to produce a C 1 -C 2 hydrocarbon stream and a C 3 -C 8 hydrocarbon stream. The C 3 -C 8 hydrocarbon stream is separated in a separation column to produce a C 3 hydrocarbon stream and a C 4 -C 8 hydrocarbon stream. The C 4 -C 8 hydrocarbon stream is transported to a location for blending with crude oil. The C 3 hydrocarbon stream is optionally recovered as a saleable product or is combined with the C 1 -C 2 hydrocarbon stream to produce a flare gas stream.

1 - 57 . (canceled) 
     
     
         58 . A method for flare recovery, comprising:
 receiving a gas inlet stream, the gas inlet stream comprising C 1 -C 8  hydrocarbons;   separating the gas inlet stream in a recovery column to produce a C 1 -C 2  hydrocarbon stream and a C 3 -C 8  hydrocarbon stream;   separating the C 3 -C 8  hydrocarbon stream in a separation column to produce a C 3  hydrocarbon stream and a C 4 -C 8  hydrocarbon stream;   recovering the C 3  hydrocarbon stream; and   combining the C 4 -C 8  hydrocarbon stream with a C 9+  hydrocarbon stream.   
     
     
         59 . The method of  claim 58 , wherein the gas inlet stream comprises 96-100 mole % C 1 -C 8  hydrocarbons, 0-2 mole % carbon dioxide, and 0-2 mole % nitrogen, the C 1 -C 2  hydrocarbon stream comprises 80 mole % C 1 -C 2  hydrocarbons, 10-20 mole % C 3  hydrocarbons, 0-2 mole % C 4 -C 8  hydrocarbons, 0-2 mole % carbon dioxide, and 0-2 mole % nitrogen, the C 3 -C 8  hydrocarbon stream comprises 5-15 mole % C 1 -C 2  hydrocarbons, 85-95 mole % C 3 -C 8  hydrocarbons, and 0-2 mole % carbon dioxide, the C 3  hydrocarbon stream comprises 30-40 mole % C 1 -C 2  hydrocarbons, 60-70 mole % C 3  hydrocarbons, 0-2 mole % C 4 -C 8  hydrocarbons, and 0-2 mole % carbon dioxide, and the C 4 -C 8  hydrocarbon stream comprises 0 mole % C 1 -C 2  hydrocarbons, 0-2 mole % C 3  hydrocarbons, and 98-100 mole % C 4 -C 8  hydrocarbons. 
     
     
         60 . The method of  claim 58 , further comprising:
 receiving a raw crude oil stream comprising C 1 -C 9+ hydrocarbons;   separating the raw crude oil stream into a C 1 -C 8  hydrocarbon stream and the C 9+  hydrocarbon stream, the C 1 -C 8  hydrocarbon stream comprising the gas inlet stream;   combining the C 3  hydrocarbon stream that is recovered with the C 1 -C 2  hydrocarbon stream to produce a flare gas stream; and   combusting the flare gas stream.   
     
     
         61 . The method of  claim 58 , further comprising:
 receiving a raw crude oil stream comprising C 1 -C 9+  hydrocarbons;   separating the raw crude oil stream into a C 1 -C 8  hydrocarbon stream and the C 9+  hydrocarbon stream, the C 1 -C 8  hydrocarbon stream comprising the gas inlet stream;   collecting the C 3  hydrocarbon that is recovered as a product, the product meeting energy requirements and vapor pressure requirements for transportation by truck or pipeline; and   combusting the C 1 -C 2  hydrocarbon stream as a flare gas stream.   
     
     
         62 . The method of  claim 61 , further comprising:
 expanding the C 1 -C 2  hydrocarbon stream to generate energy; and   compressing the gas inlet stream with the energy generated from the expansion.   
     
     
         63 . The method of  claim 62 , further comprising compressing, cooling, and drying the gas inlet stream before the gas inlet stream is separated by the recovery column. 
     
     
         64 . The method of  claim 63 , wherein the recovery column and the separation column are multi-stage distillation columns, and the recovery column and the separation column are the only two multi-stage distillation columns used in the method. 
     
     
         65 . The method of  claim 64 , wherein no refrigeration processes are used in the flare recovery method. 
     
     
         66 . The method of  claim 65 , wherein the C 1 -C 2  hydrocarbon stream is not compressed after being separated from the C 3 -C 8  hydrocarbon stream. 
     
     
         67 . The method of  claim 66 , wherein the gas inlet stream and the C 3 -C 8  hydrocarbon stream are separated in distillation columns operating at 200 pounds per a square inch (psi) to 500 psi. 
     
     
         68 . The method of  claim 67 , wherein the C 3 -C 8  hydrocarbon stream cannot be combined with raw crude oil stream because a combination of the C 3 -C 8  hydrocarbon stream and the raw crude oil stream would not meet a crude oil specification, and a combination of the C 4 -C 8  hydrocarbon stream and the C 9+  hydrocarbon stream meets the crude oil specification. 
     
     
         69 . The method of  claim 68 , wherein the gas inlet stream comprises 96-100 mole % C 1 -C 8  hydrocarbons, 0-2 mole % carbon dioxide, and 0-2 mole % nitrogen. 
     
     
         70 . The method of  claim 69 , wherein the C 1 -C 2  hydrocarbon stream comprises 80 mole % C 1 -C 2  hydrocarbons, 10-20 mole % C 3  hydrocarbons, 0-2 mole % C 4 -C 8  hydrocarbons, 0-2 mole % carbon dioxide, and 0-2 mole % nitrogen. 
     
     
         71 . The method of  claim 70 , wherein the C 3 -C 8  hydrocarbon stream comprises 5-15 mole % C 1 -C 2  hydrocarbons, 85-95 mole % C 3 -C 8  hydrocarbons, and 0-2 mole % carbon dioxide. 
     
     
         72 . The method of  claim 58 , further comprising transporting the C 4 -C 8  hydrocarbon stream to a location for blending with raw crude oil. 
     
     
         73 . The method of  claim 58 , further comprising compressing, cooling, and separating the gas inlet stream through a series of compressors, coolers, and separators before separating the gas inlet stream in the recovery column. 
     
     
         74 . The method of  claim 58 , further comprising sweetening the C 3  hydrocarbon stream to remove hydrogen sulfide from the C 3  hydrocarbon stream. 
     
     
         75 . A set of process equipment for flare recovery, comprising:
 a first multi-stage distillation column configured to receive a gas inlet stream and produce a first overhead stream and a first bottoms stream, the gas inlet stream comprising C 1 -C 8  hydrocarbons, the first overhead stream comprising C 1 -C 2  hydrocarbons, and the first bottoms stream comprising C 3 -C 8  hydrocarbons;   a second multi-stage distillation column configured to receive the first bottoms stream and produce a second overhead stream and a second bottoms stream, the second overhead stream comprising C 3  hydrocarbons, and the second bottoms stream comprising C 4 -C 8  hydrocarbons;   a piping line configured to receive and recover the C 3  hydrocarbons; and   a mixer configured to combine the C 4 -C 8  hydrocarbons with C 9+  hydrocarbons, and the first multi-stage distillation column and the second multi-stage distillation column are the only two multi-stage distillation columns in the set of process equipment.   
     
     
         76 . The set of process equipment of  claim 75 , wherein the gas inlet stream comprises 96-100 mole % C 1 -C 8  hydrocarbons, 0-2 mole % carbon dioxide, and 0-2 mole % nitrogen, the first overhead stream comprises 80 mole % C 1 -C 2  hydrocarbons, 10-20 mole % C 3  hydrocarbons, 0-2 mole % C 4 -C 8  hydrocarbons, 0-2 mole % carbon dioxide, and 0-2 mole % nitrogen, the first bottoms stream comprises 5-15 mole % C 1 -C 2  hydrocarbons, 85-95 mole % C 3 -C 8  hydrocarbons, and 0-2 mole % carbon dioxide, the second overhead stream comprises 30-40 mole % C 1 -C 2  hydrocarbons, 60-70 mole % C 3  hydrocarbons, 0-2 mole % C 4 -C 8  hydrocarbons, and 0-2 mole % carbon dioxide, and the second bottoms stream comprises 0 mole % C 1 -C 2  hydrocarbons, 0-2 mole % C 3  hydrocarbons, and 98-100 mole % C 4 -C 8  hydrocarbons. 
     
     
         77 . The set of process equipment of  claim 75 , further comprising:
 a heavy hydrocarbons separator configured to receive a raw crude oil stream comprising C 1 -C 9+ hydrocarbons and separate the raw crude oil stream into a C 1 -C 8  hydrocarbon stream and a C 9+  hydrocarbon stream, the C 1 -C 8  hydrocarbon stream comprising the gas inlet stream; and   a mixer configured to combine the second bottoms stream with the C 9+  hydrocarbon stream.   
     
     
         78 . The set of process equipment of  claim 77 , wherein the first bottoms stream cannot be combined with raw crude oil stream because a combination of the first bottoms stream and the raw crude oil stream would not meet a crude oil specification, and a combination of the second bottoms stream and the C 9+  hydrocarbon stream meets the crude oil specification. 
     
     
         79 . The set of process equipment of  claim 75 , wherein the second overhead stream is recovered as C 3  product, and the C 3  product meets energy requirements and vapor pressure requirements for transportation by truck or pipeline. 
     
     
         80 . The set of process equipment of  claim 75 , wherein the second overhead stream is combined with the first overhead stream to produce a flare gas stream. 
     
     
         81 . The set of process equipment of  claim 75 , further comprising an expander, the expander being configured to expand the first overhead stream to generate energy, and the energy being used to compress the gas inlet stream before the gas inlet stream is fed to the first multi-stage distillation column. 
     
     
         82 . The set of process equipment of  claim 75 , further comprising:
 a compressor configured to compress the gas inlet stream;   a cooler configured to cool the compressed gas inlet stream; and   a dehydrator configured to remove water from the cooled and compressed gas inlet stream.   
     
     
         83 . The set of process equipment of  claim 75 , wherein no refrigeration equipment is included within the set of process equipment. 
     
     
         84 . The set of process equipment of  claim 75 , wherein the second bottoms stream is transported to a location for blending with raw crude oil. 
     
     
         85 . The set of process equipment of  claim 75 , wherein the first overhead stream is not compressed after being separated from the first bottoms stream. 
     
     
         86 . The set of process equipment of  claim 75 , wherein the first multi-stage distillation column and the second multi-stage distillation column are configured to be operated in a pressure range of 200 pounds per a square inch gauge (psi) to 500 psi. 
     
     
         87 . The set of process equipment of  claim 75 , wherein the gas inlet stream comprises 96-100 mole % C 1 -C 8  hydrocarbons, 0-2 mole % carbon dioxide, and 0-2 mole % nitrogen. 
     
     
         88 . The set of process equipment of  claim 87 , wherein the first overhead stream comprises 70-80 mole % C 1 -C 2  hydrocarbons, 10-20 mole % C 3  hydrocarbons, 0-2 mole % C 4 -C 8  hydrocarbons, 0-2 mole % carbon dioxide, and 0-2 mole % nitrogen. 
     
     
         89 . The set of process equipment of  claim 88 , wherein the first bottoms stream comprises 5-15 mole % C 1 -C 2  hydrocarbons, 85-95 mole % C 3 -C 8  hydrocarbons, and 0-2 mole % carbon dioxide. 
     
     
         90 . The set of process equipment of  claim 75 , further comprising multiple sets of compressors, coolers, and separators, the multiple sets of compressors coolers, and separators are arranged in series, and the multiple sets of compressors coolers, and separators are configured to compress, cool, and separate the gas inlet stream before the gas inlet stream is fed to the first multi-stage distillation column. 
     
     
         91 . The set of process equipment of  claim 75 , further comprising a hydrogen sulfide removal unit that is configured to remove hydrogen sulfide from the second overhead stream. 
     
     
         92 . A set of process equipment, comprising:
 a first column that is configured to receive a C 1 -C 8  hydrocarbon stream and produce a C 1 -C 2  hydrocarbon stream and a C 3 -C 8  hydrocarbon stream;   a second column that is configured to receive the C 3 -C 8  hydrocarbon stream and produce a C 3  hydrocarbon stream and a C 4 -C 8  hydrocarbon stream;   a piping line configured to receive and recover the C 3  hydrocarbon stream;   a mixer configured to combine the C 4 -C 8  hydrocarbon stream with a C 9+  hydrocarbon stream;   an expander that is configured to expand the C 1 -C 2  hydrocarbon stream to generate energy; and   a compressor that is configured to compress the C 1 -C 8  hydrocarbon stream using the energy generated by the expander before the C 1 -C 8  hydrocarbon stream is fed to the first column.   
     
     
         93 . The set of process equipment of  claim 92 , wherein the C 1 -C 8  hydrocarbon stream comprises 96-100 mole % C 1 -C 8  hydrocarbons, 0-2 mole % carbon dioxide, and 0-2 mole % nitrogen, the C 1 -C 2  hydrocarbon stream comprises 80 mole % C 1 -C 2  hydrocarbons, 10-20 mole % C 3  hydrocarbons, 0-2 mole % C 4 -C 8  hydrocarbons, 0-2 mole % carbon dioxide, and 0-2 mole % nitrogen, the C 3 -C 8  hydrocarbon stream comprises 5-15 mole % C 1 -C 2  hydrocarbons, 85-95 mole % C 3 -C 8  hydrocarbons, and 0-2 mole % carbon dioxide, the C 3  hydrocarbon stream comprises 30-40 mole % C 1 -C 2  hydrocarbons, 60-70 mole % C 3  hydrocarbons, 0-2 mole % C 4 -C 8  hydrocarbons, and 0-2 mole % carbon dioxide, and the C 4 -C 8  hydrocarbon stream comprises 0 mole % C 1 -C 2  hydrocarbons, 0-2 mole % C 3  hydrocarbons, and 98-100 mole % C 4 -C 8  hydrocarbons. 
     
     
         94 . The set of process equipment of  claim 92 , further comprising a heavy hydrocarbons separator that is configured to receive a raw crude oil stream comprising C 1 -C 9+ hydrocarbons and separate the raw crude oil stream into the C 1 -C 8  hydrocarbon stream and the C 9 + hydrocarbon stream. 
     
     
         95 . The set of process equipment of  claim 92 , further comprising piping that is configured to transfer the C 4 -C 8  hydrocarbon stream to a location for blending with crude oil. 
     
     
         96 . The set of process equipment of  claim 92 , further comprising piping that is configured to transfer the C 3  hydrocarbon stream to a location for removal by truck, rail, or pipe. 
     
     
         97 . The set of process equipment of  claim 92 , further comprising a molecular sieve that is configured to remove water from the C 1 -C 8  hydrocarbon stream before the C 1 -C 8  hydrocarbon stream is fed to the first column. 
     
     
         98 . The set of process equipment of  claim 92 , wherein the first column and the second column are configured to be operated at pressures from 200 pounds per a square inch gauge (psi) to 500 psi. 
     
     
         99 . The set of process equipment of  claim 92 , wherein the set of process equipment recovers more than 50 mole % of the C 3  hydrocarbons from the C 1 -C 8  hydrocarbon stream. 
     
     
         100 . The set of process equipment of  claim 92 , wherein the C 1 -C 2  hydrocarbon stream is not compressed after being separated from the C 3 -C 8  hydrocarbon stream. 
     
     
         101 . The set of process equipment of  claim 92 , wherein the first column and the second column are configured to be operated in a pressure range of 200 pounds per a square inch gauge (psi) to 500 psi. 
     
     
         102 . The set of process equipment of  claim 92 , wherein the C 1 -C 8  hydrocarbon stream comprises 96-100 mole % C 1 -C 8  hydrocarbons, 0-2 mole % carbon dioxide, and 0-2 mole % nitrogen. 
     
     
         103 . The set of process equipment of  claim 102 , wherein the C 1 -C 2  hydrocarbon stream comprises 70-80 mole % C 1 -C 2  hydrocarbons, 10-20 mole % C 3  hydrocarbons, 0-2 mole % C 4 -C 8  hydrocarbons, 0-2 mole % carbon dioxide, and 0-2 mole % nitrogen. 
     
     
         104 . The set of process equipment of  claim 103 , wherein the C 3 -C 8  hydrocarbon stream comprises 5-15 mole % C 1 -C 2  hydrocarbons, 85-95 mole % C 3 -C 8  hydrocarbons, and 0-2 mole % carbon dioxide. 
     
     
         105 . The set of process equipment of  claim 92 , further comprising multiple sets of compressors, coolers, and separators, the multiple sets of compressors, coolers, and separators being arranged in series, and the multiple sets of compressors, coolers, and separators are configured to compress, cool, and separate the C 1 -C 8  hydrocarbon stream before the C 1 -C 8  hydrocarbon stream is fed to the first column. 
     
     
         106 . The set of process equipment of  claim 92 , further comprising a hydrogen sulfide removal unit that is configured to remove hydrogen sulfide from the C 3  hydrocarbon stream.