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Streams (11) of natural gas contaminated with significant amounts of carbon dioxide can be efficiently and economically processed to create Syngas (16). An available source (1) of flue gas that might otherwise be dispersed into the atmosphere in conjunction with such a CO2-laden natural gas stream (

Streams (11) of natural gas contaminated with significant amounts of carbon dioxide can be efficiently and economically processed to create Syngas (16). An available source (1) of flue gas that might otherwise be dispersed into the atmosphere in conjunction with such a CO2-laden natural gas stream (11) renders the process even more economical and efficient through the creation of multiple feedstreams (14, 27, 34) that are combined to deliver a composite near equal mixture of methane and CO2 to a plasma reactor (15) or the like that will generate Syngas. When coupled with a Fischer-Tropsch reactor (40), the overall process provides a particularly efficient and economical process for producing synthetic liquid hydrocarbons.

대표청구항 ▼

1. A process for producing Syngas in a plasma reactor from a natural gas stream containing a significant quantity of CO2, which process comprises: providing a natural gas stream that contains CH4 and between about 2 and 40% CO2 and treating such stream in a semipermeable membrane device to provide a

1. A process for producing Syngas in a plasma reactor from a natural gas stream containing a significant quantity of CO2, which process comprises: providing a natural gas stream that contains CH4 and between about 2 and 40% CO2 and treating such stream in a semipermeable membrane device to provide a first permeate stream that contains CO2 and CH4 in an about 50/50 molar ratio and a methane-rich concentrate stream which is at least about 90% methane,combusting a substream from said methane-rich concentrate stream with air in a cogeneration apparatus to produce electrical power,delivering an exhaust gas stream from said cogeneration apparatus to another semipermeable membrane device and separating a predominantly CO2 permeate stream,blending said predominantly CO2 permeate stream with another substream of said methane-rich concentrate stream to create a blended feedstream containing CO2 and CH4 in an about 50/50 molar ratio,delivering a composite feedstream made up of said first permeate stream and said blended feedstream, containing CO2 and CH4 alone in a 1:1 mole ratio with no more than a 2% excess of CO2, to a microwave plasma reactor which converts such composite feedstream to a stream of Syngas,whereby Syngas of a composition suitable as a feedstock for a Fischer-Tropsch (F-T) reactor is produced in an environmentally friendly process from natural gas containing up to about 40% CO2, the overall process being controlled to generate sufficient electric power to operate said membrane separation devices and said microwave plasma reactor, anddelivering said stream of Syngas as a feedstock directly to a F-T reactor which is operated to create liquid hydrocarbons, heat and tail gases. 2. The process of claim 1 wherein heat from said F-T reactor contributes to generation of electric power in the cogeneration apparatus and wherein said tail gases are combusted in the cogeneration apparatus to provide additional carbon dioxide. 3. The process of claim 1 wherein said semipermeable membrane devices employ polymeric membranes selected from the group consisting of polydimethylsilicone (PDMS), polyimides, polyarylethers, polyarylketones, polycarbonates, polysulfones, and polyacetylenes. 4. The process of claim 1 wherein said semipermeable membrane devices employ polydimethylsilicone (PDMS) sheet material as a laminate with a supporting porous polymeric membrane. 5. The process of claim 1 wherein said natural gas stream contains between about 5% and 35% CO2, wherein said methane-rich concentrate stream comprises at least about 98% methane, and wherein an export substream is split from said methane-rich concentrate stream and exported as pipeline quality natural gas. 6. A process for producing Syngas in a microwave plasma reformation device from a natural gas stream containing a significant quantity of CO2, which process comprises: providing a natural gas stream that contains CH4 and between about 2 and 40% CO2 and separating such stream in a semipermeable membrane device to provide a first permeate stream that is increased in CO2 content and contains CO2 and CH4 in an about 50/50 molar ratio and a methane-rich concentrate stream containing at least about 90% methane,combusting a substream from said methane-rich concentrate stream with air in a cogeneration apparatus to produce electrical power,delivering an exhaust gas stream from the cogeneration apparatus to another semipermeable membrane device and separating a predominantly CO2 permeate stream,blending said predominantly CO2 permeate stream with another substream of said methane-rich concentrate stream to create a blended feedstream containing CO2 and CH4 in an about 50/50 molar ratio,delivering a composite feedstream made up of said first permeate stream and said blended feedstream, containing CO2 and CH4 alone in a 1:1 mole ratio with no more than a 2% excess of CO2 to a microwave plasma reformation device which converts such to a first Syngas product stream,splitting a third substream from said methane-rich concentrate stream and feeding such to a second microwave plasma reformation device as a mixture with steam and/or water to convert such mixture to a second Syngas product stream of a higher hydrogen content than said first Syngas product stream, andcombining said first and second Syngas product streams to provide an ultimate Syngas stream,whereby Syngas having a relatively high hydrogen content is produced in an environmentally friendly process from natural gas containing a significant quantity of CO2, which process is controlled to generate sufficient electric power to operate said membrane separation devices and both said microwave plasma reformation devices. 7. The process of claim 6 wherein a portion of said second Syngas product stream, before its combining with said first Syngas product stream, is directed to a Water Shift Reactor (WSR) where a CO fraction thereof is reacted with water and/or steam to produce additional H2, and wherein H2 from the WSR is then combined, as a hydrogen-rich stream, with said first Syngas product stream and the remainder of said second Syngas product stream. 8. The process of claim 7 wherein the output from said WSR is delivered to a Pressure Swing Adsorption unit to produce (a) the hydrogen-rich stream and (b) a CO2-rich sidestream that is added to the predominantly CO2 permeate stream. 9. A process for producing Syngas in a microwave plasma reformation device from a flue gas stream and a natural gas stream, which process comprises: providing a flue gas stream from a carbon or hydrocarbon combustor and separating such stream in a first semipermeable membrane device into a first predominantly CO2 stream and a second stream containing predominantly N2,providing a natural gas stream that contains CH4 and between about 2 and 40% CO2 and separating such stream in a second semipermeable membrane device to provide a first feedstream that contains CO2 and CH4 in an about 50/50 molar ratio and a third stream containing at least about 90% methane,blending a first substream from said third stream with said first predominantly CO2 stream to create a second feedstream containing CO2 and CH4 in an about 50/50 molar ratio,combusting a second substream from said third stream with air in a cogeneration apparatus to produce electrical power,delivering an exhaust gas stream from the cogeneration apparatus to a third semipermeable membrane device and separating a second predominantly CO2 gas stream, andblending said second predominantly CO2 stream with a third substream of said third stream to create a third feedstream containing CO2 and CH4 in an about 50/50 molar ratio, anddelivering a composite feedstream made up of said first, second and third feedstreams, containing CO2 and CH4 alone in a 1:1 mole ratio with no more than a 2% excess of CO2 to the microwave plasma reformation device which converts such to Syngas,whereby Syngas is produced in an environmentally friendly process from natural gas containing up to about 40% CO2 and a flue gas stream, which process is controlled to generate sufficient electric power to operate said first, second and third membrane separation devices and said microwave plasma reformation device. 10. The process of claim 9 wherein said stream of Syngas is provided as a feedstock to a Fischer-Tropsch (F-T) reactor which creates liquid hydrocarbons, heat and tail gases. 11. The process of claim 10 wherein heat from said F-T reactor contributes to generation of electric power in the cogeneration apparatus and wherein said tail gases are combusted in the cogeneration apparatus to provide additional carbon dioxide in such stream. 12. The process of claim 9 wherein said second semipermeable membrane device employs a polymeric membrane selected from the group consisting of polydimethylsilicone (PDMS), polyimides, polyarylethers, polyarylketones, polycarbonates, polysulfones, and polyacetylenes. 13. The process according to claim 12 wherein said semipermeable membrane is a dimethylsilicone polymer. 14. The process of claim 9 wherein said first semipermeable membrane device employs polymeric sheet material as its semipermeable membrane and said first stream permeates through said membrane. 15. The process of claim 14 wherein said semipermeable membrane in said first semipermeable device comprises PDMS sheet material having a thickness between about 0.1 micron and 10 microns. 16. The process of claim 14 wherein said semipermeable membrane in said first semipermeable device is polydimethylsilicone sheet material as a laminate with a supporting porous polymeric membrane.