Membrane/distillation method and system for extracting CO2 from hydrocarbon gas
AssigneeNational Tank Company
InventorsDavid Parro, Edgar S. Sanders, Jr.
Life of this patent
Estimating the term…
Abstract
A method of separating CO2 from a hydrocarbon gas inlet stream that is within predetermined pressure and temperature ranges, including the steps of subjecting the inlet stream to fractional distillation providing a CO2 bottom product stream and a distillation overhead stream, passing the distillation overhead stream to the inlet of a primary reflux drum producing a primary reflux liquid stream and a hydrocarbon vapor stream, subjecting the hydrocarbon vapor stream to membrane separation to provide a hydrocarbon product stream and a permeate stream, compressing the permeate stream and recycling the compressed permeate stream to the inlet of the primary reflux drum thereby providing a CO2 liquid product and a hydrocarbon gas product.
Claims17
A method of separating CO2 from a hydrocarbon gas inlet stream that is within predetermined pressure and temperature ranges, comprising the steps of:
- (a) subjecting the inlet stream to fractional distillation providing a CO2 bottom product stream and a distillation overhead stream;
- (b) passing the distillation overhead stream to the inlet of a primary reflux drum producing a primary reflux liquid stream and a hydrocarbon vapor stream;
- (c) subjecting the hydrocarbon vapor stream from step (b) to membrane separation to provide a hydrocarbon product stream and a permeate stream;
- (d) compressing the permeate stream from step (c) to provide a compressed permeate stream;
- and
- (e) recycling the compressed permeate stream from step (d) to said inlet of said primary reflux drum thereby providing a primary reflux liquid stream and a hydrocarbon gas product vapor stream.
A method of separating CO2 from a hydrocarbon gas inlet stream that is within predetermined pressure and temperature ranges comprising the steps of:
- (a) subjecting the inlet stream to fractional distillation in a distillation column providing a CO2 bottom product stream and a distillation overhead stream;
- (b) subjecting said distillation overhead stream of step (a) to membrane separation, providing a hydrocarbon gas product stream and a permeate stream;
- (c) compressing said permeate stream to provide a compressed permeate stream;
- and
- (d) refluxing said compressed permeate stream from step (c) through a primary reflux drum having a primary reflux liquid stream outlet in communication with said distillation column.
A method of separating CO2 from a hydrocarbon gas inlet stream that is within predetermined pressure and temperature ranges, including the steps of:
- (a) subjecting the inlet stream to a distillation column producing a bottom product stream and a distillation overhead stream;
- (b) condensing said distillation overhead stream of step (a) in a primary reflux drum producing a primary reflux liquid stream and a hydrocarbon vapor stream;
- (c) recycling said primary reflux liquid stream of step (b) to said distillation column as a reflux stream;
- (d) separating said concentrated hydrocarbon vapor stream from step (b) by membrane separation into a hydrocarbon gas product stream and a permeate stream;
- (e) compressing said permeate gas stream from step (d) to produce a compressed permeate stream;
- (f) condensing said compressed permeate stream of step (e) to produce a primary reflux liquid stream that is conveyed to an upper portion of said distillation column;
- (g) pumping said bottom product stream from step (a) to provide an elevated pressure liquid CO2 product;
- and
- (h) subjecting said bottom product stream of step (a) to a reboiler separator to produce a CO2 liquid product and a reboiler separator vapor stream that is recycled to a bottom portion of said distillation column.
A system for separating CO2 from a hydrocarbon gas inlet stream that is within predetermined pressure and temperature ranges, comprising:
- a distillation column receiving the hydrocarbon gas inlet stream and providing a CO2 bottom product stream and a distillation overhead stream;
- a primary reflux drum having an inlet receiving the distillation overhead stream and producing a primary reflux liquid stream and a hydrocarbon vapor stream;
- a membrane unit receiving the hydrocarbon vapor stream from said primary reflux drum to provide a hydrocarbon gas product stream and a permeate stream;
- a compressor receiving said permeate stream from said membrane unit to provide a compressed permeate stream;
- and
- piping to recycle said compressed permeate stream to said inlet of said primary reflux drum thereby providing a liquefied CO2 product and a hydrocarbon gas product.
A system for separating CO2 from a hydrocarbon gas inlet stream that is within prescribed pressure and temperature ranges comprising:
- a distillation column for receiving and fractionally distilling the hydrocarbon gas inlet stream providing a CO2 liquid product and a distillation overhead stream;
- a membrane unit receiving the distillation overhead stream and providing a hydrocarbon gas product and a permeate stream;
- a compressor receiving the permeate stream and providing a compressed permeate stream;
- and
- a primary reflux drum receiving said compressed permeate stream providing a primary reflux liquid stream that is refluxed back into said distillation column.
Dependencies are inferred from the claim text.