Method and device for dehydrating a co2 containing gas

Abstract

Proposed is a method for dehydrating a CO 2 containing gas ( 1 ) by cooling the gas ( 1 ) and separating the condensed water from the gas ( 1 ), wherein the gas is contacted with liquid CO 2 to condense water contained in the gas ( 1 ) and the condensate is separated from the remaining gas. Further, a device for dehydrating a CO 2 containing gas is proposed, comprising a gas feeding system for feeding the gas which has to be dehydrated, wherein the device comprises a CO 2 feeding system for feeding liquid CO 2 , a contacting device (C) for contacting the gas and the liquid CO 2 for cooling the gas ( 1 ) to condense the water contained in the gas ( 1 ), and which comprises a first separator ( 4 ) for separating the condensate from the remaining gas.

What is claimed is: 
     
         1 . A method for dehydrating a CO 2  containing gas by
 cooling the gas ( 1 ) and separating the condensed water from the gas ( 1 ),   wherein the gas ( 1 ) is contacted with liquid CO 2  for cooling the gas ( 1 ) to condense water contained in the gas ( 1 ) and the condensate is separated from the remaining gas, and   wherein the remaining gas which comprises gaseous CO 2  is expanded to condense water contained in the gas, and the thus obtained liquid phase comprising liquid CO 2  water ( 10 ) and, optionally, hydrates is separated from the dehydrated gas.   
     
     
         2 . (canceled) 
     
     
         3 . The method according to  claim 1 , characterized in that the obtained liquid phase ( 10 ) is at least partially used for contacting with the gas to be dehydrated. 
     
     
         4 . The method according to  claim 1 , wherein the liquid CO 2  to be mixed with the gas has a temperature within a range of −60° C. to 20° C. 
     
     
         5 . The method according to  claim 1 , wherein the gas to be mixed with the liquid CO 2  has a temperature within a range of −40° C. to 50° C. 
     
     
         6 . The method according to  claim 1 , wherein the temperature of the gas is lowered by expansion below 0° C. 
     
     
         7 . The method according to  claim 1 , wherein the pressure of the gas is lowered by expansion below 7000 kPa. 
     
     
         8 . The method according to  claim 1 , wherein the obtained liquid phase comprising liquid CO 2 , water ( 10 ) and, optionally, hydrates has a pressure of 100 kPa to 7000 kPa and a temperature of −63° C. to 20° C. 
     
     
         9 . A device for dehydrating a CO 2  containing gas, comprising
 a gas feeding system for feeding the gas ( 1 ) to be dehydrated,   a CO 2  feeding system for feeding liquid CO 2 ,   a contacting device (C) for contacting the gas ( 1 ) and the liquid CO 2  for cooling the gas ( 1 ) to condense water contained in the gas ( 1 ),   a first separator ( 4 ) for separating the condensate from the remaining gas, and   an expansion device for cooling the remaining gas which comprises gaseous CO 2  and for obtaining a liquid phase comprising liquid CO 2 , water ( 10 ) and, optionally, hydrates.   
     
     
         10 . (canceled) 
     
     
         11 . Device for dehydrating a CO 2  containing gas according to  claim 9 , wherein the expansion device is a turbine ( 13 ). 
     
     
         12 . Device for dehydrating a CO 2  containing gas according to  claim 9 , wherein the device comprises a second separator ( 9 ) for separating the liquid phase ( 10 ) from the dehydrated gas, wherein the second separator ( 9 ) is fluidicly connected to the contacting device (C). 
     
     
         13 . Device for dehydrating a CO 2  containing gas according to  claim 11 , wherein the device comprises a compressor ( 14 ) for application of pressure on the dehydrated gas ( 12 ), wherein the turbine ( 13 ) is mechanically connected to the compressor ( 14 ) in such a manner that the torque generated by the turbine ( 13 ) is usable or is used for driving the compressor ( 14 ). 
     
     
         14 . A method comprising using a device for dehydrating a CO 2  containing gas according to  claim 9  for dehydrating a CO 2  containing gas ( 1 ), wherein the CO 2  containing gas is natural gas.