Method and apparatus for separation of a gaseous mixture at sub-ambient temperature

Abstract

In a method for separating a gaseous mixture by separation at sub-ambient temperature, a gaseous mixture at a first pressure is cooled, then separated in a separation unit, a liquid is withdrawn from the separation unit and vaporized to form a pressurized gaseous product, and at least part of the heat of vaporization of the liquid is supplied by a heat pump using the magnetocaloric effect, of which the hot source exchanges heat, directly or indirectly, with the liquid which vaporizes.

1 - 15 . (canceled) 
     
     
         16 . A method for separating a gaseous mixture by separation at sub-ambient temperature, the method comprising the steps of:
 cooling a gaseous mixture at a first pressure;   separating the cooled gaseous mixture in a separator unit comprising a system of columns comprising at least one column; and   withdrawing a liquid from the separation unit and vaporizing the liquid to form a pressurized gaseous product, wherein the liquid has a heat of vaporization,   wherein at least part of the heat of vaporization of the liquid is supplied by a heat pump using a magnetocaloric effect of which the hot source exchanges heat, directly or indirectly, with the liquid during vaporization of the liquid.   
     
     
         17 . The method as claimed in  claim 16 , in which the cold source of the heat pump exchanges heat with at least part of the gaseous mixture and/or of a gas derived from the separation method which cools, or even condenses, at least partially. 
     
     
         18 . The method as claimed in  claim 16 , in which the vaporized liquid contains at least 70% oxygen, or at least 80% nitrogen, or at least 60% carbon dioxide, or at least 60% methane, or at least 60% carbon monoxide. 
     
     
         19 . The method as claimed in  claim 16 , further comprising pressurizing the pressurized gaseous product to a higher pressure than the pressure at which the pressurized gaseous product is withdrawn. 
     
     
         20 . The method as claimed in  claim 16 , further comprising depressurizing the pressurized gaseous product to a pressure lower than the pressure at which the pressurized gaseous product is withdrawn, 
     
     
         21 . The method as claimed in  claim 16 , in which the separation is performed by distillation and the system comprises at least one distillation column. 
     
     
         22 . The method as claimed in  claim 16 , in which a fluid, which may or may not participate in the separation, is brought into direct contact with a magnetocaloric material of the heat pump. 
     
     
         23 . The method as claimed in  claim 16 , in which the exchange of heat is performed at least in part between at least a fluid which may or may not participate in the separation and a heat-transfer fluid in contact with a magnetocaloric material of the heat pump through an exchanger. 
     
     
         24 . The method as claimed in  claim 16 , in which the exchange of heat is performed at least in part between at least a fluid which may or may not participate in the separation and the heat-transfer fluid that has been in contact with a magnetocaloric material of the heat pump through an intermediate heat-transfer circuit. 
     
     
         25 . The method as claimed in  claim 16 , in which the gaseous mixture is air, the pressurized liquid is rich in oxygen or in nitrogen, all of the gaseous mixture is compressed to a single pressure and at least part of the gaseous mixture is at least partially condensed, transferring heat to the cold source of the heat pump. 
     
     
         26 . The method as claimed in  claim 16 , in which the gaseous mixture is air, the pressurized liquid is rich in oxygen or in nitrogen, all of the gaseous mixture is compressed to a first pressure, a part of the gaseous mixture is compressed from the first pressure to a second pressure higher than the first pressure, and at least part of the compressed gaseous mixture at the second pressure is at least partially condensed, transferring heat to the cold source of the heat pump. 
     
     
         27 . A device for separating a gaseous mixture by separation at sub-ambient temperature, the device comprising:
 cooling means for cooling a gaseous mixture at a first pressure;   a separation unit, comprised of a system of columns comprising at least one column, which is connected to the cooling means;   a pipe configured to withdraw a liquid from the separation unit;   means for vaporizing the liquid to form a pressurized gaseous product; and   a heat pump using the magnetocaloric effect capable of supplying at least part of the heat of vaporization of the liquid and means allowing the hot source of the heat pump to exchange heat, directly or indirectly, with the liquid which vaporizes.   
     
     
         28 . The device as claimed in  claim 27 , further comprising means for allowing an exchange of heat between the cold source of the heat pump and at least part of the gaseous mixture and/or of a gas derived from the separation method which becomes cooled, or even condenses at least partially. 
     
     
         29 . The device as claimed in  claim 27 , further comprising means for withdrawing a liquid containing at least 70% oxygen, or at least 80% nitrogen, or at least 60% carbon dioxide, or at least 60% methane or at least 60% carbon monoxide. 
     
     
         30 . The device as claimed in  claim 27 , further comprising means for placing a fluid, which may or may not participate in the separation, into direct contact with a magnetocaloric material of the heat pump. 
     
     
         31 . The device as claimed in  claim 27 , further comprising an exchanger in which the exchange of heat is performed at least in part between at least a fluid which may or may not participate in the separation and a heat-transfer fluid in contact with a magnetocaloric material of the heat pump.