Process and installation for supplying gaseous carbon monoxide and/or a gaseous mixture containing at least 10% carbon monoxide

Abstract

In a process for providing gaseous carbon monoxide and/or a mixture containing at least 10% carbon monoxide, carbon monoxide is stored in liquid form in a storage vessel ( 47 ) and, when required, is withdrawn from the storage vessel and vaporised in a vaporiser ( 53 ) to produce gaseous carbon monoxide when the gaseous production of carbon monoxide is insufficient.

1 - 16 . (canceled)  
   
   
       17 . A process for supplying gaseous carbon monoxide and/or a gaseous mixture containing at least 10% carbon monoxide in which: 
 a) a feed gas ( 1 ) containing carbon monoxide as at least one of its principal components and preferably at least one of nitrogen, methane and hydrogen as other principal components is separated in a separation unit;    b) the separation unit separates the feed gas to produce gaseous carbon monoxide, wherein the gaseous carbon monoxide is a final product ( 37 ) and/or a gaseous mixture ( 73 ) is a final product containing at least 10% carbon monoxide, possibly by mixing gaseous carbon monoxide ( 72 ) with at least one other gas ( 71 ) from the separation unit;    c) liquid carbon monoxide is stored in a storage vessel ( 47 ); and    d) liquid carbon monoxide is withdrawn from the storage vessel and at least part ( 61 ) of the liquid is vaporized to produce gaseous carbon monoxide, the gaseous carbon monoxide forming at least part of the gaseous carbon monoxide product and/or being mixed with another gas to form at least part of the gaseous mixture containing at least 10% carbon monoxide,    wherein the withdrawal and vaporization of the liquid carbon monoxide take place:    i) if there is a reduction in the amount of feed gas sent to the separation unit and/or    ii) where the feed gas is purified using an adsorption step in one of at least two adsorbent beds ( 3 ) to produce a purified feed gas to be sent to the separation unit, during at least part of the period at the beginning of the adsorption step before the adsorbent bed is saturated with carbon monoxide and/or    iii) when the product requirement exceeds the maximum capacity of the separation unit.    
   
   
       18 . The process of  claim 17 , wherein the separation unit operates by cryogenic distillation, permeation or adsorption.  
   
   
       19 . The process of  claim 18 , wherein the separation unit operates by cryogenic distillation and comprising the steps of purifying the feed gas using an adsorption step in one of at least two adsorbent beds ( 3 ) to produce a purified feed gas to be sent to the separation unit, cooling at least part of the purified feed gas in a heat exchanger ( 5 ) to form cooled purified feed gas, feeding the separation unit with at least part of the cooled purified feed gas and separating the purified feed gas by cryogenic distillation in a system of columns ( 7 , 19 , 27 ) to produce gaseous carbon monoxide and/or a gaseous mixture containing at least 10% carbon monoxide as final product(s).  
   
   
       20 . The process of  claim 18 , wherein the cryogenic separation unit comprises a CO/CH 4  column ( 27 ) for separating a mixture containing principally carbon monoxide and methane, the storage vessel ( 47 ) preferably forming an integral part of this column.  
   
   
       21 . The process of  claim 20 , wherein at least part of the gaseous carbon monoxide product is withdrawn from the CO/CH 4  column ( 27 ) and the liquid carbon monoxide to be sent to the storage vessel is either formed by liquefying carbon monoxide from a carbon monoxide refrigeration cycle forming part of the separation unit and/or by removing liquid carbon monoxide from the CO/CH 4  column and/or by liquefying gaseous carbon monoxide in a heat exchanger by heat exchange between the gaseous carbon monoxide and a colder fluid derived from an external source, for example liquid nitrogen.  
   
   
       22 . The process of  claim 18 , wherein the separation unit comprises a methane wash column ( 7 ) and wherein a first flow ( 57 ) of liquid carbon monoxide is vaporized to cool the methane wash column, a second flow of liquid carbon monoxide ( 61 ) is vaporized in the heat exchanger and a third flow of liquid carbon monoxide ( 51 ) is vaporized only if one of conditions i) to iii) of  claim 17  is fulfilled.  
   
   
       23 . The process of  claim 17 , wherein the withdrawn liquid ( 51 ) is pressurized prior to vaporization using at least one pump or the vaporized liquid is compressed in a compressor ( 35 ).  
   
   
       24 . The process of  claim 17 , wherein the storage vessel ( 47 ) stores the liquid carbon monoxide at a pressure between 1 and 60 bars, preferably at the supply pressure of the gaseous carbon monoxide and/or of the gaseous mixture containing at least 10% carbon monoxide.  
   
   
       25 . The process of  claim 17 , wherein the vaporized liquid carbon monoxide from the vaporizer is compressed using a compressor ( 35 ) of a carbon monoxide refrigeration cycle and/or a carbon monoxide product compressor ( 35 ).  
   
   
       26 . An installation for supplying gaseous carbon monoxide and/or a gaseous mixture containing at least 10% carbon monoxide by vaporization of liquid carbon monoxide including: 
 a) a separation unit;    b) a storage vessel ( 47 );    c) a vaporizer ( 53 );    d) a conduit ( 43 ) to send liquid carbon monoxide to the storage vessel;    e) a conduit for withdrawing liquid carbon monoxide from the storage vessel and for sending liquid carbon monoxide to the vaporizer where it is vaporized;    f) a conduit ( 55 ) for removing vaporized carbon monoxide from the vaporizer;    g) a conduit for sending a feed gas ( 1 ) containing at least carbon monoxide as a principal component and preferably at least one of nitrogen, methane and hydrogen as other principal components to the separation unit and a conduit for removing gaseous carbon monoxide from the separation unit and characterized in that it comprises means for sending the liquid carbon monoxide to the vaporizer: 
 1) if there is a reduction in the amount of feed gas sent to the separation unit and/or  
 2) where there is an adsorption unit upstream the separation unit for purifying the feed gas, during at least part of the period at the beginning of the adsorption step before the adsorbent bed is saturated with carbon monoxide and/or  
 3) when the product requirement exceeds the maximum capacity of the separation unit.  
   
   
   
       27 . The installation of  claim 26 , wherein the separation unit is a cryogenic distillation unit, an adsorption unit or a permeation unit.  
   
   
       28 . The installation of  claim 26 , wherein the separation unit includes a cold box, a system of columns comprising at least one cryogenic distillation column ( 7 ,  18 ,  27 ), means for sending cooled purified feed gas ( 1 ) containing carbon monoxide as one principal component and at least one of nitrogen, methane and hydrogen as other principal components to the system of columns and further comprising a heat exchanger ( 5 ) and an adsorption unit ( 3 ).  
   
   
       29 . The installation of  claim 28 , wherein the cryogenic separation columns include a methane washing column ( 7 ) associated with a heat exchanger ( 59 ) used to cool the column by heat exchange with vaporizing carbon monoxide ( 57 ) and the vaporizer ( 53 ) is a heat exchanger other than that associated with the methane washing column.  
   
   
       30 . The installation of  claim 28 , wherein the cryogenic separation columns comprise a methane washing column ( 7 ), a methane/carbon monoxide separation column ( 27 ) and a stripping column ( 19 ) or a phase separator, and the cold box contains a conduit ( 13 ) for feeding bottom liquid from the methane washing column to the stripping column or to the phase separator, a conduit ( 23 ) for feeding bottom liquid from the stripping column or from the phase separator to the methane/carbon monoxide separation column, a conduit ( 49 ) for removing carbon monoxide from the methane/carbon monoxide separation column, a conduit ( 27 ) for removing methane from the methane/carbon monoxide separation column and a conduit ( 9 ) for sending methane from the methane/carbon monoxide separation column to the top of the methane washing column.  
   
   
       31 . The installation of  claim 27 , wherein the storage vessel is within the cold box and is fed with liquid carbon monoxide derived from one of the cryogenic separation columns, preferably from a carbon monoxide/methane separation column ( 27 ).  
   
   
       32 . The installation of  claim 27 , wherein the vaporizer ( 53 ) is situated outside the cold box of the cryogenic separation unit.