Method and apparatus for producing at least one argon-enriched fluid and at least one oxygen-enriched fluid from a residual fluid

Abstract

The invention relates to a method for producing an argon-enriched fluid and an oxygen-enriched fluid from a fluid resulting from a method for purifying of oxy-fuel combustion fumes, wherein said method comprises purifying the residual gas by a purification method in order to produce a gas enriched with carbon dioxide and a residual gas lean in carbon dioxide, pre-treating the residual gas lean in carbon dioxide in order to obtain a flow enriched with carbon dioxide and a flow lean in carbon dioxide, treating the flow lean in carbon dioxide by a cryogenic technique so as to extract at least an argon-enriched fraction, an oxygen-enriched fraction, and a fraction lean in argon and/or oxygen.

1 - 18 . (canceled) 
     
     
         19 . A method for producing at least one argon-enriched fluid and at least one oxygen-enriched fluid from a residual fluid resulting from a method for purifying a residual gas, the residual gas containing carbon dioxide and oxygen and/or argon, the residual gas being derived from an installation supplied with oxygen containing argon, which is an oxy-fuel combustion installation, comprising the following steps:
 recovering fumes resulting from the oxy-combustion of a fuel by means of a gas rich in oxygen and in carbon dioxide and containing argon in the combustion chamber of a boiler as they leave the boiler,   purifying the fumes by a low-temperature purification method, so as to produce a first stream enriched with carbon dioxide and a residual fluid depleted of carbon dioxide;   pre-treating the residual fluid depleted of carbon dioxide in order to obtain a second stream enriched with carbon dioxide and a stream lean in carbon dioxide; and   cryogenically treating the stream lean in carbon dioxide so as to extract therefrom at least one fraction enriched or rich in argon and at least one fraction enriched or rich in oxygen and at least one fraction depleted of argon and/or oxygen.   
     
     
         20 . The method of  claim 19 , wherein the cryogenic treatment of the stream lean in carbon dioxide further comprises a step of cooling in at least one exchanger, and a step of distillation in a distillation column. 
     
     
         21 . The method of  claim 20 , wherein said at least one exchanger is selected from the group consisting of a reboiler, a condenser, a reversible exchanger, and a regenerator exchanger. 
     
     
         22 . The method of  claim 19 , wherein the air is separated in an air separation apparatus, in order to produce an oxygen-rich flow containing at most 99% oxygen, and argon, and the oxygen-rich flow is sent to the oxy-fuel combustion. 
     
     
         23 . The method of  claim 22 , wherein the air separation is by cryogenic distillation. 
     
     
         24 . The method of  claim 22 , wherein the oxygen-rich flow contains at most 98% oxygen. 
     
     
         25 . The method of  claim 22 , wherein the oxygen-rich flow contains at most 97% oxygen 
     
     
         26 . The method of  claim 22 , wherein the oxygen-rich flow contains at least 2 mol % of argon. 
     
     
         27 . The method of  claim 22 , wherein the oxygen-rich flow contains at least 3 mol % argon. 
     
     
         28 . The method of  claim 19 , wherein the fraction enriched or rich in oxygen is used for the oxy-combustion of the fuel and/or for the pretreatment of the residual gas depleted of carbon dioxide. 
     
     
         29 . The method of  claim 19 , wherein the cryogenic treatment recovers a fraction enriched or rich in nitrogen. 
     
     
         30 . The method of  claim 23 , wherein one or more fluid(s) which come from a unit for separating gas from air or the unit for separating the gases in air, delivering at least part of the oxygen for the installation supplied with oxygen, are used in the treatment of the stream lean in carbon dioxide, wherein at least one column of the unit for separating gas from air and at least one column of the treatment unit may be contained in a single coldbox. 
     
     
         31 . The method of  claim 30 , wherein one of these fluids is a nitrogen-rich liquid which at least partially cools the cryogenic treatment of the flow lean in carbon dioxide. 
     
     
         32 . The method of  claim 30  wherein one of these fluids is a nitrogen-rich gas which will be used as a cycle gas for at least one reboiler and/or at least one condenser of the cryogenic treatment. 
     
     
         33 . The method of  claim 23 , wherein the pre-treatment removes at least 50 mol % of the carbon dioxide in the residual gas before the cryogenic treatment. 
     
     
         34 . The method of  claim 33 , wherein the pre-treatment is carried out at least partially by antisublimation/sublimation of the carbon dioxide in a plurality of exchangers in parallel. 
     
     
         35 . The method of  claim 34 , wherein the sublimation of the carbon dioxide is carried out in the presence of the oxygen-enriched fraction so as to constitute a carbon dioxide/oxygen mixture used for the oxy-combustion of the fuel. 
     
     
         36 . The method of  claim 19 , wherein the pre-treatment is carried out at least partly by a process of the TSA, PSA or VPSA type thereby producing a fraction enriched with carbon dioxide and a fraction depleted of carbon dioxide but enriched with argon. 
     
     
         37 . The method of  claim 19 , wherein the pre-treatment is carried out at least partly by an absorption process. 
     
     
         38 . The method of  claim 19 , wherein the pre-treatment is carried out by washing with methanol. 
     
     
         39 . The method of  claim 19 , wherein the pretreatment is carried out at least in part by permeation. 
     
     
         40 . The method of  claim 19 , wherein the flow enriched with carbon dioxide, produced by the pretreatment, is recycled into the installation consuming oxygen. 
     
     
         41 . The method of  claim 40 , wherein the flow enriched with carbon dioxide is recycled to the oxy-fuel combustion boiler. 
     
     
         42 . The method of  claim 40 , wherein the flow enriched with carbon dioxide is recycled to the combustion chamber. 
     
     
         43 . An installation for producing at least one argon-enriched fluid and at least one oxygen-enriched fluid from a residual fluid resulting from a method for purifying a residual gas, the residual gas containing carbon dioxide and argon and/or oxygen, the residual gas being derived from an installation supplied with oxygen containing argon, which is an oxy-fuel combustion installation, comprising:
 a unit for purifying the residual gas, comprising fumes leaving a boiler for oxy-combustion of a fuel by means of a gas rich in oxygen and carbon dioxide, in which case the purification unit may be a low-temperature purification unit so as to produce a fluid enriched with carbon dioxide and a residual fluid depleted of carbon dioxide;   a unit for pretreatment of the residual fluid in order to obtain a flow enriched with carbon dioxide and a flow lean in carbon dioxide; and   a unit for cryogenic treatment of the flow lean in carbon dioxide so as to extract therefrom a fraction enriched with argon, a fraction enriched with oxygen and a fraction depleted of argon and/or oxygen.   
     
     
         44 . The installation as claimed in  claim 43 , wherein the unit for cryogenic treatment of the flow lean in carbon dioxide comprises at least one exchanger and at least one distillation column.