System and process for capture of acid gasses at elevated-pressure from gaseous process streams

Abstract

A system, method, and material that enables the pressure-activated reversible chemical capture of acid gasses such as CO 2 from gas volumes such as streams, flows or any other volume. Once the acid gas is chemically captured, the resulting product typically a zwitterionic salt, can be subjected to a reduced pressure whereupon the resulting product will release the captures acid gas and the capture material will be regenerated. The invention includes this process as well as the materials and systems for carrying out and enabling this process.

What is claimed is: 
     
         1 . A method for removing CO 2  from a gaseous volume comprising the steps of:
 contacting a dry gaseous volume containing CO 2  with at least one CO 2  binding organic compound containing a neat (anhydrous) tertiary alkanolamine that chemically binds CO 2  to form a zwitterionic product at a pressure greater than 100 psi and   removing said zwitterionic alkylcarbonate product from said gaseous stream or volume.   
     
     
         2 . The method of  claim 1  further comprising the step of depressurizing said zwitterionic alkylcarbonate to release said chemically bound CO 2  and regenerate said CO 2  binding organic compound. 
     
     
         3 . The method of  claim 1 , wherein said binding organic compound is a liquid. 
     
     
         4 . The method of  claim 1 , wherein said tertiary alkanolamine is selected from the group consisting of: N,N-Dimethylethanolamine (DMEA); N,N-Diethylethanolamine (DEEA), N,N-Diisopropylethanolamine (DIPEA); 2-(dimethylamino)-2-methyl-1-propanol (2-DMAM-PrOH); and combinations thereof. 
     
     
         5 . The method of  claim 1 , wherein the zwitterionic product is an alkylcarbonate. 
     
     
         6 . A method for chemically binding and removing CO 2  from a gaseous volume comprising the step of:
 binding CO 2  in said gaseous volume using at least one CO 2  binding organic compound containing a neat tertiary amine that when mixed with a primary or secondary alcohol chemically binds CO 2  in said volume to form a zwitterionic alkylcarbonate product that removes the CO 2  from said volume or stream.   
     
     
         7 . A system for removal of CO 2  from a gaseous volume or stream, characterized by:
 at least one CO 2  binding organic compound comprising a neat tertiary alkanolamine that forms a zwitterionic product when contacted by CO 2  at a pressure above ambient that chemically binds and removes CO 2  from said volume.   
     
     
         8 . The system of  claim 7 , wherein the total system pressure is 100 psi. 
     
     
         9 . The system of  claim 7 , wherein the tertiary amine is a tertiary ethanolamine selected from the group consisting of: N,N-Dimethylethanolamine (DMEA); N,N-Diethylethanolamine (DEEA), N,N-Diisopropylethanolamine (DIPEA); 2-(dimethylamino)-2-methyl-1-propanol (2-DMAM-PrOH); and combinations thereof. 
     
     
         10 . The system of  claim 7 , wherein said binding organic compound is a liquid. 
     
     
         11 . The system of  claim 7 , wherein said binding organic compound further comprises a polar/aprotic non-aqueous solvent of up to about 50 wt % selected from the group consisting of: dimethylsulfoxide, dimethylformamide, acetone, and combinations thereof. 
     
     
         12 . The system of  claim 7 , wherein the zwitterionic product is an alkylcarbonate. 
     
     
         13 . A pressure swing reversible acid gas capture agent having the structure: wherein n is any carbon based chain and R is a carbon based chain or a carbon containing alcohol in the absence of water. 
       
         
           
           
               
               
           
         
       
     
     
         14 . A Method for removing acid gasses from a gaseous volume characterized by the step of:
 contacting a gaseous volume containing an acid gas with at least one acid gas binding organic compound that chemically binds with the acid gas to form a zwitterionic product at a pressure greater than 100 psi;   removing said zwitterionic product from said gaseous stream or volume; and   exposing said zwitterionic product to a lower pressure to release said acid gas and regenerate said acid gas binding organic compound.