Electrochemical Co-Production of Chemicals from Carbon Dioxide Using Sulfur-Based Reactant Feeds to Anode

Abstract

The present disclosure includes a system and method for producing a first product from a first region of an electrochemical cell having a cathode and a second product from a second region of the electrochemical cell having an anode. The method may include a step of contacting the first region with a catholyte comprising carbon dioxide, producing a first product which may include carbon monoxide or an alkli metal formate. The method may include another step of contacting the second region with an anolyte comprising a sulfur-based reactant and producing a second product including oxygen and sulfur dioxide. Further, the method may include a step for introducing the separated oxygen from second region of the electrochemical cell with a hydrogen sulfide stream in a catalyst reactor bed, converting the hydrogen sulfide to sulfur dioxide. The sulfur dioxide may then be liquefied as a product, or a portion of the sulfur dioxide may be recycled to the second region of the electrochemical cell where it may be converted to sulfuric acid. The sulfuric acid may then be reacted with another reactant, such as ammonia, to produce an ammonium sulfate product.

What is claimed is: 
     
         1 . A method for producing a first product from a first region of an electrochemical cell having a cathode and a second product from a second region of the electrochemical cell having an anode, the method comprising the steps of:
 contacting the first region with a catholyte including carbon dioxide, the catholyte including an alkali metal bicarbonate;   contacting the second region with an anolyte including sulfuric acid;   applying an electrical potential between the anode and the cathode sufficient to produce a first product and unreacted carbon dioxide recoverable from the first region and oxygen and unreacted sulfuric acid from the second region;   separating the first product from the unreacted carbon dioxide;   recycling at least a portion of the first product to the first region and recycling the unreacted carbon dioxide to the first region;   separating the oxygen product recoverable from the second region from the anolyte;   recycling the anolyte to the second region; and   contacting the oxygen product with hydrogen sulfide in a catalyst reactor bed to convert the hydrogen sulfide to a sulfur dioxide product.   
     
     
         2 . The method according to  claim 1 , wherein the first product is an alkali metal formate. 
     
     
         3 . The method according to  claim 1 , wherein the first product is carbon monoxide. 
     
     
         4 . The method according to  claim 1 , wherein reacting the oxygen with hydrogen sulfide to produce sulfur dioxide is performed at an operating temperature from about 90-400 degrees Celsius. 
     
     
         5 . The method according to  claim 1 , wherein the alkali metal bicarbonate includes at least one of sodium bicarbonate or potassium bicarbonate. 
     
     
         6 . The method according to  claim 1 , wherein the cathode and the anode are separated by an ion permeable barrier that operates at a temperature less than 600 degrees Celsius and the ion permeable barrier includes one of a polymeric or inorganic ceramic-based ion permeable barrier. 
     
     
         7 . The method according to  claim 1 , further comprising:
 condensing the sulfur dioxide product to a sulfur dioxide liquid product.   
     
     
         8 . The method according to  claim 1 , further comprising:
 converting the sulfur dioxide to another sulfur-based product.   
     
     
         9 . The method according to  claim 7 , further comprising:
 recycling at least a portion of the sulfur dioxide liquid product to the second region.   
     
     
         10 . The method according to  claim 1 , further comprising:
 reacting unreacted sulfuric acid with ammonia to produce ammonium sulfate.   
     
     
         11 . A method for producing a first product from a first region of an electrochemical cell having a cathode and a second product from a second region of the electrochemical cell having an anode, the method comprising the steps of:
 contacting the first region with a catholyte including carbon dioxide, the catholyte including an alkali metal bicarbonate;   contacting the second region with an anolyte including sulfuric acid;   applying an electrical potential between the anode and the cathode sufficient to produce an alkali metal formate and unreacted carbon dioxide recoverable from the first region and oxygen and unreacted sulfuric acid from the second region;   separating the oxygen product recoverable from the second region from the anolyte;   recycling the anolyte to the second region; and   contacting the oxygen product with hydrogen sulfide in a catalyst reactor bed to convert the hydrogen sulfide to a sulfur dioxide product.   
     
     
         12 . The method according to  claim 11 , wherein reacting the oxygen with hydrogen sulfide to produce sulfur dioxide is performed at an operating temperature from about 90-400 degrees Celsius. 
     
     
         13 . The method according to  claim 11 , further comprising:
 reacting unreacted sulfuric acid with ammonia to produce ammonium sulfate.   
     
     
         14 . The method according to  claim 11 , wherein the alkali metal bicarbonate includes at least one of sodium bicarbonate or potassium bicarbonate. 
     
     
         15 . The method according to  claim 11 , wherein the cathode and the anode are separated by an ion permeable barrier that operates at a temperature less than 600 degrees Celsius and the ion permeable barrier includes one of a polymeric or inorganic ceramic-based ion permeable barrier. 
     
     
         16 . The method according to  claim 11 , further comprising:
 condensing the sulfur dioxide product to a sulfur dioxide liquid product.   
     
     
         17 . The method according to  claim 11 , further comprising:
 converting the sulfur dioxide to another sulfur-based product.   
     
     
         18 . The method according to  claim 11 , further comprising:
 recycling at least a portion of the sulfur dioxide liquid product to the second region.   
     
     
         19 . A method for producing a first product from a first region of an electrochemical cell having a cathode and a second product from a second region of the electrochemical cell having an anode, the method comprising the steps of:
 contacting the first region with a catholyte comprising carbon dioxide, the catholyte including an alkali metal bicarbonate;   contacting the second region with an anolyte comprising a sulfur-based component including sulfuric acid;   applying an electrical potential between the anode and the cathode sufficient to produce a first product and unreacted carbon dioxide recoverable from the first region and an oxygen product from the second region recoverable from the second region, the first product including a carbon monoxide;   separating the first product from the unreacted carbon dioxide;   recycling at least a portion of the first product to the first region and recycling the unreacted carbon dioxide to the first region;   separating the oxygen product recoverable from the second region from the anolyte;   recycling the anolyte to the second region; and   contacting the oxygen product with hydrogen sulfide in a catalyst reactor bed to convert the hydrogen sulfide to a sulfur dioxide product.