Carbon dioxide conversion device and carbon dioxide conversion method

Abstract

A carbon dioxide conversion device includes: a carbon dioxide supply part configured to supply a supply gas containing carbon dioxide gas; a flow rate adjusting part that includes flow rate adjusting valves configured to distribute the supply gas to be supplied from the carbon dioxide supply part; an electrolysis part that includes electrolysis cell stacks configured to receive the supply gas distributed through the flow rate adjusting valves; a voltage measuring part that includes voltmeters configured to measure voltages across the electrolysis cell stacks; and a control part configured to adjust opening degrees of the flow rate adjusting valves in response to voltage signals to be received from the voltmeters.

What is claimed is: 
     
         1 . A carbon dioxide conversion device, comprising:
 a carbon dioxide supply part configured to supply a supply gas containing a carbon dioxide gas;   a flow rate adjusting part that includes flow rate adjusting valves configured to distribute the supply gas to be supplied from the carbon dioxide supply part;   an electrolysis part that includes electrolysis cell stacks configured to receive the supply gas distributed through the flow rate adjusting valves;   a voltage measuring part that includes voltmeters configured to measure voltages across the electrolysis cell stacks; and   a control part configured to adjust opening degrees of the flow rate adjusting valves in response to voltage signals to be received from the voltmeters.   
     
     
         2 . The device according to  claim 1 , wherein
 an equal load current is supplied to each of the electrolysis cell stacks, the equal load current having a theoretical current value according to the flow rate of the supply gas to be supplied from the carbon dioxide supply part.   
     
     
         3 . The device according to  claim 1 , wherein
 the supply gas is supplied from the carbon dioxide supply part, the supply gas having a flow rate according to the sum of the load currents through the electrolysis cell stacks.   
     
     
         4 . The device according to  claim 1 , wherein
 the control part is configured to calculate a mean voltage of the voltages,   when one of the voltages is lower than the mean voltage, an opening degree of one of the flow rate adjusting valves corresponding to the one of the voltages is decreased, and   when one of the voltages is higher than the mean voltage, the opening degree of one of the flow rate adjusting valves corresponding to the one of the voltages is increased.   
     
     
         5 . The device according to  claim 1 , wherein
 the control part is configured to calculate a mean voltage of the voltages and adjust an opening degree of one of the flow rate adjusting valves corresponding to be proportional to a ratio of one of the voltages to the mean voltage.   
     
     
         6 . A carbon dioxide conversion method, comprising:
 distributing a supply gas containing carbon dioxide gas through flow rate adjusting valves to supply to electrolysis cell stacks, and supplying load currents to the electrolysis cell stacks; and   measuring voltages across the electrolysis cell stacks and adjusting opening degrees of the flow rate adjusting valves according to the voltages.   
     
     
         7 . The method according to  claim 6 , further comprising:
 supplying an equal load current to each of the electrolysis cell stacks, the equal load current having a theoretical current value according to a flow rate of the supply gas.   
     
     
         8 . The method according to  claim 6 , further comprising:
 distributing the supply gas to supply to the electrolysis cell stacks, the supply gas having a flow rate according to the sum of the load currents through the electrolysis cell stacks.   
     
     
         9 . The method according to  claim 6 , further comprising:
 calculating a mean voltage of the voltages;   decreasing an opening degree of one of the flow rate adjusting valves corresponding to one of the voltages when the one of the voltages is lower than the mean voltage; and   increasing the opening degree of one of the flow rate adjusting valves corresponding to one of the voltages when the one of the voltages is higher than the mean voltage.   
     
     
         10 . The method according to  claim 6 , further comprising:
 calculating a mean voltage of the voltages; and   adjusting an opening degree of one of the flow rate adjusting valves corresponding to be proportional to a ratio of one of the voltages to the mean voltage.