Electrogenerative chemical reactors

Electrogenerative processes are electrochemical ones in which the exothermic energy of chemical reaction is converted to direct electric current while a desired chemical product is produced. Fuel cells processes actually are related but differ in that they normally involve complete fuel combustion. Conventional electrochemical processes differ from electrogenerative processes in that they consume power although they may give similar desired products. Furthermore, electrogenerative electrodes may operate in different potential regions determined by potentials produced by the chemical reactions taking place. For example, the electrogenerative reduction of benzene takes place with energy production in acid solution and can be represented by Anode(−) 3H2 → 6H+ + 6e, (1) Cathode (+) C6H6 + 6H+ + 6e → C6H12. (2) In contrast, the electrochemical reduction of benzene by conventional means requires the supply of a negative potential of several volts and special solvents. Here, several electrogenerative processes are reviewed as well as the design and operation of electrogenerative reactors. The importance of electrocatalysis is illustrated. Possibilities for incorporating electrogenerative and related processes into existing chemical processing technology are discussed from the standpoint of conserving and recovering energy that is presently lost as heat.