Electrochemical Processing of Carbon Dioxide



With respect to the negative role of carbon dioxide on our climate, it is clear that the time is ripe for the development of processes that convert CO2 into useful products. The electroreduction of CO2 is a prime candidate here, as the reaction at near-ambient conditions can yield organics such as formic acid, methanol, and methane. Recent laboratory work on the 100 A scale has shown that reduction of CO2 to formate (HCO2) may be carried out in a trickle-bed continuous electrochemical reactor under industrially viable conditions. Presuming the problems of cathode stability and formate crossover can be overcome, this type of reactor is proposed as the basis for a commercial operation. The viability of corresponding processes for electrosynthesis of formate salts and/or formic acid from CO2 is examined here through conceptual flowsheets for two process options, each converting CO2 at the rate of 100 tonnes per day.