REDUCTION OF CARBON-DIOXIDE IN A CLOSED SYSTEM

Within the closed system of a manned space station or other such environment, it is necessary to establish a life support system that recovers CO2 produced metabolism and produces O2. As a step toward this goal, we performed a basic test and a continuous reduction test, and also conducted simulation calculations with respect to the Bosch reduction reaction which changes CO2, removed from the air and concentrated, into solid carbon and water. We then selected the optimum conditions by examining the influence of each parameter on CO2 reduction performance. The results indicated that to improve the Bosch reaction effectively, two-stage reactions (i.e. 1st and 2nd) at different temperatures and gas circulation are both required. In addition, it has become clear that the optimum operating conditions for reduction of that CO2 produced by two persons are set temperatures for the 1st and 2nd reactors of 1, 200K and 850K respectively, a catalyst filling column height of 0.1 m for each, and a circulating gas flow rate of 0.75 m3 (STP) h-1. © 1990, The Society of Chemical Engineers, Japan. All rights reserved.