CONTINUOUS GAS SEPARATION WITH LIQUID IMPREGNATED PARTICLES IN GAS-SOLID REACTORS

The absorption of a gas in liquid filled porous particles in gas-solid reactors was studied both theoretically and experimentally. In the th eoretical study a micro model, describing mass transport accompanied w ith reaction inside the particles, was implemented in the macro balanc e for several asymptotic operation modes. The theoretical study showed that the gas separation can be carried out very efficiently with the liquid filled porous particles, especially for the countercurrent mode of operation. The results of the simulations for the removal of H2S f rom a gas stream also containing CO2 showed that a very selective abso rption process can be obtained. For these kind of selective absorption processes the simulations showed that the residence time of the parti cles is a crucial parameter. In the experimental part of this contribu tion the absorption of CO2 in porous gamma-alumina particles filled wi th water or 2M aqueous solutions of tertiary- or primary alkanolamines was investigated. Experiments were carried out in a gas-solid reactor where the particles were falling down in an empty tube while gas was flowing co-or countercurrently. The conversion for the particles fille d with water or the aqueous primary alkanolamine was predicted satisfa ctorily. For the particles filled with the tertiary alkanolamines, how ever, the experimental conversions were much higher than theoretically predicted. This difference probably must be attributed to an underest imation of the surface adsorption of CO2 on the gamma-alumina carrier which was very important for the slowly reacting tertiary alkanolamine s.