Analysis of a two-stage membrane reactor integrated with porous membrane having Knudsen diffusion characteristics for the thermal decomposition of hydrogen sulfide

Using basic equation for material balance, the thermal decomposition of hydrogen sulfide to produce hydrogen was investigated in a two-stage membrane reactor integrated with porous membrane having Knudsen diffusion characteristics. It was evaluated the effect of membrane area ratio Sm,P/Sm,R and the pressure in the 1st permeate chamber pP1 on H2 concentration in the 2nd permeate chamber yH2,P2 and the flow rate of H2 in the 2nd UH2. With the decrease of Sm,P/Sm,R, yH2,P2 increases and takes constant value which is larger than the H2 concentration in the permeate chamber for the single-stage membrane reactor by about 1.7 times. There is (Sm,P/Sm,R)limit corresponding to the condition that no flow in the 1st permeate chamber. With the increase of Sm,P/Sm,R, UH2 increases and takes maximum value UH2,max at (Sm,P/Sm,R)limit. There is an optimum pP1 for higher UH2,max, but the difference between the highest value of UH2,max and the lowest one is small. The maximum value of UH2,max is larger than the amount of H2 obtained in the single-stage by about 1.1 times.