Development of high temperature gas cleanup system with molten carbonate membrane

We have proposed a novel high temperature gas cleanup system in which sulfi des contained in the syngas are removed and transferred into the carrier ga s through a molten carbonate membrane. On the syngas side of the membrane, gaseous sulfide is absorbed into molten carbonate iu produce sulfide ion, a nd the reverse reaction proceeds on alternate side, i.e. carrier gas side, of the membrane with CO2 and H2O contained in the carrier gas. With this sy stem. sulfides thus removed from the syngas can he concentrated into the ca rrier gas employing higher CO2 and H2O concentration in the carrier gas. In this article, we present the results of preliminary experiments to demonst rate the feasibility vf this concept. Experimental results show that over 5 0% of inlet 0.7% H2S is removed from simulated syngas in a flow channel who se length is only 4 cm. The maximum sulfide concentration at the exit of th e simulated carrier gas is about double of that at the simulated syngas inl et. and degree of concentration are expected to become higher by reducing s imulated carrier gas flow rate. The reaction of gaseous sulfide with molten carbonate membrane is shown to be prompt. and the apparent diffusion coeff icient of sulfide ion migrating through the membrane is estimated to be c.a . 3x10(-11)[m(2)/s].