Superior sorbent for natural gas desulfurization

New sorbents were investigated for desulfurization of natural gas by adsorption at ambient temperature. The new sorbents included Cu(I)Y zeolite, CuCl/MCM-41, and CuCl/SBA-15 and were compared with the best commercial sorbents, AgY and activated carbon. H2S and dimethyl sulfide (DMS) were used as the model sulfur compounds. Ab initio molecular orbital calculations on adsorption energies showed that Cu(I)Y > A-Y > Cu(II)Y for both H2S and DMS and H2S adsorbs more strongly than DMS, both in full agreement with experimental results. Moreover, Cu(I)Y, CuCl/MCM-41, and CuCl/SBA-15 were fully regenerable, while A-Y was not. Fixed-bed adsorber breakthrough results indicated severe diffusion limitation in sulfur capture; C thus, the mesoporous sorbents are advantageous for very high throughput applications.