Deep desulfurization of natural gas with metal oxide desulfurizers

Qualitative and quantitative analysis methods for ultra trace sulfides in natural gas were established based on GC-MS and GC-SCD, and utilized to determine the sulfides in the domestic natural gas of Beijing. The results indicate that the natural gas contains three kinds of sulfides, and the main component accounting for 94.2% is tetrahydrothiophene (THT). ZnO/Al₂O₃ was prepared by co-precipitation, and ZnO/γ-Al₂O₃, CuO/γ-Al₂O₃ and CuO-ZnO/γ-Al₂O₃ were prepared by impregnation. Experimental research on the deep removal of THT in the city natural gas was carried out with these desulfurizers. It is found that THT can be removed to less than 10×10^-9 (molar fraction)with CuO/γ-Al₂O₃ and CuO-ZnO/γ-Al₂O₃ in a wide temperature range from 50~500℃, which can meet the requirements of desulfurization depth and working temperature width for distributed PEMFC power station based on natural gas.