First Row Transition Metal Oxide Based Catalysts for the In-situ Reactions of Methanation and Desulfurization in the Removal of Sour Gases from Simulated Natural Gas

Abstract

The objective of this novel catalyst development is to achieve both low temperature and high conversion of sour gases of H 2 S and CO 2 present in the natural gas. The results showed that the conversion of H 2 S to elemental sulfur on all of the potential catalysts was achieved 100 %. However, methanation of CO 2 in the presence of H 2 S yielded 0.7 % CH 4 over Fe/ Zn/ Cu/ Ti-Al 2 O 3 catalyst, 1.1 % CH 4 over Fe/ Zn/ Cu-Al 2 O 3 catalyst and the highest is 6.1 % CH 4 over Pr/ Co/ Ni-Al 2 O 3 catalyst at maximum studied temperature of 300 o C. The catalysts were further characterized by X-rays Photoelectron Spectroscopy and Nitrogen Adsorption analysis. XPS results revealed Ni 2+ ion in the NiO and Ni 3+ in Ni 2 O 3 species, spinel compound of Co 3 O 4 on the Pr/ Co/ Ni-Al 2 O 3 catalyst. N 2 adsorption-desorption analysis illustrated 7.9 % increment of surface area over the spent Pr/ Co/ Ni-Al 2 O 3 catalyst, which assumed to be responsible for the dramatical increased of the methanation activity of this catalyst at the reaction temperature of 300 o C.