Alloy Catalysts with Monolith Supports for Methanation of Coal-Derived Gases. Final Technical Progress Report, September 20, 1977-September 20, 1980

摘要

The activity, selectivity and stability of alumina-supported nickel and nickel bimetallics in methanation of CO was investigated. Support geometry, in situ H sub 2 S poisoning tests, and carbon deposition tests initiated during the previous contract were completed. The results show that: (1) at high conversions and high through-put conditions monolithic supported catalysts are more active than pellet supported catalysts; (2) Ni-MoO sub 3 is more active and sulfur resistant than Ni, and (3) in carbon deposition tests Ni-Pt and Ni-Co maintain catalytic activity longer than Ni. High temperature reactor tests reveal that catalysts prepared in this laboratory are more active and in some cases more thermally stable than commercial catalysts and that carbon deposition is a major factor but not the only factor causing deactivation at high temperatures. A comprehensive investigation of methanation kinetics over nickel (and to a lesser extent ruthenium) and deactivation by carbon was conducted. The results provide significant insights into the mechanisms of the reaction and the deactivation by carbon. Effects of temperature, H sub 2 S concentration, and other reaction variables on the sulfur poisoning rate of nickel during methanation were also investigated. The results provide a basis for modeling the deactivation process and predicting catalyst life. These and other significant results are presented and discussed. (ERA citation 06:004462)