ACTIVITY, ADSORPTION, AND SULFUR TOLERANCE STUDIES OF FLUIDIZED-BED METHANATION CATALYSTS

Methanation catalysts under consideration for the BI-GAS Process by Bituminous Coal Research, Inc., were tested for methanation activity and resistance to poisoning by H2S. Catalysts included Mo/Al2O3, Ni-Co/SiO2-AI2O3, Ni-Cu-Mo/AI2O3, and two preparations of Ni-Mo/SiO2-AI2O3. An alumina-supported Ni catalyst prepared in the BYU Catalysis Laboratory was tested for comparison. Tests included hydrogen chemisorption measurements, measurements of specific rate for fresh and presulfided catalysts under two sets of conditions (140 kPa, 498-523 K and 2500 kPa, 723-773 K), deactivation tests over 1-3 days with 10 ppm of H2S in the reactant mixture, and measurements of H2S desorption isotherms at 723 and 773 K. Results of H2S desorption and in situ deactivation measurements confirm the strong and irreversible nature of sulfur-metal interactions resulting in relatively rapid, substantial poisoning of methanation catalysts. Compared to Ni catalysts, Ni-Mo catalysts evidence the same or slightly greater methanation activity and significantly improved sulfur resistance. © 1979, American Chemical Society. All rights reserved.