Simultaneous removal of H{sub 2}S and NH{sub 3} in coal gasification processes. Quarterly progress report, January 1--March 31, 1995

The objective of this study is to develop advanced high-temperature coal gas desulfurization mixed-metal oxide sorbents with stable ammonia decomposition materials at 550--800 C. The specific objectives of the project are to: (1) develop combined sorbent-catalyst materials which shall be capable of removing hydrogen sulfide to less than 20 ppmv and ammonia by at least 90%; (2) carry out comparative fixed-bed studies of absorption and regeneration with various formulations of sorbent-catalyst systems and select the most promising sorbent-catalyst type; and (3) conduct long-term (at least 30 cycles) durability and chemical reactivity in the fixed-bed with the superior sorbent-catalyst. The activities of the HART 39 and HART 40 sorbent-catalysts were tested at 700 C using simulated coal gas. Figures show the H{sub 2}S removal ability, its ammonia decomposition activity, and the H{sub 2}S breakthrough profiles as a function of time. The pre-breakthrough H{sub 2}S level was below 100 ppm. Nearly complete sorbent conversion (100%) was observed at breakthrough. The HART 39 and HART 40 sorbent-catalysts showed moderate catalytic activity (39% average conversion for HART 39; 46% average conversion for HART 40) for ammonia decomposition