High temperature hydrogen sulfide and carbonyl sulfide removal with manganese oxide (MnO) and iron oxide (FeO) on .gamma.-alumina acceptors

A process has been developed to remove H[sub 2]S and COS at high temperatures (675-1,075 K) from fuel gases produced by a coal gasification plant. The process uses MnO or FeO on [gamma]-Al[sub 2]O[sub 3] acceptors which can be regenerated after sulfidation with a gas containing steam. The acceptors should be used in a fixed bed or moving bed reactor. It is important to know what influence the raw fuel gas composition of a coal gasification plant and operating temperature and pressure have on the sulfidation behavior of the acceptors. Experiments are carried out in a laboratory setup to determine these influences. After an initial deactivation the acceptors can be used over 400 sulfidation-regeneration cycles. Water adversely affects the capacity, whereas CO favors the capacity due to the water-gas shift reaction. Trace compounds can influence the capacity negatively as, e.g., HCl, whereas hydrocarbons do not influence acceptor performance. An optimum between capacity and stability is reached at a operating temperature of 875 K. An increasing pressure does not influence the sulfidation reaction, but the water-gas shift reaction may be positively influenced.