E. Sasaoka et al., CATALYTIC ACTIVITY OF ZNS FORMED FROM DESULFURIZATION SORBENT ZNO FORCONVERSION OF COS TO H2S, Industrial & engineering chemistry research, 34(4), 1995, pp. 1102-1106
In order to understand the behavior of COS in the ZnS zone of a packed
bed high-temperature desulfurization reactor, the catalytic character
of ZnS for the conversion of COS to H2S in the presence of gases whic
h are composed of coal-derived gas was studied. ZnS was active for the
catalytic hydrolysis of COS in simulated coal-derived gases; ZnS was
also active for the hydrogenation of COS to H2S, but the activity, was
considerably lower than that for the hydrolysis of COS. In simulated
coal-derived gases, ZnS was also active for the reverse reaction; H2S
was converted to COS over ZnS. The water gas shift reaction did not pr
oceed in parallel with hydrolysis of COS over ZnS. From the results of
this work, it is suggested that if the contact time of COS with ZnS w
as sufficient, the equilibrium of the conversion of COS to H2S was con
trolled by the following reaction: 2COS + H2 + H2O <-- --> 2H2S + CO CO2.