Simultaneous removal of HS and COS using Zn-based solid sorbents in the bench-scale continuous hot gas desulfurization system integrated with a coal gasifier.

A bench-scale continuous hot gas desulfurization system using Zn-based solid sorbents was developed to remove HS and COS simultaneously in a 110 Nm/h of real coal-gasified syngas. The bench-scale unit, which consisted of a fast fluidized-bed type desulfurizer and a bubbling fluidized-bed type regenerator, was integrated with a 3 ton/day-scale coal gasifier installed at the Institute for Advanced Engineering. The solid sorbents, which consisted of 50 wt% of ZnO for sulfides sorption and 50 wt% of supporters for mechanical strength, were manufactured by a spray drying method and supplied by Korea Electric Power Corporation Research Institute. The bench-scale unit was designed to operate at the high temperature of above 500 °C and the high pressure of 19 kg/cm gauge. Integration of the bench-scale unit with a coal gasifier was first performed to investigate the operation stability of the integrated system. And the long-term continuous operation above 30 h was performed to analyze the desulfurization performance of the bench-scale unit. The concentration of both HS and COS in the syngas was measured by a continuous UV gas analyzer and an online gas chromatograph and that of both HS and COS after desulfurization was measured by an online gas chromatograph. Through the above 30-h continuous operation, the sulfur removal reached up to 99.9%. [ABSTRACT FROM AUTHOR]