Inhibition and elimination of carbon deposition in dry gas desulfurization process under oxy-fuel IGCC derived coal gas environment

摘要

Oxy-fuel IGCC is a concept of new coal fueled power generation with CO2 capture capability without large penalty on thermal efficiency. It is estimated that thermal efficiency will attain 44% at lower heating value, LHV along with 99% CO2 capture capability. An imperative issue to be solved to realize this concept is to reconcile pre-combustion sulfur removal and retaining the inorganic gas composition of the coal derived gas. Although introduction of dry gas sulfur removal is desired to protect gas turbine from corrosion and to preserve the gas composition, the sulfur removal sorbent containing zinc ferrite installed in the process may suffer from the severe side reaction of carbon deposition. Although it was found that mixing the coal gas with the circulating exhaust in the plant would effectively prevent the carbon deposition in the process, exhaust will not be available until gas turbine comes into normal operation after the plant start-up.