The alkali metals are major causative agents along with sulfur in the fouling and corrosion behaviors of gas turbine blades and vanes. The burning of coal to provide the hot motive gas introduces these species in quantities greater than usually experienced when firing gaseous or liquid fuels, giving rise to fears of excessive performance degradation. Alkali metal corrosion may be reduced by capturing the alkali metals as aluminates, silicates, or aluminosilicates. The latter, particularly complex aluminosilicates, should not be corrosive. Computer simulation of the equilibrium composition of pressurized fluidized bed combustion gases was used to model the Curtiss-Wright pressurized fluidized bed technology rig which has a high heat loss in the ducting and cyclones, followed by liquid fuel reheat. Several alkali metal slag compounds were added to the computer library for this study. The agreement between calculated alkali metal compound concentrations at the gas turbine entrance and experimental values is reasonably good. Conclusions reached are that the thermal history of the solids in the technology rig should have no influence on projecting rig performance to pilot plant scale-up; that the amount of alkali metal compounds thought to be significant in corrosion that reaches the turbine is less related to combustion conditions, turbine inlet temperature, and system heat loss than to the presence of natural getters and to the efficiency of solids removal; and, based on the rig analysis, alkali metal corrosion will probably not be a problem.