The use was investigated of natural minerals and commercial sorbents to remove HCl vapor contaminant from high temperature coal gas mixtures used for molten carbonate fuel cell (MCFC) applications. Sodium carbonate-based sorbents can reduce the level of HCl to about 1 ppM in coal gas streams at 535 to 650/sup 0/C. In the laboratory-scale phase of this study of three minerals and two commercial sorbents, the total capacity of the sorbent for retaining HCl was found to depend on its sodium content and porosity. The mineral nahcolite after calcinatin was found to have a capacity of 54 wt % chloride because of its high sodium content and moderate porosity. Although commercial sorbents have high surface areas, they had much lower chloride capacities because of their low sodium content. The reaction between HCl vapor and the sorbents was rapid and the initial rate was controlled by gas phase mass transfer. The bench scale phase of this study conducted with simulated ''simple''coal gas containing only HCl as an impurity and a ''complex''coal gas containing H/sub 2/S, organic, and trace metal impurities in addition to HCl confirmed the results of the laboratory study. H/sub 2/S was captured by the sorbents only in minor quantities and it did not interfere with the chloride removal. Arsenic and antimony were the trace metal impurities significantly retained by the sorbents. Preliminary techno-economic analysis of the HCl removal process identified nahcolite as the most economic sorbent. Capital and operating costs for a 100-MWe commercial size unit were estimated to range from $0.0017 to $0.0031 per kWh depending on the type of gasifier.