Thermochemical water splitting for hydrogen production. Annual report, 1 January-31 December 1979

Investigation of the sulfur-iodine process at General Atomic Company (GA) continued during 1979. The major accomplishment for this year was the incorporation of most of the process improvements, developed under the Gas Research Institute (GRI)/GA-sponsored chemistry investigation program, into the engineering flow sheet, resulting in a process thermal efficiency of 47 percent. The effort has centered principally on six areas: (1) Investigation of the thermodynamics of the main solution reaction (2H2O + SO2 + xI2 - 2HIx + H2SO4) to develop a model of the system. (2) Investigation of the H2SO4 boost reaction to increase the yield of sulfuric acid from the main reaction. (3) Support of the flow sheet effort to incorporate chemistry process improvements into the process. (4) Investigation of decomposition of hydrogen iodide in the liquid phase. (5) Investigation of vapor pressures and solubilities associated with the lower phase process mixtures and other HI/I-containing process liquids. (6) Investigation of the gas-liquid phase relationships resulting from treatment of the lower phase. The results achieved in these areas are described in detail in this report.