Aqueous High-Temperature Chemistry of Carbo- and Heterocycles. 21. Reactions of Sulfur-Containing Compounds in Supercritical Water at 460 .degree.C

Ten sulfur-containing compounds were selected to serve as models for the sulfur-containing impurities in heavy oils. They were subjected to aquathermolysis in water, 15% aqueous formic acid, and 15% aqueous sodium formate solution for 7 min at 460° C. Refractory materials were rerun over 1 h at the same temperature. In each instance the sulfur compound was exposed to the same time/temperature regime in cyclohexane in order to compare any thermal decomposition with the aqueous results. Thiophene (5) was completely unchanged, and benzo[b]thiophene (33) showed little (< 4%) or no change in any medium over 1 h. Diphenyl sulfide (44) was rapidly reduced to benzene (2) in formic acid over 1 h but showed little change in other media