Hydrogen production through the sulfur–iodine cycle using a steam boiler heat source for risk and techno-socio-economic cost (RSTEC) reduction

Abstract A modified sulfur-iodine cycle with a non-nuclear heat source is proposed to enhance the economics and reduce risk and damage to society in terms of cost. A modified sulfur cycle employs a steam boiler as a heat source. The modified sulfur iodine cycle is composed of fewer reactions than the original. Thermodynamic feasibility analysis, economic evaluation, risk assessment, and socio-economic analysis are carried out on both the sulfur-iodine cycle and modified sulfur-iodine cycle, and the results are compared. 50.9 kJ/mol of steam was required for the minimum entropy range without the violation of the second law. The results show that the modified process is thermodynamically feasible with a positive entropy region at operating temperatures. The capital cost and operating cost are reduced by 40% and 29% for 1 kmol/h hydrogen production, respectively. The failure rate in the modified process is reduced by 64% compared to that of the original. The social health cost in the modified cycle is reduced by 41% compared to that of the original.