Energy and exergy analyses of integrated hybrid sulfur isobutane system for hydrogen production

This paper analyzes an integrated HyS cycle (hybrid sulfur cycle), isobutane cycle and electrolyzer for hydrogen production. The operating parameters such as concentration, pressure and temperature are varied to investigate their effects on the energy and exergy efficiencies of the system with/without heat recovery and integration, as well as the decomposer and rate of hydrogen produced. A new heat exchanger network is also developed to recover heat within the HyS cycle in the most efficient manner. The exergy destruction rate in each component is analyzed and discussed. From the results, increasing the pressure is beneficial up to 3222 kPa, after which the performance remains constant. The exergy efficiency varies more significantly with operating parameters than the energy efficiency. The maximum exergy destruction occurs in the heat exchanger so this component should be the focus to enhance the overall performance of the system. Copyright (c) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.