Simulation,optimization And Preliminary Design Of Heat Exchange Network Of Iodine Sulfur Process For Hydrogen Production

Sulfur iodine cycle is one of the most efficient thermochemical water-splitting approaches for massive hydrogen production,,and has been taken as the primary option for nuclear energy hydrogen production in several countries,including Japan,France,Korea and some others.Sulfur iodine cycle process is composed of three reactions,i.e.,the Bunsen reaction,sulfuric acid decomposition reaction and hydrogen iodide decomposition reaction.In addition,the process involves a number of separation processes and a variety of chemical species with complex thermodynamic properties,which lead to difficulties for the process design and optimization of the whole process.On the other hand,the process efficiency,which is dependent on the energy consumption in the sulfur iodine cycle,will be improved by heat exchange or recovering of the waste heat.R&D on the nuclear hydrogen production through IS process has been developed for many years in the Institute of Nuclear and New Energy Technology(INET)of Tsinghua University.An integrated laboratory scale IS facility with hydrogen production of 100NL/h has been erected.To improve the efficiency of IS process,simulation,optimization and preliminary design of heat exchange net were carried out using Aspen plus,a powerful and comprehensive chemical program with embedded self-made models.the modeling analysis of the hydrogen station frame,including unit operation,each section and whole process,were conducted.The mass balance,as well as energy balance,were obtained.Besides the self-made models the mixed electrolytes models in the OLI database was taken as the default thermodynamic methods.Through the process simulation of the mass and energy balance calculation results,the heat consumption data were collected The pinch analysis technology was used to design the heat exchange net for sulfate decomposition and hydriodic acid decomposition section.Based on the optimization results and operation costs,the the minimum heat transfer temperature is determined as 20℃,Sulfuric acid decomposition process of initial cold and hot utilities were 797.71KJ/ mol-H2 and 1099.66KJ/ mol-H2.After preliminary heat exchanger network design and optimization of the parameters required for the total cold and hot utilities were 326.33 kJ / mol-H2 and 632.98 kJ / mol-H2,cold and hot public engineering energy consumption were reduced the 471.38 kJ / mol-H2(59.09%)and 466.68 kJ / mol-H2(42.44%).Hydriodic acid decomposition portion of the initial process in cold and hot utilities were as high as 5728.17KJ/mol-H2 and 6295.69 mol-H2 and improve in the process of hydriodic acid conversion rate and the overhead gas phase material and design of networks for heat exchanger,cold and hot utilities fell to 2360.38 KJ/mol-H2 and 1852.36 KJ/mol-H2,hot and cold utility consumption savings were the 3367.89 KJ/mol-H2(53.50%)and 4443.33KJ/mol-H2(70.58%).