Process Simulation Of Sulfur-iodine Cycle For Hydrogen Production And Experimental Research On Bunsen Reaction

As a new type of efficient and clean energy carrier, Hydrogen is considered to be a very important energy in the world energy stage in21century. With the pollution of the environment and fossil energy crisis getting worse, a lot of attention is paying to the construction of the hydrogen system in the future. Thus, low-cost and large-scale hydrogen production is the first issue of hydrogen economy. Compared with other hydrogen production processes, the sulfur-iodine thermochemical cycle is the most promising thermochemical cycle for mass hydrogen production due to its attractive features, such as mild reaction conditions, available to realize large-scale industrialization.Bunsen reaction is the first step of sulfur-iodine cycle. Considering that the economic and technical sustainability of the whole process is very sensitive to several factors involved in Bunsen reaction, such as liquid-liquid equilibrium (LLE) phase separation performance, side reaction and the excess of iodine and water, the study of Bunsen reaction has got wide concern. Experimental investigations have been carried out with the continuous tower like bubbling reactor system. Several cognitions were obtained by the study taken under different reaction conditions, such as SO2flow rate and S02concentration. Then the influences of temperature, flow rate and concentration on the solubility and absorption characteristics of SO2in the liquid phase were investigated. As the reaction progresses, HI concentration and I2concentration first increase and then decrease. After separation, the concentration of HI and I2reduce sharply until stabilized. The concentration of H2SO1increases with the reaction proceeding. There is a sharp increase after the separation. Increasing concentration of SO2has a positive effect on Bunsen reaction. With the increase of the inlet velocity, Bunsen reaction will speed up, but the impurity also will increase. Increasing temperature and velocity as well as decreasing concentration has negative influence on the solubility and absorption of SO2. With our experimental data, a flowsheet of sulfur-iodine thermochemical cycle for hydrogen production is designed and simulated by Aspen Plus. Heat and mass balance as well as thermal efficiency are calculated at fixed H2production rate of0.348mol/s. Thermal efficiency for hydrogen production is68.46%. H1concentration in H1phase will increase through the optimization of Bunsen reaction process. The decomposition rate of S03has a great influence on the thermal efficiency of the system.