Experimental study of Bunsen reaction in the framework of massive hydrogen production by the Sulfur-Iodine thermochemical cycle

Abstract

The optimization of the Sulfur-Iodine (SI) thermochemical cycle necessitates to reduce the amounts of iodine and water introduced in Bunsen reaction (SO 2 + xI 2 + nH 2OH 2SO 4 + (n-2)H 2O + 2HI + (x-1)I 2). When iodine is initially in excess, the solution produced by this reaction spontaneously separates in two liquid phases. Bench-scale experiments have been performed to study the miscibility gap in the quaternary system H2SO 4/HI/I 2/H 2O at 308K. First results showed that increasing the amounts of I2 lead to better HI and H2SO 4 separation in each of the two liquid phases, on the contrary water had to be decreased to improve phase separation. An experimental device has also been designed in order to optimize Bunsen reaction at 393K in terms of rate efficiency and phase separation.