Abstract
A new hybrid water decomposition cycle consisting of the following four reactions is proposed.
4HBr → 2H2 + 2Br2 (electrolysis)
5/3As2O3 + 2Br2 + 3H2O → 2H3AsO4 + 4/3AsBr3 (aqueous solution)
4/3AsBr2 + 2H2O → 2/3As2O3 + 4HBr (aqueous solution)
2H3AsO4 → As2O3 + 3H2O + O2 (750°C)
Each constituent reaction was investigated thermodynamically and experimentally. It was proved that this cycle was advantageous in the source of thermal energy and the separation of products. The highest reaction temperature in the cycle was 750°C, which was required for the thermal decomposition of As2O5 to As2O3 and O2. The products in each reaction could be obtained in two or three separate phases as a solid, a liquid, a gas and/or a concentrated aqueous solution.
