Proposed Concept Design for the High Temperature Sulphuric Acid Decomposition Reactor Applicable to the Hybrid Sulphur (HyS) Process

The utilization of alternate sources of energy is becoming more important due to the constantly growing world-wide demand for energy. The production of hydrogen via the Hybrid Sulphur process is a possible alternative that may contribute to alleviating the pressure on energy resources. The current field of interest is to investigate the operation of the sulphuric acid decomposition reactor operating at pressure ranges between 8 and 9 MPa. The reduction of SO₃ to SO₂ is, however, favoured at low pressures while maintaining high operating temperatures. Considering this, the need to investigate the possibility of operating at lower operating pressures is important in striving for higher process efficiencies. The proposed decomposition reactor is a multi-stage reactor system operated adiabatically with inter-stage heating in order to simplify the reactor design and improve the over-all conversion and efficiency of the process. At a pressure of 8–9 MPa and temperature of 900°C, the maximum conversion of SO₃ to SO₂ that can be achieved is between 48% and 54%. The proposed multi-stage reactor system has 5 packed bed (catalyst) reactor stages with 4 intermediate heat exchangers, and by lowering the operating pressure to 3 kPa, a maximum conversion of 72% could be achieved. The viability of the HyS process mainly depends on the performance of the SO₃ decomposition reactor.