Transition metal oxides for hot gas desulphurisation

Thermodynamic equilibrium simulations were made to determine suitable materials for intensive desulphurisation of fuel gases from an IGCC. Zinc-based materials are the most promising for high temperature intensive desulphurisation, but cause evaporation and regenerability problems. To overcome these problems, a new material was synthesised, containing zinc oxide supported on a titanium dioxide support. The material is able to reduce H2S levels from 3250 ppm to the thermodynamic equilibrium values in a synthetic fuel gas mixture at atmospheric pressure. At 600 degrees C, the material can be regenerated completely. Sorbent sulphur capacity increases upon regeneration until 100% sorbent usage. Comparing experimental and simulation results, it is also concluded that Aspen Plus is a powerful tool in calculating high-temperature gas-solid equilibria. (C) 1999 Elsevier Science Ltd. All rights reserved.