The Preparation of Regenerable Sorbents for High Temperature Desulphurisation of Fuel Gases

Abstract

The preparation of some oxides and mixed oxide sorbents with aluminosilicate type of binders for high temperature desulphurisation of fuel gases is discussed. The sorbents investigated are extrudates of ZnO, Indian iron-ore fines and slimes, ZnO-iron ore fines , ZnO-iron ore slimes, CuO-iron ore slimes, combusted coal ashes (CCA), CuO-CCAs, ZnO-Fe₂O₃, CuO-Fe₂O₃ and CuO-Fe₂O₃- Al₂O₃. These sorbents have been found highly efficient in absorbing sulphurous gases. The fresh, sulphidised, regenerated sorbents of mixed metal oxides and their chemical phases have been identified by X-ray diffraction technique. The presence of χ-chalcopyrite, ZnS, morihoikite, CuFe₂S₃, CuFeS₃, Cu₃(SO₄)(OH)₄ and CuSO₄ 5H₂O in both major and minor phases in the sulphidised samples indicate the absorption of sulphur from sulphurous gases at high temperatures. The crushing strength of the fresh, sulphidised, regenerated and resulphidised sorbents has been determined. The performance of the sorbents is discussed in terms of absorption efficiency.