SULFUR RECOVERY FROM SOUR GAS BY USING A MODIFIED LOW-TEMPERATURE CLAUS PROCESS ON SEPIOLITE

In order to introduce an alternative catalyst for the reduction at low temperature, 343-423 K, of the Claus process streams tail gas, the au thors studied the performance of sepiolite, a natural, very abundant a nd cheap hydrated magnesium phylosilicate whose unique textural and st ructural characteristics confer the solid with the possibility of use as an adsorbent and catalyst. Apart from the effectiveness of the soli d in catalysing the sulphur dioxide reduction by hydrogen sulphide, an expression for the reaction rate has been deduced from the analytical data. The kinetic expression tells about a mechanism in which the che mical reaction between adsorbed species is the controlling step of the process. Water present in the Claus stream as a reaction by-product i s adsorbed on the substrate and plays an important role in the reactio n kinetics. From deactivation experiments under mass control condition s a better performance of sepiolite with respect to gamma-alumina is m ade apparent.