Christophe Nedez

Claus Catalysis and H2S Selective Oxidation

Abstract This review article deals with the development of sulfur recovery from the Claus process to H2S selective oxidation. Governments are constantly tightening regulations to limit the emission of sulfur compounds into the air. This makes it necessary to constantly enhance the level of sulfur recovery from natural, refinery, or coal gasification geses, and many improvements in the Claus process have been introduced to this end. In this review, emphasis has been put on the mechanism of reactions occurring in most of the sulfur recovery units, reactions between H2S and SO2 or O2 and side reactions such as hydrolysis of COS and CS2 or sulfation of the catalyst.

A new Claus catalyst to reduce atmospheric pollution

Abstract The discovery of two new concepts have made it possible to draw the physico-chemical map of the best alumina Claus catalyst. An optimized profile of the ultramacroporosity, between 0.1 and 1 μm, reduces diffusional constraints. A low sodium (Na 2 0) content (

New concepts for a new generation Claus alumina

Abstract We have developed a new Claus alumina which presents a particular ultramacroporosity, between 0.1 and 1 μm (to reduce diffusional constraints) and a well-defined soda content (below 2500 ppm Na 2 O) to reduce the sulfation of the surface and, thus, prolong the life of the catalyst.

Understanding claus catalyst deactivation mechanisms: Optimization of alumina using physico-chemical parameters

This work is devoted to the comprehension of mechanisms involved in the deactivation of Claus catalysts. The principal cause of deactivation of alumina is sulphation of the surface. The optimization of the alumina (Na 2 O level content, macroporosity around 0.1 μm., etc.) reduces considerably the consequences of aging, given a high level of catalytic performance.