Sulphuric acid Claus process

The physical wash processes can be designed so that H2S and CO2 are absorbed separately, meaning that both gases can be reeovered at high concentration. The CO2 stream may be compressed for CCS (refer to Section 1.4.2). The H2S stream is converted either into elementary sulphur by the Claus process or into concentrated sulphuric acid by the WSA process [291]. 

The Claus process has been the standard of the sulphur recoveiy indushy, but limitations and problems relating to composition may restrict its effectiveness for fuel cell applications. Traditional Claus plant may be used for sulphur recoveiy from a rich feed gas stream, with at least 50% H2S by volume. However, for lower H2S content (5-50% volume) a modification of the traditional Claus plant is needed (McIntyre and Lyddon, 1997). In addition, acid gas feeds may contain undesirable components such as ammonia and hydrocaibons, which cause problems during processing. For an optimum conversion of H2S, a 2 1 H2S S02 ratio is required. The reactions involved in a Claus plant are as follows ... 

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