GB1318257A - Process for the production of elemental sulphur from sulphur dioxide - Google Patents

Abstract

1318257 Sulphur; purification of waste gases SHELL INTERNATIONAL RESEARCH MAATSCHAPPIJ BV 24 Aug 1970 [26 Aug 1969] 40648/70 Heading C1A Sulphur is prepared from SO 2 by passing a portion of the SO 2 into a reactor in which a hydrocarbon is undergoing a catalytic conversion at elevated temperature and recovering, from the products, an H 2 S-containing gas which is combined with the unreacted SO 2 according to the conventional Claus reaction, the Claus reaction may be carried out at elevated temperature over an alumina catalyst, or in a liquid which promotes the reaction, such as, diethylene and triethylene glycols, dipropanolamines and sulpholane. The quantity of SO 2 added to the converter may be up to 10% of the hydrocarbon and may be in gaseous or liquid state. If the SO 2 is to be the sole source of H 2 S two-thirds (molar) of the SO 2 is converted to H 2 S; alternatively, is there is H 2 S available from other sources, e.g. when the impurities in the hydrocarbon undergoing conversion liberate H 2 S, then only sufficient SO 2 is converted to bring the molar ratio of H 2 S : SO 2 to 2 : 1. Suitable hydrocarbon conversion processes include catalytic cracking, e.g. using a synthetic SiO 2 /Al 2 O 3 catalyst, and reforming or cracking processes carried out under hydrogen pressure such as hydrodesulphurization, and hydrocracking. The SO 2 is conveniently obtained by preparing an SO 2 -rich gas stream from the SO 2 present in waste gases, for example by absorbing the SO 2 on a solid acceptor comprising a carrier on which a metal and/or a metal compound, e.g. copper and/or copper compounds, have been deposited and regenerating the acceptor with a reducing gas such as hydrogen or hydrocarbons to yield an SO 2 -rich gas.