Abstract: The method of performing the Claus process includes the steps of connecting in parallel two combustion furnaces with waste heat boilers, further reacting, after the partial combusting in the combusion furnaces, in a single Claus reactor which is connected to both of the waste heat boilers of the combustion furnaces so as to receive partially combusted gas from the combustion furnaces, and partially combusting the reactant gas in only one of the combustion furnaces, when a hydrogen sulfide mass flow rate of the hydrogen sulfide fed with the reactant gas is below a certain threshold, and partially combusting of the reactant gas in both of the combustion furnaces, when the hydrogen sulfide mass flow rate of the hydrogen sulfide is greater than the threshold value. The production capacity of the single Claus reactor is designed for a maximum expected hydrogen sulfide mass flow rate in the inflowing reactant gas.

Abstract: A method of removing hydrosulfide from a crude gas produced by partial oxidation of carbon-containing material comprises the steps of treating a gas at a temperature between 10.degree. and 60.degree. C. with a suitable absorption solution, regenerating the absorption solution loaded durhg the treating, and cooling the crude gas which has been precleaned and pre-cooled to a temperature of 110.degree.-150.degree. C. before entering the absorption column, in a stepped manner in indirect heat exchange, the cooling including supplying the gas first through a reboiler of a desorption column and then through a heat exchanger which serves for preheating of the loaded absorption solution.