Process for the production of carbonaceous adsorption agents doped with elementary sulfur and a process for waste gas cleaning using such adsorption agents

A process for waste gas cleaning using carbonaceous adsorption agents doped with elementary sulfur comprising:

• providing said carbonaceous adsorption agents doped with elementary sulfur for reversible mercury adsorption, in which a mixture consisting of solid sulfur mixed with solid adsorption agent is provided, the mixture is heated to a temperature of between 120° C. and 150° C. and the temperature is maintained over a period of between 0.5 and 1 hour, wherein heating of the mixture is effected under a controlled oxygen-bearing atmosphere wherein the oxygen content is set between 13 and 21% by volume and kept in the set range throughout said period wherein surface oxides formed on said carbonaceous agent during said heating are in chemical equilibrium with said oxygen, wherein said adsorption agent is further characterized in that absorbed mercury does not chemically compound with said elementary sulfur thereby providing said reversible mercury adsorption wherein said carbonaceous adsorption agent can repeatedly absorb mercury at a temperature of between 60° C. and 120° C. and liberate mercury at a temperature of between 150° C. and 200° C., in which adsorption and desorption of mercury from the waste gas flow is effected alternately, by means of a fixed bed adsorber.