The invention concerns a carbonaceous sorbent in powder or grain form for the dry cleaning of waste gases from thermal processes. The sorbent includes carbon adsorbents from the group of activated carbon and/or brown coal cokes which are modified with sulfur and/or sulfur compounds. The sorbent is distinguished in that the specific surface area of the carbon adsorbents in m2/g in relation to the pore volume of the micropores in cm3/g is between 2400 and 2700.