The invention relates to a process for producing synthesis gas from liquid and semi-solid to solid hydrocarbons. The solid phase which is formed and separated from the gas stream consists essentially of soot and metals and/or metal compounds. The metals and/or metal compounds are extracted from this phase in the separation apparatus by treatment with acid
PURPOSE: To environmentally safely treat by-produced carbon particles, metals and/or metal compounds by cooling crude synthetic gas obtained by partially oxidizing, particularly high-ash liquid, semisolid or solid hydrocarbons, cooling and scrubbing the crude synthesis gas with water and treating the filter residue of the washed water with an acid.
CONSTITUTION: Crude synthesis gas obtained by the partial oxidation of hydrocarbons is cooled in a radiant cooler and then in a convection cooler and subsequently scrubbed with water in a wet separator. This washed water is optionally combined with the aqueous phase of the radiant cooler and separated, in a separation apparatus (preferably, a filter press) into a residue essentially containing carbon, metals and/or metal compounds and water and purified water as the filtrate. The steam-saturated crude synthesis gas is cooled to separate off water and solid-free synthesis gas is obtained. Said filter residue is optionally partially dewatered in said separation apparatus and then treated with an acid to take off the resulting metal salt solution and the remaining carbon is returned to the partial oxidation step.