Process for recovering heat of a tar-containing high-temperature gas

Abstract

A process for recovering heat from a tar-containing gas while simultaneously cooling the gas in a 3-stage cooling step by (1) directing a tar-containing gas through a jet cooler comprising a bed of solid particles so that the gas contacts the solid particles and forms a fluidized bed with the flow of the tar-containing gas, which jet cooler comprises a central draft tube into which the gas is directed and indirect heat exchange lines containing a liquid coolant therein disposed inside the central draft tube and wherein the gas and solid particles are cooled by such indirect heat exchange lines such that the tar from the gas condenses on the solid particles; (2) directing the gas through a tar cooler in the second stage wherein the gas-containing residual tars and other impurities resulting from the treatment in the jet cooler are sprayed with a circulating tar from a nozzle to remove a residual tars and impurities from the gas and wherein the gas is further cooled in said tar cooler by means of an indirect heat exchange unit containing a liquid coolant therein; and (3) further cooling the gas by introducing the thus-treated gas into an indirect heat exchange unit wherein the gas is further cooled with lines carrying a liquid cooling medium and the gas finally sprayed with a light-gravity tar to remove the remainder of tar and other impurities from the gas. By the aforementioned method, heat is recovered from the gas by the liquid coolants, etc., used in the cooling stages.