Patent ID: 7674366

Claim:
A method for treating gaseous effluent from a hydrocarbon pyrolysis unit, the method comprising: (a) cooling the gaseous effluent at least to a temperature at which tar, formed by reaction among constituents of the effluent, condenses; (b) passing the mixed gaseous and liquid effluent from step (a) through at least one tar knock-out drum, where the condensed tar separates from the gaseous effluent; (c) cooling the gaseous effluent from step (b) to condense a liquid effluent quench oil; (d) passing the mixed gaseous and liquid effluent from step (c) through at least one quench knock-out drum, where the condensed quench oil separates from the gaseous effluent; (e) cooling the gaseous effluent from step (d) to condense a liquid effluent comprising pyrolysis gasoline and water condensed from steam; (f) passing the mixed gaseous and liquid effluent from step (e) to a distillate drum, where the cooled gaseous effluent, liquid pyrolysis gasoline and liquid water are at least partially separated from each other to form a gaseous effluent stream which is directed to a recovery train, a liquid pyrolysis gasoline rich stream and a liquid water rich stream; and (g) passing the liquid pyrolysis gasoline rich stream to a tailing tower which produces an overhead stream rich in pyrolysis gasoline and a bottoms stream rich in gas oil; and further, wherein the gaseous effluent from the hydrocarbon pyrolysis unit is cooled without a primary fractionator.