Method of producing pitch coke

Claim 1

Method for the manufacture of pitch coke with needle-like structure which comprises: (a) mixing pyrolysis oil condensate formed in the coking of coal-tar pitch with a coal-tar pitch having a softening point between 70° and 150° C. in the proportion of 70 to 95% by weight coal-tar pitch and 5 to 30% by weight pyrolysis oil condensate, (b) filtering said mixture of condensate and pitch at a temperature 100° C. to 200° above the softening point of the pitch, (c) passing the filtrate in a restricted stream through a heating zone and heating the filtrate therein to a temperature between about 450° and 525° C., (d) discharging the thus heated filtrate to a coking chamber wherein the heated filtrate forms a non-volatile carbonaceous residue as coke and volatile vapor and gas, (e) releasing the volatile vapor and gas from the coking chamber and passing the vapor and gas to a fractionating zone with an overhead temperature of between about 150° and 200° C. at pressures of about 0.5 to 2.0 bar and a bottom temperature of about 300° C., in which the vapor is condensed to form pyrolysis oil condensate, (f) withdrawing said condensate from the fractioning zone, and returning at least a part of said condensate for mixing with additional incoming coal-tar pitch prior to said filtering.