Patent ID: 7972482

Claim:
A hydrocarbon cracking apparatus comprising: (a) a reactor for pyrolyzing a hydrocarbon feedstock, the reactor having an outlet through which gaseous pyrolysis effluent can exit the reactor; (b) at least one heat exchanger connected to and downstream of the reactor outlet for cooling the gaseous effluent, wherein said at least one heat exchanger includes at least one primary transfer line heat exchanger and at least one secondary transfer line heat exchanger connected to and downstream of the reactor outlet; (c) at least one tar knock-out drum connected to and downstream of the at least one heat exchanger for separating tar from the gaseous effluent; (d) a cooling train comprising at least one indirect heat exchange condenser having an inlet connected to a gaseous effluent outlet of the at least one knock-out drum, without an intervening primary fractionation tower, for further cooling the gaseous effluent to less than 100° C. so as to condense a hydrocarbon fraction having a boiling point range between about 150° C. to about 540° C. from said effluent; (e) a separator tank for removing said hydrocarbon fraction from said gaseous effluent; and (f) a fractionator downstream of said separator tank for fractionating said hydrocarbon fraction into a heavy fraction and a light fraction having a boiling point range between about 150° C. to about 230° C.