A SEQUENTIAL CRACKING PROCESS

摘要

A sequential cracking process for the thermal cracking of a hydrocarbon feedstock in a cascade of cracking units wherein said hydrocarbon feedstock is heated in a furnace to a predetermined maximum temperature and thermally cracked in the cascade of cracking, such that the formation of coke is reduced.

主权项

1. A sequential cracking process for the thermal cracking of a hydrocarbon feedstock in a cascade of cracking units wherein said hydrocarbon feedstock is heated in a furnace to a predetermined maximum temperature and thermally cracked in said cascade of cracking units, the process comprising the following steps:
a. heating said hydrocarbon feedstock in said furnace to a cracking temperature T1; b. introducing the heated hydrocarbon feedstock into a first cracking unit operating at a temperature T1; c. passing the product stream from said first cracking unit to a first fractionation; d. recovering as separate streams from said first fractionation a light fraction boiling below 370 degrees C. and a heavy fraction boiling above 370 degrees C.; e. introducing said heavy fraction from said first fractionation into a second cracking unit operating at a temperature T2; f. passing the product stream from said second cracking unit to a second fractionation; g. recovering as separate streams from said second fractionation a light fraction boiling below 370 degrees C. and a heavy fraction boiling above 370 degrees C. and h. introducing said heavy fraction from said second fractionation into a third conversion unit operating at a temperature T3, wherein temperature T1 is not equal to temperature T2, and temperature T2 is not equal to temperature T3, wherein the temperature in the first cracking unit T1, the second cracking unit T2 and the third conversion unit T3 is in the sequence of T1