Prodn. of lower alkene(s) for chemical intermediates and fuels - comprises thermal cracking of hydrocarbon feedstocks and sepn. into streams for compression and condensing into fractions

摘要

Prodn. (esp. of ethene, propene and isobutene) comprises thermal cracking of liq. and/or gaseous hydrocarbon feedstocks and sepn. of the prods. in several steps, when the gaseous prods. are subjected to two or more compression stages and then fractionally condensed under high pressure to C2, C3 and C4 liq. fractions. The raw hydrocarbon feed is divided into two streams, one contg. the usual hydrocarbons for the prodn. of ethene, which is cracked at 800-900 deg. C/1-5 bar; while the second stream is rich is isobutane is cracked at 650-830 eg.C/10-50 bar, yielding a liq. fraction (4 or more C prods) and a gaseous fraction (1-3 C prods) which is recycled to the high pressure cracking stream. The higher hydrocarbon (5+ C) fractions from the two streams are combined for further processing, and the 4 C fractions are selectively hydrogenated and sepd. USE - The process is continuous and economical in producing valuable chemical, intermediates and fuels. (10pp Dwg.No.0/3)