GB1186982A - Thermal Cracking. - Google Patents

Abstract

1,186,982. Thermal cracking. MONSANTO CO. 22 May, 1968 [22 May, 1967], No. 24464/68. Heading C5E. A feedstock comprising a normally liquid hydrocarbon is thermally cracked in a tubular reactor to give a product, which is quenched in a quench zone, consisting of unsaturated and aromatic. hydrocarbons mainly ethylene, propylene,. benzene and toluene, a vaporized hydrocarbon having at least 4 carbon atoms being injected at a point. which lies beyond the first 90% of the length of the tubular reactor and prior to the quench. zone. The vaporized hydrocarbon may be the same as the feedstock which may be a petroleum condensate or naphtha, and which may contain a normally gaseous hydrocarbon such as butane. An inert, diluent such as steam is preferably present during the cracking and also mixed with the vaporized hydrocarbon before injection. If the tubular reactor has both a convection section and a cracking section a suitable mixture of vaporized hydrocarbon and steam may be withdrawn from the convection section. The thermal cracking may be carried out at 1300-1600‹ F. and the temperature of the injected vaporized hydrocarbon may be 750-1300‹ F. The vaporized hydrocarbon is preferably injected between the outlet of' the tubular reactor and the quench zone.