Process for producing ethylene and propene by catalytic pyrolytic cracking

Catalytic taken by the method of thermal cracking of heavy hydrocarbons to ethylene and propylene, is the preheating of the heavy hydrocarbon oil in a riser or downflow transfer line reactor, in the presence of steam at a high temperature and a molecular sieve containing pillared clay catalyst and / or a phosphorus and aluminum or magnesium or calcium modified high silica pentasil zeolite, the reaction temperature is 650 ~ 750 ℃, reaction pressure 1.5 ~ 4 × 10