The present invention provides a process for producing lower olefins by catalytic
cracking a feedstock comprising an olefins-enriched mixture containing C4 or higher olefins and optionally an organic
oxygenate compound. The technical problem mainly addressed in the present invention is to overcome the defects presented in the prior art including low yield and selectivity of lower olefins as the target products, and short regeneration period of catalyst. The present process, which is carried out under the conditions of catalytic
cracking olefins and adopts as a feedstock an olefins-enriched mixture containing one or more C4 or higher olefins and optionally an organic
oxygenate compound, comprises the steps of: a) letting the feedstock firstly enter a first
reaction zone to contact with a first crystalline
aluminosilicate catalyst having a SiO2 / Al2O3
molar ratio of at least 10, to thereby produce a first reaction
effluent containing lower olefins; b) letting the first reaction
effluent enter in turn at least one second
reaction zone to contact with a second crystalline
aluminosilicate catalyst having a SiO2 / Al2O3
molar ratio of at least 10, to thereby produce a second reaction
effluent containing lower olefins; and c) separating lower olefins from the second reaction effluent; wherein the reaction temperatures in the first and second reaction zones are controlled. The present process, which desirably solves the above technical problem, can be used in industrial production of lower olefins.