Patent attributes
A process for producing lower olefins is disclosed. The technical problem is to overcome the defects presented in the prior art including high reaction pressure, high reaction temperature, low yield and selectivity of lower olefins as the target products, poor stability and short life of catalyst, and limited suitable feedstocks. The disclosed 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 contact with a crystalline aluminosilicate catalyst having a SiO2/Al2O3 molar ratio of at least 10, to thereby produce a reaction effluent containing lower olefins; and b) separating lower olefins from the reaction effluent; wherein, the reaction pressure is from −0.1 MPa to <0 MPa.
