摘要:
A riser reactor for propylene production, comprises pipelines with an upper part and a lower part, the upper part is a straight pipeline, and the lower part is a expanding-diameter pipeline, and the expanding-diameter pipeline is a circular truncated cone-shaped pipeline with an angle of 1˜60 o between generatrix and axes, wherein, the diameter of upper surface of the circular truncated cone-shaped pipeline is larger than or equal to the diameter of the straight pipeline. Employed the riser reactor, propylene is produced by the method of catalytic cracking with stratified injections of heavy oil and light olefins. Average gas linear velocity in axial direction of the straight pipeline of riser reactor is 3˜25 m/s, and that in the expanding-diameter pipeline is 0.1 to 5 m/s. The outlet temperature of the riser reactor is 460 to 600° C., and the light olefins are no more than 50% of the total feedstock by weight. The yield and selectivity of propylene was improved, accompanied with production of diesel and gasoline with high octane number.