Patent ID: 6646175
Filing Date: 2003-11-11
Classification: C10G

Abstract:
A process for the catalytic cracking of at least one olefin in an olefinic stream containing impurities, the cracking process being selective towards light olefins in the effluent, the process comprising contacting at an inlet temperature of from 500 to 600Â° C. a feedstock olefinic stream containing at least 100 ppm of at least one impurity selected from the group consisting of nitrogen, sulphur and oxygen with a MFI crystalline silicate catalyst, the catalyst having been heated in steam to reduce the tetrahedral aluminum in the crystalline silicate framework and subjected to an aluminum extraction process to remove aluminum from the pores of the crystalline silicate after which the catalyst has a silicon/aluminum atomic ratio of from 180 to 1000, to produce an effluent stream having substantially the same olefinic content by weight as, but a different olefin distribution than, the feedstock contains.