MULTI-STEP METHOD OF CONVERTING A CHARGE CONTAINING OLEFINS WITH FOUR, FIVE OR MORE CARBON ATOMS IN ORDER TO PRODUCE PROPYLENE

摘要

The invention relates to a method of producing propylene from, for example, a C4 and/or C5 fraction derived from steam cracking and/or catalytic cracking, preferably comprising both butenes and pentenes. The inventive method comprises at least one oligomerisation step, followed by a step involving the catalytic cracking of the oligomers formed. The pre-oligomerisation, e.g. of a large fraction of the charge, optimises the yields, conversion and selectivity to the propylene in relation to direct cracking. In addition, the cracking can be performed on a fixed, mobile or fluidised bed and, optionally, oligomers can be co-produced for uses other than the production of propylene.