Patent ID: 8153851

Claim:
A process for the production of propylene, the process comprising: fractionating a hydrocarbon stream comprising n-butenes, isobutylene, and paraffins into at least two fractions including a light C 4 fraction comprising isobutylene and a heavy C 4 fraction comprising n-butenes and paraffins; contacting at least a portion of the heavy C 4 fraction with a metathesis catalyst to form a metathesis product comprising ethylene, propylene, C 4+ olefins, and paraffins; fractionating the metathesis product into at least four fractions including an ethylene fraction, a propylene fraction, a C 4 fraction comprising C 4 olefins and paraffins, and a C 5+ fraction; cracking the light C 4 fraction and the C 5+ fraction to produce a cracking product comprising ethylene, propylene, and heavier hydrocarbons; and fractionating the cracking product into at least two fractions including a light fraction comprising propylene and a fraction comprising C 5 to C 6 hydrocarbons.