A process for the production of propylene, the process including: fractionating a hydrocarbon stream comprising n-butenes, isobutylene, and paraffins into at least two fractions including a light C4 fraction comprising isobutylene and a heavy C4 fraction comprising n-butenes and paraffins; contacting at least a portion of the heavy C4 fraction with a metathesis catalyst to form a metathesis product comprising ethylene, propylene, C4+ olefins, and paraffins; fractionating the metathesis product into at least four fractions including an ethylene fraction, a propylene fraction, a C4 fraction comprising C4 olefins and paraffins, and a C5+ fraction; cracking the light C4 fraction and the C5+ 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 C5 to C6 hydrocarbons.