Processes for producing a polypropylene product by using a lower purity propylene stream. An operating parameter of the separation zone for a dehydrogenation zone effluent may be adjusted or controlled to lower the purity of the propylene stream produced by the separation zone. The reflux rate of propylene-propane splitter may be reduced. The duty of the reboiler for the propylene-propane splitter may be lowered. The number of stages in the propylene-propane splitter may be decreased.