Process for separating a highly pure propylene product from a liquefied petroleum gas stream is disclosed, which eliminates a C3 splitter having over 120 trays and the additional equipment that a C3 splitter requires. The process includes passing a feed stream to a dividing wall column to produce an overhead stream, a first side draw stream, a second side draw stream, and a product stream. The first side draw stream is passed to a treatment unit to produce a treated stream. The treated stream is passed to a membrane unit and a permeate stream is passed from the membrane unit to produce a polymer grade propylene stream.