Energy reduction and improved product recovery with enhanced safety of industrial scale propane‐propylene separation process.

Summary: Propylene is the most essential raw material and intermediate in the petrochemical sector. Industrial separation of propane and propylene is energy‐intensive and challenging, as they have similar molecular size and physical properties such as relative volatility. Based on the principle of solubility and diffusivity, alternatives for improved separation with energy reduction are being attempted. Also, separation based on molecular size difference is being explored to improve the propylene recovery as well as alleviate the high energy consumption. The present work reports an energy reduction, and a loss minimization achieved after implementation of the research outcome in the propylene fractionator (PF) located in the cracker complex of an industrial zone in India. At the cracker plant, the conventional PF operating at higher pressure (18 kg/cm2g) is used to produce Polymer grade Propylene. At the feed purification unit (FPU), the heat pump‐vapor recompression column operates at low pressure (10 kg/cm2g). This column is used to upgrade chemical‐grade propylene to polymer grade propylene. Process simulation with different scenarios has been developed for both the separation systems in Aspen Plus. Based on detailed study and adopted strategies, the energy consumption significantly reduced by 68% at FPU and waste heat utilization increased at PF column. Also, propylene losses were minimized after adopting the innovative concept of heat integration in both the separation units. The significant operational improvement for energy reduction up to 70% and product recovery up to 3% with enhanced safety achieved without major modification and cost at the industrial operation, reported in this work. [ABSTRACT FROM AUTHOR]