Simulation of Hydroperoxide Process for the Production of Propylene Oxide

Propylene Oxide, also known as Epoxypropane is one of the significant organic compounds produced in chemical industries. Propylene Oxide finds major application in the production of polyether polyols and along with diisocyanates is used to produce polyurethanes. Traditional production methods involve Chlorohydrin process which is slowly replaced by other processes because of large disposal problems. Major alternative production routes include Hydroperoxide process, Cumene process etc. The present work is focussed on process development for production of Propylene Oxide using Hydroperoxide process. Hydroperoxide process is based on the peroxidation of Ethylbenzene to Ethylbenzene hydroperoxide which in turn reacts with Propylene producing Propylene Oxide and alcohol. Kinetic data and operating conditions for the main reactions, namely peroxidation and epoxidation were obtained from available literature. A spreadsheet tool was developed to perform material and energy balance of the process without recycle operation. Basis for the process was chosen as 100 kmol/h. Multicomponent distillation column was designed using Fenske-Underwood-Gilliland correlations. Adiabatic plug flow reactor for epoxidation reaction was also designed considering the reaction as first order gas phase irreversible exothermic reaction. Simultaneous ODEs were solved in Scilab 5.5.1 for designing the reactor. Further, the entire process flowsheet was also simulated using Aspen Plus (V8.6, Aspen Tech, Inc., USA) and the results obtained were compared with that of spreadsheet appropriately. Aspen Plus was also used to collect thermophysical properties of components involved and to decide the operating conditions for the process specifically for flash drum and distillation column. Assuming 1 % entrainment from equipment, effluent treatment analysis was carried out and environmental factor (E factor) was computed and compared to a typical petrochemical industry.