Recycle optimization of an ethylene oxide production process based on the integration of heat exchanger network and reactor

Abstract

Ethylene oxide is an essential product with increasing demand and its production consumes a large amount of energy. For a practical ethylene oxide production process, the recycle of the reaction block is studied as it influences the reactor, the Heat Exchanger Network (HEN) and the profit of the process, and could be adjusted easily and efficiently. The recycle optimization of a practical EO production process is studied based on the integration of HEN and reactor. On the basis of the kinetic and thermodynamic equilibrium, relations among the recycle ratio, outlet temperature and the removed heat of the reactor are deduced. With both HEN and the reactor considered, the integration model is built, and an economic analysis diagram is developed to illustrate the variation of revenue and cost along the recycle ratio; the optimal recycle ratio is identified to be 1.7, the maximum annual profit is 8.4% more than the current value, the recovered energy increases by 29.8% and no other equipment or process changes required.