Abstract: The rectification process with double tower for separating industrial grade n-hexane from hydrogenated raffinate oil was simulated by selecting BK10 model in Aspen Plus software. Firstly, the production process under full load was simulated, and the results are compared with the practical operation data. The relative errors of these two were less than 5%, which verified the parameters selected were reasonable, such as HETP, the column efficiency and model. Secondly, the optimized process conditions were obtained by analyzing the effect of operation pressure, reflux temperature, feed position and the heat conditions of feed on the process energy consumption, and then countermeasures for revamping were proposed. Finally, according to the characteristics of the system, an energy-saving program with backward-feed double-effect distillation and heat-integration was proposed. The hydraulic calculation results confirmed the technical feasibility of this program, and the process simulation results show that adopting this proposal, a 53.1% reduction in operation cost might be obtained, i.e. a cost saving of 3.009 Million RMB annually.

Key words: Hydrogenation raffinate oil, N-hexane, Double-effect distillation, Energy-saving, Simulation