Simultaneous optimization of the feed location and thermodynamic feed conditions for a distillation column based on column grand composite curves
LIU Xuegang, ZHANG Bingjian, CHEN Qinglin
Guangdong Engineering Technology Research Center for Petrochemical Energy Conservation, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China
Abstract：The study used the column grand composite curve (CGCC) method to simultaneously optimize the feed location and feed conditions for a distillation column to reduce the total utility costs. The CGCC method based on the near-minimum thermodynamic condition (PNMTC) can be decomposed into two theoretical curves for the overall rectifying and overall stripping curves. The intersection point O of the two theoretical curves is not only the ideal feed point, but also the partitioning point for the amount of feed preheating. The total cost of the cold and hot utilities is used as the objective function to optimize the feed preheating and to identify the intersection point location O. The optimal feed location in the distillation column is then found using the enthalpy difference, ΔHn, def, between the intersection point and the actual feed point. The feed location and the feed conditions are then optimized using the CGCC curves. A benzene and toluene column was used to evaluate the accuracy of this graphic method. The maximum savings for the cold and hot utilities is about 1.24 RMB/h. The feed preheating is 1.98 MW and the enthalpy difference, ΔHn, def, is 0.038 MW. The optimal feed location is the 21th stage. The CGCC results compare well with Aspen Plus results with differences only 1%-3%.
刘雪刚, 张冰剑, 陈清林. 基于分馏塔总组合曲线进料位置与进料状态的同步优化[J]. 清华大学学报（自然科学版）, 2016, 56(7): 700-706.
LIU Xuegang, ZHANG Bingjian, CHEN Qinglin. Simultaneous optimization of the feed location and thermodynamic feed conditions for a distillation column based on column grand composite curves. Journal of Tsinghua University(Science and Technology), 2016, 56(7): 700-706.
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2016, Vol. 56 
