环己酮生产中的环己烷三效精馏节能优化

Energy saving optimization of cyclohexane three-effect distillation in cyclohexanone production

针对某6万吨/年环己酮装置工艺特点,采用Aspen plus模拟软件及NRTL物性方法,建立了环己烷氧化产物三效精馏全流程计算模型并进行了数据优化。以烷一塔、烷二塔、烷三塔塔顶馏出物醇酮含量、外送热冷烷量为约束条件,对各精馏塔回流量、烷一塔和烷二塔回流量比值、烷三塔回流量、蒸汽消耗量等变量进行优化,将优化的工艺参数用于实际生产装置的节能优化。结果表明:在烷一塔、烷二塔回流量总和8.02kg/s、烷一塔及烷二塔回流量比值0.67、烷三塔回流量17.93kg/s的条件下,理论上蒸气消耗可从5.53kg/s降至3.9kg/s,实际优化结果发现可节约蒸气0.28kg/s,节约年运行成本约144万元。

According to the process characteristics of a 60kt/a cyclohexanone unit,the whole process calculation model of three-effect distillation of cyclohexane oxidation product separation system was established by using Aspen plus simulation software and NRTL physical property method,and the data were optimized.Taking the cyclohexanone and cyclohexanol content of overhead distillates of 1st alkane tower,2nd alkane tower,3rd alkane tower and the amount of hot/cold cyclohexane sent out as constraints,the variables such as reflux of each distillation tower,reflux ratio of 1st alkane tower and 2nd alkane tower,reflux of alkane 3rd tower and steam consumption were optimized,and the optimized process parameters were applied to the energy-saving optimization of actual production units.The results showed that the steam consumption can be reduced from 5.53kg/s to 3.9kg/s theoretically under the condition of 8.02kg/s total reflux of 1st alkane tower and 2nd alkane tower,0.67 reflux ratio of 1st alkane tower and 2nd alkane tower,and 17.93kg/s reflux of 3rd alkane tower.The actual optimization results showed that 0.28kg/s steam could be reduced and the annual operation cost could be reduced by about 1.44 million yuan.