PTA装置醋酸异丁酯回收塔的改造

介绍回收塔的改造及其效果。增加塔径、塔高,采用高效填料,增加再沸器加热回收冷凝水,将塔顶改为强制回流,塔温与再沸器流量和塔顶回流量串级控制,重新核算灵敏板等。改造后塔温平稳,塔顶醋酸甲酯采出纯度为94%,水质量分数平均小于3%,醋酸异丁酯质量分数小于0.3%,单耗由2.1kg降为1.9kg,塔底COD降为3500mg/L。

Modification of isobutyl acetate recovery column in PTA unit

The modification of the recovery column and its effect were introduced.The column diameter and column height were increased,the high performance stuffing was used, the heating recovery condensed water in re-ebullator was increased,the back flow type at the top of the column was changed into the forced reflux,the column temperature,the re-ebullator flow and the back flow at the top of the column was concatenate controlled,the sensitive plate was reaccount.After modification,the column temperature is steady,the collected purity of methyl acetate at the top of column is 94%,the average mass fraction of water is less than 3%,the mass fraction of isobutyl acetate is less than 0.3%,the unit consumption is reduced from 2.1 kg to 1.9 kg,the COD at the bottom of the column is decreased to 3 500 mg/L.