电石法生产PVA回收六塔及七塔技术改造  

Technical renovation for recovery columnⅥ and Ⅶ of a PVA producing plant using calcium carbide process

作　　者：孙雪婷 欧阳志 SUN Xue-ting;OUYANG Zhi(Beijing Xianfeng Innovation Technology Development Co.,Ltd.,Beijing 100020,China;Inner Mongolia Shuangxin Environment-Friendly Material Co.,Ltd.,Erdos 016064,Inner Mongolia,China)

机构地区：[1]北京先锋创新科技发展有限公司,北京100020 [2]内蒙古双欣环保材料股份有限公司,内蒙古鄂尔多斯016064

出　　处：《化学工程》2022年第9期74-78,共5页Chemical Engineering(China)

摘　　要：内蒙古某一公司回收车间回收六塔是原采用醋酸异丙酯作为共沸剂的共沸精馏塔,回收七塔为共沸剂回收塔,从来自上游的稀醋酸中分离和精制出醋酸。为降低回收六塔共沸剂循环量、回收七塔塔釜废水中共沸剂的含量及能耗,同时提高装置产能,现对回收六塔和回收七塔进行技术改造,将共沸剂更换为携带水分能力更强的醋酸正丁酯,增加回收七塔塔釜再沸器,增加回收七塔塔顶回流,同时将回收六塔和回收七塔的普通筛板更换为高效导向筛板等。技术改造后,每单位醋酸产品的共沸剂循环量、共沸剂损耗量和蒸汽消耗量分别降低了66%、22%和35.5%;回收七塔塔釜废水中醋酸正丁酯质量分数低于5×10^(-4),整体技改效果明显。The recovery columnⅥin PVA recycling unit of a company in Inner Mongolia was designed as an azeotropic distillation column using isopropyl acetate as the azeotropic agent.The function of recovery columnⅦin this unit was to recover the azeotropic agent.The recovery columnⅥandⅦwere used to separate and refine the acetic acid from dilute acetic acid.In order to reduce the azeotropic agent circulation rate of the recovery columnⅥ,reduce the mass concentration of the azeotropic agent in recovery columnⅦbottom,reduce the energy consumption,and improve the processing capacity of the two columns at the same time,serial technical renovations were performed for the two columns.The azeotropic agent was replaced with n-butyl acetate which had a much better performance in carrying water.Reboiler and reflux for recovery columnⅦwere added.The plates of the two columns were also changed to high-efficiency guiding sieve plates.After technical renovation,the azeotropic agent circulation rate,the loss rate of azeotropic agent,and steam consumption rate per ton of acetic acid product dropped 66%,22%and 35.5%,respectively.The mass concentration of n-butyl acetate in recovery columnⅦbottom is lower than 5×10^(-4).It can be seen that the effect of this technical renovation is very successful.

关 键 词：醋酸 醋酸异丙酯 醋酸正丁酯 共沸精馏 节能 

分 类 号：TQ208[化学工程—有机化工]