The invention relates to a method for the recovery of dichloromethane in the B7 section of pyridine hydrochloride, which includes the following steps: A. makes the crude dichloromethane and water fully reacted and washed in the stratified tower; the upper part of the B. stratified tower is dichloromethane in the lower part of the water phase, and dichloromethane is extracted into the reservoir to be neutralized, and the alkaline wastewater in the upper layer of the stratified tower is discharged to the sewage pool. C. pumps dichloromethane to neutralizing kettle and neutralizes it to pH value 8; D. is stirred to statically stratify, and the lower pure dichloromethane is divided into dichloromethane storage tank. The advantage of the invention is that the recovery efficiency is greatly improved by using a layered tower than in the kettle recovery. The original dichloromethane is directly added to the liquid base to consume a large amount of liquid base, and the mixture of water and dichloromethane is used to wash the liquid alkali, and the use of the liquid alkali is greatly reduced. At the same time, the installation of rotator flowmeter is more convenient for process operation, convenient for process monitoring, and increase the safety of operation.
【技术实现步骤摘要】
吡啶盐酸盐B7工段二氯甲烷的回收方法
:本专利技术涉及一种原料药的制备方法,特别涉及一种吡啶盐酸盐生产中B7工段二氯甲烷的回收方法。
技术介绍
:吡啶盐酸盐是生产胃药泮托拉唑的原料药,全称2-氯甲基-3,4-二甲氧基吡啶盐酸盐。吡啶盐酸盐的生产,现国内外的生产厂家主要采用甲基麦芽酚经过甲酯化、氨化、氯化、氧化、醇化、酐化以及成盐精制工段,生产过程为甲基麦芽酚经过硫酸二甲脂,酯化后通氨水氨化,再加入三氯氧磷氯化,再滴加双氧水氧化,加入甲醇醇化,加入醋酐酐化,加入氯化亚砜成盐后加入无水乙醇精制即可的成品。本专利技术涉及的是其中的B7成盐工段,其反应原理为:反应完成后要减压回收多余的二氯甲烷溶剂,因反应有剩余的氯化亚砜混合在二氯甲烷当中,所以回收的二氯甲烷不能直接使用,需经过纯化去除里面的其他杂质方能使用,原先处理方法为,预先在反应釜中加入氢氧化钠溶液,然后向釜内缓慢滴加减压回收的混有少量氯化亚砜的二氯甲烷,因反应过程中剧烈发烟,所以整个滴加过程需带尾气,尾气引至B7工段尾气处理塔处理。滴加完成充分搅拌后静置一个小时,分出纯净的二氯甲烷储存待用。因为此种回收方法全程带尾 ...
【技术保护点】
吡啶盐酸盐B7工段二氯甲烷的回收方法,其特征在于包括如下步骤:a.将上工段得到的粗品二氯甲烷从分层塔上部加入,同时开启打料泵向分层塔下部进水,使粗品二氯甲烷和水在分层塔内充分反应洗涤;b. 洗涤过程动态稳定后,分层塔上部为水相下部为二氯甲烷相,开启分层塔塔底阀门,采出的酸性二氯甲烷进入储槽待中和,分层塔上层碱性废水排至污水池;C.当酸性二氯甲烷储槽采出到一定量时,开启打料泵把酸性二氯甲烷泵至中和釜,加入液碱进行中和反应,调至PH值为8即可;d.充分搅拌静置一个小时后,进行分层,将下层纯净的二氯甲烷分至纯品二氯甲烷储槽待用。
【技术特征摘要】
1.吡啶盐酸盐B7工段二氯甲烷的回收方法,其特征在于包括如下步骤:a.将上工段得到的粗品二氯甲烷从分层塔上部加入,同时开启打料泵向分层塔下部进水,使粗品二氯甲烷和水在分层塔内充分反应洗涤;b.洗涤过程动态稳定后,分层塔上部为水相下部为二氯甲烷相,开启分层塔塔底阀门...
【专利技术属性】
技术研发人员:许传久,陈永旭,郭佳佳,
申请(专利权)人:安徽金禾实业股份有限公司,
类型:发明
国别省市:安徽,34
还没有人留言评论。发表了对其他浏览者有用的留言会获得科技券。