可溶酸液相合成法三聚甲醛制备的工艺管理

Process Management of Synthesise of Trioxymethylene from Soluble Acid Solution

可溶酸液相合成法制备三聚甲醛工艺是目前研究时间长、工艺比较成熟、应用较为广泛的一项工艺路线。三聚甲醛、甲醛和水可形成共沸物,因此加入萃取剂进行萃取精馏是传统的工艺。该工艺包括甲醛浓缩工序、三聚甲醛合成工序、三聚甲醛萃取精馏工序、稀甲醛回收工序。甲醛在硫酸催化剂的催化条件下生成的三聚甲醛浓度2%~4%,浓度较低,且伴有副反应发生,需要进一步的提纯。三聚甲醛作为聚甲醛生产过程的重要中间单体,其品质非常重要。水、甲酸、甲醇等杂质影响聚合反应,因此在三聚甲醛合成精制过程中,控制上述三者的浓度在三聚甲醛产品的品质管理中是重中之重。同时在该工艺中存在管线设备阻塞、腐蚀和反应液白浊等影响连续生产的因素,必须做好工艺控制。

The process of synthesise trioxymethylene from soluble acid is a process which has been studied for a long time,mature and widely used.The azeotrope can be formed by trioxymethylene,formaldehyde and water,so adding extractant for extractive distillation is a traditional process.The process includes formaldehyde concentration process,trioxymethylene synthesis process,trioxymethylene extraction distillation process,dilute formaldehyde recovery process.Formaldehyde in sulfuric acid catalyst under the catalytic conditions of the formation of the concentration of 2%-4% of trioxymethylene,it’s low concentration,and accompanied by side reactions,so it need to be further purification.As an important intermediate monomer in the production of polyformaldehyde,the quality of trioxymethylene is very important.Water,formic acid,methanol and other impurities affect the polymerization reaction,so in the process of trioxymethylene synthesis refining,the control of the concentration of the above three in the quality management of trioxymethylene products is the most important.At the same time,there are some factors affecting the continuous production,such as blockage of pipeline equipment,corrosion and turbidity of reaction liquid,which must be controlled well.