聚酯生产中低温酯化和洁净真空工艺研究

Research on low temperature esterification and clean vacuum process in polyester production

为了使聚酯生产能够更加节能,降低单耗增收效益,本文对一种低温酯化和洁净真空缩聚反应工艺进行研究。由于缩聚系统中后缩比前缩对真空要求更高,因此,将缩聚系统的液封槽采出,并采用EG逐级向前置换,减少前聚新鲜EG置换量,增多后聚EG的置换量。在不影响总系统EG平衡的前提下,降低各级缩聚系统的EG含水量,并将采出置换的EG全部先送入工艺塔提纯后再送到配浆EG罐。此方法可使各缩聚反应系统和酯化反应系统的EG含水量降低到一个理想需求值,具有一定的推广价值。

In order to make polyester production more energy-efficient,reduce unit consumption,and increase revenue,this article studies a low-temperature esterification and clean vacuum polycondensation reaction process.Due to the higher vacuum requirements of the post polymerization system compared to the pre polymerization system,the liquid seal tank of the condensation system is extracted and EG is gradually replaced forward to reduce the replacement amount of fresh EG in the pre polymerization and increase the replacement amount of post polymerization EG.On the premise of not affecting the overall system EG balance,reduce the water content of EG in each stage of the polycondensation system,and first send all the replaced EG to the process tower for purification before sending it to the slurry EG tank.This method can reduce the water content of EG in various polycondensation and esterification reaction systems to an ideal demand value,which has certain promotional value.