旋转填料床精馏五亚甲基二异氰酸酯的应用研究

Purification of pentamethylene diisocyanate in a rotating packed bed

采用旋转填料床(RPB)分离纯化五亚甲基二异氰酸酯(PDI),得到了高含量、低水解氯、低色度的PDI单体。考察了再沸器温度、超重力因子(β)和回流比对PDI含量和收率、水解氯含量的影响。结果表明,在再沸器温度为100℃、操作压力为150 Pa、β值为400、回流比为4的条件下,RPB的分离性能最佳;PDI含量高达99.9%,收率为86.5%,水解氯可降至52 mg/L,色度10 APHA。与常规精馏塔相比,PDI含量提高了0.3%,收率提高了8.9%,分离时间缩短了50%,RPB适用于工业化制备高质量的PDI。

Crude pentamethylene diisocyanate(PDI)is purified in a rotating packed bed(RPB)to obtain PDI monomer with high purity,low hydrolyzed chlorine content and low chroma.The effects of reboiler temperature,high gravity factor(β)and reflux ratio on PDI purity,hydrolyzed chlorine content and yield are investigated.It is found that RPB shows the best separation performance when reboiler temperature is 100℃,the operating pressure is 150 Pa,βis 400 and reflux ratio is 4.Meanwhile,the purity of PDI product is as high as 99.9%,the yield is 86.5%,the content of hydrolyzable chlorine drops to 52 ppm and the chroma is 10 APHA.Compared with that in a conventional distillation column,the purity of PDI product increases by 0.3%,the yield is 8.9%higher and the separation time is shortened by 50%.RPB shows more suitable for industrial purification of PDI.