对位芳纶生产中溶剂精制工艺的优化与控制

Optimization and control of solvent purification process for para-aramid fiber production

在聚对苯二甲酰对苯二胺(PPTA)纤维生产中,以N-甲基吡咯烷酮(NMP)和氯化钙(CaCl_2)的混合液为溶剂,溶剂精制系统是生产工艺流程中重要的操作单元,探讨了溶剂精制工艺中主要的控制参数,以及精制溶剂质量对PPTA黏度的影响。结果表明:通过对进料温度、真空度、精制塔釜温度、回流比等主要工艺参数的优化控制,得到的精制溶剂含水量小于等于120μg/g,CaCl_2质量分数为7%~8%,可以满足PPTA聚合反应要求。

The solvent purification unit using the mixture solution of N-methy-2-pyrrolidone（ NMP） and calcium chloride（ CaCl2） as the solvents is an important operation unit for the production of poly-p-phenylene terephthamide（ PPTA） fiber. The dominant control parameters were discussed for the solvent purification process,as was the effect of the quality of the purified solvent on the viscosity of PPTA. The results showed that the purified solvent could satisfy the requirement of PPTA polymerization reaction with the water content not higher than 120 μg/g and 7%-8% CaCl2 by mass fraction through the control optimization of the main process parameters,such as feeding temperature,vacuum degree,purification tower temperature,reflux ratio.