PVC生产中氯乙烯精馏系统的研究及工业优化

Optimal design of vinyl chloride distillation system in PVC production

研究分析了氯乙烯单体质量分数对聚氯乙烯树脂质量的影响,指出了传统氯乙烯精馏系统存在的不足,通过改善塔设备回流方式,提高低沸塔、高沸塔操作压力,增加高沸物回收装置,以及更换分离效率较高的塔内件实现精馏生产过程的最优化。研究结果表明,优化后氯乙烯单体中乙炔等低沸物质量分数由1×10^(-5)降至0~1×10^(-6),二氯乙烷等高沸物质量分数由3×10^(-5)降至0~3×10^(-6),单体质量分数由99.95%提高到99.999%,高、低沸塔精馏改造共节约操作费用3 472.1万元/a,高沸物回收增加经济效益583.98万元/a。

The effect of the purity of vinyl chloride（ VCM） monomer on the quality of poly（ vinyl chloride） resin has been summarized. The shortage of the traditional VCM distillation system is pointed out. By changing the refluxing mode,increasing the operating pressure of low boiling tower and high boiling tower,adding recycling equipment for highboiling residue and replacing the tower internals,a systematically optimal design is proposed. After simulation and optimization,the content of low-boiling residues has dropped from 1 × 10^-5 to 0- 1 × 10^-6,and the content of highboiling residues has decreased to from 30 × 10^-5 to 0- 3 × 10^-6. The purity of VCM has increased from 99. 95% to99. 999%. The transformation of high-boiling and low-boiling tower is expected to save 34. 71 million Yuan per year,and the high-boiling residues recycle system is expected to bring benefit of 5. 83 million Yuan per year.