高纯乙腈提纯精制工艺节能优化方案

Energy saving optimization scheme of high-purity acetonitrile production process

针对丙烯氨氧化法生产丙烯腈副产乙腈工艺中,存在的乙腈产品纯度不稳定,设备易堵塞等问题,进行了原因分析和优化改造。简述了乙腈的主要工业生产工艺,分析了乙腈产品纯度不稳定、吨产品能耗高及设备易聚易堵的原因,通过优化换热网络,对原乙腈提纯精制工艺进行适当的工艺、管线及设备优化,使乙腈产品的纯度可稳定达到99.9%以上;吨乙腈产品0.5 MPa(G)蒸汽耗量减少3.0 t左右,循环水耗量减少160 t左右;并通过在易聚易堵点位添加阻聚剂,在一定程度上缓解了装置堵塞的问题。

In the process of acrylonitrile production by the propylene ammoxidation with acetonitrile as byproduct, there were problems of unstable product purity and easy equipment blockage, and the cause analysis and optimization renovation were carried out. The main industrial production process of acetonitrile was described, and the analysis was made on factors of unstable product purity, high energy consumption per ton of product, easy polymerization and blockage of equipment. By improving the heat exchange network and properly optimizing the process, piping and equipment of the existing acetonitrile purification process, the purity of acetonitrile product could reach more than 99.9%, 0.5 MPa(G) steam consumption per ton of acetonitrile product could be reduced by about 3.0 t, and the circulating water consumption could be reduced by about 160 t.At the same time, the problem of the plant blockage was alleviated to certain extent by adding the polymerization inhibitor at the location where the polymerization and blockage would occur easily.