NMP purification system

workmanship：Using the NMP waste liquid generated by the NMP recovery system as the raw material, a dual tower continuous purification process with gas-phase feed is adopted based on the types and composition characteristics of impurities in the waste liquid. The waste liquid is filtered to remove trace solid impurities, distilled to remove water, refined to remove heavy impurities, and other steps to obtain the finished product.

Process principle：By utilizing the difference in volatility between NMP and water, the waste liquid is heated and partially vaporized in the purification tower. Due to the higher volatility of water compared to NMP, the moisture concentration in the gas phase is higher than that in the liquid phase. Similarly, when the waste liquid vapor partially condenses in the purification tower, the concentration of NMP in the liquid phase is higher than that in the gas phase. After multiple partial vaporization and condensation in the purification tower, the water concentration in the gas phase is much higher than that of NMP, while the NMP concentration in the liquid phase is much higher than that of water. Finally, high concentration liquid phase NMP is obtained at the bottom of the purification tower, and high concentration gas phase water is obtained at the top of the purification tower, thereby achieving the separation of NMP and water.