Method and device for separating methylamine from methylamine-containing reaction sewage and application of method and device to ephedrine and pseudoephedrine production process

The invention provides a method and a device for separating methylamine from methylamine-containing reaction sewage and application of the method and the device to the ephedrine and pseudoephedrine production process. The method comprises the following steps: heating the methylamine sewage by means of phased temperature rise, enabling the methylamine steam and the water vapor to exchange heat and separate in a packed distillation column, enabling the methylamine steam to be separated from the water vapor and flow out, entering a cooler, and condensing into liquid methylamine. According to the method and the device, methylamine in the methylamine sewage is fully recovered, reused and recycled, and moreover, the nitrogen content of the sewage with methylamine recycled is enabled to meet the national second sewage discharge standard. 本发明提供了种从含有甲胺的反应废水中分离甲胺的方法和装置及在麻黄碱和伪麻黄碱生产工艺中的应用，所述方法包括以下步骤：通过阶段性升温的方式加热甲胺废水，使甲胺蒸气和水蒸汽在填料精馏塔内进行热交换和分离，甲胺蒸气脱离水分子并逸出，进入冷却器后凝结成液态甲胺。本发明提供的方法和装置可以将甲胺废水中的甲胺全部回收套用并循环使用，同时可以确保回收甲胺之后的废水的氨氮含量