Patent ID: 8519157
Filing Date: 2013-08-27
Classification: C07D

Abstract:
1. A method for producing N-methyl pyrrolidone, comprising: feeding methylamine into N-methyl pyrrolidone to react for about 0.5 to 1.5 hours at temperatures of 5 to 20° C., and the N-methyl pyrrolidone is dehydrated by passing through a 4A molecular sieve with a velocity of flow of 5 to 7 L/min; providing complex composite membranes with aperture of 0.1 to 0.2 μm as filter membranes to carry out two membrane filtrations, filtrate is rectified at a pressure of 20 to 80 KPa, and fractions of 80 to 120° C. are collected from a top of a rectifying tower; the fraction is filtered third through microporous film to get a target product.