用于从N-甲基吗啉-N-氧化物，N-甲基吗啉，吗啉或它们的混合物的稀释的水溶液中分离水的混合物，以及任选的整理剂，将溶液根据本发明压入反渗透单元通过半透膜。 富集的材料吗啉和N-甲基吗啉可以以已知的方式，以N-甲基-N-氧化物进行转换。 在纤维素处理使用这种方法时，即当NMMO过程，所获得的织物可以循环使用，这取决于在该过程，由此两个物理和化学损失大大降低的浓度，使得环境负担降低，效率提高。

For separating water from a diluted aqueous solution of N-methylmorpholine-N-oxide, N-methylmorpholine, morpholine or mixtures thereof, and optionally finishing agent, the solution is pressed into a reverse osmosis unit through a semipermeable membrane according to the invention. The enriched substances morpholine and N-methylmorpholine can be reacted in known manner to form N-methylmorpholine -N-oxide. Using this method in cellulose processing, namely the NMMO process, the materials obtained can be recycled, depending on concentration in the process, thereby both physical and chemical losses are greatly reduced, so that the environmental impact is reduced and efficiency is increased.