Method of Recovering Aqueous N-methylmorpholine-N-Oxide Solution Used in Production of Lyocell Fiber

摘要

A method of recovering an aqueous N-methylmorpholine-N-oxide (NMMO) solution used in production of Lyocell fiber includes: decoloring the aqueous NMMO solution by mixing the same with activated carbon using an agitation blower and by alternately energizing and de-energizing the agitation blower to contact the activated carbon with the aqueous NMMO solution thoroughly in an energy-efficient manner; filtering the aqueous NMMO solution which has been decolored through coarse filtration followed by ultrafiltration to remove the activated carbon and impurities from the aqueous NMMO solution; and concentrating the aqueous NMMO solution which has been filtered using one of a mechanical vapor recompression evaporator and a triple effect evaporator to remove water from the aqueous NMMO solution.