The invention relates to a technology for recovering NMP (N-methyl pyrrolidone)
waste gas in
lithium battery production with a membrane
separation method and belongs to the technical field of organicwaste gas
recovery. The technology comprises steps as follows: NMP
waste gas in a
lithium battery
pole piece drying box is fed into an absorption
tower by blast apparatus and absorbed by utilizing water as a
solvent, NMP
effluent is formed at the bottom of the absorption
tower and enters a porous
ceramic filtering membrane separator through a
circulating pump, NMP and water penetrate through a porous
ceramic filtering membrane under the action of
pressure difference before and after NMP and water penetrate through the porous
ceramic filtering membrane, an NMP-water
clear liquid is formed on the rear side of the porous ceramic filtering membrane, and an intercepted liquid returns to a circulating tank; the NMP-water
clear liquid is stored in a
clear liquid tank and enters a heater for heating under the action of a
feed pump; when the heated clear liquid passes through a
pervaporation membrane, water penetrates through the membrane while NMP is intercepted, and accordingly, NMP and waterare separated. The
operating temperature is lower than the
boiling point of an NMP recovered liquid in the
recovery process, recovered NMP does not need high temperature and negative pressure and haslow probability of producing new impurities,
energy consumption is low, operation is simple, and the technology is a green NMP
waste gas recovery technology.