Patent ID: 7862744

Claim:
A method for isolating N,N-dimethylformamide (â€œDMFâ€) from a composition comprising DMF, water, and methanol, comprising: introducing a composition comprising DMF, water, and methanol into a single-tower separation system, the single tower separation system comprising a lower section and an upper section, and the composition being introduced into the lower section; heating the composition; isolating DMF from the composition; drying the isolated DMF, whereby a substantially pure DMF is produced; and the heating of the composition comprising the steps of: reducing the pressure of the separation system by using a vacuum system; maintaining the temperatures of the lower section at about 25-45Â° C., whereby methanol is substantially removed from the composition; and maintaining the temperatures of the lower section at about 45-75Â° C., whereby water is substantially removed from the composition.