Sugaring-out separation of acetonitrile from its aqueous solution

The separation of acetonitrile (ACN) from an ACN-water azeotrope is of particular interest to industrial chemists and process engineers. In the work reported in this article, sugaring-out, a new phase separation method is reported and used to obtain high purity ACN from an ACN-water mixture. With the addition of a mono-sugar (glucose, xylose, arabinose or fructose) or a disaccharide (sucrose or maltose) into an ACN-water mixture, a phase separation is observed if the sugar concentration exceeds a threshold. The upper phase is rich in ACN while the lower phase is rich in water. The ACN concentration in the upper phase increases when more sugar is added into the ACN-water mixture. When the glucose concentration is > 35 g/L, the ACN concentration in the upper phase is > 40%. In the Sudan I extraction test with a glucose-triggered two-phase system, an extraction rate of > 80% is achieved when the glucose concentration is greater than 25 g/L.