Patent ID: 7407643

Claim:
A process for the removal of water from a mixture comprising water and zinc chloride, which comprises adding to said mixture comprising water and zinc chloride an aprotic, polar diluent whose boiling point in the case where an azeotrope is not formed between said diluent and water is higher than the boiling point of water and which is in liquid form at this boiling point of water or which forms an azeotrope or heteroazeotrope with water, and distilling the mixture comprising water, zinc chloride and the diluent with removal of water or said azeotrope or said heteroazeotrope from this mixture, giving an anhydrous mixture comprising zinc chloride and said diluent, wherein the aprotic, polar diluent employed is an aliphatic, olefinically unsaturated nitrile selected from the group consisting of 2-cis-pentenenitrile, 2-trans-pentenenitrile, 3-cis-pentenenitrile, 3-trans-pentenenitrile, 4-pentenenitrile, E-2-methyl-2-butenenitrile, Z-2-methyl-2-butenenitrile, 2-methyl- 3 -butenenitrile or a mixture thereof.