Recovery of acetonitrile from aqueous waste by a combined process: Solvent extraction and batch distillation

Separation of azeotropic mixtures is a task usually encountered in the fine chemicals industry. Solvent extraction can be an attractive alternative when distillation is not a cost-effective option. In this paper, a systematic study for the separation of the acetonitrile–water mixture by using a combined process is performed. First, separation of acetonitrile from the binary original mixture is carry out by crosscurrent liquid extraction process. The adequate extractive agent was chosen taking into account the distribution coefficient determined from activity coefficient at infinite dilution. Then, the recovery of acetonitrile from the solvent-rich phase is studied by batch distillation. The feasibility of the proposed flowsheet was first validated via simulation by using the commercial software SuperPro Designer and ProSim Batch. Finally, the operating conditions obtained by simulation were corroborated in an experimental bench installation and an adequate agreement was obtained between calculated and experimental values.