Adsorptive separation of liquid water/acetonitrile mixtures

Twenty-nine adsorbents of different adsorbent classes, compromising zeolites, activated carbon, silicagel and metal–organic frameworks (MOF) were tested in batch adsorption experiments with liquid water/acetonitrile mixtures. Their performance in the selective separation of water from acetonitrile (ACN) was evaluated by analyzing these experimental batch isotherm data with a breakthrough model. Water isotherms (296 K) and diffusion coefficients of both water and ACN are presented for promising adsorbents. 4A zeolite was identified as a suitable adsorbent; it allowed successful fixed bed adsorption column separation of liquid water/acetonitrile mixtures with water contents up to 40 wt.%. The breakthrough curves were compared to numerical and analytical models for fixed bed adsorption, using independently determined diffusion and adsorption equilibrium parameters.

► Adsorption of water from liquid water/acetonitrile mixtures.
► Screening of 29 adsorbents.
► Kinetics study for water adsorption on 4A and 13X.
► Breakthrough modeling with velocity variation.