Dehydration of 1-butanol with deep eutectic solvent by liquid-liquid extraction

Considering the separation of 1-butanol and water, extraction has received increasing attention due to the advantages of easy operation and low energy consumption. In this work, deep eutectic solvents (DESs) were introduced as hydrophilic solvents for 1-butanol dehydration. COSMO-SAC model was employed for DESs screening and choline chloride – urea 1:2 DES (reline) was selected as the corresponding solvent. Via various quantum chemical methods, hydrogen bonds were proved to be the main molecular interactions, wherein a stronger interaction in water + reline was the fundamental for achieving the 1-butanol dehydration. Liquid-liquid equilibria were measured at three temperatures and the results indicated reline had an excellent separation performance especially under conditions of lower temperature or lower water content. Furthermore, NRTL model was used to correlate experimental data to obtain binary parameters, and the extraction process was simulated. By the investigation of operation parameters, 1-butan...