Modified Rackett equation for modelling the molar volume of deep eutectic solvents

• The basic Rackett assumption does not hold for the case of DES densities.
• The original Rackett density model was modified and its parameters identified.
• The new model attained more than 50% improvement in standard deviation.

Deep eutectic solvents are emerging as potential substitutes for ionic liquids in many chemical and engineering applications. The characterization of physico-chemical properties of these fluids is of high importance for process design and equipment sizing. Despite the few attempts in this area, the huge variety of DES types and structures necessitate the development of models with high prediction quality for calculating their basic physical properties. In this work, molar volume data for common types of DESs was collected as a function of temperature. The Racket model was analyzed and modified to be suitable for DES applications. A modified model was tested and validated with the experimental molar volume DES data. An average percentage deviation of 0.211% was attained. This is about one third the deviation achieved when using the Rackett original model. The newly developed model, can be utilized for predicting molar volume and density in process simulators calculations as well as during the design and operation stages of processes involving the use of DES.