The
use of ionic liquids (ILs) in the biorefinery process has been
increasing for the past few decades. In biorefinery, the separation
process with respect to sugars needs to be evaluated for an efficient
process design. Therefore, the present work aims to investigate the
separation of sugars and ILs by means of a precipitation process using
an antisolvent method. For this purpose, both theoretical and experimental
studies were conducted. Initially, the conductor-like screening model
for real solvents model was employed to screen the suitable antisolvents
for the separation of sugars from the ILs. From the screening study,
dichloromethane (DCM) and 1,2-dichloroethane were found to be the
better antisolvents for the separation process. With the selected
antisolvents, precipitation experiments were conducted for the mixtures
involving four different sugars and three ILs at different experimental
conditions. The process variables such as different antisolvents,
sugars, ILs, antisolvent–IL molar ratios, and temperatures
were examined in terms of their effect on sugar removal and IL recovery.
DCM was found to be the most suitable antisolvent in this study with
90–99% of sugar removal and 80–98% of IL recovery. Further,
molecular dynamics simulations were adopted to understand the structural
properties of carbohydrates with ILs and antisolvents via interaction
energies, hydrogen bonding, and coordination numbers. It was observed
that the interaction energy between the sugars and IL plays a critical
role in the removal of sugar. Higher the interaction energy between
the sugars and IL, lower is the sugar removal.