Ionic
liquids are expected to be potential solvents for biorefinery
purposes. However, the high cost has limited widespread implementation,
making their recycling essential to the process. Herein, the capacity
to recover and reuse the ionic liquid 1-allyl-3-methylimidazolium
chloride ([Amim][Cl]) in the fractionation of Pinus
radiata wood using microwave heating was evaluated.
In the proposed process, cellulose- and lignin-rich materials were
obtained. The ionic liquid used was recovered and reused in the forthcoming
cycles up to five times. Characterization of [Amim][Cl] recovered
demonstrated that although the structure of the ionic liquid remained
unaltered, some woody fractions were accumulated. As a consequence,
a reduction of the fractionation yields was obtained, and variations
of the composition and amorphicity of the fractions recovered were
produced. Through a global mass balance, this study gives an overall
approximation of the concentration of the main components and the
characteristic streams involved in successive cycles.