Evaluation of solvent recyclability in fast microwave liquefaction with glycol ether of pine wood for preparation of lignocellulosic micro-fines

Lignocellulosic micro-fines (LCMFs) were prepared from pine wood meal by glycol ether liquefaction using microwave irradiation for 90 s. The recovery method and reusability of the solvent (glycol ether) for the liquefaction process were examined. When the volume of the dehydrated recovered solvent was compared with that of the original solvent, the recovery rate was about 97% and this recovery rate remained similar even when solvent recycling was repeated. IR spectrum of the dewatered recovered reagent was very similar to that of the virgin reagent. The yield and residual lignin content of LCMFs prepared by primary and secondary recycled solvents were almost the same as those obtained using virgin solvents. Similarly, no difference was found in the particle size distribution, crystallographic index, and chemical properties of these LCMFs. In conclusion, LCMFs can easily be prepared by rapid microwave irradiation with glycol ether. Furthermore, wood liquefaction for LCMFs using glycol ether is a very economical method because the solvent can be recycled very simply.