Ionic liqs. are of great interest as potential solvents/catalysts for the prodn. of fuels and chems. from lignocellulosic biomass. Attention has focused particularly on the pretreatment of lignocellulose to make the cellulose more accessible to enzymic hydrolysis. Any biomass processing requires a redn. in the size of the harvested biomass by chipping and/or grinding to make it more amenable to chem. and biol. treatments. This paper demonstrates that significant energy savings can be achieved in the grinding of pine wood chips when the ionic liq. is added before the grinding operation. We show that this is due to the lubricating properties of the ionic liqs. and not to physico-chem. modifications of the biomass. A brief impregnation of the chipped biomass results in higher savings than a longer treatment. [on SciFinder(R)]