Ionic Liquids for the Utilization of Lignocellulosics
Given the ever increasing world-wide demand for energy, coupled with the instability of current petroleum resources, the development of sustainable, biologically-derived energy and commodity chemical feedstock sources is critical. A great deal of interest and effort is currently being focused on the development of technologies to convert lignocellulosic material (“woody” biomass) into renewable replacements and augments for current petroleum-derived platform chemicals and fuels. These technologies must address the challenge of “biomass recalcitrance”– the natural resistance plant matter exhibits to biodegradation. Recently, a novel class of compounds, ionic liquids, has been presented as a possible solution to the challenge of biomass recalcitrance. These compounds have demonstrated the ability to dissolve either the entirety of the lignocellulosic biomass or the individual fractions selectively. While the potential for ionic liquids to serve as solvents for the chemical and biochemical processing of biomass is high, the body of scientific knowledge is still in the early stages of exploration and many challenges remain to be resolved. The purpose of this article is to provide a “state-of-the-art” review of the scientific literature and to identify trends that are developing and issues that remain.