A possible means of realizing a sacrifice-free three component separation of lignocellulose from wood biomass using an amino acid ionic liquid

Lignocellulose materials are potentially valuable resources for transformation into many bio-products. However, because of the difficulty in fractionating them into cellulose, hemicellulose, and lignin by a simple method directly from wood biomass, their economical conversion into high value-added products has been greatly limited. We found that N-methyl-N-(2-methoxyethyl)pyrolidin-1-ium 2,6-diaminohexanoate ([P1ME][Lys]) dissolved lignin very well below 60 °C, but that 80 °C was required for it to dissolve cellulose. Taking advantage of this difference in dissolution ability, direct extraction of lignin from wood biomass has been accomplished under mild conditions without the use of any hazardous reagents. Since lignin acts as the essential glue that binds cellulose and hemicellulose and gives plants their structural integrity, we have achieved the demonstration of the sacrifice-free separation of cellulose, hemicellulose, and lignin from wood biomass (Japanese cedar: Cryptomeria japonica).