Biorefinery with Ionic Liquids

We have developed novel polar ionic liquids (ILs) which dissolves cellulose under mild conditions (Figure 1).[1] In addition, they extract cellulose from plant biomass under mild condition. As the latest result, tetrabutylphosphonium hydroxide (TBPH) aqueous solution was found to be an excellent solvent for cellulose. Since it dissolves cellulose in the presence of a certain amount of water, resulting in biomass processing of “wet” biomass.[2]
     We also have prepared ILs having contradicting properties such as high polarity and hydrophobicity.[3] They have a potential to provide novel and powerful process for biomass treatment.
     ILs are very useful for extraction of not only polysaccharides but also other biopolymers such as bioplastic. We succeeded to collect poly(3-hydroxybutyrate) from wet micro algae with the aid of ILs.[4]
     Development of analytical methodologies of cellulose in polar ILs is also very important. We successfully applied polar ILs into HPLC as mobile phase by designing low viscous polar IL, called “HPILC” (Figure 2).[5] This HPILC clarifies molecular weight distribution of many kinds of cellulose which enables us to conduct direct analysis of cellulose depolymerization in polar ILs.