Study On A Green Method On The Seperation Of Lignin And Cellulose

At present, the structures of lignin and cellulose are ofter undermined by solvents such as acids, alkali, or ether, dioxane, benzene, and also the environment is polluted durling the process of lignocellose's separation. So a series of phosphite-based ionic liquids were synthesized, and also the structure characterized by FT-IR and NMR.The species of cationic in IL and the way of dissolution were first discussed in this article. It was found that the solubility of lignin in 1,3-dimethylimidazolium phosphate [Mmim]DMP was 60% under the way of microwave,which the solubility was enhanced 15% compared to conventional way, and also the SEM, XRD and FT-IR were used to characterize the regenerated lignin. It was also found that [Mmim]DMP can be the benign solvent during the seperation of lignin and cellulose because of its good solubility of lignin, cellulose and lignocellulose.The lignocellulose was dissolved step-by-step by water of which as the precipitation agent according to the different solubility of lignin and cellulose in the system of water-IL. It was found that separation efficiencies of cellulose and lignin were respectively 50% and 65% in the system of nutshell-IL which the concentration was 4%. The hydrogel PNIPPAm synthesised which has the property of temperature-sensitive to separate lignin and cellulose were also tried in the solution of nutshell-IL. In addition, After the ILs were used for five times, their solubility for the lignocellulose was still good.