Pretreatment Of Lignocellulosic Biomass By Using Ionic Liquids

Recently,Energy and environmental problems have seriously restricted the further development of our society and economy.Fossil fuels such as coal,oil will gradually run out and the use of these fossil fuels will cause severe environmental pulution,so,it is essential for us to look for a renewable energy.Biofuels production from abundant,cheap and renewable lignocellulosic biomass is promising.Lignocellulose mainly consists of cellulose,hemicellulose and lignin,both of the components have complex structure and good resistance to chemical or biological degradation ability,in general,biomass is very stable so we can not use it directly.Therefore,we need to pretreat biomass firstly,then hydrolysis it to obtain glucose,finally hydrolysis glucose to get the fuel ethanol.Ionic liquids(ILs)would be the promising solvents for pretreatment of lignocellulosic biomass owing to their excellent physiochemical properties.However,the traditional ILs,such as imidazolium ILs,have been proved to be highly and toxic and poorly biodegradable,and some new type of ionic liquids,such as cholinium amino acids ionic liquids can overcome the these problems.In this paper,cholinium amino acids ILs,imidazolium ILs,amino ILs were synthesized,with the comparison of these ILs,we found that[Ch][Ala]is the best one for poplar pretreatment.Different conditions have great influence on the performance of pretreatment,in this paper we found the best temperature and time for[Ch][Ala]'s pretreatment.Under the optimum conditions,the digestibility of 88.19%for cellulose and the sugar yield of 66.14%for glucose were achieved in the enzymatic hydrolysis of the residues,eompared with the other methods,[Ch][Ala]showed the excellent result in poplar pretreatment.