The Effect Of [BMIM]Cl-water System On Lignin、Cellulose And Hemicellulose

With oil, natural gas and other non-renewable resources being consumed, the development and utilization of biomass was widely concerned. As a large agricultural country, there are abundant straw and other agricultural waste in china, but most of them were burned, which cause a serious problem of wasting resources and environmental pollution.In this paper, the effect of [BMIM] Cl-water system on lignin、cellulose and hemicellulose, which based on dealing with straw by a green solvent-imidazole ionic liquid-water system, was studied. The main process include:after ionic liquid-water system deal with lignin, cellulose and hemicellulose, the samples obtained in this process were mischaracterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), thermography analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy SEM, et al. Researching the influence of different temperature、time and ionic liquids-water quality equivalent ratio on lignin, cellulose and hemicellulose. Through the analysis, the following conclusions:1.We studied the dissolution of the lignin in the ionic liquid-water system, when the ionic liquid content is60percent, the solubility of the lignin is the maximum. By1H-NMR and solubility parameters explain the dissolved law of lignin in the system. By TG and gel permeation chromatography analysis, after ionic liquids-water system treatment, renewable precipitated lignin molecular weight become average;2.The effect of ionic liquid-water system on cellulose contains two aspects, one is that the decrystallized of the crystalline portion of cellulose, the second is the non-crystalline portion of the cellulose dissolved. Temperature、time and ionic liquid content make the degree of crystallinity of the microcrystalline cellulose was fluctuation trends;3.Ionic liquid-water system can dissolve amorphous cellulose, as the ionic liquid content increases, the increase in the quality of the dissolution of non-crystalline cellulose, regenerated cellulose sheet-like structure also becomes larger;4. With the content of the ionic liquid increases, the dissolution of the mass of xylan increases.