Wood Biomass Liquefaction By Ionic Liquids And Application Of Its Product

The objective of this paper is to obtain the following results. First, alkyl imidazole ionic liquids and allyl imidazole ionic liquids are synthesized. By using them as wood liquefacients, the wood raw material characteristics and liquefaction conditions are studied, and the wood liquefaction mechanisms by ionic liquids and the relationship between structures of ionic liquids and properties of wood liquefaction are discussed, thereby the method of wood liquefaction by ionic liquids is established. Secondly, a kind of suspending agent is prepared by sulfonation and condensation using liquefaction products with this method as materials. And its suspension properties and formulation applications in suspending seed coating agent are studied in order to obtain the theoretical and experimental data for the further application of wood liquefaction products.The main innovative works are as follows.1. The bis (1-methylimidazole) ethyl chloride ionic liquid (I) by1-methylimidazole and1,2-dichloroethane, and bis (1-methylimidazole) ethyl chloride aluminum trichloride ionic liquid (II) by ionic liquid (I) and aluminum trichloride were synthesized and confirmed by GC-MS and FT-IR. The method of wood liquefaction by ionic liquids was established by liquefying wood without any pretreatment in ionic liquids liquefacients, contrasting to the traditional liquefaction method of phenol. Under the conditions of liquid/wood ratio20:1,110-120℃,25min and metal halide ratio0.67, the properties of ionic liquids were much more better than those of phenol liquefacient, and the ionic liquid could be recycled and re-used in the liquefaction.2. The chemical composition, properties and liquefaction characteristics of Chinese fir were studied, sampling from the Jinzhai, Huoshan and Shuchen, three Chinese fir-producing areas. The chemical composition of Chinese fir had been less affected by geographic area, wherein, the cellulose content was higher, and hemicellulose and lignin content were close to the middle level. Cellulose was the most difficult to be liquefied in all components, needed higher reaction temperature and longer reaction time than lignin, markedly affecting properties of Chinese fir liquefaction. The cellulose and hemicellulose contents of Chinese fir were higher than those of fir bark, the ash and extractives contents of it were relatively low, the liquefaction efficiency of it was lower, and the amount of residue of it was less under the same conditions.3. In order to reduce the temperature of the liquefaction reaction,1-butyl-3-allyl imidazolium chloride ionic liquid ([BAIM][Cl]) and1-methyl-3-allyl imidazolium chloride ionic liquid ([MAIM][Cl]) were synthesized by1-butylimidazole,1-methylimidazole reacting respectively with3-chloropropene, mixed into salts with aluminum trichloride, and confirmed by GC-MS and FT-IR. The liquefaction rates of [BAIM][Cl/AlC13] and [MAIM][Cl/AlCl3] were better than corresponding [BAIM][Cl] and [MAIM][Cl]. Especially the residue rate of [BAIM][Cl/AlCl3] reduced to about10%at80℃, corresponding to the level of the ionic liquid (Ⅱ) at100℃, and the effective liquefaction temperature was reduced significantly. It was shown that during the course of the observation by polarizing microscope for fir powder liquefaction in [BAIM][Cl/AlCl3], cellulose crystalline region was partially destroyed at60℃and disappeared gradually with the rise of the reaction temperature and the extension of reaction time, the fir powder was mainly swelled in the surface by [BAIM][Cl] at this time, but not significant effect by phenol.4. The acidic and catalytic properties of ionic liquids and the relationship between structures of ionic liquids and properties of wood liquefaction were studied by infrared spectroscopy with pyridine probe. Based on the pyridine probe, it was shown that [Cl/AlCl3] had different acidity with the changes of N, the Lewis acidity was indicated when N was0.50-0.67, the Br(?)nsted acidity was indicated when N was greater than0.67, and this acidic structure for wood liquefaction with high catalytic property. The coordination structure similar to [Cl/AlCl3] could be obtained by the metal halide such as SnCl2and FeCl3combining with the precursor anion, also had such catalysis for liquefaction.According to product composition in various liquefaction stages, the mechanism of wood liquefaction by [BAIM][Cl/AlCl3] could be considered that cellulose was degraded first of all, which was the key of liquefaction, followed by hemicellulose and lignin, and the reaction rate in each step had more changes. The anions [Cl], metal ions M, and alkyl or allyl in the ring of cationic imidazole were in favor of wood liquefaction in the structure and properties of ionic liquids. The neutral ionic liquids such as [BPy][Cl],[BMIM][BF4] and [BMIM][PF6] had basically no liquefaction property.5. A kind of suspending agent, wood liquefaction sulfonation (WLS), had been prepared by the synthetic route of sulfonation, condensation and neutralization with the product of wood liquefaction. The optimum conditions for the reaction were obtained, reaction temperature of sulfonation and condensation were at85℃and90℃, reaction time of sulfonation and condensation were for2.5h and3.0h, reaction temperature of neutralization were at85℃and90℃, under these conditions the average suspension rate of the product was91.1%.The results of WLS suspension properties in seed coating suspension agents of the four kinds of crops showed that, WLS had a certain surface activity, but no apparent turning point on the curve of concentration-surface tension, and produced auxiliary swelling property in Attapulgite system when mixed with Tween80. In the binary and ternary mixtures, WLS had good compatibility, which produced synergistic effect with other components such as non-ionic surfactant, and showed excellent suspension property and little change in viscosity at room or high temperature. The suspension rates of the ternary system Attapulgite/WLS/Tween80to seed coating agent of4crops were more than90%, which were better than those of the binary system and a single component.After component selection and formulation design, the composition and dosage of suspended seed coating formulation had been determined, and then a kind of20%thiram/carbofuran suspended seed coating agent had been prepared. The coating application showed that the measurement results of each quality control index of the formulation could meet quality standards, the suspension properties were more prominent, the samples were better than uncoated seeds in the four indicators including germination potential, germination rate, germination index and vigor index, and field germination was more reliable.