生物质资源是自然界存在最广泛，储量最大的可再生能源，对于生物质资源的高效利用能够有效缓解人类生活对于化石能源的依赖，到目前为止，人们对于生物质资源的利用率仍旧较低。实现生物质资源中组分的高效分离是高效利用生物质资源的关键，因此开发高效绿色的生物质预处理分离方法仍旧是当前研究的重要课题。当前，对于生物质资源的利用多集中于纤维素和半纤维素。而作为生物质组分中唯一以芳香类化合物为骨架结构的木质素，相关研究及利用较少，开发高效的木质素转化策略对于未来实现木质素高效利用具有重要意义。离子液体作为一种新型的绿色溶剂，由于其较强的氢键作用，极低的饱和蒸气压和较高的溶氢能力，在生物质预处理及生物质组分催化转化领域展现出了巨大的优势。本文围绕离子液体强化生物质分离和转化开展工作，主要创新结果如下：（1）发展了质子型醇胺类离子液体预处理生物质秸秆方法。采用一步质子化方法设计合成了一系列醇胺类质子型离子液体，系统研究了阳离子中含有不同羟基数目的离子液体预处理分离秸秆机制。通过对离子液体成本价格进行计算表明，合成所得离子液体成本价格大约为1 $/kg，这相对于传统的离子液体具有很好的价格优势。秸秆组分分离研究证明，合成所得质子型离子液体具有很好的生物质预处理分离能力，其中，以N-羟基二乙醇胺甲烷磺酸盐（[BHEM]mesy）作为预处理溶剂具有最优的分离效果，在140 oC，常压6个小时条件下，秸秆中木质素和半纤维素去除率均达到>90 wt%。XRD表征分析证明，实验所得纤维素为I型纤维素材料，并且纤维素结晶度由原来的37%提高到59%。离子液体溶解木质素和半纤维素过程研究表明，离子液体选择性打破秸秆中位于外层的木质素和半纤维素，并在一定程度上降解了两种组分从而进一步溶解，从而实现了纤维素I型材料的高效分离提取。（2）发展了离子液体强化和催化木质素衍生酚类和醚类化合物加氢脱氧研究。通过设计制备一系列基于不同金属的负载型催化剂结合离子液体建立了高效的木质素衍生物加氢脱氧催化体系。在该催化体系筛选中，以Ru/SBA-15和1-丁基,3-甲基咪唑六氟磷酸盐（[Bmim]PF6）离子液体所建立的催化体系具有最优的催化活性。通过催化剂表征分析证明，制备所得催化剂可以均匀分散在载体表面，其催化活性与金属颗粒大小规律相反，即金属颗粒越小，催化活性越高。应用该催化体系，在常温氢气2 MPa，温度130 oC，6个小时条件下，木质素衍生物的转化率均达到>99.0%，目标产物的选择性>90.0%。研究证明，在该催化体系中，金属催化剂主要催化反应过程中的加氢反应，离子液体则主要催化了反应过程中的脱氧反应，其中，离子液体阴离子起关键性作用。（3）开展了基于质子型离子液体催化木质素衍生物脱氧研究。构建了基于廉价质子型离子液体结合碳负载金属催化剂的催化体系，并将其应用于木质素衍生酚类及醚类化合物的加氢脱氧过程。研究证明，以Rh/C和N-甲基二乙醇胺三氟甲烷磺酸盐（[BHEM]TfO）离子液体所建立的催化体系具有最高的催化活性。在该反应体系中，常温氢气压力4 MPa，温度120 oC，6小时条件下，苯酚转化率100%，环己烷和联环己烷的产率分别为93.3%和2.1%。该催化体系对不同的木质素衍生酚类及醚类化合物也表现出了较好的催化活性，在一定条件下，木质素衍生物转化率均达到>99.0%，目标产物的选择性>90.0%。;Biomass is the most abundand renewable resource in earth. The efficient utilization of biomass resources could alleviate our heavy dependence on fossil energy during our daily life. However, there is very little biomass resource that has been efficiently utilized up to now. It is well known that efficient fractionation of biomass into cellulose, hemicelluloses and lignin is the key scientific technology for complete utilization of biomass resources. Therefore, developing more efficient and green technologies for separation of biomass compositions is still one of important topics to the current research. At present, the utilization of biomass resources is mainly focused on the development and application of cellulose and hemicelluloses. Lignin, as the only renewable aromatic polymer in biomass, has not received widespread attention for its utilization. Due to the complex chemical structure and stable characteristics, most of lignin is still disposed as industrial waste or burning directly. Devloping more efficient conversion strategies for lignin to value added chemicals is highly desirable for fully utilization of lignin resource. Ionic liquids (ILs), as one kind of novel green solvent, have shown great potential application in biomass fractionation and lignin conversion fields owing to their specific characteristics, such as strong hydrogen bonding , near-zero vapor pressure and high hydrogen solubility, etc. The mainly work and results are summarized as follows:(1) Developing the pretreatment of corn straw with low-cost protic ILs. A series of low-cost proton ILs (about 1 $/kg) are synthesized by one-step protonation reaction. Meanwhile, the systematic study about corn straw pretreatment by using these ILs are conducted under mild conditions. The research confirms that all the ILs based on the anion of methane sulfonic shows good separation ability for corn straw. Among them, 2-hydroxy-N-(2-hydroxyethyl)-Nmethylethanaminium ethanesulfonate ([BHEM]mesy) exhibits the highest efficiency for separation of cellulose I materials from corn straw. More than 90 wt% of lignin and hemicelluloses in corn straw could be efficiently dissolved and further separated with cellulose. XRD characterization analysis certifies that the obtained materials are cellulose I crystal structure with an increasing crystallinity index from 37% of corn straw to 59%. The mechanism of cellulose separation could be verified by GC-MS analysis, it confirms that [BHEM]mesy degrades the lignin and hemicelluloses in corn straw selectively, and then dissolving the degradation products to achieve the separation of cellulose.(2) Developing the hydrodeoxygenation (HDO) of lignin-derived phenols and dimeric ethers based on ILs catalytic system. The catalytic systems that used in this work are developed by using selected ILs combining with the prepared metal catalysts. Meanwhile, the characterization of metal catalysts confirms that all nano metal particles are well-disperesed on the carriers. The catalytic experiments proves that the smaller nano metal paricles, the higher catalytic activity for HDO of lignin-derived compounds. Among them, the [Bmim]PF6-Ru/SBA-15 catalytic system shows the most excellent catalytic activity for HDO of lignin-derived compounds. The conversion of lignin-derived compounds are up to >99.0%, and the yields of corresponding alkane are >90.0% at 130 oC for 6 h with the H2 pressure 2 MPa. The research confirms that the metal catalyst promotes the hydrogenation reaction, while the IL catalyzes the deoxygenation processes for the whole reaction, the anion of IL is the key factor for this reaction process.(3) Study on the HDO of lignin-derived compounds based on low-cost protic ILs catalytic system. The catalytic system that using in this work are prepared with the synthesized low-cost protic ILs combining with carbon based metal catalysts. The research confirms that Rh/C-[BHEM]TfO catalytic system has the best catalytic activity for HDO of lignin-derived compounds. The conversion of phenol is up to 100% at 120 oC for 6 h with the H2 pressure 4 MPa, the yields of cyclohexane and bicyclohexyl are 93.3% and 2.1%, respectively. Meanwhile, the catalytic system also shows high efficiency for HDO of all selected lignin-derived compounds with the conversion >99.0%, and >90.0% yield of corresponding alkane.