Conversion of Cellulosic Biomass into Renewable Gasoline, Aviation Biofuels and Bio-based Chemicals – towards the Development of 5-HMF-Platform Biorefinery

纤维素生物质丰富且价格低廉，在农业和林业部门作为残留物(玉米杆、麦秆、锯末、树皮等)大量产生。葡萄糖是纤维素生物质的主要组成部分，可以通过酸或酶解的方法从纤维素生物质中轻松、廉价地生产葡萄糖。葡萄糖可通过催化脱水转化为5-羟甲基呋喃甲醛(5-HMF)。5-HMF被美国能源部认为是市场潜力最大的十大生物化学品之一，因为它是一种用于合成各种生物燃料和生物化学品的多功能中间平台前体。与其他生物平台化学品，如生物乙醇和乙酰丙酸相比，5-HMF在碳利用效率方面特别有希望，因为它保留了葡萄糖的全部六个碳原子。这项研究计划的长期目标是开发新型的5-HMF平台生物精炼厂，将纤维素生物质转化为可再生燃料和化学品。作为短期目标，我在未来五年的研究工作将集中在开发将葡萄糖转化为生物燃料(可再生汽油和航空生物燃料)和生物基化学品的新型连续工艺和多相催化剂，特别是(1)开发将葡萄糖转化为5-HMF的高效连续工艺和多相催化剂；(2)在连续反应器中以5-HMF为原料生产可再生汽油和航空生物燃料；(3)将5-HMF转化为2，5-二羟甲基呋喃和2，5-呋喃二酸，并生产生物聚合物。 在这个项目中，将开发一种使用多相催化剂的新的连续工艺，并将其用于将葡萄糖转化为5-羟甲基呋喃。5-羟甲基呋喃将进一步催化转化为2，5-二甲基呋喃(DMF)和2，5-二甲基四氢呋喃(DMTF)。DMF和DMTF可以是能量含量比5-HMF高得多的可再生汽油。在连续工艺和多相催化剂的作用下，5-羟甲基呋喃也将转化为2，5-二羟甲基呋喃和2，5-呋喃二酸(FDCA)，用于生产生物聚合物，如生物基聚对苯二甲酸乙二醇酯(PET)。此外，作为一种芳香醛化合物，5-HMF将通过自身安息香缩合转化为偶联产物-C12呋喃，然后通过加氢转化为C12碳氢化合物。到目前为止，文献中报道的葡萄糖到5-羟甲基呋喃的过程大多是采用均相催化剂的实验室规模的间歇反应体系。为了更经济地大规模生产5-羟甲基呋喃，开发连续的工艺和高活性的多相催化剂(便于催化剂回收)是关键。NSERC DG研究项目的成功可以通过为加拿大森林和农业部门创造更多的利润流，并为加拿大的化学工业提供可再生化学品/材料，从而在长期内增强加拿大的经济可持续性。此外，该计划预计将在生物精炼的广泛领域培训10多名高素质人员-这对加拿大的生物经济发展具有重要意义。

Cellulosic biomass is abundant and inexpensive, and is generated at large quantities in the agricultural and forestry sectors as residues (cornstalks, wheat straw, sawdust, bark, etc.). Glucose is the main building block of cellulosic biomass, and it can be readily and inexpensively produced from cellulosic biomass via acid or enzymatic hydrolysis. Glucose can be converted into 5-hydroxymethyl-furfural (5-HMF) via catalytic de-hydration. 5-HMF is considered by the U.S. Department of Energy to be among the “top 10 list of bio-based chemicals” in terms of the market potential as it is a versatile intermediate platform precursor for the syntheses of a wide range of biofuels and bio-based chemicals. Compared with other bio-platform chemicals, such as bio-ethanol and levulinic acid, 5-HMF is particularly promising in terms of carbon utilization efficiency as it retains all six carbon-atoms of glucose. The long-term goal of this research program is to develop novel 5-HMF-platform biorefinery for conversion of cellulosic biomass into renewable fuels and chemicals. As short-term objectives, my research efforts in the next five years will be centered on developing novel continuous processes and heterogeneous catalysts for conversion of glucose into biofuels (renewable gasoline and aviation biofuels) and bio-based chemicals, specifically (1) to develop highly efficient continuous processes and heterogeneous catalysts to convert glucose to 5-HMF; (2) to produce renewable gasoline and aviation biofuels from 5-HMF in a continuous reactor; (3) to transform 5-HMF into 2,5-dihydroxymethyl furan and 2,5-furandicarboxylic acid and produce biopolymers. In this project, a novel continuous process using heterogeneous catalysts will be developed and used for cost-effective conversion of glucose to 5-HMF. 5-HMF will be further catalytically converted to 2,5-dimethylfuran (DMF) and 2,5-dimethyltetrahydrofuran (DMTF). DMF and DMTF can be renewable gasoline with a much higher energy content than5-HMF. With the continuous process and heterogeneous catalysts, 5-HMF will also be converted to 2,5-dihydroxymethyl furan and 2,5-furandicarboxylic acid (FDCA) for production of biopolymers such as bio-based polyethylene terephthalate (PET) by replacing terephthalic acid with FDCA. Furthermore, as an aromatic aldehyde compound, 5-HMF will be transformed to a coupled product - C12 furoin via self-benzoin condensation and then to C12 hydrocarbons as a potential aviation biofuel by hydrogenation. The glucose-to-5-HMF processes reported so far in the literature are mostly lab-scale batch systems with homogeneous catalysts. In order to produce 5-HMF more economically on a large scale, developing continuous processes and highly active heterogeneous catalysts (to ease catalyst recycling) is the key. The success of this NSERC DG research program could enhance Canada’s economic sustainability in a long term, by creating additional profit streams to the Canadian forest and agricultural sectors and offering renewable chemicals/materials to the Canadian chemical industries. Moreover, this program is expected to train more than 10 highly qualified personnel in a broad area of biorefinery – an area of great significance to Canada’s bioeconomy development.