CAREER: Toward a mechanistic and quantitative understanding of oxidative conversion of biorefinery lignin to open chain hydrocarbon fuel - a new approach to dispel lignin myth

PI姓名：小张提案ID：1454575未来的生物经济将通过工业生物精炼厂来实现，这些生物精炼厂从可再生植物生物质资源（如草，农业残留物和森林残留物）中生产可持续的生物燃料，生物产品和生物能源。在大多数目前的纤维素生物燃料操作中，植物生物质的纤维素部分转化为糖，然后发酵成生物燃料。 剩余的木质素被燃烧用于生物发电。 木质素通常是植物生物质中仅次于纤维素的第二丰富的材料。 将木质素转化为液体燃料，而不是燃烧它，可以显着增加生物质的生物燃料生产，并减少生物炼制操作的碳足迹。 然而，木质素是一种复杂的材料，很难转化为有价值的产品。 这项研究旨在开发一种创新的化学反应途径，将木质素选择性地转化为类似于喷气燃料的开链烃。 如果成功，研究结果将导致生产可持续燃料的新工艺，并提高生物炼制操作的经济性和环境可持续性。 将木质素转化为液体燃料可以显著提高生物质的生物燃料产量。然而，目前的木质素转化技术主要基于氢化/加氢脱氧反应途径，其需要高温、高压和大量的氢气（H2）消耗。 该CAREER奖项的技术目标是对一种新的原子效率化学途径的反应机理和动力学进行基本了解，以通过连续的氧化芳环开环，烯烃复分解和二烯低聚反应将纤维素生物燃料生产中的木质素残留物选择性地转化为开链烃燃料。 为此，研究计划有三个目标。 第一个目标是制备和表征代表性的生物炼制木质素样品，其反映了木质素性质、结构和由各种生化转化过程产生的功能的变化的广度。 第二个目标是确定生物炼制木质素氧化解聚的关键反应动力学参数，建立不同反应条件下木质素结构性质与二羧酸产物选择性之间的定量关系。 第三个目标是阐明反应机理，并获得对木质素衍生的二羧酸的烯烃复分解和支化共轭二烯低聚成喷气燃料前体的反应动力学的理解。 这项研究的结果将为生物炼制木质素转化化学的系统水平的理解提供基础，从而导致大规模木质素利用的新工艺。 与该奖项相关的教育和推广计划旨在培养未来的生物质转化技术科学家和工程师，以帮助为未来的生物炼制提供训练有素的劳动力。 教育计划将与工业合作伙伴一起开发，以积极招募高中，本科和研究生，特别是那些来自代表性不足的群体，并为学生提供生物质转化技术的实践和研究经验，以支持当前和未来的生物炼制业务。 具体活动包括未来科学家和工程师的生物炼制计划，生物炼制为导向的夏季实习，和工业领导研讨会系列。

PI Name: Xiao ZhangProposal ID: 1454575 The bioeconomy of the future will be realized by industrial biorefineries which produce sustainable biofuels, bioproducts, and biopower from renewable plant biomass resources such as grass, agricultural residues, and forest residues. In most current cellulosic biofuel operations, the cellulosic fractions of plant biomass are converted to sugars and then fermented into biofuels. The residual lignin is burned for biopower. Liginin is typically the second most abundant material in plant biomass next to cellulose. Conversion of the lignin into liquid fuel, as opposed to burning it, can significantly increase biofuel production from biomass, and reduce the carbon footprint of biorefinery operations. However, lignin is a complex material which is very difficult to convert to products of value. This research award seeks to develop an innovative chemical reaction pathway to selectively convert lignin to open chain hydrocarbons similar to those that make up jet fuel. If successful, the results from the research will lead to new processes to produce sustainable fuel, and improve the economics and environmental sustainability of biorefinery operations. The conversion of the lignin to liquid fuel can significantly increase biofuel production from biomass. However, current lignin conversion technologies are mostly based on hydrogenation/ hydrodeoxygenation reaction pathways that require high temperatures, pressures, and substantial hydrogen (H2) consumption. The technical goal of this CAREER award is to develop a fundamental understanding of the reaction mechanisms and kinetics of a new, atom-efficient chemical pathway to selectively convert lignin residue from cellulosic biofuel production to open-chain hydrocarbon fuels through sequential oxidative aromatic ring opening, olefin metathesis, and diene oligomerization reactions. Towards this end, the research plan has three objectives. The first objective is to prepare and characterize representative biorefinery lignin samples that reflect the breadth of variations in lignin properties, structure, and the functionality resulting from various biochemical conversion processes. The second objective is to determine the key reaction kinetic parameters of oxidative depolymerization of biorefinery lignin, and establish a quantitative relationship between lignin structural properties and dicarboxylic acid product selectivity under different reaction conditions. The third objective is to elucidate reaction mechanisms and gain an understanding of reaction kinetics in olefin metathesis of lignin-derived dicarboxylic acids and oligomerization of branched conjugated dienes to jet fuel precursors. The results from this research will provide the foundation for a systems-level understanding of biorefinery lignin conversion chemistry, leading to new processes for large-scale lignin utilization. The education and outreach programs associated with this award seek to train future scientists and engineers in biomass conversion technologies to help provide a trained workforce for the biorefineries of the future. Educational programs will be developed in conjunction with industrial partners to proactively recruit high school and undergraduate and graduate students, especially those from underrepresented groups, and provide students with practical and research-based experiences in biomass conversion technologies that support current and future biorefinery operations. Specific activities include the Future Scientists and Engineers for Biorefinery program, the Biorefinery-Oriented Summer Practicum, and the Industrial Leadership Seminar Series.