Oligomers vs. Phenolics from Hydrolytic Lignin Pyrolysis

了解和控制木质素热解是一个重要的问题，解决这个问题可能会使以生物质为原料生产生物燃料和高价值化学品具有成本效益。木质素是一种复杂的物质，其热解是一个丰富的科学研究领域。传统的研究木质素热解的方法受到以下限制：无法知道或设定木质素样品在反应区的停留时间，未知的温度分布，以及无法区分二次产品和初级产品。拟议的研究中使用的反应堆能够快速加热到明确定义的温度，并将木质素保持在这些温度下特定的时间间隔。这项研究的成果有可能提高木质素化学的基础知识，并为天然木质素受控分解为生物油和附加值产品提供指导。该研究旨在发展关于均质木质素在气相中解聚的基本化学基础知识。一个关键的目标是研究解聚的主要过程，同时避免传统热解带来的挑战，包括依赖于样品大小和表面效应的质量和热传输限制，以及影响后热解二次焦油反应中产品分布的表面效应。拟议的研究将侧重于了解在非传统激光驱动的均相热解和连续液滴蒸发反应器中形成低聚物与酚类化合物的优先顺序。最终目的是更好地从根本上了解木质素的解聚机理以及中间物种(低聚物)在间歇裂解反应器中产物分布中的作用。研究成果将被纳入路易斯安那州立大学的教育和推广项目，特别强调吸引未被充分代表的少数族裔学生，并指导他们追求科学和工程领域的职业生涯。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Understanding and controlling lignin pyrolyis is an important problem whose solution may enable cost-effective production of biofuels and high-value chemicals from biomass feedstocks. Lignin is a complex material and its pyrolytic decomposition is a rich field for scientific inquiry. Conventional methods of studying lignin pyrolysis are limited by the inability to know or set the residence time of the lignin samples in the reaction zone, unknown temperature profile, and inability to differentiate between secondary and primary products. Reactors used in the proposed study are capable of rapid heating to well-defined temperatures and holding the lignin at these temperatures for specific time intervals. The outcome of the proposed research has the potential to enhance the fundamental knowledge of lignin chemistry and provide guidelines for the controlled deconstruction of natural lignin to bio-oil and value-added products.The proposed research aims to develop fundamental knowledge concerning the underlying chemistry of homogeneous lignin depolymerization in the gas phase. A key objective is to investigate the primary processes of depolymerization, while avoiding the challenges posed by conventional pyrolysis, including mass and heat transport limitations, that depend om sample size, and surface effects, that affect product distribution in the post pyrolysis secondary tar reactions. The proposed research will focus on understanding the priority of formation of oligomers vs. phenolic compounds in unconventional laser powered homogeneous pyrolysis and continuous droplet evaporation reactors. The ultimate objective is a better fundamental understanding of the depolymerization mechanism of lignin and the role of intermediate species (oligomers) in the products distribution obtained from batch pyrolysis reactors. The research results will be incorporated into educational and outreach programs at Louisiana State University with special emphasis on engaging underrepresented minority students and mentoring them into pursuing careers in science and engineering.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.