CAREER: An Integrated Research and Educational Plan to Develop Selective Pyrolysis Reactors and Improve the Capacity of Students to Work in Multidisciplinary Teams

(加西亚-佩雷斯)1150430拟议活动的智力价值：位于生物质资源附近的分布式快速热解装置可将60%至75%的木质纤维原料转化为粗生物油，其中40%可通过农村或集中式生物油精炼厂的加氢处理进一步转化为运输燃料。尽管这些反应器很重要，但现有的关于木质纤维材料中的动力学和传输现象的知识还没有被适当地整合到热解反应器的设计中。木质素热解反应产生运输燃料前体(单酚和木质素低聚物)的机理还缺乏研究。这项建议将促进对木质素热解反应和相关传输现象的理解，以支持为设计选择性热解反应器而开发多尺度数学模型，并利用与这些反应器设计相关的问题来培养K-12、本科生和研究生的多学科团队工作技能。研究部分涉及综合实验和模拟任务，以便查明最大限度地利用木质纤维材料热解生产运输燃料前体的条件。提出的设计选择性俄歇裂解反应器的方法需要详细了解一次反应和二次反应的动力学、液体中间体的蒸发和裂解、细胞水平的传热传质、颗粒尺寸和固体停留时间分布以及描述单个生物质颗粒行为的模型。该项目将促进人们对木质素解聚反应的理解，强调木质素液体中间体作为生产木质素低聚物的前体的作用。建立了多尺度数学模型来设计选择性俄歇裂解反应器。该模型将首次集成(1)新的木质素热解动力学模型，(2)描述生物质细胞结构演变对有效轴向和径向导热系数和质量扩散系数的影响的模型，以及(3)考虑轴向和径向热质传递和二次反应的单颗粒模型，以确定最大限度地生产运输燃料前体的条件。更广泛的影响：该项目将产生的木质素热解动力学参数，结合文献中报告的动力学信息，将支持开发多尺度模型来设计和评估更多选择性的热解反应器。这一贡献意义重大，因为从木质纤维材料生产运输燃料前体的预期收益可以大大增加生物燃料的产量，并减少该国对进口石油的依赖。发展一套系统的热解反应器设计方法，将对今后其他热化学反应器的设计研究，如气化和加氢反应器的设计做出重大贡献。因此，该项目的成果不仅有望从根本上推动生物质热化学转化领域的发展，而且还将产生广泛和高度积极的社会影响。将实施和评估一项教育计划，以发展K-12、从事选择性热解反应器开发的本科生和研究生的多学科团队工作技能。因此，这项提案的教育部分也将产生广泛的影响，因为它的实施方式将有助于在教学模块、实验设置和设计选择性热解反应器的同时，帮助K-12、本科生和研究生在多学科小组中工作。

(Garcia-Perez)1150430 Intellectual merit of the proposed activity: Distributed fast pyrolysis units located close to biomass resources could convert between 60 and 75 % of lignocellulosic materials into crude bio-oils of which 40 % could be further transformed into transportation fuels via hydrotreatment in rural or centralized bio-oil refineries. In spite the importance of these reactors, the available knowledge on kinetics and transport phenomena in lignocellulosic materials has not been properly integrated for the design of pyrolysis reactors. The mechanism of lignin pyrolysis reactions responsible for the production of precursors of transportation fuels (mono phenols and lignin oligomers) also remains poorly studied. This proposal will advance the understanding of lignin pyrolysis reactions and the associated transport phenomena to support the development of multi-scale mathematical models for the design of selective pyrolysis reactors and take advantage of the problems associated with the design of these reactors to developed multidisciplinary team working skills in K-12, undergraduate and graduate students. The research component involves integrated experimental and simulation tasks that will allow for the identification of conditions maximizing the production of precursors of transportation fuels from the pyrolysis of lignocellulosic materials. The approach proposed to design selective Auger pyrolysis reactors requires a detailed understanding of the kinetics of primary and secondary reactions, the evaporation and cracking of liquid intermediates, heat and mass transfer at the cell level, particle size and solid residence time distribution and a model to describe the behavior of single biomass particles. The proposed project will advance the understanding of lignin depolymerization reactions stressing on the role of lignin liquid intermediates as precursors for the production of lignin oligomers. A multi-scale mathematical model will be developed to design selective Auger pyrolysis reactors. For the first time this model will integrate (1) new kinetic models for lignin pyrolysis, (2) a model to describe the effect of the evolving biomass cell structures on the effective axial and radial thermal conductivity and mass diffusivity and (3) a single particle model that takes into account axial and radial heat and mass transfer and secondary reactions to identify the conditions which maximize the production of precursors of transportation fuels. Broader impact: The kinetic parameters of lignin pyrolysis that will result from this project, in conjunction with kinetic information reported in the literature, will support the development of multi-scale models to design and evaluate more selective pyrolysis reactors. This contribution is significant because the expected gains in the production of precursors of transportation fuels from lignocellulosic materials could significantly increase the production of bio-fuels and reduce the nation's dependency on imported oil. The development of a systematic methodology to design pyrolysis reactors will be a significant contribution to future research on the design of other thermochemical reactors such as gasification and torrefaction reactors. Thus, the outcome of this project is not only expected to fundamentally advance the field of biomass thermo-chemical conversion but also have broad and highly positive societal impacts. An educational plan to develop multidisciplinary team working skills in K-12, undergraduate and graduate students working in the development of selective pyrolysis reactors will be implemented and assessed. Thus the educational component of this proposal will also have a wide reaching impact because it will be conducted in such a way that will contribute to the teaching of K-12, undergraduate and graduate students to work in multidisciplinary teams while developing teaching modules, experimental set-ups and designs of selective pyrolysis reactors.