Collaborative Proposal: Elucidation and Evaluation of Strategies to Mitigate Secondary Reactions in Cellulose Pyrolysis for Enhanced Production of Hydrolysable Anhydrosugars

合作提案：阐明和评估减轻纤维素热解中二次反应以提高可水解脱水糖产量的策略

• 批准号: 1435228
• 负责人: Linda Broadbelt
• 金额: $ 16.03万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1435228&HistoricalAwards=false
• 关键词: Collaborative; Proposal; Elucidation; Evaluation; Strategies

1434073 (Garcia-Perez), 1435228 (Broadbelt)Title: Elucidation and Evaluation of Strategies to Mitigate Secondary Reactions in Cellulose Pyrolysis for Enhanced production of Hydrolysable Anhydrosugars Abstract: The production of sugars from forest and agricultural wastes is a critical step for making bio-fuels and bio-chemicals to replace petroleum. One way to do this is by using an ancient technique called ?pyrolysis?, which simply involves heating up this biomass. When cellulose (one of the main components in plant cell tissues) is heated very fast between 300 and 600 oC (fast pyrolysis) under vacuum it is possible to convert almost 95 % of it into sugars that can be easily upgraded into bio-fuels and bio-chemicals. The quantity of sugars obtained with this process is comparable to other well-developed, more expensive methods like enzymatic hydrolysis. Unfortunately, when the biomass is heated very fast at atmospheric pressure in commercial fast pyrolysis reactors, the production of sugars is much lower than when using vacuum. In fact, we typically see less than 20 % of the original cellulose. The decreased sugar yield at atmospheric pressure is due to very poorly understood secondary reactions that happen during fast pyrolysis on plant cell walls. In this proposal we will combine laboratory experiments and computer modeling tools to understand the reasons for the low quantities of sugars obtained at atmospheric pressure. New practical strategies are proposed to dramatically increase the production of sugars during fast pyrolysis and in this way reduce the price of bio-fuels derived from our renewable biomass resources. The main practical goal of this proposal is to better understand the role of intermediate pyrolysis liquid phase oligomeric sugars (cellobiosan, cellotriosan,?) that typically are lost through undesirable dehydration, cross-linking, and polycondensation secondary reactions. We will combine innovative experimental and kinetic modeling tools to better understand these secondary reactions and the mechanisms by which acids, for example, mitigate some of the undesirable interactions with the lignocellulosic matrix (or their products). Micro-explosion enhancers (blowing agents) will be evaluated to promote anhydrosugar aerosolization to decrease residence time in the pyrolytic liquid intermediate as well as the probability for undesirable secondary reactions to occur inside the pyrolysis reactor. We will broaden our impact by working with Walla-Walla Community College (WWCC) in the development and evaluation of courses for associate degrees in Bioenergy Operations and in Renewable Resource Recovery Operations. We will organize an annual workshop between our graduate students, postdoctoral researchers and WWCC students to exchange ideas and encourage WWCC students to continue their professional development. This project will also serve as a platform for undergraduate electrical engineering students to conduct their Senior Design Project constructing and improving new wire mesh fast pyrolysis reactors capable of vacuum operation. Results from this project will be incorporated into lectures in graduate-level courses on kinetics and reaction engineering at Northwestern University and on biomass thermochemical conversion at Washington State University. Prof. Broadbelt will participate in a program to interest girls in science and engineering. Joint collaboration between WSU and Northwestern University will yield cross-institutional synergy in the future.

1434073（Garcia-Perez），1435228（Broadbelt）标题：阐明和评估减轻纤维素热解中的二次反应以增强可水解脱水糖的生产的策略摘要：从森林和农业废物中生产糖是制造生物燃料和生物化学品以取代石油的关键步骤。其中一种方法是使用一种古老的技术，称为？热解？，这仅仅涉及到加热这些生物质。当纤维素（植物细胞组织中的主要成分之一）在真空下在300至600摄氏度之间快速加热（快速热解）时，几乎95%的纤维素可以转化为糖，这些糖可以很容易地升级为生物燃料和生物化学品。用这种方法获得的糖的量与其他成熟的、更昂贵的方法（如酶水解）相当。不幸的是，当生物质在商业快速热解反应器中在大气压下非常快速地加热时，糖的产量比使用真空时低得多。事实上，我们通常只看到不到20%的原始纤维素.在大气压下糖产量的降低是由于对植物细胞壁快速热解过程中发生的次级反应知之甚少。在这个建议中，我们将结合联合收割机实验室实验和计算机建模工具，以了解在大气压下获得的糖的低数量的原因。提出了新的实用策略，以大幅增加快速热解过程中糖的产量，并以这种方式降低来自可再生生物质资源的生物燃料的价格。该建议的主要实际目标是更好地了解中间热解液相低聚糖（纤维生物聚糖，纤维三聚糖，？）其通常通过不希望的脱水、交联和缩聚二次反应而损失。我们将结合联合收割机创新的实验和动力学建模工具，以更好地了解这些二次反应和机制，其中酸，例如，减轻一些不良的相互作用与木质纤维素基质（或其产品）。将对微爆增强剂（发泡剂）进行评估，以促进脱水糖雾化，从而减少在热解液体中间体中的停留时间以及在热解反应器内发生不期望的二次反应的可能性。我们将通过与Walla-Walla社区学院（WWCC）合作，在生物能源运营和可再生资源回收运营方面开发和评估副学士学位课程，扩大我们的影响。我们将组织我们的研究生，博士后研究人员和WWCC学生之间的年度研讨会，以交流思想，并鼓励WWCC学生继续他们的专业发展。该项目也将作为一个平台，本科电气工程专业的学生进行他们的高级设计项目建设和改进新的丝网快速热解反应器能够真空操作。该项目的成果将纳入西北大学动力学和反应工程研究生课程和华盛顿州立大学生物量热化学转化研究生课程的讲座。Broadbelt教授将参加一个让女孩对科学和工程感兴趣的项目。WSU和西北大学之间的联合合作将在未来产生跨机构的协同作用。