CAREER: From Biomass to Liquid Fuels: Ab initio Molecular Dynamics Investigation of Glucose to 5-Hydroxymethylfurfurl Conversion

[844882]钱向红这项为期五年的职业发展计划的重点是发展生物燃料的综合研究和教育计划，这将有助于生物燃料作为化石燃料的替代品的商业化。本研究的重点是了解控制葡萄糖转化和选择性到5-羟甲基糠醛（HMF）的基本过程，并提高HMF的收率。教育部分将为新兴的生物炼制行业培养未来的工程师。项目重点包括：-利用最先进的从头算和经典分子动力学模拟，结合先进的元动力学（MTD）技术，研究溶剂对葡萄糖在水、有机溶剂和离子液体中转化为HMF的机制和能量的影响。-为本科生研究人员建立创意生物能源集群（CBC），提供生物燃料多方面的教育和培训机会。-与国家实验室和国际生物燃料研究界建立合作关系。开发一门新的本科/研究生水平的计算材料科学与工程课程，应用于包括生物燃料在内的可再生能源。生物燃料，如2,5 -二甲基呋喃（DMF）和液态碳氢化合物是新兴生物炼制行业的替代运输燃料。HMF是将生物质转化为DMF、液态烷烃和许多其他增值产品的关键和通用中间体。然而，生物质碳水化合物的转化率仍然是关键问题，特别是葡萄糖，生物质中最丰富的单体糖。目前，葡萄糖的HMF产率非常有限，并且对加工条件，特别是溶剂非常敏感。了解溶剂对葡萄糖转化为HMF的机理和能量学的影响，将为开发具有成本效益的转化工艺和提高HMF收率提供重要的见解。假设溶剂和溶剂结构对酸催化葡萄糖转化为羟甲基糠醛反应的转化率和选择性都有影响。b -葡萄糖环上羟基的质子化（C2-OH）和随后的C-O键断裂是转化的限速步骤。因此，由于糖环上的羟基与溶剂之间对质子的竞争，溶剂结构的质子亲和性将对反应势垒产生重大影响。竞争反应是由其他羟基或葡萄糖上的O环的质子化以及溶剂从反应中间体中提取质子的能力引发的。在离子液体中，Cr （II）离子促进葡萄糖异构化为果糖，从而催化葡萄糖转化为HMF。基于Car-Parrinello的从头算分子动力学（CPMD）模拟与先进的MTD技术是唯一适合研究化学反应和过程。在这个CAREER项目中，CPMD-MTD将用于研究溶剂对葡萄糖在水、DMSO、离子液体及其混合物中转化为HMF的机理、限速步骤、自由能和反应障碍的影响。该研究的成功完成将有助于提高葡萄糖HMF的产量，并为糖途径工程提供重要启示，以获得所需的中间体和产品，以经济有效地利用生物质。更广泛的影响开发生物燃料，如来自生物质的液态烷烃，作为化石燃料的替代品，将产生巨大的社会影响：生物燃料是可再生和可持续的能源，而化石燃料不是；使用生物燃料可以帮助减少温室气体的排放，从而限制全球变暖。将通过建立创意生物能源集群（CBC）来培训未来生物炼制行业的工程师。CBC将为各级本科生提供教育和培训机会，包括国际研究机会以及在工业和国家实验室的实习机会。将开设新的计算材料科学与工程高级本科/研究生课程。本职业项目的研究成果将被纳入本课程。向代表性不足的少数民族宣传科学和工程的外联活动是拟议活动的一个组成部分。研究和教育成果将在同行评议的期刊上广泛传播。这个CAREER项目的成功完成将导致与国家实验室、工业和海外大学的一些新的合作伙伴关系。

0844882 Qian, Xianghong This five year CAREER proposal focuses on the development of an integrated research and education program in biofuels which will aid in the commercialization of biofuels as an alternative to fossil fuels.The research component focuses on understanding the fundamental processes governing the conversion and selectivity of glucose to 5-Hydroxymethylfurfurl (HMF) and improving HMF yield. The education component will result in the training of future engineers for the emerging biorefinery industry. Highlights of the proposed CAREER project include:- Use state-of-the-art ab initio and classical molecular dynamics simulations with advanced metadynamics (MTD) technique to investigate the effects of solvent on the mechanisms and energetic of glucose to HMF conversion in water, organic solvent and ionic liquids.- Establish a Creative Bioenergy Cluster (CBC) for undergraduate researchers to provide multifaceted educational and training opportunities in biofuels.- Build collaborations with national laboratories and international biofuels research community.- Develop a new senior undergraduate / graduate level Computational Materials Science and Engineering course with applications in renewable energy including biofuels.Intellectual Merit of Proposed ActivityBiofuels such as 2, 5-dimethylfuran (DMF) and liquid hydrocarbons are alternative transportation fuels in the emerging biorefinery industry. HMF is a critical and versatile intermediate for converting biomass to DMF, liquid alkanes and many other value-added products. However, the conversion yields from biomass carbohydrates remain critical issues, particularly from glucose, the most abundant monomer sugar from biomass. Currently the HMF yield from glucose is very limited and extremely sensitive to the processing conditions, particularly the solvent. Understanding the effects of solvent on the mechanism(s) and energetics for glucose to HMF conversion will provide significant insights into developing the costeffective conversion processes and improving HMF yields.It is hypothesized that solvent and solvent structures affect both the conversion and selectivity for the acid-catalyzed glucose to HMF conversion reaction. Protonation of the hydroxyl group on the B-Dglucose ring (C2-OH) and the subsequent breaking of the C-O bond is the rate limiting step for the conversion. As a result, proton affinity of the solvent structure will have a significant impact on the reaction barrier due to the competition for protons between the hydroxyl group on the sugar ring and the solvent. Competing reactions are initiated by the protonation of the other hydroxyl groups or the ring O on glucose, and the solvent's ability to extract a proton from the reaction intermediates. Cr (II) ion promotes glucose isomerization to fructose in ionic liquids thus catalyzing glucose to HMF conversion.Car-Parrinello based ab initio molecular dynamics (CPMD) simulations with advanced MTD technique is uniquely suited to investigate chemical reactions and processes. In this CAREER project, CPMD-MTD will be used to investigate the effects of solvent on the mechanisms, rate-limiting steps, free energies and reaction barriers for glucose to HMF conversion in water, DMSO, ionic liquids and their mixtures. Successful completion of the proposed research will help improve HMF yields from glucose and shed significant light on sugar pathway engineering to obtain desired intermediates and products forcost-effective utilization of biomass.Broader ImpactsDevelopment of biofuels such as liquid alkanes from biomass as a replacement for fossil fuels will have tremendous societal impacts: biofuels are renewable and sustainable energy sources whereas fossil fuels are not; use of biofuels can help minimize emissions of greenhouse gases to the environment thus limiting global warming. Training of engineers for careers in future biorefineries will be achieved by establishing a Creative Bioenergy Cluster (CBC). The CBC will provide education and training opportunities including international research opportunities as well as internships in industry and in national laboratories for undergraduates at all levels. A new senior undergraduate / graduate level course in Computational Materials Science and Engineering will be developed. The results of the research component of this CAREER project will be integrated into the course. Outreach activities which promote science and engineering to underrepresented minorities are an integral part of the proposed activities. The research and education results will be disseminated widely in peer reviewed journals. Successful completion of this CAREER project will lead to a number of new partnerships with national laboratories, industry and overseas universities.