Collaborative Research: Rational design of bifunctional catalysts for the conversion of Ievulinic acid to gamma-valerolactone

摘要#1159739/ #1159863Bond，Jesse Q. / Heyden，Andreas现代石化工业通过对一些关键的化学原料进行选择性转化，在满足社会需求方面取得了令人印象深刻的效率。 未来自我维持的生物精炼工业将同样基于可再生构件的选定平台，这些构件可产生运输燃料或商品和特种化学品。最近的一项研究确定了10种有前途的生物质衍生物，它们有可能成为未来生物炼油厂的基石。其中，乙酰丙酸（LA）是特别有前途的，因为它可以通过多种木质纤维素原料的硫酸水解以低成本和高产率生产。LA转化为燃料添加剂、化学品和塑料和纺织品单体的过程已经得到证实，但尚未商业化。一种衍生化学物质，？β-戊内酯（GVL）是一种有前途的、极其灵活的中间体，从其可以获得这些相同的许多期望的终产物。 尽管GVL有无数的应用，但其大规模生产尚未建立，这主要是由于与其直接前体LA的纯化相关的困难。来自锡拉丘兹大学的邦德认为这些问题有解决方案，并获得了NSF的这一奖项，以建立基础科学，使木质纤维素生物质衍生平台化学品GVL的生产在商业规模上可行。在现有技术中，LA必须经历昂贵的纯化方案以在转化为GVL之前从纤维素水解中除去残留的硫酸。H2SO 4必须回收和再循环，这符合生物精炼工艺长期可持续性的承诺。GVL是足够疏水的，以允许通过用低沸点乙酸盐萃取，然后通过容易的蒸馏从含水硫酸中进行能量有效的分离。有人提出了简化这一步骤的催化办法。然而，新的挑战是目前可用的HDO催化剂不足以加工未精制的LA。Heyden和Bond建议使用计算和实验相结合的方法来获得对在水溶液和稀硫酸溶液中在Ru/C和RuRe/C催化剂上LA到GVL的温和非均相催化加氢脱氧的反应机理的基本理解，导致潜在的改进催化剂，从而使整个战略更具工业相关性。该项目的基本目标是创建一个为合理设计新型多相催化剂提供了科学依据，该催化剂具有上级的活性、选择性和稳定性，可用于在硫酸水溶液中将LA加氢合成GVL。 成功的结果在木质纤维素生物质的水相加工中广泛相关。 此外，计算和实验相结合的研究方法的成功表明，这种策略不仅增加了我们对反应机理的理解，而且减少了设计新的非均相催化剂所需的时间和财政资源，以满足资源有限的世界不断变化的需求。 参与该项目的博士生将成为计算和实验催化实践和整合的专家。 此外，研究成果将被纳入选修课"多尺度建模：从电子到化学反应器“正在由海登在南卡罗来纳州和”多相催化“正在由邦德在锡拉丘兹大学提供。

Abstract#1159739 / #1159863Bond, Jesse Q. / Heyden, AndreasThe modern petrochemical industry has achieved impressive efficiencies in meeting societaldemands through selective transformations of a few, key building block chemicals. A future self-sustaining biorefining industry will similarly be based on a selected platform of renewable building blocks which may yield transportation fuels or commodity and specialty chemicals. A recent study has identified 10 promising biomass derivatives that have the potential to serve as building blocks for future bio-refineries. Of those, Levulinic Acid (LA) is particularly promising as it can be produced inexpensively and in high yields by sulfuric acid hydrolysis of a variety of lignocellulosic feedstocks. Conversion processes of LA to fuel additives, chemicals, and monomers for plastics and textiles have been demonstrated, but not commercialized. A derived chemical, ?×-valerolactone (GVL), is a promising and extremely flexible intermediate, from which these same numerous desirable end-products can be obtained. Despite a myriad of applications for GVL, its large scale production is not yet established, owing largely to difficulties associated with the purification of its immediate precursor, LA.Professor Andreas Heyden from the University of South Carolina and Professor Jesse Q. Bond from Syracuse University believe these issues have solutions, and have received this NSF award to establish the underlying science that can make feasible the production of the lignocellulosic biomass-derived platform chemical GVL on a commercial scale. In the present state of the art, LA must undergo a costly purification scheme to remove residual sulfuric acid from cellulose hydrolysis prior to conversion to GVL. H2SO4 must be recovered and recycled, in line with a commitment to the long term sustainability of biorefining processes. GVL is sufficiently hydrophobic to allow an energy efficient separation from aqueous sulfuric acid by extraction with a low-boiling acetate followed by facile distillation. A catalytic approach to streamline this step has been proposed. However, the new challenge is the inadequacy of presently available HDO catalysts for processing of unrefined LA. Heyden and Bond propose to use a combined computational and experimental approach to obtain fundamental understanding of the reaction mechanism of the mild, heterogeneously catalyzed hydrodeoxygenation of LA to GVL over Ru/C and RuRe/C catalysts in both aqueous and dilute sulfuric acid solutions, leading to potential improved catalysts and thus making the entire strategy more industrially relevant.The fundamental objective of this project is to create a scientific basis for the rational design of novel heterogeneous catalysts with superior activity, selectivity, and stability for the HDO of LA to GVL in aqueous sulfuric acid. A successful outcome is broadly relevant in aqueous phase processing of lignocellulosic biomass. Further, success of the combined computational and experimental research approach illustrates that such a strategy not only increases our understanding of reaction mechanisms, but also reduces the time and financial resources needed for the design of new heterogeneous catalysts tailored to meet the changing needs of a world with limited resources. The PhD students involved in this project will become experts in the practice and integration of computational and experimental catalysis. Also, the research results will be incorporated into the elective classes ¡§Multiscale Modeling: From Electrons to Chemical Reactors¡¨ being taught by Heyden at the University of South Carolina and ¡§Heterogeneous Catalysis¡¨ being offered by Bond at Syracuse University.