题名基于离子液体的生物质催化转化制备5-羟甲基糠醛和生物汽油
作者石春艳
学位类别博士
答辩日期2014-04
授予单位中国科学院研究生院
导师张香平
关键词5-羟甲基糠醛 生物汽油 离子液体 双相反应器 二氧化碳
其他题名Production of 5-Hydroxymethylfurfural and Bio-gasoline from Biomass Based on Ionic Liquids
学位专业化学工程
中文摘要将生物质转化为生物化学品和液体燃料不仅能够弥补化石资源短缺带来的问题,而且有助于保护生态环境,其合理利用对建立高效、可持续的全球能源系统、保障国家能源安全以及减轻大气污染起到积极作用,具有巨大现实和深远的社会意义。本论文针对目前生物质转化制备5-羟甲基糠醛和生物汽油中存在的催化效率低、反应温度高、产品分离困难、反应路线长等关键问题,开展了CO2作为“相分离开关”的新型离子液体-有机溶剂双相反应体系中制备5-羟甲基糠醛,以及直接利用生物原料转化合成生物汽油的集成方法和过程研究。 本论文主要创新性的工作及成果如下: (1) 开发了集反应、分离、分析一体化的离子液体-超临界流体原位研究装置。该装置能够在苛刻(高温、高压及高腐蚀性)和连续条件下同时完成离子液体介质中反应和超临界流体萃取等单元操作,通过实时成像系统记录反应釜中反应行为,并且集成原位红外分析仪器、色谱仪等分析装置,在线进行定量、定性分析,同时实现全系统的自动控制。该装置应用于离子液体-超临界CO2体系中制备5-羟甲基糠醛的研究,实现了反应-分离一体化过程。 (2) 基于离子液体的5-羟甲基糠醛制备过程中重点考察了离子液体不同种类的阴离子和阳离子分别对反应的影响规律,并采用分子动力学模拟验证实验结果。实验结果表明:烷基链长度>4的咪唑类离子液体,因烷基链具有明显的团簇现象,会导致反应活性降低;反之烷基链长度≤4时,因结构不存在明显团簇现象则对反应有利;阴离子对反应的影响更甚于阳离子,离子液体的阴离子若与果糖分子能形成较强的氢键,进而会形成较强的分子间相互作用能,更有利于果糖脱水生成5-羟甲基糠醛。 (3) 设计开发了基于CO2作为“相分离开关”的新型离子液体-有机溶剂双相反应体系,实现5-羟甲基糠醛反应-分离耦合一体化过程;研究了离子液体-有机溶剂-CO2相行为,获得离子液体-有机溶剂-CO2的三元相图,了解和掌握离子液体和有机溶剂的分相条件;考察了5-羟甲基糠醛在离子液体和有机溶剂中的分配系数以及在双相系统中制备条件(反应、温度、溶剂体积比、CO2压力、复配离子液体比例)对反应的影响,得出最佳制备条件;设计了连续循环双相反应系统,并应用于制备5-羟甲基糠醛过程中,结果表明本系统可有效回收溶剂和CO2并循环使用,对产品进行多次连续萃取后,萃取率达到95%。 (4) 开发了一种直接由生物质原料转化生成生物汽油的较短路线的新型集成方法,通过水解、催化、聚合、加氢方法获得碳链长度为C5-C15的生物汽油。研究了温和条件下快速构建C-C键的方法,且产品选择性接近100%。在通过加氢脱氧制备生物液体烷烃的最佳反应条件下,生成的烷烃多为C8和C9烷烃,符合高品质生物汽油所需的液体烷烃碳数。 基于以上研究成果,本研究将为深入研究离子液体-超临界流体体系在反应-萃取-分离方面独特优势提供研究平台;创新性提出的双相反应器制备HMF方法以及较短路线制备生物汽油的集成方法,将为HMF和生物汽油高效、清洁生产提供有效途径。
英文摘要The conversion of biomass into bio-chemical and bio-fuels is an important method in dealing with the shortage of fossil fuels and decreasing the levels of greenhouse gases. It will lead to a high ef?ciency, sustainable energy system and secure the supply of reliable energy. The research of this article was mainly expected to deal with low catalyst conversion efficiency, high reaction temperature, difficult products separation and long reaction route, which exist in production of 5-hydroxymethylfurfural (HMF) and bio-gasoline from biomass. To overcome those problems, a switchable biphasic reaction-separation coupling system with CO2 as a “phase separation switch” is proposed to prepare HMF. We also developed an integrated process to produce bio-gasoline from commonly available biomass. The detailed contents and innovative results are listed as follows: (1) Integrating reaction, separation and analysis equipment in situ was designed and manufactured, which can be operated with ionic liquids (ILs) and supercritical fluids for reaction and extraction processes at high temperature, pressure and corrosivity. Through a real time imaging system, the reaction and separation processes carried out in the equipment were observed and recorded. The in situ quantitative and qualitative analyses were achieved by coupling IR and HPLC through automatic controlling system. This equipment was used to prepare HMF in ionic liquids -supercritical CO2 system for coupling reaction and separation processes. (2) Ionic liquids used as a medium with various alkyl chains of imidazolium cations and various kinds of anions were selected to study the effects of cations and anions on fructose for HMF preparation. Molecular dynamics simulations were also performed to verify the experimental results. The yield of HMF was strongly affected by aggregations of cations and the hydrogen bonds between anions and fructose. The imidazolium cationic ILs with the alkyl chain of the cations shorter than 4 are suitable for HMF preparation. The anion of ILs, formed strong hydrogen bonds between ILs and fructose molecules or the acid radical lead to high reaction activity. (3) A switchable biphasic reaction-separation coupling system is proposed, in which the reaction-separation coupling process of HMF preparation is proceeded. The phase behavior of ionic liquids-acetone-CO2 ternary systems was studied and obtained. The separation conditions of ionic liquids and organic solvents were investigated. The effect of temperature, volume ratio of ILs and acetone, CO2 pressure and compound ILs on reaction were studied. Compared with several single-phase systems, the biphasic system with coupling reaction-separation process could benefits the HMF preparation. Moreover, the biphasic system for continuous production of HMF is proposed, which is a step toward the more economical production through recycling of the inexpensive and abundantly available solvents and CO2. After repeating 3 times, about 95% HMF was extracted into the upper phase and collected in container. (4) An integrated process that converts commonly available biomass into gasoline was developed. Strategies of this process are to form carbon-chain-prolonged oxygenated intermediate products from functional chemicals produced by catalytic treatment of biomass in mild conditions (selectivity about 100%), and then to remove the oxygen of intermediate products by hydrodeoxygenation to produce C5-C15 gasoline-ranged liquid alkanes. The research shows that it produced alkanes most of them are C8 and C9 alkenes, which is in the carbon number suitable for the requirement of gasoline from cellulose-hemicelluloses and sugar containing biomass. Base on the above research, it will provide green, high efficiency preparation methods for HMF and gasoline.
语种中文
公开日期2015-07-08
内容类型学位论文
源URL[http://ir.ipe.ac.cn/handle/122111/15533]  
专题过程工程研究所_研究所(批量导入)
推荐引用方式
GB/T 7714
石春艳. 基于离子液体的生物质催化转化制备5-羟甲基糠醛和生物汽油[D]. 中国科学院研究生院. 2014.
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