共查询到16条相似文献,搜索用时 46 毫秒
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生物质转化合成新能源化学品乙酰丙酸酯 总被引:2,自引:0,他引:2
生物质是唯一可替代化石资源获取液态燃料和化学品的可再生资源,近年来由生物质转化合成乙酰丙酸酯引起了研究者们越来越广泛的关注。乙酰丙酸酯是一类重要的化学中间体和新能源化学品,具有高的反应特性和广泛的工业应用价值。目前开发的从生物质资源出发转化合成乙酰丙酸酯的潜在合成途径可概括为4种:直接酸催化醇解法、经乙酰丙酸酯化、经5-氯甲基糠醛醇解和经糠醇醇解。本文分别介绍了这4种转化合成途径的化学反应过程及最新研究进展,从反应合成工艺、催化体系、经济可行性等方面评述了各自的特点与发展趋势,并分析了目前工业规模转化生物质合成乙酰丙酸酯仍面临的一些科学难点。最后,对今后该领域的研究前景进行了展望。 相似文献
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化石燃料的过度消耗导致了能源短缺和环境破坏,因此可再生清洁能源的开发已成为当务之急.在众多可再生能源中,太阳能因其环境友好,储量巨大且分布广泛等特点而引起了研究者们的兴趣.光电催化(PEC)是一种能够将可再生太阳能转化为化学能的方法,而最受关注的是通过PEC水分解来获得高附加值的氢能源.欲使PEC系统实现水分解,理论上... 相似文献
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甲壳素是地球上储量丰富且含有生物固定氮元素的天然高分子。将甲壳素生物质高选择性转化为高值含氮化学品是利用甲壳素的有效策略,已经引起研究者的关注。本文综述了近年来由甲壳素及其衍生物(如壳聚糖等)合成氨基糖、氨基醇、氨基酸和杂环化合物等含氮高附加值化学品的研究进展,对甲壳素生物质的高值化利用进行了展望。 相似文献
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电催化生物质转化是以间歇式能源产生的电能驱动生物质电转化为高附加值有机化学品的过程,将其与水分解耦合能够产生高纯度氢气,具有有效降低化石燃料消耗、优化能源结构及解决环境问题的潜力.然而,由于生物质具有多个官能团及其转化反应涉及多个电子参与,电催化生物质转化面临着转化效率低、选择性差和稳定性不足等挑战.通过调控表面本征结构、构筑表面空位、引入表面杂原子和构建表面协同界面等一系列表界面化学工程对二维电催化材料进行设计和改性,实现对其表面电子结构和几何结构的优化,可以有效地改善二维材料的电转化效率、选择性和稳定性.本综述详细介绍了表界面化学改性二维材料电催化生物质转化的最新研究进展,总结了该研究领域存在的问题,并展望了其研究前景. 相似文献
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This review covers the characteristics of pyrolysis and catalytic pyrolysis bio‐oils by focusing on the fundamental factors that determine bio‐oil upgradability. The abundant works on the subject of bio‐oil production from lignocellulosic biomass were studied to establish the essential attributes of the bio‐oils for assessment of the oil stability and upgradability. Bio‐oils from catalytic pyrolysis processes relating to catalysts of different compositions and structures are discussed. A general relationship between the higher heating value and the oxygen content in the catalytic pyrolysis oils exists, but this relationship does not apply to the thermal pyrolysis oil. Reporting bio‐oil yield is meaningful only when the oxygen content of the oil is measured because the pyrolytic oil stability is mainly determined by the oxygen content. Isoenergy plot that associates bio‐oil yield with oxygen content is presented and discussed. 相似文献
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木质纤维基生物质是一类新的能够生产液体燃料和化学品的可再生资源. 本文研究了木质纤维生物质在水热条件下, 以少量无机酸作为酸催化剂, 氧气作为氧化剂(2.0 MPa), 经过"一锅两步法"转化成乙酸的反应. 以玉米秸秆作为反应原料时, 最高可以获得21.3 wt%的乙酸, 占据整个液体产物质量比例的84.6% (选择性). 同时, 将反应推广到玉米芯, 甘蔗渣, 竹子, 杨木和松木等多种生物质原料的转化, 同样取得了较高的乙酸产率. 最后, 我们对木质纤维生物质转化到乙酸的反应过程进行了研究. 研究表明木质纤维生物质中的碳水化合物六碳糖是乙酸的主要来源, 六碳糖经过脱水和水解生成乙酰丙酸中间体, 乙酰丙酸在氧化条件下断裂C-C键生成乙酸. 相似文献
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Carina A. Esteves Costa Carlos A. Vega-Aguilar Alírio E. Rodrigues 《Molecules (Basel, Switzerland)》2021,26(15)
Lignin is the second most abundant component, next to cellulose, in lignocellulosic biomass. Large amounts of this polymer are produced annually in the pulp and paper industries as a coproduct from the cooking process—most of it burned as fuel for energy. Strategies regarding lignin valorization have attracted significant attention over the recent decades due to lignin’s aromatic structure. Oxidative depolymerization allows converting lignin into added-value compounds, as phenolic monomers and/or dicarboxylic acids, which could be an excellent alternative to aromatic petrochemicals. However, the major challenge is to enhance the reactivity and selectivity of the lignin structure towards depolymerization and prevent condensation reactions. This review includes a comprehensive overview of the main contributions of lignin valorization through oxidative depolymerization to produce added-value compounds (vanillin and syringaldehyde) that have been developed over the recent decades in the LSRE group. An evaluation of the valuable products obtained from oxidation in an alkaline medium with oxygen of lignins and liquors from different sources and delignification processes is also provided. A review of C4 dicarboxylic acids obtained from lignin oxidation is also included, emphasizing catalytic conversion by O2 or H2O2 oxidation. 相似文献
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Banana pseudostem fiber which is a lignocellulosic material, relatively inexpensive, and abundantly available was assessed in terms of its fiber‐matrix adhesion and dispersion in composites. Different types of adhesives were used. The mechanical and water absorption properties were investigated. Overall, for the produced composites, the incorporation of sawdust‐urea‐formaldehyde resin into prehydrolyzed banana fiber resulted in the best mechanical properties. Good adhesion‐fiber interaction is believed to be responsible for the good ultimate performance. The superior reinforcing characteristics of sawdust resin were shown by scanning electron microscopy (SEM), which revealed better fiber‐matrix adhesion. Water absorption tests revealed that the presence of the adhesives affected the amount of water absorbed. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献