Effective production of octane from biomass derivatives under mild conditions.
Effective production of octane from biomass derivatives under mild conditions.
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DOI：
10.1002/cssc.201100361
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发表时间：
2011-12
期刊：
影响因子：
8.4
通讯作者：
Wenjie Xu;Qineng Xia;Yu Zhang;Yong Guo;Yanqin Wang;G. Lu
中科院分区：
文献类型：
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作者：
Wenjie Xu;Qineng Xia;Yu Zhang;Yong Guo;Yanqin Wang;G. Lu
化石燃料储量的减少使得从可再生生物质资源生产液体燃料特别具有吸引力，并且全世界已经做出许多努力来将生物质转化为运输燃料。2]当将木质纤维素生物质转化为烃燃料时的总体目标是除去氧和形成C C键;后者控制最终烃的分子量。到目前为止，存在两种从生物质衍生的碳水化合物生产液体烷烃的综合方法，都是由Dumesic的小组开发的。在“水相加工”中，C1糠醛或5-羟甲基糠醛（HMF）首先在碱性催化剂的存在下与丙酮进行羟醛缩合，然后氢化缩合产物（4- 5.5MPa）。然后，通过脱水/氢化（5.2-6 MPa，250-260 ℃）形成长链烷烃。另一种方法涉及通过脱水/氢化（4 MPa，200 ° C）由乙酰丙酸产生的g-戊内酯（GVL）到液体烷烃的集成催化转化。在该方法中，GVL的脱羧首先在升高的温度和压力（3.6MPa，375 ° C）下发生以产生由丁烯和CO2组成的气流。然后将该料流直接进料到低聚反应器中以形成可冷凝的烷烃。这两种策略都是创造性的，但必须在高压或高温下操作。最近，我们开发了一种新的Pt/Co_2AlO_4催化剂，用于在温和条件下（1- 1.5MPa，130-150 ℃）由糠醛直接开环制备戊二醇。4-（2-呋喃基）-3-丁烯-2-酮1具有类似于糠醛的分子结构。它是糠醛与丙酮的单一羟醛加合物，也是将木质纤维素生物质转化为辛烷的水相加工中的重要中间体。然而，它必须在4.5- 5.5MPa下在Ru/C或Pd/Mg 0 ZrO 2催化剂上氢化，以防止在下一步骤中C=C在Pt/酸催化剂上聚合。若能在类似糠醛的Pt/Co2 AlO 4催化剂上加氢，则可在温和条件下得到1，7-辛二醇和2，5-辛二醇。已知二醇或多元醇的脱水/氢化比四氢呋喃衍生物更容易。因此，该方法的反应条件将比上述两种方法温和得多。在这里，我们展示了糠醛（一种生物质产品，从木糖脱水获得）如何在温和的条件下以高产率转化为辛烷。方案1显示了由糠醛和丙酮生产辛烷的反应途径的基本特征，包括糠醛与丙酮的羟醛缩合，
The diminishing reserves of fossil fuels have rendered the production of liquid fuels from renewable biomass resources particularly attractive, and worldwide many efforts have been devoted to the conversion of biomass into transportation fuels. 2] The overall goals when converting lignocellulosic biomass to hydrocarbon fuels are the removal of oxygen and the formation of C C bonds; the latter to control the molecular weight of the final hydrocarbons. So far, two integrated processes to produce liquid alkanes from biomass-derived carbohydrates exist, both developed by Dumesic’s group. In “aqueous-phase processing”, c] furfural or 5-hydroxymethylfurfural (HMF) first undergoes an aldol condensation with acetone in the presence of a basic catalyst, followed by hydrogenation of the condensation products (4– 5.5 MPa). Then, long-chain alkanes are formed by dehydration/ hydrogenation (5.2–6 MPa, 250–260 8C). The other process involves the integrated catalytic conversion of g-valerolactone (GVL), produced from levulinic acid by dehydration/hydrogenation (4 MPa, 200 8C), to liquid alkanes. In this process, the decarboxylation of GVL first occurs at elevated temperature and pressure (3.6 MPa, 375 8C) to produce a gas stream composed of butene and CO2. This stream is then fed directly into an oligomerization reactor to form condensable alkanes. Both strategies are creative, but must be operated at high pressure or temperature. Very recently, we developed a new Pt/Co2AlO4 catalyst to directly open furan rings and produce pentanediols from furfural under mild conditions (1–1.5 MPa, 130–150 8C). 4-(2-Furyl)-3buten-2-one 1 has a molecular structure that is similar to furfural. It is a single aldol adduct of furfural with acetone and also an important intermediate in aqueous phase processing for converting lignocellulosic biomass to octane. However, it must be hydrogenated over a Ru/C or Pd/Mgo ZrO2 catalyst at 4.5–5.5 MPa to prevent polymerization of C=C over a Pt/acid catalyst in the next step. If it could be hydrogenated over a Pt/ Co2AlO4 catalyst similar to furfural, 1,7and 2,5-octanediol would be obtained in mild conditions. The dehydration/hydrogenation of diols or polyols is known to be easier than for tetrahydrofuran derivatives. As a result, the reaction conditions of the process would be much milder than for the two processes mentioned above. Herein, we show how furfural (a biomass product, obtained from the dehydration of xylose) can be converted to octane under mild conditions with high yield. Scheme 1 shows the essential features of the reaction pathways for the production of octane from furfural and acetone, comprising the aldol condensation of furfural with acetone,