生物油轻质组分模型化合物重整制氢研究

发布时间：2018-07-06 19:53

  本文选题：生物质油 + 乙酸　； 参考：《浙江大学》2015年硕士论文

【摘要】：生物质作为含碳的可再生资源,通过快速热解直接得到生物质油进而加以能源化利用,是缓解能源危机和环境污染以及生物质利用的重要方向。生物质油具有较强酸性和高含水量等特点,通过减压蒸馏的分级处理后可得到基本不含水和酸的高沸点馏分(重质组分)和富含水及少量酸、醛、酮、醇、酚等含氧有机物的低沸点馏分(轻质组分)。重质组分通过进一步催化提质可得到液体燃料,轻质组分中的含氧有机物则可通过与水重整来制氢。 重整反应的关键在于催化剂高效稳定性和反应条件经济性。因此,本论文以乙酸为生物油轻质组分模型化合物,采用常压固定床流动态反应工艺,开展镍基催化剂上生物油轻质组分低温水蒸气重整制氢研究,获得如下主要研究结果： 采用浸渍法制备了MgO、Y-Al2O3、ZrO2和CeO2载体负载镍的催化剂,通过考察其在乙酸低温水蒸气重整反应中的反应性能,获得了乙酸在350℃的低温常压下转化率接近100%、重整制氢活性高并且稳定的Ni/CeO2催化剂。结果表明,Ni/MgO和Ni/γ-Al2O3催化剂由于Ni组分与载体相互作用很强导致其可被还原利用的金属Ni少,不利于反应；而Ni/CeO2催化剂由于Ni与Ce02相互弱作用,易于还原,可被利用的金属Ni多,使其具有高的重整制氢能力。因此,载体与镍之间的相互作用程度是影响催化剂重整制氢性能的主要因素。 以铈锆复合氧化物为载体,通过对不同Ce/Zr比CeO2-ZrO2载体负载Ni催化剂的研究,获得了比Ni/CeO2催化剂性能更佳的Ni/CeO2-ZrO2乙酸水蒸气重整制氢催化剂。不同Ce/Zr比主要影响了CexZr1-xO2固溶体的结构,并对负载Ni物种的可还原度、晶粒尺寸等产生影响。改变Ni的负载量以及焙烧温度的研究进一步表明了Ni/CeO2-ZrO2催化剂的催化性能与可还原的镍物种的数目及其晶粒尺寸存在一定对应关系。 通过改变还原温度、反应温度以及反应物中乙酸含量,研究了Ni/CeO2-ZrO2催化剂的乙酸水蒸气重整特性。结果表明,在该体系的催化剂上,乙酸的水蒸气重整制氢存在二条途径,在金属Ni上可直接发生水蒸气重整,而在载体上则通过酮基化形成丙酮再在邻近的Ni组分上发生重整。
[Abstract]:Biomass as a carbon-bearing renewable resource, biomass oil is directly obtained by rapid pyrolysis and energy utilization, which is an important direction to alleviate the energy crisis and environmental pollution as well as biomass utilization. Biomass oil has the characteristics of strong acidity and high water content. The high boiling point fractions (heavy components) without water and acid can be obtained by the fractionation of vacuum distillation, which are rich in water, aldehydes, ketones, alcohols, etc. A low boiling point fraction (light component) of oxygenated organics, such as phenol. Liquid fuel can be obtained by further catalytic extraction of heavy components, and hydrogen can be produced by reforming hydrogen with water by reforming oxygen-containing organic compounds in light components. The key of reforming reaction lies in the high stability of catalyst and the economy of reaction conditions. Therefore, in this paper, acetic acid was used as the model compound of light component of bio-oil, and the reaction process of fixed-bed flow state was used to study the hydrogen production of light component of bio-oil by low-temperature steam reforming of bio-oil on nickel-based catalyst. The main results are as follows: MgO- Y-Al _ 2O _ 3 ZrO _ 2 and CeO2 supported nickel catalysts were prepared by impregnation method, and their reaction performance in low-temperature steam reforming of acetic acid was investigated. The Ni / CEO _ 2 catalyst with high catalytic activity and stable hydrogen production activity was obtained. The conversion of acetic acid was close to 100 at 350 鈩，

本文编号：2103914