碳基整体式催化剂催化制备生物柴油

发布时间：2018-10-15 12:57

【摘要】：生物柴油,作为一种可再生的替代能源,在世界范围内有巨大的潜在市场。将生物油脂经过简单的甲醇酯交换反应即可得所谓的第一代生物柴油,具有来源广泛,不含硫、氮等杂原子的特点,是一种低环境效应的燃料,可直接供给柴油机使用。目前其流行生产工艺主要为硫酸催化预酯化和氢氧化钠催化酯交换再接着进行减压蒸馏分离的所谓两步法,该方法存在设备腐蚀与能耗高的弊端。本文根据生物油脂与甲醇进行酯交换反应的特点,利用反应物、主产物均为重组分的特点,发展了一种独特的催化蒸馏技术路线,设计并制备了一种在不锈钢丝网构成的拉西环构件上生长碳纳米管的整体式催化蒸馏构件,并对碳纳米管进行固体酸功能化,应用于该催化蒸馏过程,将反应、分离集成于一体完成,取得了具有重要意义的进展。完成的工作包括：1)选择了合适的不锈钢丝网作为生长碳纳米管催化剂的基底,试验了不同前处理条件对生长碳纳米管的影响,找到了合适的前处理条件,将处理好的丝网放置在生长炉中,用同时在沉积气体碳源中添加茂金属作为浮动催化剂的催化气相沉积法(FCCVD)在丝网上生长碳纳米管,探索了最佳反应条件,获得了不锈钢丝网基底上阵列整齐,长度均一,与基底结合紧密的碳纳米管材料。2)对上述表面生长有碳纳米管阵列的丝网构件进行整体硫化、氧化获得表面牢固固定有磺酸基团的整体固体酸材料,采用谱学定性与定量测量结合的方法详细表征了该固体酸材料的性质,证实该材料酸位密度高,机械加工性能好,结构稳定性较好。3)使用上述填料组成微型催化蒸馏反应塔,生物油脂原料从塔顶滴流加入反应塔,在向下流动的过程中与上升的甲醇蒸汽在构件表面发生催化酯交换反应,生成的高纯度产物脂肪酸甲酯直接流入反应塔釜中,令人惊讶的是副产物甘油在此过程中在反应塔中进一步转化为甲酯更高的产物并可从塔顶分离出来。上述过程具有很好的理论探索意义,也有良好的应用前景,值得进行深入研究与应用推广。
[Abstract]:Biodiesel, as a renewable alternative energy, has a huge potential market worldwide. The so-called first generation biodiesel can be obtained by the simple methanol transesterification reaction. It is a low environmental fuel and can be directly used for diesel engine because of its wide source, no sulfur, nitrogen and other hetero atoms. At present, the popular production processes are sulfuric acid catalyzed preesterification and sodium hydroxide catalyzed transesterification followed by vacuum distillation separation. This method has the disadvantages of equipment corrosion and high energy consumption. According to the characteristics of transesterification between bio-oil and methanol, a unique catalytic distillation technique has been developed based on the recombination of reactants and main products. A monolithic catalytic distillation component for carbon nanotubes (CNTs) was designed and fabricated on the stainless steel wire forming Rasich ring. The carbon nanotubes were functionalized by solid acid, and then applied to the catalytic distillation process, and the reaction was carried out. Separation and integration have been completed, and significant progress has been made. The results are as follows: 1) the suitable stainless steel wire mesh is selected as the substrate of the catalyst for the growth of carbon nanotubes, and the effects of different pretreatment conditions on the growth of carbon nanotubes are tested, and the appropriate pretreatment conditions are found. The treated wire mesh was placed in the growth furnace, and the carbon nanotubes were grown on the wire mesh by catalytic vapor deposition (FCCVD) with metallocene as floating catalyst in the carbon source of the deposited gas. The optimum reaction conditions were explored. The carbon nanotube materials with uniform length and uniform length on the stainless steel mesh substrate were obtained. 2) the wire mesh members with carbon nanotube arrays on the above surface were vulcanized as a whole. The solid acid material with sulfonic acid group firmly immobilized on the surface was obtained by oxidation. The properties of the solid acid material were characterized in detail by the method of qualitative and quantitative measurement. It was proved that the material had high acid potential density and good machinability. The structure stability is good. 3) the micro catalytic distillation reaction tower is composed of the above mentioned fillers. The bio-oil feedstock is added into the reaction tower from the top of the tower. During the downward flow process, catalytic transesterification occurs with the rising methanol vapor on the surface of the component. The high purity fatty acid methyl ester produced directly flows into the reactor. It is surprising that the by-product glycerol is further transformed into a higher methyl ester product in the reaction tower and can be separated from the top of the column. The above process has good theoretical significance and good application prospect, which is worthy of further study and application.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O643.36;TE667

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