固体碱催化剂的制备、表征及其在餐饮废油制备生物柴油中的应用

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征。结果表明，在 700 ℃焙烧制备的 Ca/Si 摩尔比为 0.2 的固体碱催化剂具有最 佳的催化活性。最佳催化剂能够很好地保持 SBA-15 材料原有的二维六方相有序 介孔结构， 比表面积达到 406.7 m2• g-1 。 在醇油摩尔比 12 : 1， 催化剂用量 5 wt.%， 氮气气氛中 65 ℃反应 7 h 的最佳反应条件下， 生物柴油产率可以达到 94.7 wt.%。 最佳催化剂经洗涤和干燥后无需活化即可继续用于下一次的反应，连续使用 5 次后， 催化剂的活性有所下降， 但制得的生物柴油产率仍能保持在 86 wt.%以上。 (3) 通过气相色谱 -质谱 (GC-MS) 对两种最佳固体碱催化剂催化制得的生 物柴油进行了成分分析。结果表明：最佳锌镧固体碱催化剂和最佳 Ca/SBA-15 固体碱催化剂制得的生物柴油成分相似， 两种生物柴油中不饱和脂肪酸甲酯的相 对含量分别为 74.0 wt.%和 70.5 wt.%，均主要含有 9 种主要的脂肪酸甲酯，含量 由高到低分别为油酸甲酯、 亚油酸甲酯、 棕榈酸甲酯、 硬脂酸甲酯、 亚麻酸甲酯、 棕榈油酸甲酯、花生一烯酸甲酯、肉豆蔻酸甲酯和花生酸甲酯。
侯谦奋 张前前 全日制学术学位 无机化学 无机合成与制备
2014
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谨以此论文献给我的恩师张前前教授 以及一直以来支持我的家人和朋友
------- 侯谦奋
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固体碱催化剂的制备、表征及其在餐饮废油 制备生物柴油中的应用 摘 要
随着化石能源的日益枯竭及其在使用过程中所带来的严重环境污染问题， 开 发与利用环境友好的可再生能源已迫在眉睫。生物柴油具有可再生、环保性好、 安全性高、 使用性能佳以及兼容性高的突出优点， 被公认为是矿物柴油的理想替 代品。我国每年都会产生大量的餐饮废油，既污染环境，又危害人们的健康。若 能将这些餐饮废油转化为生物柴油， 不仅能够有效消除餐饮废油的危害， 而且可 以为制备生物柴油提供充足的原料，具有很高的应用价值。因此，本论文选取购 买的餐饮废油为初始原料来制备生物柴油。 首先对餐饮废油进行纯化处理，使其 达到制备生物柴油的原料要求。然后通过所合成的锌镧固体碱和 Ca/SBA-15 固 体碱催化酯交换反应将纯化后的餐饮废油转化为生物柴油， 优化了固体碱催化剂 的制备条件和酯交换法制备生物柴油的反应条件， 表征了最佳催化剂的相关理化 性质，考察了最佳催化剂的重复使用性能，并对制得的生物柴油进行了成分分析 和产率计算。本论文的主要研究成果如下： (1) 采用共沉淀法，以草酸铵为沉淀剂，制备了锌镧固体碱催化剂，将其应 用于催化酯交换反应制备生物柴油。通过热重 -差热分析 (TG-DTA)、 X 射线衍 射 (XRD) 、电感耦合等离子体原子发射光谱 (ICP-AES) 以及扫描电子显微镜 (SEM) 等方法对催化剂的组成和形貌进行表征。结果表明，700 ℃焙烧制备的 Zn/La 摩尔比为 3 : 1 的固体碱催化剂具有最佳的催化活性。 最佳催化剂是由 ZnO 和 La2O3 均匀混合组成，粒径在 100 nm 左右。在醇油摩尔比为 36 : 1、催化剂用 量 5 wt.% (为油的质量)、200 ℃反应 3 h 的最佳反应条件下，生物柴油产率能够 达到 91.6 wt.%。最佳催化剂在使用过程中存在一定程度的流失问题，但连续使 用 4 次后，生物柴油的产率仍能保持在 80 wt.%以上。 (2) 采用溶胶凝胶法，以正硅酸四乙酯为硅源、乙酸钙为钙源、P123 为模板 剂，经一步焙烧制备了 Ca/SBA-15 固体碱催化剂，将其应用于催化酯交换反应 制备生物柴油。通过 X 射线衍射 (XRD)、傅里叶变换红外 (FT-IR) 光谱、透射 电子显微镜 (TEM) 以及 N2 吸附 -脱附分析等方法对催化剂的组成和形貌进行表
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leaching problem, the biodiesel field can remain above 80 wt.% after the fourth circle. (2) The Ca/SBA-15 solid base catalyst was prepared through the sol-gel method, using tetraethyl orthosilicate as the silicon source, lime acetate as the calcium source and P123 as the structure-directing agent, used in the transesterification into biodiesel and characterized by X-ray diffraction (XRD), fourier transform-infrared (FT-IR) spectroscopy, transmission electron microscope (TEM) and N2 adsorption-desorption analysis. The result shows that the catalyst with Ca/Si molar ratio of 0.2, calcined at 700 ℃ exhibits the optimum catalytic activity, which can well maintain the original two-dimensional p6mm hexagonal order mesoporous structure and have a BET surface area of 406.7 m2• g-1. The biodiesel field can reach 94.7 wt.% under the optimum reaction conditions of a methanol/oil molar ratio of 12:1, a catalyst amount of 5 wt.% (referred to oil), a reaction temperature of 65 ℃ and a reaction time of 7 h in the N 2 atmosphere. Washed and dried, the catalyst can be directly reutilized in the next circle without reactivation. After the fifth circle, the catalytic activity decreases but the biodiesel yield is still above 86 wt.%. (3) The biodiesel produced by the optimum solid base catalyst was analyazed through the gas chromatograph-mass spectrometer (GC-MS). The result shows that the composition of the biodiesel produced by the optimum zinc and lanthanum solid base catalyst is very similar to that produced by the optimum Ca/SBA-15 solid base catalyst and the percentages of the unsaturated fatty acid methyl esters in the 2 kinds of biodiesels are 74.0 wt.% and 70.5 wt.%, respectively. Both of the biodiesels contain 9 kinds of fatty acid methyl esters, which are oleic acid methyl ester, linoleic acid methyl ester, palmitic acid methyl ester, stearic acid methyl ester, linolenic acid methyl ester, palmitoleic acid methyl ester, 11-eicosenoic acid methyl ester, myristic acid methyl ester and arachidic acid methyl ester in descending order according to the content.
固体碱催化剂的制备、表征及其在餐饮废油 制备生物柴油中的应用
Synthesis and Characterization of Solid Base Catalyst and Its Application in the Biodiesel Production from Waste Cooking Oil
With the rapid depletion of fossil energy and the serious environmental pollution problems caused by the use of fossil energy, it is very necessary to develop and utilize environment-friendly renewable energy. Biodiesel is recognized as a promising substitute for fossil diesel due to its renewable nature, environmentally beneficial attribute, high safety, excellent using performance and high compatibility. Moreover, every year in China, a large amount of waste cooking oil is produced, which not only pollutes the environment, but also endangers people ’s health. If the waste cooking oil could be transformed into biodiesel, then it would eliminate the harm of waste cooking oil and supply adequate feedstock for the biodiesel production. Therefore, in this thesis, purchased waste cooking oil was first purified and used as the feedstock to produce biodiesel. Through the transesterification of the refined waste cooking oil into biodiesel over the prepared zinc and lanthanum solid base and Ca/SBA-15 solid base, respectively, both the optimum solid base catalyst preparation conditions and the optimum transesterification reaction conditons were investigated, the relative physicochemical properties of the optimum catalyst were characterized, and the reutilization performance of the optimum catalyst was studied. The composition of the produced biodiesel was analyzed and the biodiesel field was calculated. (1) The zinc and lanthanum solid base catalyst was prepared by means of the coprecipitation method with ammonium oxalate as the precipitant, used in the transesterification into biodiesel and characterized by TG-DTA, X-ray diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and scanning electron microscopy (SEM). The result shows that the catalyst with 3 : 1 molar ratio of zinc to lanthanum, calcined at 700 ℃ exhibits the optimum catalytic activity, which is composed of ZnO and La2O3 with the particle size of approximate 100 nm. The biodiesel field can reach 91.6 wt.% under the optimum conditions of a methanol/oil molar ratio of 36 : 1, a catalyst amount of 5 wt.% (referred to oil), a reaction temperature of 200 ℃ and a reaction time of 3 h. Although the optimum catalyst still has the