疏水性纳米氧化铁的制备及其煤液化性能研究

发布时间：2018-03-08 13:09

本文选题：疏水性纳米氧化铁　切入点：煤直接液化　出处：《新疆大学》2015年硕士论文　论文类型：学位论文

【摘要】：催化剂在煤直接液化(Direct Coal Liquefaction)反应过程中起着至关重要的作用。高效的催化剂应具备以下几个特点:与煤粉颗粒具有良好的接触性、高的递氢活性、高的催化裂解及催化加氢活性、相对低廉的制备成本或具有易再生、易回收的特点。而铁基催化剂因为拥有来源广泛、价格相对低廉、环境友好、相对较高的催化活性等特点,成为最常用的煤直接液化催化剂。影响铁基催化剂催化活性的因素主要包括颗粒尺寸和分散性。因此,制备小尺寸高分散性的铁基催化剂在近几十年来已经受到了人们的广泛关注。本论文通过二相溶剂热法和“铁盐强迫水解/二相法”分别制备了疏水性纳米Fe2O3和疏水性纳米β-FeOOH催化剂。并对比了所得产物与商品Fe2O3在催化新疆西沟煤直接液化上的催化效果。主要研究内容和所得结论如下:一、以油胺(OAm)辅助二相溶剂热法制备了油胺包覆型的疏水性Fe2O3纳米粒子。通过调控油胺量成功获得了不同粒径分布的疏水性纳米Fe2O3颗粒,结果表明,随着油胺用量的增加,产物粒径呈现出减小趋势。TEM和XRD结果表明,当体系中加入的Fe与油胺摩尔比为1:3、1:6和1:9时,分别得到了平均粒径分别为108 nm、64 nm和52 nm的Fe2O3纳米粒子。FT-IR结果表明纳米粒子表面存在油胺分子包覆层。二、开展了油胺包覆的疏水性纳米Fe2O3的放大合成研究(将反应物料整体放大3倍)。通过实验室初级放大制备得到了较高产量(250 mL单釜产物大约为0.22 g)的疏水性纳米Fe2O3。XRD和TEM表征表明,经过实验室初步放大,产物的形貌及物相没有发生明显改变。在反应物料放大3倍的条件下,通过调控油胺量,可以获得平均粒径分别在96 nm,69 nm和53 nm左右的疏水性纳米Fe2O3。通过进一步分析XRD、TEM和FT-IR谱图,确定了油胺辅助二相溶剂热法制备的疏水性纳米Fe2O3表面确实存在油胺分子包覆层。以所得产物和商品Fe2O3作为催化剂,对阜康西沟煤进行了直接液化性能测试。结果显示,当液化体系中分别加入铁含量为干基无灰煤的3.0 wt%的疏水性纳米Fe2O3和商品Fe2O3催化剂时,其转化率、油产率和液化率分别达到了95.9 wt%、77.4 wt%和87.1 wt%(Fe/OAm=1:3);92.3 wt%、73.6 wt%和81.5 wt%(Fe/OAm=1:6);92.3 wt%、70.2 wt%和72.3 wt%(Fe/OAm=1:9);93.8%、67.6%和75.9%(商品Fe2O3)。液化结果表明,合成的三种疏水性纳米Fe2O3催化剂的油产率相比于商品Fe2O3催化剂分别提高了14.5%、8.9%和3.8%。三、采用简单的水解法大批量制备了亲水性β-FeOOH纳米粒子,并用油酸钠对其改性,获得了疏水性β-FeOOH纳米粒子。首先,通过铁盐的强迫水解,获得了大批量(422 g)的亲水性β-FeOOH纳米粒子。其次,以油酸钠作为改性剂,以两相法制备了油酸(OA)包覆的疏水性β-FeOOH纳米粒子。XRD和TEM结果表明,产物为长约120 nm直径50 nm的纺锤形β-FeOOH纳米粒子。FT-IR结果表明,粒子表面包覆有油酸分子层。以亲水性和疏水性β-FeOOH纳米粒子作为催化剂,研究了其煤直接液化催化效果。结果显示,其转化率、油产率和液化率分别达到了86.4 wt%、57.7 wt%和69.0 wt%(空白);88.3 wt%、66.7 wt%和73.7 wt%(亲水性β-FeOOH);92.6 wt%、73.8 wt%和80.8 wt%(疏水性β-FeOOH)。实验结果表明,通过铁盐水解和油酸包覆能实现亲水性β-FeOOH纳米粒子的大批量制备和疏水改性,并且产物对催化西沟煤直接液化展现了较好的液化效果。此外,由于该合成方案反应条件温和、操作简单和易于放大,故具有良好的工业应用前景。
[Abstract]:The catalyst in direct coal liquefaction (Direct Coal Liquefaction) plays a crucial role in the reaction process. Efficient catalyst should have the following characteristics: have a good contact performance and delivery of coal particles, high catalytic activity, catalytic cracking and catalytic hydrogenation activity is high, relatively low cost of preparation or is easy to regenerate, the characteristics of easy recovery. The iron-based catalyst because they have a wide range of sources, the price is relatively cheap, environmentally friendly, relatively high catalytic activity and other characteristics, has become the most commonly used direct coal liquefaction catalyst. Factors influencing the iron-based catalyst of catalytic activity mainly include particle size and dispersity. Therefore, the preparation of small size and high dispersion of iron based catalyst has received widespread attention in recent years. This paper through the two-phase solvothermal method and Fe / two-phase forced hydrolysis method were used to prepare hydrophobic nano Fe preparation 2O3 and hydrophobic nano beta -FeOOH catalysts. And compared the products and commodities in Xinjiang Fe2O3 catalytic Xigou coal direct liquefaction on the catalytic effect. The main research contents and conclusions are as follows: first, using oil amine (OAm) hydrophobic Fe2O3 nanoparticles coated oil amine was prepared by phase assisted solvothermal method. The regulation of oil amine quantity was successfully obtained with different particle size distribution of hydrophobic Fe2O3 nanoparticles. The results show that with the increase of oil amine content, particle size showed a decrease of.TEM and XRD results show that, when added to the system of Fe and oil amine 1 molar ratio of:3,1:6 and 1:9, respectively, the average particle size were 108 nm, Fe2O3 64 nm and 52.FT-IR nanoparticles results show that nm nanoparticles are oil amine molecules coating. Two, carried out the research of hydrophobic nano Fe2O3 coated oil amine amplification (Synthesis of the reaction mass overall amplification 3 Times). Through laboratory primary amplification were prepared with high yield (250 mL single reactor product is about 0.22 g) hydrophobic nano Fe2O3.XRD and TEM characterization showed that after preliminary laboratory amplification, morphology and product phase showed no change. 3 times larger in terms of the reaction materials, by regulating the amount of oil amine can be obtained, the average particle size was 96 nm, hydrophobic nano Fe2O3. 69 nm and 53 nm through the further analysis of XRD, TEM and FT-IR spectra, the oil amine assisted two-phase solvent thermal preparation of hydrophobic nano Fe2O3 surface exists oil amine molecules coating layer. The products and goods as Fe2O3 the catalyst of Fukang Xigou coal for direct liquefaction performance test. The results show that when the iron content were added for liquefaction system dry ash free coal 3 wt% hydrophobic nano Fe2O3 and commercial Fe2O3 catalyst, the conversion rate , oil yield and liquefaction rate reached 95.9 wt%, 77.4 wt% and 87.1 wt% (Fe/OAm=1:3); 92.3 wt%, 73.6 wt% and 81.5 wt% (Fe/OAm=1:6); 92.3 wt%, 70.2 wt% and 72.3 wt% (Fe/OAm=1:9); 93.8%, 67.6% and 75.9% (Fe2O3). The results show that the liquefaction, compared to three synthetic the hydrophobic nano Fe2O3 catalyst on the oil yield of commercial Fe2O3 catalysts were increased by 14.5%, 8.9% and three 3.8%., using a simple hydrolysis preparation of hydrophilic beta -FeOOH nanoparticles, and the modification by sodium oleate, the hydrophobic beta -FeOOH nanoparticles. Firstly, by forced hydrolysis of ferric salts, the mass (422 g) hydrophilic beta -FeOOH nanoparticles. Secondly, using sodium oleate as modifier to phase were prepared by oleic acid (OA) coated with hydrophobic beta -FeOOH nanoparticles.XRD and TEM results showed that the product was about 120 nm long and 50 nm diameter spindle shaped -FeOOH nano beta .FT-IR nanoparticles results show that particles coated with oleic acid. The molecular layer of hydrophilic and hydrophobic beta -FeOOH nanoparticles as catalyst on the catalytic effect of direct coal liquefaction. The results showed that the conversion rate, oil yield and liquefaction rate reached 86.4 wt%, 57.7 wt% and 69 wt% (blank); 88.3 wt% 66.7, wt% and 73.7 wt% (hydrophilic beta -FeOOH); 92.6 wt%, 73.8 wt% and 80.8 wt% (hydrophobic beta -FeOOH). The experimental results show that the ferric hydrolysis and oleic acid coated mass business to achieve hydrophilic beta -FeOOH nanoparticles and preparation of hydrophobic modification, and the product of catalytic Xigou coal direct liquefaction show the liquefaction effect is good. In addition, the synthesis scheme of mild reaction conditions, simple operation and easy amplification, so it has good prospects for industrial applications.

【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ138.11;TB383.1

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