氢化燃烧合成制备镁铝合金的水解制氢性能毕业论文
2022-01-23 21:11:32
论文总字数:24609字
摘 要
氢化镁和铝成本低廉、环境友好、理论制氢量高。氢化镁的理论储氢量可高达1703 mL·g-1,铝的理论制氢量则可达到1245 mL·g-1,被认为是理想的水解制氢材料。然而,由于氢化镁和铝与水反应会分别生成不溶于水的钝化层附着在固相反应物表面,导致氢化镁和铝的实际水解制氢性能较差。本课题欲探究镁铝合金在制备过程和水解过程中影响水解制氢性能的因素,使用氢化燃烧合成法,以市售车削镁粉和铝粉为原料,制备镁铝氢化物合金样品,并考察原料预处理方式、水解溶液以及球磨时间的不同对镁铝合金样品水解制氢性能的影响。
本课题借助X射线衍射仪测试了镁铝合金样品的组分及其颗粒尺寸,自制水解制氢测试装置测试镁铝合金样品的水解制氢性能。得出结论:1)经过超声分散预处理制得的样品的水解制氢性能较好,这与样品中含有较多未氢化完全的Mg在溶液中与Al形成了原电池有关。2)在本课题选取的三种溶液中,镁铝合金样品在AlCl3和MgCl2溶液中水解制氢性能较好,因为这两种溶液呈酸性,溶液中的H 可破坏样品表面生成的钝化层。3)球磨时间对镁铝合金样品水解制氢性能有显著影响。球磨1 h的样品具有较好的水解制氢性能,而球磨时间过长会使样品制氢性能下降,这主要是因为过长时间的球磨使颗粒发生团聚,导致样品比表面积减小。
关键词:氢化燃烧合成 球磨 水解 制氢 镁铝合金
Hydrolysis Performance of Magnesium-Aluminum Alloy Prepared by Hydriding Combustion Synthesis
ABSTRACT
Magnesium hydride and aluminium have advantages of low cost, environmentally friendly and high theoretical hydrogen production capacity. The theoretical hydrogen production of magnesium hydride can be as high as 1703 mL·g-1, and that of aluminium can be as high as 1245 mL·g-1. So they are considered to be ideal materials for hydrogen production by hydrolysis. However, magnesium hydride and aluminium can react with water and then form water-insoluble passivation layers attached to the surface of the solid, which results in poor hydrogen production by hydrolysis of magnesium hydride and aluminium. In this paper, we are to explore the factors that affect the hydrogen production by hydrolysis during the preparation and hydrolysis of magnesium-aluminium alloy. The magnesium-aluminium hydride alloy samples were prepared from turning magnesium powder and aluminium powder by hydriding combustion synthesis method. The effects of pre-treatment methods, solutions for hydrolysis and ball milling time on the hydrogen production performance of magnesium-aluminium alloy samples were investigated.
The composition and particle sizes of Mg-Al alloy samples were tested by X-ray diffractometer. Hydrogen production performance of the samples was tested by self-made hydrogen production test device. The conclusions are as follows: 1) The sample prepared by ultrasonic dispersion pre-treatment has better hydrogen production by hydrolysis, because ultrasonic sample contained more unhydrogenated Mg, which formed the primary cell with Al in solution. 2) Among three kinds of solutions selected in this study, the samples of Mg-Al alloy in AlCl3 and MgCl2 solutions have rather better hydrogen production performance because of the acidity of the two solutions, which destroyed the passivation layer formed on the surface of the samples. 3) The milling time has a significant effect on the hydrogen production from hydrolysis of Mg-Al alloy samples. The samples milled for 1 h had better hydrogen production performance by hydrolysis, but the hydrogen production performance of the samples would be reduced if the ball milling time was too long, which was mainly due to the agglomeration of particles and this led to the reduction of specific surface area of the samples.
Key words: Hydriding Combustion Synthesis Ball Milling Hydrogen Production Hydrolysis Mg-Al Alloy
目 录
摘 要 I
ABSTRACT II
第一章 文献综述 1
1.1 引言 1
1.2 储氢方式研究现状 2
1.2.1 高压气态储氢 2
1.2.2 低温液态储氢 2
1.2.3 物理吸附储氢 3
1.2.4 有机碳氢化合物储氢 3
1.2.5 金属氢化物储氢 4
1.3 水解制氢研究现状 4
1.3.1 配位氢化物水解制氢 5
1.3.2 镁基金属材料水解制氢 5
1.3.3 铝基金属材料水解制氢 7
1.4 问题的提出与本文的研究内容 8
第二章 实验方法 9
2.1 实验原料 9
2.2实验仪器 9
2.2.1 HCS反应装置 9
2.2.2 行星式球磨机 11
2.2.3水解制氢反应测试装置 11
2.2.4 其它仪器设备 12
2.3 结构及性能分析 13
2.3.1 XRD分析 13
2.3.2 Rietveld全谱拟合分析 13
第三章 实验数据与分析 14
3.1 镁铝合金样品的制备 14
3.2 预处理方式对Mg90Al10合金样品水解制氢性能的影响 16
3.3 水解溶液的不同对Mg90Al10合金样品水解制氢性能的影响 18
3.4 球磨时间对Mg90Al10合金样品水解制氢性能的影响 20
第四章 结论与展望 22
4.1 结论 22
4.2 展望 22
参考文献 24
致 谢 26
第一章 文献综述
1.1 引言
人类社会的发展很大程度上依赖能源技术的进步。随着传统化石燃料资源的日渐枯竭和大规模使用化石燃料导致的环境污染日益严重,为了实现人类社会的可持续发展,人们对于实用的新型清洁能源技术的需求越来越迫切。在种类繁多的新能源类型中,水能、潮汐能、风能、太阳能、核能等是具有代表性的新能源类型,但是它们各有各的巨大缺陷:水能受河流和地形的制约很大,只有在水资源丰富且地形高低落差较大的地区才能建设水力发电站;潮汐能的情况与水能类似,只能在沿海地区进行建设;风力发电则对风能密度和可利用的风能年累积小时数有较高的要求,因此只能在部分风力资源丰富的地区建立风力发电站;太阳能在夜间无法获取,这意味着一天中将近一半的时间里太阳能发电站不能工作;核能虽然安全系数较高,但是核燃料一旦发生泄漏,往往就会造成严重的核污染事故,对环境和人体造成极大危害[1];同时,核能的利用对科学技术水平的要求很高,目前世界上只有中俄美英法日等少数科技水平较高的国家能够建设并运营核电站。
除上述的几种类型的新能源外,氢能也是备受瞩目的一种新能源类型。与上述各种新能源相比,氢能具有以下优势:1)热值高,将1 kg H2完全燃烧,其产生的热量等效于3 kg汽油或4.5 kg焦炭完全燃烧释放的热量,高达1.25×106 kJ;2)产物无污染,氢气燃烧只生成水,反应不产生任何有毒有害的副产物;3)储量极为丰富,地球表面超过70%的面积被水覆盖,组成水分子的氢元素可以说是地球上储量最为丰富的化学元素;4)成本低廉,氢气可通过风能、水能、太阳能等较廉价的一次能源分解水来直接获取。
请支付后下载全文,论文总字数:24609字