钌基催化剂的制备及其HCl氧化性能考察毕业论文
2022-04-26 22:45:54
论文总字数:18533字
摘 要
氯气是需求旺盛的重要化工原料,广泛应用于化学、冶金、造纸、纺织、医药、石油化工、饮水消毒和环保工业。我国的氯产品有 200 余种,主要品种有70多个。然而,许多使用氯的过程会产生副产物HCl. 目前,相关企业多采用水吸收法,将副产品 HCl制成盐酸回用或低价出售. 盐酸价格便宜、腐蚀性强、储存难、不易长途运输. 当盐酸滞销时只能中和后排放,既造成氯资源的浪费,也带来了环境污染问题.使用负载于γ-Al2O3上的 Cu, Cr, K 氧化物作催化剂,采用较高的 HCl/O2 摩尔比,得到的氧气接近完全转化,可直接使用产物混合气用于有机氯化过程,成为另一种解决副产HCl的途径. 但工业上对氯的需求不断增长,人们迫切希望找到一种既经济又安全的生产过程,从 HCl中回收氯,实现氯元素在体系中的闭路循环。
由 HCl 制氯主要有电解法、直接氧化法和催化氧化法。电解法投资大、能耗高,直接氧化法存在废液处理难、HCl转化不完全等问题,因此,电解法和直接氧化法难以令工业界满意.氯化氢的用途相当广泛,小到一颗小药片的制造,大到对金属设备清洗都离不开氯化氢。在氯化氢催化氧化制备氯气的催化剂体系中,钌催化剂也是一个重要的体系,一直受到国外研究公司的重视。在1966年中报道了以钌做为氯化氢催化氧化的催化剂,并说明在钌化合物中氯化钌是特别有效的,然而在催化剂的使用过程中却存在着严重的挥发问题,导致催化剂活性下降太快,这对工业应用是十分不利的。在2007年介绍一种生产氯气的氧化钌催化剂的制备方法和一种生产氯气时容易移走反应热,控制反应温度的操作方法。这种操作方法的特点在于催化剂不是一段填装,而是分两部分填装。氯化氢转化率为93%,氧化钛载持钌催化剂的处理氯化氢能力为0.013 molHCl/ gcat/ h。
对钌金属作为氯化氢氧化制氯气的催化剂的性能进行了研究。Walsdorff等用氧化钌、氯化钌或其他钌化合物负载在二氧化硅、氧化铝、二氧化钛或二氧化锆上制成催化剂,同时加入金、钯、铂、锇、铼、银、铱等贵金属或者是三氧化二铬等作为助催化剂,氯化氢的单程转化率在40%~90%。Stelter等在2010年制备了一种在非热能离子作用下制备了钌负载在二氧化硅上的催化剂,其中所用的反应装置是在一个由钛酸钡材料合成的有栅栏的反应管内,非热能离子可以通过
静电子释放电荷再生。了解了氯气制备中氯化氢气体的作用,以及制备方法,以后的生产中就可以省略掉很多不必要的麻烦。
关键词:氯化氢 催化氧化 钌基 二氧化钛
Abstract
Chlorine demand is an important chemical raw material, widely used in chemical, metallurgy, paper making, textile, pharmaceutical, petrochemical, water disinfection and environmental industries. Our products are more than 200 species of chlorine, the main varieties are more than 70. However, many of the process using chlorine byproducts HCl. At present, the relevant enterprises to use more water absorption, will be made of hydrochloric acid HCl byproduct reuse or sold at low prices. Cheap hydrochloric acid, corrosion resistance, difficult to store and difficult long-distance Transportation When hydrochloric acid unmarketable only during and after discharge, resulting in a waste of both chlorine resources, but also brought the problem of environmental pollution. Use supported on γ-Al2O3 of Cu, Cr, K oxide as a catalyst, use of higher HCl / O2 molar ratio of (8), to obtain nearly complete conversion of oxygen, the product may be used directly for the mixture of organic chlorination process, to become an alternative way to solve the by-product HCl, but the demand for chlorine industrially growing people are eager to find an economical and safe production process, recovering chlorine from HCl, the realization of chlorine in the system of closed cycle.
HCl chlorine from the main electrolysis system, direct oxidation and catalytic oxidation. Electrolysis investment, high energy consumption, waste water treatment difficult existence, HCl incomplete conversion issues such as direct oxidation, therefore, electrolysis and direct oxidation process difficult for the industry to be satisfied. Hydrogen chloride uses a wide range of small to a small tablet manufacturing, large metal cleaning equipment are inseparable from hydrogen chloride. Hydrogen chloride as the catalyst in the catalyst system in chlorine oxide, ruthenium catalyst system is also an important, it has been the company's emphasis on study abroad. Reported in 1966 in the ruthenium as a catalyst for the catalytic oxidation of hydrogen chloride, and ruthenium compounds described in ruthenium are particularly effective, however, in the course of the catalyst, but there is a serious problem volatile, resulting in catalyst activity decreased too fast, which is very unfavorable for industrial applications. Preparation in 2007 describes a process for producing chlorine ruthenium oxide catalyst and method of operation is easy to remove when a production of chlorine reaction heat, controlling the reaction temperature. Features of this method of operation is that the catalyst is not a time to fill, but fill in two parts. Conversion of hydrogen chloride was 93%, titanium oxide supporting the processing capability of ruthenium chloride catalyst was 0.013 molHCl / gcat / h.
Performance of the catalyst of ruthenium metal as chlorine oxidation of hydrogen chloride were studied. Walsdorff etc. with ruthenium oxide, ruthenium chloride or other ruthenium compound supported on silica, alumina, titania or zirconia to prepare a catalyst, while adding gold, palladium, platinum, osmium, rhenium, silver, iridium, or a noble metal such as a chromium oxide as a co-catalyst, hydrogen chloride-way conversion rate of 40% to 90%. Stelter et al 2010 in a composite material of barium titanate fenced reaction tube, prepared a non-thermal energy ions in a non-ruthenium catalyst supported on silica was prepared, in which the reaction apparatus used is ions can be regenerated by the release of static electronic charge. Understanding the role of chlorine in the preparation of hydrogen chloride gas, and a method for future production can be omitted a lot of unnecessary trouble.
Keywords: catalytic oxidation of hydrogen chloride ruthenium-based titanium dioxide
目 录
摘 要 I
Abstract III
目 录 1
第1章 文献综述 2
1.1 研究背景 2
1.2 氯化氢制备氯气工艺研究 2
1.2.1 电解法 3
1.2.2.直接氧化法 3
1.2.3 催化氧化法 3
1.3 氯化氢氧化制氯气的反应 4
1.4 钌系催化剂 4
1.5 本论文研究内容 5
第2章 实验部分 7
2.1 实验部分 7
2.1.1 催化剂的制备 8
2.1.2 实验主要仪器 8
2.2 催化剂的表征 9
2.2.1 X-射线衍射(XRD) 9
2.2.2 拉曼光谱(Raman) 9
2.2.3 N2吸附-脱附测试 9
2.2.4 环境扫描电镜(SEM) 9
2.2.5 H2程序升温还原(H2-TPR) 9
第3章 RuO2/TiO2的表征及催化性能研究 10
3.1 催化剂的表征结果分析 10
3.1.1 不同载体的钌基催化剂活性测试 10
3.1.2 TiO2 XRD谱图 11
3.1.3不同负载量的RuO2/ TiO2催化剂活性测试 12
3.2 不同温度焙烧偏钛酸作为载体制备的2RuO2/TiO2-X催化剂表征结果及氯化氢催化氧化性能测试 13
3.2.1 XRD谱图分析 13
3.2.2 SEM图分析 14
3.2.3 BET测试结果 15
3.2.4 2RuO2/TiO2-X催化剂的活性测试 16
3.3 结论 16
参考文献 18
致 谢 20
第1章 文献综述
1.1 研究背景
氯气是一种重要的应用广泛的基础化工原料,在化工、农业、建筑、纺织、运输、医药、造纸和环保等领域均有重要应用[1]。氯化氢是有机氯取代反应的一种直接副产物。更多情况下,氯元素以氯化氢的形式从化工中间体中移除来获得不含氯的最终产品[2]。副产的氯化氢直接排放会污染环境而且造成氯资源的浪费。因此,找到一种有效的方法将氯化氢氧化为氯气已经引起了广泛的关注。氯化氢制氯气的方法大体有三种:电解法、直接氧化法和催化氧化法。目前电解法虽然已由汞电解槽工艺发展为隔膜电解槽工艺,但电解法仍然存在能耗大、电极易腐蚀等问题。直接氧化法采用硝酸和浓硫酸的混合物为氧化剂,存在设备腐蚀、废酸难处理和HCl不完全转化等问题,无法实现大规模工业化生产[3]。
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