基于铝水反应—碳热还原法的铝能源循环系统基础研究
发布时间：2018-11-24 20:02
【摘要】：能源危机和环境污染是当前人类面临的两大问题,开发无污染的新型能源成为迫在眉睫的任务,氢能正是这样一种能量密度高并且对环境友好的可再生能源。铝水反应能够制取氢气,同时产生大量热量,能够在多种场合下进行利用。以铝为燃料的制氢能源系统在降低能耗和保护环境方面具有突出的优势,对于发展资源节约型和环境友好型社会具有重要意义。本文首先研究了铝水反应的动力学特性以及镁锂对该反应的促进效果。实验主要在THERMO CAHN's Thermax500压力热天平上进行,铝的比例为85%,镁和锂的比例从0%变化至15%。在连续通水条件下,添加镁和锂能够提升反应效率,使反应铝的比例超过50%甚至达到89%。反应过程具有三阶段变化规律,而且这三个阶段分别对应Li,Mg和A1三种金属与水蒸气的反应。铝水反应后的主要产物为LiAlO_2,Li_2Al_4O_7,Al_2O_3,和MgO,添加镁和锂通过三种不同的机理促进铝水反应的进行,包括形成局部高温条件、与氧化产物反应以及摩擦碰撞作用等破坏氧化铝薄膜,提升金属铝的反应效率。碳热还原制铝由于其低能耗、低污染的特点被认为是未来的制铝方法。本文对A1-C两步反应模型进行了热动力学分析。高温条件有利于提升第一步反应的反应效率,却会降低其拥效率,而第二步反应变化规律正好相反。能量分析发现反应过程中存在一个反应效率和拥效率都很高的最佳温度窗口。实际应用中,余热利用能够提升反应效率和拥效率,理论上可以使反应能耗从11335 kW·h/t(Al)降到8063kW·h/t(Al)。和电解铝进行比较时,真空氯化碳热还原法能够实现67%的(?)效率,达到电解铝的1.7倍。从铝水反应和碳热还原法出发,利用铝水反应生成的氧化铝作为碳热还原制铝的原料,达到循环利用的目的,建立了铝能源系统。对碳热还原过程进行生命周期评价,发现其相对于电解铝过程能够减少17.9%的总能源消耗,降低34.3%的温室气体排放,对人体毒性指数也大幅下降,表明其是一个对环境影响较小的过程,在环境保护和能源节约上极具发展潜力。
[Abstract]:Energy crisis and environmental pollution are two major problems facing mankind at present. It is an urgent task to develop new energy sources without pollution. Hydrogen energy is a kind of renewable energy with high energy density and friendly to the environment. Aluminum-water reaction can produce hydrogen and produce a lot of heat, which can be used in many situations. The hydrogen production energy system based on aluminum has outstanding advantages in reducing energy consumption and protecting the environment. It is of great significance for the development of resource-saving and environment-friendly society. In this paper, the kinetic characteristics of Aluminum-water reaction and the promoting effect of Mg-Li on the reaction were studied. The experiment was carried out on the THERMO CAHN's Thermax500 pressure balance, the ratio of aluminum to lithium was 85%, and the ratio of magnesium and lithium changed from 0% to 15%. Under the condition of continuous water opening, the reaction efficiency can be improved by adding magnesium and lithium, and the ratio of reactive aluminum exceeds 50% or even reaches 89%. The reaction process has a three-stage variation law, and these three stages correspond to the reaction of Li,Mg and A1 metals with water vapor, respectively. The main products of the reaction are LiAlO_2,Li_2Al_4O_7,Al_2O_3, and MgO, and the addition of magnesium and lithium promotes the reaction of aluminum and water through three different mechanisms, including the formation of local high temperature conditions. The reaction with oxidation product and friction collision can destroy the aluminum oxide film and improve the reaction efficiency of aluminum metal. Because of its low energy consumption and low pollution, carbothermal reduction is considered as the future method of aluminum production. In this paper, the thermal kinetic analysis of A _ 1-C two-step reaction model is carried out. The reaction efficiency of the first step can be improved by high temperature condition, but the efficiency of the second step reaction will be decreased, but the change law of the second step reaction is just the opposite. Energy analysis shows that there is an optimal temperature window with high efficiency and high efficiency during the reaction. In practical application, the utilization of waste heat can improve the efficiency of reaction and the efficiency of holding, and theoretically reduce the energy consumption of the reaction from 11335 kW / t / t (Al) to 8063kW / h / t (Al). Compared with electrolytic aluminum, the vacuum chlorinated carbothermal reduction method can achieve 67% (?) The efficiency is 1.7 times higher than that of electrolytic aluminum. In this paper, the aluminum energy system was established by using aluminum oxide produced by the reaction of aluminum and water as the raw material for the production of aluminum by carbothermal reduction from the reaction of aluminum with water and by the method of carbothermal reduction, and the purpose of recycling was achieved. The life cycle evaluation of the carbothermal reduction process shows that compared with the aluminum electrolysis process, it can reduce the total energy consumption by 17.9%, the greenhouse gas emission by 34.3%, and the toxicity index to the human body by a large margin. It is shown that it is a process with small environmental impact and has great potential for development in environmental protection and energy conservation.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ116.2
本文编号：2354862
[Abstract]:Energy crisis and environmental pollution are two major problems facing mankind at present. It is an urgent task to develop new energy sources without pollution. Hydrogen energy is a kind of renewable energy with high energy density and friendly to the environment. Aluminum-water reaction can produce hydrogen and produce a lot of heat, which can be used in many situations. The hydrogen production energy system based on aluminum has outstanding advantages in reducing energy consumption and protecting the environment. It is of great significance for the development of resource-saving and environment-friendly society. In this paper, the kinetic characteristics of Aluminum-water reaction and the promoting effect of Mg-Li on the reaction were studied. The experiment was carried out on the THERMO CAHN's Thermax500 pressure balance, the ratio of aluminum to lithium was 85%, and the ratio of magnesium and lithium changed from 0% to 15%. Under the condition of continuous water opening, the reaction efficiency can be improved by adding magnesium and lithium, and the ratio of reactive aluminum exceeds 50% or even reaches 89%. The reaction process has a three-stage variation law, and these three stages correspond to the reaction of Li,Mg and A1 metals with water vapor, respectively. The main products of the reaction are LiAlO_2,Li_2Al_4O_7,Al_2O_3, and MgO, and the addition of magnesium and lithium promotes the reaction of aluminum and water through three different mechanisms, including the formation of local high temperature conditions. The reaction with oxidation product and friction collision can destroy the aluminum oxide film and improve the reaction efficiency of aluminum metal. Because of its low energy consumption and low pollution, carbothermal reduction is considered as the future method of aluminum production. In this paper, the thermal kinetic analysis of A _ 1-C two-step reaction model is carried out. The reaction efficiency of the first step can be improved by high temperature condition, but the efficiency of the second step reaction will be decreased, but the change law of the second step reaction is just the opposite. Energy analysis shows that there is an optimal temperature window with high efficiency and high efficiency during the reaction. In practical application, the utilization of waste heat can improve the efficiency of reaction and the efficiency of holding, and theoretically reduce the energy consumption of the reaction from 11335 kW / t / t (Al) to 8063kW / h / t (Al). Compared with electrolytic aluminum, the vacuum chlorinated carbothermal reduction method can achieve 67% (?) The efficiency is 1.7 times higher than that of electrolytic aluminum. In this paper, the aluminum energy system was established by using aluminum oxide produced by the reaction of aluminum and water as the raw material for the production of aluminum by carbothermal reduction from the reaction of aluminum with water and by the method of carbothermal reduction, and the purpose of recycling was achieved. The life cycle evaluation of the carbothermal reduction process shows that compared with the aluminum electrolysis process, it can reduce the total energy consumption by 17.9%, the greenhouse gas emission by 34.3%, and the toxicity index to the human body by a large margin. It is shown that it is a process with small environmental impact and has great potential for development in environmental protection and energy conservation.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ116.2
【参考文献】
相关期刊论文 前10条
1 常进法;肖瑶;罗兆艳;葛君杰;刘长鹏;邢巍;;水电解制氢非贵金属催化剂的研究进展[J];物理化学学报;2016年07期
2 王寒;;世界氢能发展现状与技术调研[J];当代化工;2016年06期
3 马琼;杨健壮;;我国电解铝工业技术发展现状[J];世界有色金属;2016年10期
4 杨卫娟;刘晓伟;张天佑;施伟;刘建忠;周俊虎;;中高温条件下铝镁锂与水反应的热重分析[J];固体火箭技术;2016年03期
5 刘凯辉;徐建全;;纯电动汽车驱动电机全生命周期评价[J];环境科学学报;2016年09期
6 邹才能;赵群;张国生;熊波;;能源革命:从化石能源到新能源[J];天然气工业;2016年01期
7 王长波;张力小;庞明月;;生命周期评价方法研究综述——兼论混合生命周期评价的发展与应用[J];自然资源学报;2015年07期
8 张天佑;杨卫娟;周俊虎;陈超;刘建忠;岑可法;;水蒸气气氛下铝锂合金反应特性及动力学分析[J];固体火箭技术;2015年01期
9 靳立军;王焦飞;郑宇;胡浩权;;炭催化甲烷裂解制氢研究进展[J];化工进展;2014年12期
10 陈冠益;孔椺;徐莹;李婉晴;马隆龙;颜蓓蓓;陈鸿;;生物质化学制氢技术研究进展[J];浙江大学学报(工学版);2014年07期
相关博士学位论文 前1条
1 韩志江;镁/水着火燃烧模型及高温均相反应机理研究[D];浙江大学;2012年
，本文编号：2354862
本文链接：https://www.wllwen.com/kejilunwen/huagong/2354862.html
