煤基碳的Boudouard气化反应性及其DC-SOFC电化学性能研究
发布时间：2018-09-07 11:47
【摘要】：煤炭是目前地球上储量最丰富、最廉价的化石燃料,约占世界一次能源的30%,燃煤发电约占全球发电量的40%。传统燃煤发电技术存在能量转换效率低,二氧化碳和其他污染物排放量大的严重缺陷,加之化石能源的有限性,因此,对煤炭的高效洁净利用是亟待解决的重大课题。燃料电池是新一代高效、清洁的发电技术,对解决我国能源匮乏和环境污染问题具有重大意义。固体氧化物燃料电池(SOFCs)是一种不经过燃烧直接将燃料的化学能转变为电能的发电装置。燃料电池的燃料不经历燃烧,污染物排放量低,对环境友好;无运动组件,工作安静,噪音低。固体氧化物燃料电池最显著的特点是其燃料的多样性,可以使用如氢气、天然气、甲醇、汽油以及固体碳等燃料,其中碳燃料具有能量密度大、安全性高、易运输与储藏的优点,而且,单一尾气二氧化碳易于捕集和减排。因此,直接碳固体氧化物燃料电池(direct carbon solid oxide fuel cells,DC-SOFC)引起越来越多研究者的关注。煤焦是煤炭高温热解得到的一种热值很高的固体产物,是适合用于直接碳固体氧化物燃料电池(DC-SOFC)的一种碳燃料。煤焦主要由固定碳、灰分、水分、挥发分等组成。研究表明,部分灰分对煤焦的逆Boudouard反应起抑制作用,而通过酸法活化可以除去这些抑制成分。因此本论文采用非含氧酸HF、HCl和及其混酸(HF+HCl)化学脱灰活化煤焦的方法,研究煤焦灰分对固体氧化物燃料电池电化学性能的影响。研究发现,HF+HCl活化后煤焦里抑制逆Boudouard反应的硅、铝氧化物的含量大大降低,逆Boudouard反应温度从845℃降低到了799℃;电池峰值功率密度从67.4 mW cm-2增加到110.2 mW cm-2;燃料活化煤焦的利用率是原煤焦的1.2倍。逆Boudouard反应是制约直接碳固体氧化物燃料电池(DC-SOFC)电化学性能的关键反应,而催化剂的引入能有效提高逆Boudouard反应速率。钢渣是一种工业废渣,其堆放会占用大量的土地资源,造成水体和空气污染。对钢渣进行回收利用不仅可以保护环境,还能充分利用自然资源,提高钢渣利用率。本论文研究了经过酸溶碱沉煅烧处理的钢渣对逆Boudouard反应的催化效应。经过实验处理的钢渣矿物相分解,得到了含Fe、Ca、Mg等元素的氧化物,这些氧化物有显著的逆Boudouard反应催化作用。结果表明,酸活化钢渣催化剂使煤焦的逆Boudouard的反应的起始温度降低了240℃,在800℃时的CO生成速率提高了4倍;在电化学性能上,酸活化钢渣催化剂使电池在850℃时的峰值功率密度从67.4 mW cm-2增加到了193.6mW cm-2,燃料利用率从41.48%增加到79.68%。
[Abstract]:Coal is by far the most abundant and cheapest fossil fuel on Earth, accounting for about 30 percent of the world's primary energy and about 40 percent of the world's electricity generated by coal. Traditional coal-fired power generation technology has the serious defects of low efficiency of energy conversion, large emissions of carbon dioxide and other pollutants, and the limitation of fossil energy. Therefore, the efficient and clean utilization of coal is an important issue to be solved urgently. Fuel cell is a new generation of efficient and clean power generation technology, which is of great significance to solve the problem of energy shortage and environmental pollution in China. Solid oxide fuel cell (SOFCs) is a power generation device which converts the chemical energy of fuel into electric energy without combustion. Fuel cell fuel does not experience combustion, low pollutant emissions, environmentally friendly; no moving components, quiet work, low noise. The most prominent feature of solid oxide fuel cells is the diversity of their fuels, which can be used in fuels such as hydrogen, natural gas, methanol, gasoline and solid carbon, among which carbon fuels have high energy density and high safety. The advantages of easy transportation and storage, and single tail gas carbon dioxide capture and emission reduction. Therefore, direct carbon solid oxide fuel cell (direct carbon solid oxide fuel cells,DC-SOFC) has attracted more and more attention. Coal char is a kind of solid product with high calorific value obtained from high temperature pyrolysis of coal. It is a kind of carbon fuel suitable for direct carbon solid oxide fuel cell (DC-SOFC). Coal char mainly by fixed carbon, ash, moisture, volatile composition. The results show that some ash can inhibit the inverse Boudouard reaction of coal char, and these inhibitory components can be removed by acid activation. In this paper, the influence of char ash content on the electrochemical performance of solid oxide fuel cells was studied by means of chemical deashing and activation of char by HF,HCl and (HF HCl). It is found that the content of aluminum oxide in coal coke after activation of HF HCl decreases greatly from 845 鈩，
本文编号：2228177
[Abstract]:Coal is by far the most abundant and cheapest fossil fuel on Earth, accounting for about 30 percent of the world's primary energy and about 40 percent of the world's electricity generated by coal. Traditional coal-fired power generation technology has the serious defects of low efficiency of energy conversion, large emissions of carbon dioxide and other pollutants, and the limitation of fossil energy. Therefore, the efficient and clean utilization of coal is an important issue to be solved urgently. Fuel cell is a new generation of efficient and clean power generation technology, which is of great significance to solve the problem of energy shortage and environmental pollution in China. Solid oxide fuel cell (SOFCs) is a power generation device which converts the chemical energy of fuel into electric energy without combustion. Fuel cell fuel does not experience combustion, low pollutant emissions, environmentally friendly; no moving components, quiet work, low noise. The most prominent feature of solid oxide fuel cells is the diversity of their fuels, which can be used in fuels such as hydrogen, natural gas, methanol, gasoline and solid carbon, among which carbon fuels have high energy density and high safety. The advantages of easy transportation and storage, and single tail gas carbon dioxide capture and emission reduction. Therefore, direct carbon solid oxide fuel cell (direct carbon solid oxide fuel cells,DC-SOFC) has attracted more and more attention. Coal char is a kind of solid product with high calorific value obtained from high temperature pyrolysis of coal. It is a kind of carbon fuel suitable for direct carbon solid oxide fuel cell (DC-SOFC). Coal char mainly by fixed carbon, ash, moisture, volatile composition. The results show that some ash can inhibit the inverse Boudouard reaction of coal char, and these inhibitory components can be removed by acid activation. In this paper, the influence of char ash content on the electrochemical performance of solid oxide fuel cells was studied by means of chemical deashing and activation of char by HF,HCl and (HF HCl). It is found that the content of aluminum oxide in coal coke after activation of HF HCl decreases greatly from 845 鈩，
本文编号：2228177
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