【摘要】：煤炭是目前地球上儲量最豐富、最廉價(jià)的化石燃料,約占世界一次能源的30%,燃煤發(fā)電約占全球發(fā)電量的40%。傳統(tǒng)燃煤發(fā)電技術(shù)存在能量轉(zhuǎn)換效率低,二氧化碳和其他污染物排放量大的嚴(yán)重缺陷,加之化石能源的有限性,因此,對煤炭的高效潔凈利用是亟待解決的重大課題。燃料電池是新一代高效、清潔的發(fā)電技術(shù),對解決我國能源匱乏和環(huán)境污染問題具有重大意義。固體氧化物燃料電池(SOFCs)是一種不經(jīng)過燃燒直接將燃料的化學(xué)能轉(zhuǎn)變?yōu)殡娔艿陌l(fā)電裝置。燃料電池的燃料不經(jīng)歷燃燒,污染物排放量低,對環(huán)境友好;無運(yùn)動組件,工作安靜,噪音低。固體氧化物燃料電池最顯著的特點(diǎn)是其燃料的多樣性,可以使用如氫氣、天然氣、甲醇、汽油以及固體碳等燃料,其中碳燃料具有能量密度大、安全性高、易運(yùn)輸與儲藏的優(yōu)點(diǎn),而且,單一尾氣二氧化碳易于捕集和減排。因此,直接碳固體氧化物燃料電池(direct carbon solid oxide fuel cells,DC-SOFC)引起越來越多研究者的關(guān)注。煤焦是煤炭高溫?zé)峤獾玫降囊环N熱值很高的固體產(chǎn)物,是適合用于直接碳固體氧化物燃料電池(DC-SOFC)的一種碳燃料。煤焦主要由固定碳、灰分、水分、揮發(fā)分等組成。研究表明,部分灰分對煤焦的逆Boudouard反應(yīng)起抑制作用,而通過酸法活化可以除去這些抑制成分。因此本論文采用非含氧酸HF、HCl和及其混酸(HF+HCl)化學(xué)脫灰活化煤焦的方法,研究煤焦灰分對固體氧化物燃料電池電化學(xué)性能的影響。研究發(fā)現(xiàn),HF+HCl活化后煤焦里抑制逆Boudouard反應(yīng)的硅、鋁氧化物的含量大大降低,逆Boudouard反應(yīng)溫度從845℃降低到了799℃;電池峰值功率密度從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反應(yīng)是制約直接碳固體氧化物燃料電池(DC-SOFC)電化學(xué)性能的關(guān)鍵反應(yīng),而催化劑的引入能有效提高逆Boudouard反應(yīng)速率。鋼渣是一種工業(yè)廢渣,其堆放會占用大量的土地資源,造成水體和空氣污染。對鋼渣進(jìn)行回收利用不僅可以保護(hù)環(huán)境,還能充分利用自然資源,提高鋼渣利用率。本論文研究了經(jīng)過酸溶堿沉煅燒處理的鋼渣對逆Boudouard反應(yīng)的催化效應(yīng)。經(jīng)過實(shí)驗(yàn)處理的鋼渣礦物相分解,得到了含F(xiàn)e、Ca、Mg等元素的氧化物,這些氧化物有顯著的逆Boudouard反應(yīng)催化作用。結(jié)果表明,酸活化鋼渣催化劑使煤焦的逆Boudouard的反應(yīng)的起始溫度降低了240℃,在800℃時的CO生成速率提高了4倍;在電化學(xué)性能上,酸活化鋼渣催化劑使電池在850℃時的峰值功率密度從67.4 mW cm-2增加到了193.6mW cm-2,燃料利用率從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，

本文編號：2228177