【摘要】：流化床具有良好的氣固接觸、高效的傳熱傳質(zhì)等特點(diǎn),被廣泛應(yīng)用于能源、化工和環(huán)境等工業(yè)過(guò)程。流化床褐煤氣化是褐煤高效利用的重要方式之一。本論文在流化床氣化裝置上,以云南小龍?zhí)逗置鹤鳛檠芯繉?duì)象,對(duì)其空氣和水蒸氣氣化特性進(jìn)行了研究,并對(duì)氣化反應(yīng)動(dòng)力學(xué)進(jìn)行了探索。以空氣和水蒸氣作為氣化劑,考察了顆粒粒徑、反應(yīng)溫度、空氣煤比和水蒸氣煤比對(duì)流化床褐煤氣化特性的影響。實(shí)驗(yàn)結(jié)果表明,隨著反應(yīng)溫度的升高,碳轉(zhuǎn)化率、產(chǎn)氣率和煤氣熱值有所增加;H_2和CO百分含量升高,CO_2百分含量下降。隨著褐煤粒徑的增大,碳轉(zhuǎn)化率、產(chǎn)氣率和煤氣熱值均有所下降;CO、CO_2和H_2百分含量有所下降。隨蒸氣煤比的升高,碳轉(zhuǎn)化率和煤氣熱值略有減小,產(chǎn)氣率基本保持不變;H_2和CO_2百分含量有所升高,CO百分含量呈現(xiàn)減小的趨勢(shì)。隨空氣煤比的升高,碳轉(zhuǎn)化率有所增加,產(chǎn)氣率和煤氣熱值先升高然后略有下降;煤氣中H_2和CO百分含量先增加,達(dá)到最大值后逐漸下降,CO_2百分含量呈上升趨勢(shì)。采用等溫流化床氣化爐法研究了小龍?zhí)逗置涸?50~950℃的反應(yīng)動(dòng)力學(xué)。分別采用均勻反應(yīng)模型、縮核反應(yīng)模型和修正體積模型對(duì)褐煤氣化轉(zhuǎn)化率與反應(yīng)時(shí)間的關(guān)系進(jìn)行擬合,其中均勻反應(yīng)模型計(jì)算得到活化能為93.95k J/mol,縮核反應(yīng)模型得到的活化能為83.37kJ/mol,修正體積模型得到的活化能為124.83kJ/mol。采用等轉(zhuǎn)化率法得到的氣化反應(yīng)活化能為104.75~131.36kJ/mol,與修正體積模型的計(jì)算結(jié)果相符,故小龍?zhí)逗置簹饣^(guò)程采用修正體積動(dòng)力學(xué)模型描述更為合理。
[Abstract]:Fluidized bed has been widely used in industrial processes such as energy, chemical industry and environment because of its good gas-solid contact and high efficiency heat and mass transfer. Fluidized bed browning coal gasification is one of the important ways to utilize lignite efficiently. In this paper, the characteristics of air and water vapor gasification of Xiaolongtan lignite in Yunnan Province were studied in a fluidized bed gasification plant, and the kinetics of gasification reaction was explored. The effects of particle size, reaction temperature, air to coal ratio and steam coal ratio on the gasification characteristics of brown coal in fluidized bed were investigated using air and water vapor as gasifier. The experimental results show that the carbon conversion, gas yield and gas calorific value increase with the increase of reaction temperature. With the increase of lignite particle size, the carbon conversion, gas yield and gas calorific value decreased. With the increase of steam / coal ratio, the carbon conversion rate and the gas calorific value decrease slightly, while the gas production rate basically remains unchanged. The percentage content of H _ (2) and CO_2 increases and the content of CO _ (2) decreases. With the increase of air-coal ratio, the carbon conversion rate increased, the gas production rate and gas calorific value first increased and then slightly decreased, and the content of H _ 2 and CO _ (2) in gas first increased, then gradually decreased to the maximum value, and then the content of CO _ (2) increased. The reaction kinetics of Xiaolongtan lignite at 850 鈩，

本文編號(hào)：2178887