褐煤流化床气化特性与动力学研究
发布时间：2018-08-12 11:17
【摘要】：流化床具有良好的气固接触、高效的传热传质等特点,被广泛应用于能源、化工和环境等工业过程。流化床褐煤气化是褐煤高效利用的重要方式之一。本论文在流化床气化装置上,以云南小龙潭褐煤作为研究对象,对其空气和水蒸气气化特性进行了研究,并对气化反应动力学进行了探索。以空气和水蒸气作为气化剂,考察了颗粒粒径、反应温度、空气煤比和水蒸气煤比对流化床褐煤气化特性的影响。实验结果表明,随着反应温度的升高,碳转化率、产气率和煤气热值有所增加;H_2和CO百分含量升高,CO_2百分含量下降。随着褐煤粒径的增大,碳转化率、产气率和煤气热值均有所下降;CO、CO_2和H_2百分含量有所下降。随蒸气煤比的升高,碳转化率和煤气热值略有减小,产气率基本保持不变;H_2和CO_2百分含量有所升高,CO百分含量呈现减小的趋势。随空气煤比的升高,碳转化率有所增加,产气率和煤气热值先升高然后略有下降;煤气中H_2和CO百分含量先增加,达到最大值后逐渐下降,CO_2百分含量呈上升趋势。采用等温流化床气化炉法研究了小龙潭褐煤在850~950℃的反应动力学。分别采用均匀反应模型、缩核反应模型和修正体积模型对褐煤气化转化率与反应时间的关系进行拟合,其中均匀反应模型计算得到活化能为93.95k J/mol,缩核反应模型得到的活化能为83.37kJ/mol,修正体积模型得到的活化能为124.83kJ/mol。采用等转化率法得到的气化反应活化能为104.75~131.36kJ/mol,与修正体积模型的计算结果相符,故小龙潭褐煤气化过程采用修正体积动力学模型描述更为合理。
[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，
本文编号：2178887
[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，
本文编号：2178887
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