低活性无烟煤固定床二氧化碳催化气化反应动力学研究

在内径18 mm的固定床反应器中研究了福建低活性无烟煤二氧化碳催化气化反应动力学。考察了消除内外扩散影响的实验条件。在750 ℃～907 ℃，以碳酸钠为催化剂分别测定了永安丰海筛无烟煤、永安加福筛无烟煤和永定无烟煤的转化率与时间的关系；以碳酸钾及纸浆黑液为催化剂测定了永定无烟煤的转化率与时间的关系。永安加福筛无烟煤采用均相一级反应模型及未反应缩芯模型进行拟合，得出气化反应速率常数、反应活化能和指前因子，与热天平的实验结果进行比较，固定床反应速率常数明显变大，活化能和指前因子也大，是由于固定床中有较高的二氧化碳到煤粒表面的传递速率和较高的升温速率所致。

Catalytic gasification kinetics of low active anthracites by carbon dioxide in a fixed bed

The catalytic gasification kinetics of low active Fujian anthracites（Volatile matter:3.56%~4.35%）by carbon dioxide was carried out in the fixed bed reactor of 18 mm inside diameter. The reaction conditions of eliminating both internal and external diffusion effects were determined. Using sodium carbonate as the catalysts, the relationships of coal conversion with reaction time for three low active anthracites (Yong′an Fengshai coal, Yong′an Jiashai coal and Yongding coal ) were explored within the temperature range from 750 ℃ to 907 ℃. Using potassium carbonate and black liquor of paper pulp plant as the catalysts, the relationships of coal conversion with the reaction time for Yongding coal were also studied. The kinetic parameters including the reaction rate constant, the reaction activation energy and the pre-exponential factor were obtained by using the homogeneous model and the shrinking core model. Comparing with the results from the thermogravimetric balance, the reaction rate constant, the reaction activation energy and the pre-exponential factor from the fixed bed are higher than those obtained from the thermogravimetric balance, which could be caused by the higher mass transfer rate of carbon dioxide to the coal surface and higher heating rate in the fixed bed.