Abstract:

In order to investigate the effect of different chemical forms of sodium salt on the CO₂ adsorption capacity and gasification of Zhundong coal, sodium salts were loaded to acid-washed coal by solution impregnation method. The gasification and the CO₂ adsorption capacity of sodium salt loaded coal samples and acid-washed coal sample were studied by thermogravimetric analyzer (TGA), and the gasification reaction kinetics model were analyzed and calculated for coal samples. The results suggested that the initial gasification temperature and the activity energy of gasification reaction were reduced significantly, while the gasification index and the CO₂ adsorption capacity were enhanced dramatically when sodium salt was loaded. The catalytic activity of four sodium salts for the CO₂ gasification reaction of Zhundong coal was in the following order:Na₂CO₃ > NaHCO₃ > Na₂SO₄ > NaCl. The strong chemisorption ability of coal samples can reflect the CO₂ gasification reactivity. The gasification process of acid-washed coal could be well described by random pore model (RPM), while the sodium salt loaded coal gasification reaction process could be well explained by modified random pore model (MRPM).

Key words: Zhundong coal, sodium salt, catalyst, chemisorption, gasification, kinetics

摘要：

为探究不同化学形态的钠盐对准东煤CO₂吸附能力及气化特性影响，对酸洗后的准东煤采用溶液浸渍法负载钠盐。利用热重分析仪研究了4种负载钠盐的煤样和酸洗煤样的气化反应性和CO₂吸附能力，并对5种煤样的反应动力学模型进行了分析和计算。结果表明：负载钠盐可显著降低煤样起始气化温度和气化所需活化能，提高气化反应活性指数和吸附CO₂的能力。实验选用的4种钠盐对准东煤CO₂气化反应催化作用强弱依次是：Na₂CO₃> NaHCO₃> Na₂SO₄> NaCl。煤样的CO₂强化学吸附能力可反映出煤样的CO₂气化反应活性。随机孔模型可以较好地描述酸洗煤的CO₂气化过程，而修正的随机孔模型则能更好地反映负载钠盐煤样的CO₂气化过程。

关键词: 准东煤, 钠盐, 催化剂, 化学吸附, 气化, 动力学