燃烧用高碱煤气相NaCl硫酸化途径的反应动力学计算

doi:10.16085/j.issn.1000-6613.2017-1394

摘要/Abstract

摘要： 为研究高碱煤烟气中气相NaCl生成硫酸钠的途径以及硫酸化比例的影响因素，对不同工况下高碱煤理论烟气中气相NaCl的硫酸化过程进行了计算，使用生成速率（ROP）分析法对体系中各基元反应进行了分析。结果表明，烟气中的NaCl主要是通过生成NaHSO₄和NaSO₄两种前体物质进行硫酸化，两种硫酸钠前体物质均可通过多个途径生成；在中温区域多种含钠中间物质均能够稳定存在，而在高温区域NaO₂、NaSO₃Cl两种物质由于分解速率较大不能稳定存在，所以中温区域NaCl硫酸化途径多于高温区域；增加过量空气系数、煤种含硫量、煤种水分含量对NaCl的硫酸化过程均有一定的促进作用；高温区域含钠中间物质分解速度增大，NaCl硫酸化途径减少，导致高温下NaCl硫酸化比例大幅度下降。

关键词: 煤燃烧, 高碱煤, 氧化钠, 三氧化硫, 气相硫酸化, 反应动力学

Abstract: In order to study the sulfation paths of gaseous sodium chloride in high alkali coal flue gas and the factors influencing the sulfation ratio,the sulfation process of gas sodium chloride in flue gas under different working conditions was calculated based on the chemical reaction kinetics theory. Each reaction in the system was analyzed by using the rate of production (ROP)method. The results showed that the gaseous sodium chloride was mainly sulfated by formation of NaHSO₄ and NaSO₄ and both of them can be formed by several paths. The sulfation paths of NaCl in middle temperature region was more than that in the high temperature region for the reason that more gaseous sodium species can stably exist in the medium temperature,while the decomposition rate of NaO₂ and NaSO₃Cl was higher in the high temperature region. Increasing excess air coefficient, coal sulfur content and coal moisture content will promote the sulfation process of gaseous sodium chloride, while increasing the flue gas temperature will significantly decrease the sulfation ratio of gaseous sodium chloride mainly due to that the decomposition rate of gaseous sodium species increased under the high temperature region, leading to the decrease of sulfation paths.

Key words: coal combustion, high alkali coal, sodium chloride(NaCl), sulfur trioxide(SO₃), gaseous sulfation, reaction kinetics

中图分类号:

TK16

肖海平, 祁超, 孙保民. 燃烧用高碱煤气相NaCl硫酸化途径的反应动力学计算[J]. 化工进展, 2018, 37(05): 1760-1766.

XIAO Haiping, QI Chao, SUN Baomin. Reaction kinetics calculations of gaseous NaCl sulfation pathway when burning high alkali coal[J]. Chemical Industry and Engineering Progress, 2018, 37(05): 1760-1766.

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