Post-flame gas-phase sulfation of potassium chloride
Post-flame gas-phase sulfation of potassium chloride
复制标题
DOI：
10.1016/j.combustflame.2013.01.010
复制
发表时间：
2013-05-01
影响因子：
4.4
通讯作者：
Glarborg, Peter
中科院分区：
文献类型：
--
作者：
Li, Bo;Sun, Zhiwei;Glarborg, Peter
生物质燃烧期间KCl的硫酸化对操作和排放具有影响：它降低了沉积和腐蚀速率，增加了气溶胶的形成，并导致气相中更高的HCl浓度和更低的SO2浓度。需要严格的均相系统来表征碱金属硫酸盐的气相形成。我们已经测量了KCl和HCl的温度和气相浓度，并检测到气溶胶的存在下，在火焰后区域的范围内的碳氢化合物火焰播种KCl，有和没有添加SO2。用不同量的N-2稀释火焰产物，确保火焰后温度在950-1400 K范围内。在没有SO2的情况下，KCl水平在火焰后区域是恒定的，即使在最低温度下也没有形成气溶胶。在SO2的存在下，KCl被消耗，HCl和气溶胶形成，在火焰中最明显，火焰后温度最低。这表明KCl在气相中被硫酸化为K2 SO 4，随后K2 SO 4均匀成核形成气溶胶。从S/Cl/K化学反应动力学模型的预测与实验结果一致。该模型表明，在硫酸化过程中的限速步骤是SO2氧化为SO 3和K2 SO 4的均匀成核。(C)2013燃烧研究所由爱思唯尔公司出版All rights reserved.
The sulfation of KCl during biomass combustion has implications for operation and emissions: it reduces the rates of deposition and corrosion, it increases the formation of aerosols, and it leads to higher concentrations of HCl and lower concentrations of SO2 in the gas phase. Rigorously homogeneous systems are required to characterize the gas-phase formation of alkali sulfates. We have measured the temperature and gas-phase concentrations of KCl and HCl, and detected the presence of aerosols in the post-flame region of a range of hydrocarbon flames seeded with KCl, with and without the addition of SO2. Dilution of the flame products with different amounts of N-2 ensured post-flame temperatures in the range 950-1400 K. In the absence of SO2, KCl levels were constant in the post-flame zone and no aerosols were formed, even at the lowest temperatures. In the presence of SO2, KCl was consumed and HCl and aerosols formed, most pronounced in flames with the lowest post-flame temperatures. This shows that KCl is sulfated in the gas phase to K2SO4, and this is followed by homogeneous nucleation of K2SO4 to form aerosols. Predictions from a kinetic model of the S/Cl/K chemistry agreed well with the experimental results. The model showed that the rate-limiting steps in the sulfation process are the oxidation of SO2 to SO3 and the homogeneous nucleation of K2SO4. (C) 2013 The Combustion Institute. Published by Elsevier Inc. All rights reserved.