Semi-dry desulfurization is an efficient means of SO removal from the effluent gases from electrolysis cells in aluminum smelters. These gases are at low temperature and contain low concentrations of SO, as opposed to thermal power plants. The removal is carried out by injecting powdered alkaline sorbent, hydrated lime (solid particles), into the SO-containing gas (gas phase) in the presence of humidity. The reaction is controlled by the adsorption of SO onto the surface of lime. This study involves the mathematical modelling of a lab-scale scrubber using a Lagrangian-Eulerian approach in order to analyze the desulfurization efficiency. The model was validated based on experimental data. A parametric study was carried out to investigate the effects of particle size, sorbent amount, and relative humidity (RH) on the desulfurization efficiency. The results show that the particle size is the most important parameter; as the particle size decreases, the desulfurization efficiency increases. However, using finer particles may increase the process cost. The loss in SO capture efficiency due to the use of coarser particle size could be compensated by increasing the relative humidity (RH) of the gas, another key parameter of the process.

中文翻译：

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基于拉格朗日-欧拉方法的半干式 SO2 洗涤器的数学建模

半干法脱硫是去除铝冶炼厂电解槽废气中二氧化硫的有效方法。与火力发电厂不同，这些气体温度较低，二氧化硫浓度较低。通过在湿度存在下将粉末状碱性吸附剂、熟石灰（固体颗粒）注入含 SO 的气体（气相）中来进行去除。该反应是通过石灰表面吸附 SO 来控制的。本研究涉及使用拉格朗日-欧拉方法对实验室规模的洗涤器进行数学建模，以分析脱硫效率。根据实验数据对模型进行了验证。进行参数研究以研究颗粒尺寸、吸附剂用量和相对湿度（RH）对脱硫效率的影响。结果表明，粒径是最重要的参数；随着颗粒尺寸的减小，脱硫效率提高。然而，使用更细的颗粒可能会增加工艺成本。由于使用较粗的颗粒尺寸而导致的 SO 捕获效率损失可以通过增加气体的相对湿度 (RH) 来补偿，这是该过程的另一个关键参数。