Experiments were carried out in a pilot-scale entrained flow reactor (EFR) to investigate the reaction of SO₃ with Ca(OH)₂ as a method of dry sorbent injection (DSI) for SO₃ removal from flue gas. The results indicate that SO₃ can be removed by Ca(OH)₂ with an efficiency that can reach 80%, and it was found that the molar ratio of Ca(OH)₂ to SO₃ ([Ca]/[S]) and reaction temperature have a significant effect on SO₃ removal efficiency. The experimental data measured inside the EFR were analyzed with a computing fluid dynamic (CFD) simulation, in which the Euler–Lagrangian frames were used for gas- and discrete-phase modeling. The CFD models were validated and applied to analyze the effects of certain parameters on SO₃ removal efficiency, such as particle velocity, [Ca]/[S], temperature and residence time. It was found that the sorbent diameter has a significant influence on SO₃ removal efficiency, with an obvious decrease in efficiency if the Ca(OH)₂ particle diameter increases. For example, if the sorbent diameter increases from 3 to 10 μm, the SO₃ removal efficiency at the reactor outlet will decrease from 99% to 55%. A detailed comparison and theoretical analysis indicated that external diffusion of SO₃ from the gas phase to the particle surface is the rate controlling step for larger Ca(OH)₂ particles, and more attention should be paid to the competition between external diffusion and surface reaction when applying the DSI method for removing SO₃ from flue gas.

中文翻译：

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在夹带流反应器中用Ca（OH）₂从烟气中脱除SO ₃

在中型夹带流动反应器（EFR）中进行了实验，以研究SO ₃与Ca（OH）₂的反应，作为干法吸附剂注入（DSI）去除烟道气中SO _3的方法。结果表明，Ca（OH）₂可以达到80％的效率去除SO ₃，并且发现Ca（OH）₂与SO ₃的摩尔比（[Ca] / [S]）和反应温度对SO ₃有显着影响去除效率。EFR内部测量的实验数据通过计算流体动力学（CFD）模拟进行了分析，其中使用Euler-Lagrangian框架进行气相和离散相建模。验证了CFD模型，并将其用于分析某些参数对SO ₃去除效率的影响，例如颗粒速度，[Ca] / [S]，温度和停留时间。发现吸附剂直径对SO ₃去除效率具有显着影响，如果Ca（OH）₂粒径增加，则吸附剂直径明显降低。例如，如果吸附剂直径从3增至10μm，则SO ₃反应器出口的去除效率将从99％降至55％。详细的比较和理论分析表明，SO ₃从气相向颗粒表面的外部扩散是较大的Ca（OH）₂颗粒的速率控制步骤，应更加注意外部扩散与表面反应之间的竞争。当采用DSI方法从烟气中去除SO _3时。