Abstract The concentration of SOX, HCl, CO, NOX etc. in the flue gas during oxy-fuel combustion is all relatively higher compared with air combustion. Higher SO3 concentration increases the risk of low-temperature corrosion. The higher concentration of HCl and CO can also cause corrosion, and they may play roles on SO3 formation. Thus homogeneous experiment and pulverized coal experiment were done on different furnace system to clarify the effects of HCl and CO on SO3 formation during oxy-fuel combustion. Different inlet concentration of HCl, CO, SO2, H2O, O2 and CO2 were used to simulate the flue gas of the combustion. The results indicated that HCl inhibited SO3 formation but CO promoted SO3 formation at the experimental temperature. HCl richens the radical pool and might generate HO2 radical which was negative to SO3 formation. CO could react with O2 to generate more O radical which was vital to SO3 formation and consume HO2 radical when steam existed. The pulverized coal experiment presented a different SO3 concentration at the same input sulfur and steam level, meaning the fly ash and other gas phase components in the flue gas could also influence SO3 formation.

中文翻译：

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HCl 和 CO 对富氧燃烧过程中三氧化硫形成机制的影响

摘要 富氧燃烧烟气中SOX、HCl、CO、NOX等的浓度均高于空气燃烧。较高的 SO3 浓度会增加低温腐蚀的风险。较高浓度的 HCl 和 CO 也会引起腐蚀，并且它们可能对 SO3 的形成起作用。因此，在不同的炉系统上进行了均质实验和煤粉实验，以阐明 HCl 和 CO 对富氧燃烧过程中 SO3 形成的影响。使用不同入口浓度的 HCl、CO、SO2、H2O、O2 和 CO2 来模拟燃烧的烟气。结果表明，在实验温度下，HCl 抑制了 SO3 的形成，而 CO 促进了 SO3 的形成。HCl 丰富了自由基池，并可能产生对 SO3 形成不利的 HO2 自由基。CO 可以与 O2 反应生成更多的 O 自由基，这对 SO3 的形成至关重要，并在蒸汽存在时消耗 HO2 自由基。煤粉实验在相同的输入硫和蒸汽水平下呈现出不同的 SO3 浓度，这意味着烟道气中的飞灰和其他气相成分也会影响 SO3 的形成。