添加CaCl2对烟气净化装置联合脱汞的规律分析

煤炭燃烧向大气中排放了大量汞。为了探究经济有效的汞排放控制方法，在管式炉中进行了CaCl₂晶体的水解实验，CaCl₂在一定温度和气氛下会水解产生HCl，HCl有利于烟气中Hg0的氧化。且随着反应温度的增加，水解率呈上升趋势。在流化床炉中进行了CaCl₂溶液蒸发协同脱汞实验。CaCl₂溶液喷洒在燃煤中可显著提高SCR脱销装置对Hg0的氧化率；煤中喷洒CaCl₂溶液可提高烟气中Hg2+的浓度和占比，从而提高湿法烟气脱硫装置（WFGD）对气态Hg的脱除效果。相比于喷洒在原煤中，将CaCl₂溶液喷洒在布袋除尘器（FF）前的蒸发干燥塔中，可显著提高FF脱除Hg的效果。整体上看，当温度越高，氯添加比越高时，烟气净化装置协同脱汞的效率也越高。

ANALYSIS ON THE LAW OF COMBINED DEMERCURATION OF FLUE GAS PURIFICATION UNIT BY ADDING CaCl2

The combustion of coal releases a large amount of mercury into the atmosphere. In order to explore cost-effective mercury emission control methods, the hydrolysis experiment of CaCl₂ crystal was carried out in a tubular furnace. Under certain temperature and atmosphere, CaCl₂ could hydrolyze to produce HCl, which was conducive to the oxidation of Hg0 in flue gas. The results showed that the hydrolysis rate increased with the increase of reaction temperature. The experiment of CaCl₂ solution evaporation combined with mercury removal was carried out in a fluidized bed furnace. Spraying CaCl₂ solution in coal could significantly improve the oxidation rate of SCR denitrification device to Hg0; compared with spraying in raw coal, spraying CaCl₂ solution in the evaporation drying tower before FF would significantly improve the effect of removing Hg by FF bag filter; spraying CaCl₂ solution into coal would increase the concentration and proportion of Hg2+ in flue gas, and the removal effect of WFGD wet desulfurization unit on gaseous Hg was improved. On the whole, the higher the temperature was and the higher the chlorine addition ratio was, the higher the synergistic mercury removal efficiency of the flue gas purification device was.