Instituto Nacional del Carbón (CSIC) , Francisco Pintado Fe, 26, 33011, Oviedo, Spain.
Environ Sci Technol. 2014 Jun 17;48(12):7164-70. doi: 10.1021/es500967d. Epub 2014 Jun 9.
This study evaluates the effect of the gases present in a typical oxy-coal combustion atmosphere on mercury speciation and compares it with the mercury speciation produced in conventional air combustion atmospheres. The work was performed at laboratory scale at 150 °C. It was found that the minor constituents (SO2, NOx, and HCl) significantly modify the percentages of Hg(2+) in the gas. The influence of these species on mercury oxidation was demostrated when they were tested individually and also when they were blended in different gas compositions, although the effect was different to the sum of their individual effects. Of the minor constituents, NOx were the main species involved in oxidation of mercury. Moreover, it was found that a large concentration of H2O vapor also plays an important role in mercury oxidation. Around 50% of the total mercury was oxidized in atmospheres with H2O vapor concentrations typical of oxy-combustion conditions. When the atmospheres have similar concentrations of SO2, NO, NO2, HCl, and H2O, the proportion of Hg(0)/Hg(2+) is similar regardless of whether CO2 (oxy-fuel combustion) or N2 (air combustion) are the main components of the gas.
本研究评估了典型的氧煤燃烧气氛中存在的气体对汞形态的影响，并将其与传统空气燃烧气氛中产生的汞形态进行了比较。该研究在 150°C 的实验室规模下进行。结果发现，少量组分（SO2、NOx 和 HCl）会显著改变气体中 Hg(2+)的百分比。当单独测试这些物质以及在不同的气体组成中混合测试时，这些物质对汞氧化的影响得到了证明，尽管其影响与它们各自影响的总和不同。在少量组分中，NOx 是参与汞氧化的主要物质。此外，还发现大量水蒸气的存在也在汞氧化中起着重要作用。在水蒸气浓度典型的富氧燃烧条件下，约有 50%的总汞被氧化。当气氛中具有相似浓度的 SO2、NO、NO2、HCl 和 H2O 时，无论 CO2（富氧燃烧）还是 N2（空气燃烧）是气体的主要成分，Hg(0)/Hg(2+)的比例都相似。
