Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706-1322, USA.
Proc Natl Acad Sci U S A. 2010 Apr 13;107(15):6622-7. doi: 10.1073/pnas.0910993107. Epub 2010 Feb 1.
Molecular beam scattering experiments are used to investigate reactions of SO(2) at the surface of a molten alkali carbonate eutectic at 683 K. We find that two-thirds of the SO(2) molecules that thermalize at the surface of the melt are converted to gaseous CO(2) via the reaction SO(2)(g) + CO(3)(2-) --> CO(2)(g) + SO(3)(-2). The CO(2) product is formed from SO(2) in less than 10(-6) s, implying that the reaction takes place in a shallow liquid region less than 100 A deep. The reaction probability does not vary between 683 and 883 K, further implying a compensation between decreasing SO(2) residence time in the near-interfacial region and increasing reactivity at higher temperatures. These results demonstrate the remarkable efficiency of SO(2) --> CO(2) conversion by molten carbonates, which appear to be much more reactive than dry calcium carbonate or wet slurries commonly used for flue gas desulfurization in coal-burning power plants.
分子束散射实验被用于研究在 683K 的熔融碱碳酸盐共晶表面上 SO(2)的反应。我们发现，在熔体表面热化的三分之二的 SO(2)分子通过反应 SO(2)(g) + CO(3)(2-) --> CO(2)(g) + SO(3)(-2)转化为气态 CO(2)。CO(2)产物是在不到 10(-6) s 内从 SO(2)形成的，这意味着反应发生在深度小于 100A 的浅层液体区域中。反应概率在 683 和 883 K 之间没有变化，这进一步表明在近界面区域中 SO(2)停留时间减少和在较高温度下反应性增加之间存在补偿。这些结果表明熔融碳酸盐将 SO(2)转化为 CO(2)的效率非常高，这似乎比燃煤电厂中常用的干法碳酸钙或湿法浆液更具反应性。
