煤燃烧过程中锡的氯化物生成机理的理论研究

A Quantum Study on the Reaction Mechanism of Stannous Chloride Series in Coal Combustion

用量子化学MP2方法对煤燃烧过程中的氯化亚锡系列化合物生成反应机理和反应动力学进行了理论研究.通过计算确定了4个反应体系的反应物、产物、中间体和过渡态的构型,在SDD基组水平上计算了它们的能量.同时,也用经典过渡态理论计算了这4个反应体系的反应速率常数.经研究发现:在煤燃烧反应中,Sn(3P0)与HCl、HOCl反应可生成SnCl,而SnCl很快被HOCl、HCl氧化生成SnCl2.因此在煤燃烧反应中,不能被控制收集的Sn(3P0),有可能在燃烧温度降低时生成离子态的锡氯化物而被污染控制系统进行有效地收集.该结论为煤燃烧过程中Sn(3P0)的污染控制提供了理论依据.

Ab initio MP2 method is performed to study the reaction mechanism and kinetics of stannous chloride series in coal combustion. Four channels are detected by calculations. The geometric configurations of reactants, intermediates, transition states and products are optimized and the energies are computed at MP2/SDD level. The intermediates and transition states are confirmed by the vibrational analysis. Besides, we use the classic transition theory to calculate the rate constants of the four channels. The results show that Sn(3P0) can react with HCl, HOCl to form SnCl, and SnCl can be further oxidized by HCl, HOCl to form the soluble product SnCl2. So, in coal combustion, Sn(3P0) without control collection may produce ionic stannous chloride series, which can be effectively collected by pollution control system. This conclusion offers a theoretical basis for pollution control of Sn(3P0) in coal combustion.