煤燃烧中汞与含氯气体的反应机理研究

REACTION MECHANISM OF MERCURY AND GASES DURING COAL COMBUSTION

预测汞的排放及其形态必须了解燃煤烟气中汞的化学反应机理。本文用量子化学从头计算研究了煤燃烧过程中汞与含氯气体的反应机理,优化得到反应物、过渡态、中间体和产物的几何构型,并计算活化能和反应热效应。采用经典过渡态理论计算反应速率常数,并与文献数据进行比较,结果比较吻合,表明量子化学是研究汞等痕量元素与气体反应的机理和动力学、热力学参数的一种有效手段。

Predicting emissions of mercury and the speciation of mercury in combustion emissions cannot be done without a fundamental understanding of the chemical reaction mechanism of mercury in flue gas. The microcosmic mechanism of reaction between mercury and gases was studied by ab initio calculations of quantum chemistry. The geometry optimizations of reactant, transition state, intermediate and product were made at MP2/SDD level. The reaction potential barriers and enthalpy were calculated. The rate constant was derived by application of transition state theory and compared with the data of reference. The results show that quantum chemistry is an effective method to study the reaction mechanism of trace elements and gas during coal combustion.