超细煤粉NO均相还原的理论研究

Superfine pulverized coal combustion is a new pulverized coal combustion technology that has better combustion stability, high combustion efficiency, comprehensive cost-effective operation and lower NOx emission than that using conventional particle sizes. An interesting finding was brought into light in our previous study that the hydroxyl radicals on superfine pulverized coal surface are accumulated substantially as a result of the mechanochemical process when ultra-fine crushed. Homogeneous reaction mechanism of NO reduction by HCN has been studied using the density functional theory at the B3LYP/6-31 G (d) level in order to understand the NOx emission decrease as the mean particle size decrease. All equilibrium and transition state structures of the proposed reaction channels are fully optimized by the density functional theory at the B3LYP/6-31 G (d) level. Single point calculations are evaluated at the CCSD/6-31 G (d) level of theory and corresponding zero-point energy are determined to give an accurate energy for potential energy surface. Calculated results indicate that NO can be reduced in two key paths, HCN→HOCN→NCO→N2+CO2and HCN→HNCO→NCO→N2+CO2. The novelty of the present work on superfine pulverized coal will provide insight into its lower NOx emission.