Effect of CO Gasification on Nitrogen Oxide Emission in Oxy-Fuel Combustion.

Due to the cumulative effect of the recycled flue gas in oxy-fuel combustion, the reduction of NO has become the focus of research in which the role of CO gasification has a nonnegligible effect. In this article, the heterogeneous gasification mechanisms of CO on coal char during oxy-fuel combustion were studied by density functional theory and transition-state theory. The zigzag char model and char(N) model were selected to investigate the CO adsorption and gratification reactions at the molecular level.

Density Functional Theory Investigation on the Catalytic Reduction of NO by CO on the Char Surface: the Effect of Iron.

The catalytic reduction of NO in the presence of CO was investigated by density functional theory calculations with consideration of the iron involved in char (Fe-adsorbed char). The quantitative information of reaction kinetics was also evaluated using canonical variational transition-state theory in the temperature range of 500-1800 K. The analysis of the associated adsorption energies indicates that the affinity of the carbon active site toward NO and CO is stronger than that at the Fe site, and the NO adsorption on the carbon site in the N-down mode is the most energetically favorable.