Char structural evolution characteristics and its correlation with reactivity during the heterogeneous NO reduction in a micro fluidized bed reaction analyzer: The influence of reaction residence time

Abstract Under simulated flue gas conditions, the effect of the residence time of different chars on the evolution of physiochemical structures during the NO reduction process was evaluated. The experimental data proved that the acid-soaking treatment contributed to the development of char structures. Both biomass chars and H-form chars showed better reactivity on NO reduction, which may be related to smaller average pore diameters, larger BET surface areas and larger pore volumes. The increasing of residence time increased the graphitization degree of all chars, and main reductions of structural defects were from within and between carbon graphene layers. Besides, with the residence time increasing, N-6 and N-5 of R-form Shenmu chars were transformed into N-Q and N-X, while N-X and N-Q (and some N-5) of R-form and H-form sawdust chars were transformed into N-6, which is related to the oxidation or reduction reaction for different chars.