Research on plasma modified fly ash denitration

Abstract

The effects of reactor parameters and process parameters on the denitration rate of modified fly ash in different gas atmospheres were studied by using a dielectric barrier plasma reactor and using orthogonal experiments. The characteristics of modified fly ash were analyzed using scanning electron microscope, specific surface area analyzer, X-ray diffraction, Boehm titration and Fourier transform infrared spectroscopy. The experimental data were processed by variance analysis and linear regression to induce the denitration mechanism. R² of the linear regression analysis model is 0.789, which means that the adsorption pore size, acid groups and basic group can explain 78.9% of the change in denitration rate. The basic group will have a significant positive impact on the denitration rate, and the adsorption pore size and acidic group will have a significant negative impact on the denitration rate. Through variance analysis of the experimental data, it was found that the input power and discharge gap have a significant effect on the denitration rate, but the ionization time and discharge length have no significant effect. The input power affects the denitration rate by impacting the basic group, and the discharge gap affects the denitration rate by influencing the adsorption pore size. There are three denitration mechanisms on the surface of fly ash: physical adsorption, chemical adsorption and absorption process. Among them, chemical adsorption is the main mechanism of action, accounting for approximately 60.86%.