Study of microwave enhancement on char reducing NO

Abstract:

To explore a NO reduction technology of coal-fired industrial boilers with high efficiency and low cost, the applewood pyrolysis char and pyrolytic semi-char which are suitable for industrial applications were used as reducing agents, and the effect of microwave on the two samples reducing NO was studied in a microwave reaction system. For explaining the NO reduction experiment results, the infrared temperature measurement experiment, and the physical and chemical properties such as pore structure and TG reactivity was studied. The results show that, compared with the pyrolytic semi-char, the pore structure of applewood pyrolysis char is more developed with higher BET specific surface area and pore volume, it also ignites earlier, the combustion reaction rate reaches its maximum earlier and burns out first. However, its combustion intensity, reaction ability of earlier stage, flammability and combustion performance are weak. When the microwave is not applied, the NO reduction ability of applewood pyrolysis char is stronger than that of pyrolytic semi-char. Both the two samples have better NO reduction ability with microwave applying, and with the increase of microwave power, the NO reduction rate increases. The effect of microwave on pyrolytic semi-char reducing NO is stronger than that of applewood pyrolysis char. Meanwhile, infrared temperature measurement that the surface temperature of two samples both increases confirms that the microwave has an obvious thermal effect which could promote the NO reduction by char.