Comparison of the NO heterogeneous reduction characteristics using biochars derived from three biomass with different lignin types

The properties of biochars derived from three biomass with different lignin types were analyzed by low-pressure nitrogen gas adsorption (LP-N 2GA), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. In this study, the heterogeneous reduction characteristics of NO by Chinese fir biochar (FB), elm biochar (EB) and bamboo biochar (BB) were compared. The reaction temperature increases from room temperature to 1073 K at a fixed heating rate of 10 K/min. Results show that the main stage of heterogeneous NO reduction with three kinds of biochars can be divided into two zones: dynamic control zone and diffusion control zone. The lignin composed of coniferyl alcohol and sinapyl alcohol derivative units will form more oxygen-containing functional groups and hydroxyl groups on EB and BB surfaces. Among the three biochars in the dynamic control zone, EB showed the highest NO reduction rate (2.69 ppm/K) and the strongest oxidation resistance. The lignin composed of a polymer with coniferyl alcohol as a basic unit form the well-developed pore characteristic of FB. The adsorption performance of FB is the best, which improves the reduction of NO in diffusion control zone.

Automated summary

The properties of biochars derived from different biomass were analyzed using LP-N2GA, FTIR, and Raman spectroscopy. Among the three biochars, elm biochar showed the highest NO reduction rate in the dynamic control zone, while Chinese fir biochar had the best performance in the diffusion control zone.