Effect of torrefaction on rice straw physicochemical characteristics and particulate matter emission behavior during combustion.
In this work, the effects of different torrefaction temperatures and durations on the physicochemical properties of rice straw (RS), and the emission characteristic of PM10 (particulate matter with aerodynamic diameters of ≤10 µm) during torrefied RS combustion, were investigated. Results indicate that the release of Cl and K, and decomposition of the organic matrix demonstrated a promoting effect during torrefaction. However, the removal of Cl and K did not reduce the emission of PM1. The emission concentration of PM1 and PM1-10 generated from torrefied RS was enhanced, and the yields of PM1-10 was much higher than those of PM1. The concentrations of K and Cl in PM1-10 increased with torrefaction temperature, combined with the microstructure, indicating that the torrefaction pretreatment promoted the heterogeneous condensation of KCl vapour to form PM1-10.