Dynamic relationships between real-time fuel moisture content and combustion-emission-performance characteristics of wood pellets in a top-lit updraft cookstove
Nan Zhao, Bowen Li, Riaz Ahmad, Fan Ding, Yuguang Zhou, Gang Li, Ali Mohammed Ibrahim Zayan, Renjie Dong
Abstract
Fuel moisture content (FMC) has an essential impact on the performance of biomass combustion. FMC typically changes during the burning process; therefore, considering only the initial FMC is inadequate for understanding clean combustion and emission control. An on-line FMC monitoring method was employed by measuring relative humidity of emissions to determine the real-time effect of FMC on modified combustion efficiency (MCE) and emission factors (EFs) of pollutants from a typical top-lit updraft cookstove fueled with wood pellets . The results obtained from a complete 16-h combustion sequence showed an overall decreasing trend of FMC, consequently increasing combustion temperature and MCE. Flaming combustion appeared in a high-power phase where the EFs of carbon monoxide (CO) and fine particulate matter (PM 2.5 ) decreased while real-time FMC decreased from 3.5% to 2.1% (wet basis). Smoldering combustion was generally dominant in a low-power phase where EFs of CO and nitric oxide (NO) decreased, while PM 2.5 increased with real-time FMC decreasing from 6.3% to 4.9% (wet basis). This paper can provide meaningful information for modeling biomass burning , quantifying pollutant emissions and understanding related impacts on the residential sector.