Effects of Bio-Syngas Blends on Combustion Characteristics of Coal: Kinetic Analysis

Abstract

The coupled combustion of biomass and coal can utilize large amounts of renewable biomass and reduce the emission of pollutants during power generation. In this study, the coal combustion characteristics were analyzed at different heating value-based biomass blending ratios and temperatures in the coupled combustion of bio-syngas and coal. The kinetic reaction mechanism of coal combustion was investigated by Micro-fluidized Bed Reaction Analyzer (MFBRA). The results indicated that the reaction time decreased with increasing the heating value-based biomass blending ratio and temperature in the coupled combustion process of bio-syngas and coal. The major conversion process of coal combustion usually took 15 s at 1273 K and the maximum reaction rate was usually below 0.14 at 873 K to 1273 K and decreased with increasing reaction temperature. The nucleation and growth model offered a most reasonable description of the coal combustion process. The activation energy was about 121.04 kJ/mol and the pre-exponential factor was of the order of 5.01 × 104 s−1 in the combustion of coal. These data are important to the understanding of the coupled combustion mechanism of bio-syngas and coal, which is beneficial for improving combustion efficiency as well as operating a combustion furnace.