Characteristics of pyrolysis and combustion of biobriquettes were studied by using an electrically heated batch combustor. The influences of biomass content of the biobriquette on the combustion characteristics which were obtained by measuring the fuel consumption profile and the experimental results were analyzed by both volume and shrinking-core reaction models.
The following conclusions were obtained (1) total volatile matter content in the biobriquette was directly proportional to its biomass content. Biomass in the biobriquette promotes ignitability and burning rate of low grade coal; (2) combustion time history was divided into two stages, in which volatile matter mainly evolved and burned to lead fixed carbon combustion; (3) in the former stage, the reaction rate constant and its order always remained linear related to biomass content; (4) in the latter stage, the combustion behavior may be simulated by using the shrinking-core reaction model and the reaction was controlled by oxygen diffusion through both the gas boundary layer film and the ash layer almost evenly, and ash layer diffusion coefficients were also linear related to biomass content.