The ignition and combustion characteristics of biochar-glycerol-water slurry fuels were studied. The effect of glycerol addition on the ignition and combustion behavior of biochar-water slurry fuels was emphasized. All the slurry fuels exhibited heterogeneous ignition of biochar residue (agglomerate) following water and glycerol evaporation. The addition of glycerol significantly reduced ignition delay time shortened burnout time and increased burning rate of the droplets. This effect was improved with increasing glycerol/water ratio in the slurry fuels. The glycerol was not completely evaporated before ignition and the remaining glycerol burned concurrently with the biochar on or near the agglomerate surface. The combustion of agglomerate after ignition was controlled by external oxygen diffusion to the outer layer of the agglomerate under the conditions tested. © 2016 The Combustion Institute. Published by Elsevier Inc.