This paper presents a characterisation of the combustion of mixtures of pelletised leather tannery waste (LTW) and hardwood pellets (HP) on a grate. The experimental investigation was carried out in a laboratory-scale combustion reactor with the use of thermogravimetric analysis (TGA). Proximate and ultimate analysis showed that leather tannery waste may constitute a promising fuel, with a relatively high heating value at the level of 16 MJ/Icg. The highest value of thermal degradation of leather was reached at 326 degrees C; the combustion characteristics of leather waste are include by two peaks corresponding to 406 and 432 degrees C. The results of the combustion process showed that doping hardwood pellets with leather waste does not significantly affect combustion temperatures in the fuel bed on the perforated flat gate of the test reactor. Furthermore, high ash content in leather waste significantly affects the formation of the ash layer, which increases along with increased contents of pelletised tannery waste. (C) 2019 Elsevier Ltd. All rights reserved.