Thermal pyrolysis of pharmaceutical wastewater sludge, brown coal, and sludge-coal blends were studied by TG dynamic runs carried out at 20 °C min in the temperature range from 25 to 850 °C. Different possible kinetic models of thermal decomposition have been considered. The best models of mechanism function for brown coal, pharmaceutical wastewater sludge, and coal-sludge blends are a first-order reaction, a N-dimensional nucleation, and growth reactions with N = 2 and 4, respectively. The Arrhenius kinetic parameters for brown coal, pharmaceutical wastewater sludge, and coal-sludge blends are proposed. [ABSTRACT FROM AUTHOR]