Thermogravimetric investigations of sewage sludge were carried out to determine the amount of released gas products in the temperature range from 30 to 1000 degreesC and to specify the parameters of kinetic reactions that took place during thermal degradation. The investigations were performed in the atmosphere of argon, which simulated phenomena occurring during pyrolysis and in the atmosphere of carbon dioxide, which simulated gasification process. The determined kinetic parameters will be used to model thermal degradation phenomena, which take place in a continuous reactor.