Online evolved gas analysis by Thermogravimetric-Mass Spectroscopy for thermal decomposition of biomass and its components under different atmospheres: part I. Lignin.

Thermogravimetric-Mass Spectroscopy (TG-MS) study on lignin decomposition under different (oxygen-containing) atmospheres was carried out to investigate thermal performance of lignin during pyrolysis, oxidative gasification, oxy/fuel combustion and CO(2) gasification. Only one significant mass loss stage was observed for lignin decomposition under helium (He), while another stage, representing char oxidation, appeared under oxygen and CO(2) conditions. No significant variation of the activation energy was presented for the first pyrolysis stage under different atmospheres (from 40.4 to 53.2kJ/mol). A much higher temperature was required for char oxidation under CO(2) than those under O(2) atmospheres, giving the activation energy of 541.9kJ/mol as compared to around 160kJ/mol for O(2)-containing atmospheres. The evolution profiles of CO and CO(2) under different atmospheres were in good accordance with the DTG curves regardless of atmospheres.