CO₂ gasification of char from spent mushroom substrate in TG-MS system

Gasification of the char obtained from the spent substrate after mushroom cultivation was carried out in a thermobalance connected to a mass spectrometer in the temperature range from 200 to 950 °C and CO₂ concentration from 5 to 100 vol%. Under non-isothermal conditions, in addition to the char gasification process, both carbonation and calcination reactions occurred. The investigation of gasification kinetics in CO₂ was carried out under isothermal conditions. The rate of gasification reaction was determined from the shrinking core model, and kinetic constant has been calculated from Langmuir–Hinshelwood kinetics. On the basis of the conducted research, it was observed that the saturation of active sites on the char particles occurred above 50 vol% CO₂, regardless of temperature. The analysis of gas composition indicates CO as the main product of gasification.