A modified microwave thermo-gravimetric-analyzer for kinetic purposes

Apply of microwave heating in a chemical reaction makes the investigation of reaction kinetics rather complex, for the challenges of measuring reaction temperature and reactantsʹ weight during the exposure time. To involve solving these matters, an original bench-scale experimental setup was built. This setup is called microwave thermo-gravimetric-analyzer (MW-TGA), because it works as a traditional thermo-gravimetric-analyzer using microwave heating instead of conventional heating. In addition, MW-TGA is equipped with an innovated thermometer (air-thermometer) that does not suffer from the traditional thermometer drawbacks, particularly when microwave heating is implemented. The efficiency of the air-thermometer was validated using a traditional thermocouple thermometer, an average percentage relative error of ±5% of the reference value was found. Eventually, MW-TGA was employed to examine the kinetics of microwave pyrolysis of sawdust. The estimated kinetic parameters were 54.5 ± 1.5 kJ/mol, 3 ± 0.9 × 105 min−1, and 2 for the reaction activation energy, pre-exponential factor, and reaction order, respectively.