Thermal behaviour of walnut shells by thermogravimetry with gas chromatography-mass spectrometry analysis.

The present study introduces thermogravimetry with gas chromatography-mass spectrometry (TG-GC-MS) at four different heating rates to investigate the activation energy and thermal degradation behaviour of walnut shell pyrolysis. The distributed activation energy model (DAEM) was applied to investigate the activation energy. According to values of the activation energy and the correlation coefficient by the DAEM, the activation energy (98.69-267.75 kJ mol-1) and correlation coefficient (0.914-0.999) were determined for pyrolysis of walnut shells. GC-MS was performed to investigate the pyrolysis products from walnut shells at different critical temperature points. More than 20 different substances were identified at different temperatures from GC-MS results. With the increasing pyrolysis temperature, furan, furfural, benzene and long chain alkanes were successively identified in different GC-MS experimental results.