Thermogravimetric characteristics and kinetic study of biomass co-pyrolysis with plastics

The pyrolysis of pure biomass, high density polyethylene (HDPE), polypropylene (PP) and polyethylene terephthalate (PET), plastic mixtures [HDPE+PP+PET (1 : 1 : 1)], and biomass/plastic mixture (9: 1, 3 : 1, 1 : 1, 1 : 3 and I : 9) were investigated by using a thermogravimetric analyzer under a heating rate at 10 degrees C/min from room temperature to 800 degrees C. Paper was selected as the biomass sample. Results obtained from this comprehensive investigation indicated that biomass was decomposed mainly in the temperature range of 290-420 degrees C, whereas thermal degradation temperature of plastic mixture is 390-550 degrees C. The percentage weight loss difference (W) between experimental and theoretical ones was calculated, which reached a significantly high value of (-)] 5 to (-)50% at around 450 degrees C in various blend materials. These thermogravimetric results indicate the presence of significant interaction and synergistic effect between biomass and plastic mixtures during their co-pyrolysis at the high temperature region. With increase in the amount of plastic mixture in blend material, the char production has diminished at final pyrolysis temperature range. Additionally, a kinetic analysis was performed to fit with TGA data, the entire pyrolysis processes being considered as one or two consecutive first order reactions.