Abstract:
Glass fibre-reinforced thermoplastic (GFRP) is the composite material of choice for
engineers to improve their design, save expenses, and achieve sustainability goals, what leads to
generation of a big quantity of GFRP waste (during production or as an end-life-product) that
needs to be disposed of safely. In order to valorise GFRP waste, this research aims to recover
phenol and acetic acid as high-added value chemical and energy products from the millions of
tons of GFRP waste produced annually during the catalytic pyrolysis process. The experiments
were performed on glass fibre-reinforced poly(methyl methacrylate)-PMMA (GF/PM) as a
common and commercial thermoplastic resin in five stages. In the first stage, the thermal
decomposition of the milled feedstock over different percentages of ZSM-5 zeolite catalyst to
feedstock in the ranges 0.5-5 wt.% (w/w) was performed using TGA. The generated volatile
products from TGA were analysed using TG-FTIR and GC/MS in the second and third stages,
respectively. The fourth stage was used to study the kinetic behaviour of catalytic pyrolysis of
the feedstock with different catalysts and at different heating conditions using isoconversional
models. In the last stage, the experimental thermal decomposition curves were simulated
numerically. The results showed that ZSM/GF/PM can decompose significantly in the ranges
320-460 ˚C. Meanwhile, 2 wt.% of catalyst-to-GF/PM ratio was sufficient to recover more than
48% of phenol, 23% of acetic acid, 19% carbon dioxide compounds at 30˚C/min with high
intensity of aromatic benzene. Also, this batch gave a higher kinetic complexity in terms of
activation energy in the ranges 100-200 kJ/mol (linear models) and 230-440 kJ/mol (nonlinear
models). These results confirm that involvement of 2 wt.% ZSM-5 zeolite catalyst in the
pyrolysis of GF/PM has a big impact on the formulated volatile components and their potential
upscaling.
