Abstract
Polyethylene terephthalate (PET), a thermoplastic polymer, is the main raw material in the manufacturing of
clear bottles used mainly for water and soft drinks. In 2022, the world plastics production was 400.3 million tons;
around 6.2 % corresponds to PET, and only 10 % of it is recycled. PET waste can only be recycled four times
because high temperatures generate chemical and physical degradation. This study aims to apply the principles
of circular economy to transform PET waste into crude oil through fast catalytic pyrolysis, under N2 atmosphere
at different temperatures and with different quantities of zeolite as a catalyst. The crude oil was characterized by
Fourier-transform infrared spectroscopy (FTIR) and solution quantitative 13C nuclear magnetic resonance (13C
NMR). To compare the test results, a simulation for the pyrolysis reactor was conducted with CHEMCAD soft-
ware. The result of FTIR analysis showed the presence of carboxylic acids and aliphatic hydroxyl groups, and 13C
NMR also shows presence of aromatic C–C and C–O bonds, aliphatic C–O and C–C bonds and carbonyl groups.
The experimental results, which were comparable to the simulation, also show that a ratio of 12.5 % zeolite
catalyst to waste PET helps the decomposition process and reduces the operating temperature needed in the
reactor. There is a positive strong correlation between the reactor temperature and pressure. The highest product
yield obtained was 20 % crude oil, 7 % solid powder, 16 % pyrolysis char, and 57 % non-condensable gases
clear bottles used mainly for water and soft drinks. In 2022, the world plastics production was 400.3 million tons;
around 6.2 % corresponds to PET, and only 10 % of it is recycled. PET waste can only be recycled four times
because high temperatures generate chemical and physical degradation. This study aims to apply the principles
of circular economy to transform PET waste into crude oil through fast catalytic pyrolysis, under N2 atmosphere
at different temperatures and with different quantities of zeolite as a catalyst. The crude oil was characterized by
Fourier-transform infrared spectroscopy (FTIR) and solution quantitative 13C nuclear magnetic resonance (13C
NMR). To compare the test results, a simulation for the pyrolysis reactor was conducted with CHEMCAD soft-
ware. The result of FTIR analysis showed the presence of carboxylic acids and aliphatic hydroxyl groups, and 13C
NMR also shows presence of aromatic C–C and C–O bonds, aliphatic C–O and C–C bonds and carbonyl groups.
The experimental results, which were comparable to the simulation, also show that a ratio of 12.5 % zeolite
catalyst to waste PET helps the decomposition process and reduces the operating temperature needed in the
reactor. There is a positive strong correlation between the reactor temperature and pressure. The highest product
yield obtained was 20 % crude oil, 7 % solid powder, 16 % pyrolysis char, and 57 % non-condensable gases
| Original language | American English |
|---|---|
| Article number | 26 |
| Pages (from-to) | 1-16 |
| Number of pages | 16 |
| Journal | Cleaner Engineering and Technology |
| State | Published - 14 Mar 2025 |
