TG–FTIR study on pyrolysis of waste printing paper

Abstract

Pyrolysis of waste printing paper was investigated by using thermogravimetric analyzer coupled with Fourier transform infrared spectrometer (TG–FTIR). The activation energies of pyrolysis reactions were obtained via the Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose methods, respectively. The kinetic model was determined by the master plot method. TG results showed that the highest mass loss rate occurred increased from 618 to 638 K as heating rate increased from 5 to 20 K min−1, indicating the pyrolysis of cellulose fibers in WPP. The mass loss above 873 K can be attributed to the decomposition of calcite used as filler. By analyzing the FTIR spectra, it was found that the major generation temperatures of the evolving gaseous products ranged from 635 to 647 K during the pyrolysis of WPP at 20 K min−1. CO2 was the primary non-condensable product, and aldehydes, organic acids, ketones were the dominating condensable products, in addition to ethers. Kinetic analysis revealed that the activation energy of the pyrolysis reaction of WPP was 189.39 kJ mol−1 for the FWO method and 189.03 kJ mol−1 for the KAS method. The reaction model function was f(α) = (1 − α)1.95, and the frequency factor A = 3.66 × 1015 min−1. All of the findings would help further understanding of pyrolysis behavior of WPP and its thermochemical utilization for fuels and chemicals.