Abstract

The isothermal CO₂ gasification characteristics of three chars derived from pyrolysis of electrical and electronic equipment (WEEE) plastics were firstly studied by using a thermogravimetric analyzer (TGA) within the temperature range of 850?1050°C. Phenolic board (PB), brominated high impact polystyrene (HIPS) and acrylonitrile butadiene styrene (ABS) are widely used for the electric and electronic equipment and were employed as model WEEE plastics for the char sample production in this study. The effects of their physicochemical properties and gasification temperature on the WEEE plastic chars conversion rate, reactivity indexes and gasification rate were investigated in detail. The random pore model (RPM), extended random pore model (eRPM) and shifted extended random pore model (s-eRPM) have been employed to fit with the CO₂ gasification rate curve of WEEE plastic chars. The kinetic parameters and correlation coefficients (R²) were evaluated by RPM, eRPM and s-eRPM, respectively. It was found that the CO₂ gasification reactivity of PB char was the highest, followed by that of HIPS char and the gasification reactivity of ABS char was the lowest, which have a close relationship with their pore and carbon crystal structure properties. In addition, it was found that the RMP could fit well with the gasification reaction rate of HIPS char whose maximum reaction rate appears at char conversion of approximate 0.4. Nevertheless, as for PB char and ABS char, their maximum gasification rate presented at char conversion of around 0.8 and 0.2, respectively. And it was observed that the eRMP and s-eRPM could predict their gasification rate of PB char and ABS char very well with higher R², respectively.

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