Thesis Archive
CARBON DIOXIDE GASIFICATION OF REFUSE PLASTIC FUEL USING POTASSIUM CARBONATE AS CATALSYT
ABASTILLAS, Luz Paula B.
BENABDUSSALAM, Rami A.
OPEÑA, Karl Paulo B.
Abstract:
Plastics degrade at very slow rates and therefore, it is important to further develop effective methods for their disposal. Gasification is a waste-to-energy conversion process that involves the thermal degradation of the feedstock to produce synthesis gas. This study seeks to provide kinetic parameters by applying gas-solid kinetic models to the carbon dioxide gasification of high-density polyethylene (HDPE) and polypropylene (PP) using potassium carbonate (K2CO3) as a catalyst. Gasification was performed in a thermogravimetric analyzer in which the reaction was carried out using a catalyst. The catalyst loading was varied from 1-5% and compared with uncatalyzed gasification reaction of the sample. The gasification process was investigated non-isothermally from room temperature to temperatures ranging from 600°C-900°C. The gasification rate was plotted against temperature and its peak values were at 50% to 80% conversion at corresponding temperatures of 490°C to 510°C for HDPE and 50 to 70% at a range of 470°C to 510°C for PP. The addition of potassium carbonate to the plastic generally resulted in lower peak gasification rates, however, there was no trend observed between the catalyst loading and the peak gasification rates observed. Therefore, the amount of catalyst had no effect on the peak gasification rates. Five kinetic models were fitted for the gasification data, which were the volumetric models, the shrinking core model and the random pore model. The best-fit model for the gasification of both HDPE and PP was determined to be the extended modified volumetric model (EMVM) with R2 values ranging from 0.9995 to 1.0000. Using EMVM for the calculation of kinetic parameters, the lowest activation energies for HDPE and PP were observed to be 357.5 and 190.2 kJ/mol at uncatalyzed conditions at 900°C and 800°C respectively, though there is no clear correlation between the value of the activation energies and experimental conditions for this study. There was no evident trend observed regarding the activation energies and the programmed gasification temperatures or the catalyst loading.
Adviser:
BUNGAY, Vergel C.