Thesis Archive
Kinetic Study on Carbon Dioxide Gasification of Philippine-indonesian Coal-char Blends (2016-2017)
Cris Paulo P. Beo
Jose Paulo A. Chua
Abstract:
-Kinetic parameters are important data in the design and operation of energy conversion technologies such as gasifiers. Coal is a carbonaceous material that has been widely used for gasification; however, its kinetic behavior can vary on the characteristics of the coal that is gasified. In this study, Philippine sub-bituminous (PH) and Indonesian lignite (IL) coal blends were gasified in a CO2 environment at 700°C, 800°C, and 900°C to investigate the effects of coal composition, gasification temperature, as well as catalytic effects of potassium carbonate (K2CO3) and calcium carbonate (CaCO3) on kinetic behavior. Conversion-time data obtained from thermogravimetric analysis were fitted into the modified volumetric (MVM) and extended modified volumetric (EMVM) models to obtain the kinetic parameters; the activation energies were also determined using Arrhenius plots. Rate constants for the uncatalyzed gasification at 700°C were found to be 0.0936, 0.4155, 0.1091, 0.3182, and 0.0800 h–1 for the pure PH, 80%PH+20%IL, 50%PH+50%IL, 20%PH+80%IL, and pure IL coals, respectively; while activation energies of uncatalyzed reactions were found to be 154.94, 115.43, 162.40, 131.75, and 173.95 kJ/mol for the same coal samples. A synergistic effect of blending coal in 80%PH+20%IL and 20%PH+80%IL proportions was observed from reactivity of the coal samples during uncatalyzed gasification. K2CO3 generally performed better as catalyst than CaCO3 with both having significant catalytic effects at 800°C and 900°C but none at 700°C; however, there was decreased catalytic effect of K2CO3 when loaded to coals with high proportion of PH coal.
Adviser:
Dr. Vergel C. Bungay