Investigation on kinetic parameters during combustion of Tetraselmis chuii microalgae under thermogravimetric analyzer

The investigation on combustion characteristic and kinetic parameters of Tetraselmis chuii microalgae was carried out under thermogravimetric analyzer. The sample of microalgae has prepared by the Center for Brackish Water Aquaculture (BBPBAP) Jepara, Indonesia. The drying out the water content in the sediment was performed by an oven at temperature 80 °C as long as 24 h. The dry sample then the crushed and followed by sieving to be mesh size of 60. The thermal decomposition of Tetraselmis chuii microalgae was investigated by a thermogravimetric apparatus, in which the 10 mg of sample was heated up in the temperatures range of 25-900 °C with an atmospheric airflow rate of 50 mL/min and a heating rate of 15 °C/min. The mass loss during temperature expansion was recorded by a computer to be a thermogravimetric (TG) graph and used to evaluate the thermal characteristic of the sample. The kinetic parameters were evaluated in the active combustion zone by the Arrhenius method, resulted in the respective values of reaction order (n), logarithmic frequency factor (log A), and activation energy (E) were 1.24, 9.0 min-1 and 101.05 kJ mol-1 for stage II, and 2.38, 33.31 min-1 and 502.88 kJ mol-1 for stage IV.