Thermogravimetric Study on the Thermal Characteristics of Tetraselmis chuii Microalgae Pyrolysis in the Presence of Titanium dioxide
Sukarni Sukarni (a,b*), Aloon Eko Widiono (c), Retno Wulandari (b) Poppy Puspitasari (b)
a) Department of Mechanical Engineering, State University of Malang, Semarang Street 5, Malang 65145, Indonesia
b) Centre of Advanced Materials for Renewable Energy, State University of Malang, Semarang Street 5, Malang 65145, Indonesia
c) Master Program of Mechanical Engineering, Graduate School, State University of Malang, Semarang Street 5, Malang 65145, East Java Indonesia
*sukarni.ft[at]um.ac.id
Abstract
Abstract. This study aims to determine the thermal characteristics of microalgae Tetraselmis chuii pyrolysis in the presence of TiO2 using thermogravimetric analysis. The algae sample was harvested after 8 days of culture on a lab scale from Jepara, Central Java, Indonesia. Meanwhile, TiO2 material that was measuring of 25 nm was obtained from Singapores SIGMA ALDRICH. The washing of the sample was done twice using distilled water, and then the algae were deposited until formed the gel. Afterward, the gel material was heated for 24 hours at 80 C to obtain a dry form. Then the dry material was broken by crusher to be a powder and then filtered on a mesh of 60. The final sample was achieved by combining 10 mg of microalgae with 0.03 mg of TiO2. To ensure the homogenius blend, the mechanically mixing process was performed by using a mortar, and subsequently, the last heating was occupied on the sample at a temperature of 80 C for 14 hours. Experiments were carried out on TG analyzer (Mettler Toledo TG DSC 1). Approximately (10.03 mg) of the sample is placed in an aluminum pan and then inserted into the chamber. The heating process was initiated at a temperature of 25 C, and constantly controlled by a computer at the rate of 10 C min until the completed temperature of 900 C. To prevent the oxidation during the thermal processes, nitrogen is chosen as a carrier gas with a flow rate of 50 ml min. From the TG experiments subsequently could be determined the mass loss of the sample during the escalation temperature and time; therefore, the thermal decomposition behavior of the material is possible to be specified. From this thermal characteristic, then the reaction kinetics, as well as thermodynamic parameters, are evaluated. By using a single heating rate, it is practicable to determine of Ea (Activation energy), A (Pre-exponential factor), and n (reaction order) using the model-fitting of Coats-Redfern. These results will be compared with the kinetic of the parent Tetraselmis chuii and will be immediately presented in the next paper.
Keywords: Thermal Characteristics, Tetraselmis chuii, Pyrolysis, Titanium dioxide
Topic: Renewable Energy