BIFUNCTIONAL Bi2O3/ZrO2 CATALYSTS FOR SYNTHESIS OF THIRD GENERATION BIODIESEL FROM NANNOCHLOROPSIS SP. LIPID

NURUL JANNAH BINTI ABD RAHMAN, NURUL JANNAH BINTI ABD RAHMAN (2021) BIFUNCTIONAL Bi2O3/ZrO2 CATALYSTS FOR SYNTHESIS OF THIRD GENERATION BIODIESEL FROM NANNOCHLOROPSIS SP. LIPID. Post-Doctoral thesis, Universiti Teknologi Petronas.

Text NURUL JANNAH BINTI ABD RAHMAN_G03700.pdf Restricted to Registered users only Download (6MB)

Abstract

Microalgae as third generation biofuel have been found to simplify the shortcomings experienced by its predecessors. However, high free fatty acid content represents the major limitation which requires the microalgae lipid to undergo a two-step process to produce biodiesel. As an alternative, in this study, bifunctional Bi2O3/ZrO2 catalysts were developed for simultaneous esterification–transesterification of Nannochloropsis sp. lipid to biodiesel. First, ZrO2 was synthesized using precipitation, sol-gel, hydrothermal and surfactant assisted hydrothermal methods, dried at 120 °C and calcined at 500 °C. The selected ZrO2 was further impregnated with 5–15 wt.% Bi2O3 loadings using incipient wetness impregnation method, dried at 120 °C followed by calcination at 500 °C. All catalysts were characterized using thermogravimetric analysis, X-ray diffraction analysis, N2 physisorption, temperature-programed desorption of NH3 and CO2 analyses and field emission scanning electron microscopy to determine their physicochemical properties. It was found that ZrO2 synthesized by surfactant assisted hydrothermal method produced higher composition of t-ZrO2 (62%) and surface area (69 m2/g) with better acidic (0.289 mmol/g) and basic (2.945 mmol/g) properties of the catalyst as compared to the other preparation methods. Impregnation of the ZrO2 with Bi2O3 improved the acidic and basic properties of the catalysts, whereas, reduced the composition of t-ZrO2 and surface area of the catalysts. From the optimization of the surface area of the catalyst using nonionic Pluronic P123 and cationic CTAB surfactants via response surface methodology coupled with central composite design (RSMCCD), it was found that 5Bi2O3/ZrO2 (CTAB) catalyst resulted in t-ZrO2 composition of 78.4%, surface area of 157 m2/g, and total acidic and basic sites of 17.38 and 4.36 mmol/g, respectively. The catalysts were tested for biodiesel production using 134:1 methanol: lipid ratio and 10 wt.% catalyst loading at 70 °C for 4 h. The highest fatty acid methyl ester (FAME) yield of 73.2% was achieved using 5Bi2O3/ZrO2 (CTAB) catalyst. The success of the catalytic activity showed by 5Bi2O3/ZrO2 (CTAB) catalyst is a result of synergistic role between large surface area, high composition of t-ZrO2 and sufficient acidic and basic properties. The 5Bi2O3/ZrO2 (CTAB) catalyst was used in the determination of optimum reaction conditions to produce biodiesel using RSMCCD. The results were validated by experimental at 107:1 methanol: lipid ratio using 15 wt.% catalyst loading at 77 °C for 4 h. Under these conditions, the experimental FAME yield obtained was 75.56%. The process obeyed pseudo-first order kinetics with calculated rate constant of 9.2 x 10-3 and activation energy of 90.71 kJ/mol. Several properties of microalgae biodiesel comply with the ASTM D6751 and EN14214 standards including cetane number, iodine value and total glycerol content. The catalyst can be effectively used for three times and sustained the activity to produce FAME between 75.56 and 69.16%.

Item Type:	Thesis (Post-Doctoral)
Subjects:	T Technology > T Technology (General)
Divisions:	Universiti > Universiti Teknologi PETRONAS
Depositing User:	Encik Mohd Zulkarnain Hassan bin Mohd Zainudin
Date Deposited:	12 Dec 2025 11:08
Last Modified:	12 Dec 2025 11:08
URI:	https://repositori.mohe.gov.my/id/eprint/133

Actions (login required)

View Item