Characterization of industrial waste derived calcium oxide catalyst for biodiesel production effect of calcunation conditions

• Main Author: Muhamad Adeeb Danial Bin Mohd Kamarudin
• Published: 2023
• Subjects: calcium oxide; transesteritication; biodiesel

Carbide lime waste (CLW) as a by-product of acetylene gas production, has resulted in environmental problems. It is a solid waste from the hydrolysis reaction of calcium carbide in the industrial production of ethylene gas, which is the raw materials of PVC and some other products. The carbide lime waste consists primarily of Ca (OH)2 which can be employed as a promising feedstock to prepare CaO based catalyst. Carbide lime waste (CLW) was used to produce CLW-750C-4H, CLW-850C-4H, CLW-950C-4H, CLW-850C-3H, CLW-850C-5H solid base catalyst using calcination reaction. The effect of different calcination temperature (750°C,850°C,950°C) and effect of different calcination time (3 hours,4hours,5hours). The characterization of raw materials (carbide lime waste) such as moisture content and density analysis were analysed. Catalytic performance of all the solid catalysts were evaluated via transesterification reaction of sunflower oil under the conditions: methanol to oil ratio 10:1; 6 wt% catalyst loading; time reaction 2 hours. Scanning electron microscope (SEM) analysis shows the surfaces of CLW changed after the calcination. Meanwhile, X-ray diffraction (XRD) shows the presence of CaO after the calcination. All the catalyst shows the same base strength and pH value which is 6.8<H_<9.3 and pH paper H_10. CLW-850C-3H achieved the highest biodiesel rate of 92.8% at 6 wt% catalyst loading. FTIR (Fourier Transform Infra-red) analysis was used to determine the ester group in biodiesel and the result shows the ester and carboxylic acid functional group exist after the transesterification process. Gas chromatography (GC) proved the presences of fatty methyl ester (biodiesel) in the end product. Solid base catalyst derives from carbide lime waste proven that have potential to produce biodiesel via transesterification and it can replace the usage of liquid catalyst.