SYNTHESIS AND CATALYTIC ACTIVITY EVALUATION OF POTASSIUM GLYCEROXIDE AS A TRANSESTERIFICATION CATALYST

• Main Author: Indila, Geby
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/86068
• Institution: Institut Teknologi Bandung

The utilization of New and Renewable Energy (NRE) in Indonesia remains far from the energy mix target set for 2025. To achieve this target, efforts to develop NRE are essential as a strategic solution to support sustainable economic growth and minimize environmental impacts. One of the promising alternatives is biodiesel, given the abundance of plant-based resources in Indonesia. Biodiesel production via transesterification requires a catalyst to accelerate the reaction, especially at low temperatures and atmospheric pressure. On an industrial scale, base catalysts (hydroxides and alkoxides) are commonly used as catalysts. Although these catalysts may achieve high conversion rates in short time, there are some drawbacks. An alternative to hydroxide and alkoxide catalysts is glyceroxide. Glyceroxide, which can be obtained from the by-products of the biodiesel industry, is considered superior in terms of safety, high availability, and its ability to reduce waste. Therefore, synthesizing glyceroxide is viewed as an innovative step in pursuing more sustainable biodiesel production. This research focuses on potassium glyceroxide synthesis and its activity test as a transesterification catalyst. Three parameters will be varied: the molar ratio of KOH to glycerol (1:1, 2:1, and 3:1), catalyst concentration (0.4%, 0.8%, and 1.2%), and the methanol to oil ratio (3:1, 6:1, and 9:1). A fractional factorial design was used, resulting in a total of 11 runs with 3 center points. Transesterification was carried out for one hour at 60–65°C. The results showed that all three parameters significantly affected the total glycerol and methyl ester content, although the obtained regression model indicated aliasing. The lowest total glycerol content (0.108%) and the highest ester content (98.877%) were obtained in the 11th run (3:1 catalyst ratio, 1.2% catalyst amount, and 9:1 methanol ratio). This variation was then compared with the KOH catalyst, and it was found that the product from the potassium glyceroxide catalyst had a higher acid number and methyl ester content, as well as lower total glycerol.