Transesterification of refined, bleached and deodorized coconut oil using pretreated calcium oxide calatalyst

• Main Authors: Bugay, Byron H., Jhun, Kang-Suk J., Velasquez, Jo-Marie U.
• Format: text
• Language: English
• Published: Animo Repository 2009
• Subjects: Coconut oil; Biodiesel fuels; Diesel fuels; Chemical Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/6513
• Institution: De La Salle University

This study aimed to evaluate calcium oxide as a catalyst for the conversion of coconut oil to biodiesel via the transesterification reaction with methanol. Biodiesel samples were made using a two-level full factorial design with four process variables affecting transesterification. These process variables include temperature, agitation time, methanol to oil ratio, and catalyst to oil ratio. Calcium oxide catalyst was pretreated by mixing the calcium oxide with ammonium carbonate solution. With pretreated calcium oxide catalyst, the expected two layers of products of transesterification reaction were produced. The biodiesel produced through the transesterification of RBD coconut oil using methanol with CaO as catalyst was evaluated by determining its physical properties (appearance and odor), percent yield, percent conversion and the amount of calcium ions in the biodiesel. It contained suspended particles which indicate that calcium ions had leached from the calcium oxide. The biodiesel phase was tested for the amount of total glycerol to estimate the percentage conversion. The lowest conversion was 91.53% while the highest was 95.70%. The effects of the four parameters to the percent conversion were evaluated using multiple regression analysis. Among the four independent variables that were assessed, temperature was the most significant variable affecting the percent conversion. The biodiesel was also tested for possible contamination of calcium. The amount of calcium detected in the samples ranged from 28.21 - 135.70 ppm. The effect of the four variables on the amount of calcium dissolved was evaluated using multiple regression analysis. The leaching of calcium ions is possibly caused by the reaction of calcium oxide and methanol. It was found out that none of the four input variables had a statistically significant effect on the amount of dissolved calcium. Nonetheless, the methanol/oil ratio and the catalyst/oil ratio were relatively significant compared to the other two variables.