Catalysts derived from waste sources in the production of biodiesel using waste cooking oil

• Published in: Catalysis today Vol. 190; no. 1; pp. 117 - 121
• Main Authors: Boey, Peng-Lim, Ganesan, Shangeetha, Maniam, Gaanty Pragas, Khairuddean, Melati
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2012
• Subjects: biodiesel; Boiler ash; calcium oxide; catalysts; catalytic activity; Cockleshell; cooking fats and oils; crabs; methanol; Mud crab shell; temperature; Transesterification; Waste cooking oil; wastes; Waste cooking oil; Mud crab shell; Transesterification; Cockleshell; Boiler ash
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2011.11.027

[Display omitted] ► Mixed CaO (mud crab and cockle shells 1:1 mass ratio) gives 98% methyl esters conversion at 5wt.% catalyst concentration; 13:1 methanol to oil molar ratio and 3h reaction time. ► Boiler ash gives 89% methyl esters conversion at 3wt.% catalyst concentration; 15:1 methanol to oil molar ratio and 0.5h reaction time. ► Mixture of 3wt.% boiler ash and 5wt.% mixed CaO gives 99% conversion in 0.5h at 15:1 methanol:oil molar ratio. ► The conditions were optimized using Central Composite Design (CCD). Catalysts fully derived from waste materials in order to make sustainable chemical reactions have been a recent topic of interest. Calcined (900°C, 2h) calcium oxide (CaO) sourced from waste mud crab shells and cockleshells were mixed in a 1:1 mass ratio to be used for transesterification of waste cooking oil (WCO) at 5wt.% catalyst and a methanol to oil molar ratio of 13:1 for 3h at methanol refluxing temperature to give 98% conversion. Then, boiler ash (BA) from agricultural waste was used to transesterify WCO at 3wt.% catalyst and a methanol to oil molar ratio of 15:1 for 0.5h at methanol refluxing temperature to give 89% conversion. In order to reduce the reaction time (for CaO-catalyzed reaction) and to increase the conversion (for BA-catalyzed reaction) various amounts of BA were added to 5wt.% of mixed CaO and optimized using Central Composite Design (CCD). The optimized conditions predicted by CCD were found to be 3.39wt.% boiler ash, with a reaction time of 32.3min and a conversion of 99.5%. The predicted results agree with the experimental results (3wt.% boiler ash, reaction time of 30min with 99% conversion).