Bifunctional Heterogeneous Catalyst for Biodiesel Production from Waste Vegetable Oil
Bifunctional solid catalysts facilitate the esterification of free fatty acids (FFA) into alkyl esters alongside the transesterification reaction, which allows for the use of waste vegetable oils with high water and FFA contents for biodiesel production. This makes the process economically viable an...
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MDPI AG
2020-05-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/10/9/3153 |
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| author | Samya Elias Ademola M Rabiu Benjamin I Okeleye Vincent Okudoh Oluwaseun Oyekola |
| author_facet | Samya Elias Ademola M Rabiu Benjamin I Okeleye Vincent Okudoh Oluwaseun Oyekola |
| author_sort | Samya Elias |
| collection | DOAJ |
| description | Bifunctional solid catalysts facilitate the esterification of free fatty acids (FFA) into alkyl esters alongside the transesterification reaction, which allows for the use of waste vegetable oils with high water and FFA contents for biodiesel production. This makes the process economically viable and greener, as the waste fats and oils are readily available. The concurrent esterification and transesterification of waste palm oil (WPO) and waste sunflower oil (WSO) with methanol was investigated in the presence of calcium oxide on alumina catalyst in a conventional batch process. The catalyst characterization showed the existence of calcium oxide aluminates (calcined at 750 °C), which exhibited crystalline phases with porous/spongy-like particles. The high concentration of CaO in CaO/Al<sub>2</sub>O<sub>3</sub> was a favorable support material in the heterogeneously-catalyzed transesterification reactions. The optimum catalyst parameters for the production of fatty acid methyl esters (FAMEs) were observed at 65 °C for 4 h with a methanol-to-oil ratio of 9:1, 60% (waste palm oil, or WPO) and 80% (waste sunflower oil, or WSO), CaO/Al<sub>2</sub>O<sub>3</sub> (% wt/wt) catalyst ratio as well as 4% CaO/Al<sub>2</sub>O<sub>3</sub> concentration (% wt.) for WSO and WPO. The simultaneous esterification/transesterification reactions at optimum conditions on WPO and WSO led to high yield of FAMEs of 89, 61 and 55% for WPO and 54, 75 and 98% for WSO at catalyst ratios (wt %) of 60, 70 and 80% respectively. The use of bifunctional heterogeneous catalyst (CaO/Al<sub>2</sub>O<sub>3</sub>) with waste vegetable oil can result in high performance and the upscaling of biodiesel production. |
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| spelling | doaj.art-5d1f4f6f29e24311b6951e47a2f7fb732023-11-19T23:12:09ZengMDPI AGApplied Sciences2076-34172020-05-01109315310.3390/app10093153Bifunctional Heterogeneous Catalyst for Biodiesel Production from Waste Vegetable OilSamya Elias0Ademola M Rabiu1Benjamin I Okeleye2Vincent Okudoh3Oluwaseun Oyekola4Department of Chemical Engineering, Faculty of Engineering and the Built Environment, Cape Peninsula University of Technology, P.O. Box 1906, Bellville 7535, South AfricaDepartment of Chemical Engineering, Faculty of Engineering and the Built Environment, Cape Peninsula University of Technology, P.O. Box 1906, Bellville 7535, South AfricaBioresource Engineering Research Group (BioERG), Department of Biotechnology, Faculty of Applied Sciences, Cape Peninsula University of Technology, P.O. Box 8000, Cape Town 8000, South AfricaBioresource Engineering Research Group (BioERG), Department of Biotechnology, Faculty of Applied Sciences, Cape Peninsula University of Technology, P.O. Box 8000, Cape Town 8000, South AfricaDepartment of Chemical Engineering, Faculty of Engineering and the Built Environment, Cape Peninsula University of Technology, P.O. Box 1906, Bellville 7535, South AfricaBifunctional solid catalysts facilitate the esterification of free fatty acids (FFA) into alkyl esters alongside the transesterification reaction, which allows for the use of waste vegetable oils with high water and FFA contents for biodiesel production. This makes the process economically viable and greener, as the waste fats and oils are readily available. The concurrent esterification and transesterification of waste palm oil (WPO) and waste sunflower oil (WSO) with methanol was investigated in the presence of calcium oxide on alumina catalyst in a conventional batch process. The catalyst characterization showed the existence of calcium oxide aluminates (calcined at 750 °C), which exhibited crystalline phases with porous/spongy-like particles. The high concentration of CaO in CaO/Al<sub>2</sub>O<sub>3</sub> was a favorable support material in the heterogeneously-catalyzed transesterification reactions. The optimum catalyst parameters for the production of fatty acid methyl esters (FAMEs) were observed at 65 °C for 4 h with a methanol-to-oil ratio of 9:1, 60% (waste palm oil, or WPO) and 80% (waste sunflower oil, or WSO), CaO/Al<sub>2</sub>O<sub>3</sub> (% wt/wt) catalyst ratio as well as 4% CaO/Al<sub>2</sub>O<sub>3</sub> concentration (% wt.) for WSO and WPO. The simultaneous esterification/transesterification reactions at optimum conditions on WPO and WSO led to high yield of FAMEs of 89, 61 and 55% for WPO and 54, 75 and 98% for WSO at catalyst ratios (wt %) of 60, 70 and 80% respectively. The use of bifunctional heterogeneous catalyst (CaO/Al<sub>2</sub>O<sub>3</sub>) with waste vegetable oil can result in high performance and the upscaling of biodiesel production.https://www.mdpi.com/2076-3417/10/9/3153CaO/Al<sub>2</sub>O<sub>3</sub>biodieselwaste palm oilwaste sunflower oil |
| spellingShingle | Samya Elias Ademola M Rabiu Benjamin I Okeleye Vincent Okudoh Oluwaseun Oyekola Bifunctional Heterogeneous Catalyst for Biodiesel Production from Waste Vegetable Oil Applied Sciences CaO/Al<sub>2</sub>O<sub>3</sub> biodiesel waste palm oil waste sunflower oil |
| title | Bifunctional Heterogeneous Catalyst for Biodiesel Production from Waste Vegetable Oil |
| title_full | Bifunctional Heterogeneous Catalyst for Biodiesel Production from Waste Vegetable Oil |
| title_fullStr | Bifunctional Heterogeneous Catalyst for Biodiesel Production from Waste Vegetable Oil |
| title_full_unstemmed | Bifunctional Heterogeneous Catalyst for Biodiesel Production from Waste Vegetable Oil |
| title_short | Bifunctional Heterogeneous Catalyst for Biodiesel Production from Waste Vegetable Oil |
| title_sort | bifunctional heterogeneous catalyst for biodiesel production from waste vegetable oil |
| topic | CaO/Al<sub>2</sub>O<sub>3</sub> biodiesel waste palm oil waste sunflower oil |
| url | https://www.mdpi.com/2076-3417/10/9/3153 |
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