Status of biodiesel production using heterogeneous alkaline catalysts

• Published in: International journal of environmental studies Vol. 69; no. 4; pp. 635 - 653
• Main Authors: Gomes, João F.P, Puna, Jaime F.B, Bordado, João C.M, Correia, M. Joana N, Dias, Ana P.S
• Format: Journal Article
• Language: English
• Published: Routledge 01.08.2012
• Subjects: Activation; alkaline earth metals; Biodiesel; Catalysis; Catalysts; Environmental studies; Heterogeneous alkaline catalysts; methanol; methanolysis; Methyl alcohol; potassium hydroxide; Sodium; sodium hydroxide; Transesterification; vegetable oil; Vegetable oils
• ISSN: 1029-0400; 0020-7233; 1029-0400
• DOI: 10.1080/00207233.2012.693286

This paper describes biodiesel production using heterogeneous alkaline catalysts instead of the conventional homogenous alkaline catalysts, such as NaOH, KOH or sodium methoxide, for the methanolysis reaction, in the search for more profitable and sustainable alternatives regarding biodiesel production. The heterogeneous catalytic process has many differences from that currently used in industrial homogeneous processes. The main advantage is that it requires lower investment costs, as there is no need for separation steps such as methanol/catalyst, biodiesel/catalyst and glycerine/catalyst. This paper also describes experimental work towards the development of new heterogeneous alkaline catalysts able to produce biodiesel from vegetable oils. The research has resulted in the selection of CaO and CaO modified with alkaline and alkaline earth metal catalysts. They show very good catalytic performances with high activity and stability. In fact, biodiesel (FAME) yields higher than 94% were observed in several consecutive reaction batches without expensive intermediate reactivation procedures. Therefore, those catalysts appear to be suitable for biodiesel production.