Article In: orcid, scopus, cienciavitae

Biodiesel production over lime. Catalytic contributions of bulk phases and surface Ca species formed during reaction

RENEWABLE ENERGY

Ana Paula Soares Dias; Jaime Puna; João Bordado2016

Key information

Authors:

Ana Paula Soares Dias (Ana Paula Vieira Soares Pereira Dias); Jaime Puna; João Gomes (João Fernando Pereira Gomes); Maria Joana Neiva Correia (Maria Joana Castelo-Branco de Assis Teixeira Neiva Correia); João Bordado

Published in

12/01/2016

Abstract

Lime is pointed out as an effective catalyst for biodiesel production by oil methanolysis. Several Ca phases are formed during reaction. Each Ca phase has different contribution to the catalyzed process. Using CaO as a catalyst, S shape kinetics curve was observed and the induction period can be ascribed to the Ca(OH)(2) formation. When Ca(OH)(2), prepared by contacting CaO with H2O, is used as catalyst the initial period with a slow rate of transesterification has almost vanished. Besides, if the catalyst surface is totally converted into methoxide species the induction period is longer than the analogous obtained with CaO. This is an indication that the methoxide species strongly bonded to Ca are less reactive. The calcium diglyceroxide material (CaO_diglyc), prepared by contacting CaO with a mixture of methanol and glycerol, displays a totally different kinetics curve with no induction period. The faster kinetics and the Ca species detected in the glycerin phase seem to underline a non-negligible homogeneous process contribution. The characterization of the post-reaction catalysts underlines the relevance of the surface and bulk catalyst modifications. Calcium hydroxide can be pointed out as the active phase whereas calcium diglyceroxide is responsible for the catalyst deactivation due to calcium leaching.

Publication details

Authors in the community:

Publication version

AO - Author's Original

Title of the publication container

RENEWABLE ENERGY

First page or article number

622

Last page

630

Volume

99

ISSN

0960-1481

Fields of Science and Technology (FOS)

chemical-engineering - Chemical engineering

Publication language (ISO code)

eng - English

Alternative identifier (URI)

http://hdl.handle.net/10400.21/7150

Rights type:

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