A Raman spectroscopic approach to investigate the production of biodiesel from soybean oil using 1-alkyl-3-methylimidazolium ionic liquids with intermediate chain length
Journal article, 2015

We present a Raman spectroscopic study of the conversion of soybean oil into biodiesel by methanol using the lipase B enzyme pseudomonas cepacia as the bio-catalyst and 1-alkyl-3-methylimidazolium ionic liquids (C n C 1 Im) as co-solvents, where the alkyl chain length is varied from ethyl (n=2) to decyl (n=10). We have limited this study to a low reaction temperature, 40°C, and a low enzyme concentration to investigate the possibility of producing biodiesel with low energy and cost demands. We also demonstrate that Raman spectroscopy is a powerful and straightforward method to estimate the yield of the transesterification reaction, by analysis of the characteristic CO stretching mode found in the range ~1730-1750cm-1. Our results indicate that both reaction yield and reaction rate increase with the chain length, but also that for chains longer than decyl further improvements are marginal. We discuss these results from the viewpoint of local interactions and local structure of the investigated ionic liquids.

Ionic liquids


Raman spectroscopy


Johanna Abrahamsson

Chalmers, Chemistry and Chemical Engineering

Emil Andreasson

Chalmers, Chemistry and Chemical Engineering

Niklas Hansson

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Nuclear Chemistry

David Sandström

Chalmers, Chemistry and Chemical Engineering

Ellinor Wennberg

Chalmers, Chemistry and Chemical Engineering

M. Maréchal

Université Grenoble Alpes

The French Alternative Energies and Atomic Energy Commission (CEA)

Centre national de la recherche scientifique (CNRS)

Anna Martinelli

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

Applied Energy

0306-2619 (ISSN)

Vol. 154 763-770

Subject Categories

Physical Chemistry



More information

Latest update

9/7/2018 1