Biodiesel production from sewage sludge lipids catalysed by Brønsted acidic ionic liquids

Magdalena Olkiewicz, Natalia V. Plechkova, Martyn J. Earle, Azael Fabregat, Frank Stüber, Agustí Fortuny, Josep Font, Christophe Bengoa*

*Corresponding author for this work

Research output: Contribution to journalArticle

44 Citations (Scopus)


Production of biodiesel from sewage sludge lipids was catalysed by six different Brønsted acidic imidazolium and long chain ammonium ionic liquids; both with an alkane sulfonic acid group and with different anions. Among the ionic liquid tested, 4-(3-methylimidazolium) butanesulfonic acid trifluoromethanesulfonate, [mimC4SO3H][SO3CF3], was selected as the best catalyst due to its high catalytic performance and purer biodiesel obtained than the equivalent ammonium ionic liquid, 4-(trihexylammonium) butanesulfonic acid trifluoromethanesulfonate, [N666(C4SO3H)][SO3CF3]. The influence of different reaction variables on the biodiesel yield was studied using [mimC4SO3H][SO3CF3] as a catalyst. The yield of fatty acid methyl esters (biodiesel) reached 90% (based on saponifiable lipids) under the following optimised conditions: 10:1 molar ratio of methanol to saponifiable lipids, 7wt% ionic liquid catalyst (wt%, based on lipids), 100°C and 5h. In addition, the ionic liquid has a good reusability and can be easily separated from the biodiesel. These acidic ionic liquids were found to be efficient catalysts for the synthesis of biodiesel from low-cost and non-edible feedstock like sewage sludge lipids.

Original languageEnglish
Pages (from-to)738-746
Number of pages9
JournalApplied Catalysis B: Environmental
Early online date28 Aug 2015
Publication statusPublished - 01 Feb 2016



  • Biodiesel
  • Esterification
  • Ionic liquid
  • Sewage sludge lipids

Cite this

Olkiewicz, M., Plechkova, N. V., Earle, M. J., Fabregat, A., Stüber, F., Fortuny, A., ... Bengoa, C. (2016). Biodiesel production from sewage sludge lipids catalysed by Brønsted acidic ionic liquids. Applied Catalysis B: Environmental, 181, 738-746.