Biodiesel production via esterification of oleic acid catalyzed by chlorosulfonic acid modified zirconia

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Biodiesel is a promising renewable alternative to fossil energy. Biodiesel production from low-cost feedstock involves an essential pretreatment step - esterification of free fatty acids (e.g. oleic acid), for avoiding soap formation and catalyst deactivation. Sulfuric acid modified zirconia (H2SO4-ZrO2) is known to be an effective heterogeneous catalyst for this reaction. However, due to rapid SO42- leaching, its reusability is low and its practical use is thus largely hindered. Herein, we report a more stable solid acid analogue for the reaction, chlorosulfonic acid modified zirconia (HClSO3-ZrO2). It was characterized by XRD, SEM, BET, EDX, IR, TGA, and NH3-TPD. Compared with H2SO4-ZrO2, there is over 3 times more sulfur content and nearly 4 times more acid sites amount for HClSO3-ZrO2. More importantly, HClSO3-ZrO2demonstrates high catalytic activity and long durability in esterification of oleic acid, in which the fatty acid methyl ester yield reaches 100% consecutively for at least 5 cycles under mild conditions.
Original languageEnglish
Pages (from-to)191-198
Number of pages8
JournalApplied Energy
Publication statusPublished - 1 Mar 2014


  • Biodiesel
  • Chlorosulfonic acid
  • Free fatty acid
  • Oleic acid esterification
  • Sulfated zirconia

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Energy(all)

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