Catalytic conversion of ethyl acetate and acetic acid on alumina as models of vegetable oils conversion to biofuels

Conversion of palm oil over stabilized alumina catalyst are performed in liquid phase at 623 K. Additionally, ethyl acetate (EA) and acetic acid (AA) conversion as model reactions are investigated over the same catalyst at atmospheric pressure with 5800 h−1 and 11,600 h−1 GHSV. Both EA and palm oil decomposition over the alumina catalyst are also studied in an in situ Infrared (IR) spectroscopy cell. Similarly, the reaction of acetic, palmitic and oleic acids on alumina is also studied in order to elucidate the reaction mechanisms at molecular level. The main products from EA and palm oil arise from ester group cracking and ketonization and decarboxylation of both the ester and the acid. IR experiments show that the main activation steps of esters on alumina consist in their adsorption on the Lewis sites of alumina through the carbonyl oxygen lone pair.

• Gas phase ethyl acetate conversion on alumina was studied.
• Liquid phase palm oil conversions on alumina studied and compared.
• Esters cracking, decomposition, ketonization, decarboxylation, H-exchange occurred.
• Esters activated by adsorption on Lewis sites through the carbonyl oxygen lone pair.