H3PO4/Al2O3 catalysts: characterization and catalytic evaluation of oleic acid conversion to biofuels and biolubricant

Abstract

Al 2 O 3 and H 3 PO 4 /Al 2 O 3 catalysts were investigated in the conversion of oleic acid to biofuels and biolubricant at 1 atm and at 623 K. The catalytic tests were performed in a fixed bed and continuous flow reactor, using an oleic acid-catalyst ratio of 4 and N 2 as the carrier gas. The reaction products were analyzed by gas chromatography and acidity measurements. N 2 adsorption-desorption, X ray diffraction, 31 P nuclear magnetic resonance and FT-IR spectroscopy were also employed to evaluate the textural, structural and acidic properties of the catalysts. The results showed that phosphoric acid impregnation improved the alumina decarboxylation activities, generating hydrocarbons in the range of gasoline, diesel oil and lubricant oil. The best catalytic performance was achieved with the highest surface area alumina impregnated with H 3 PO 4 , which was the solid that allied high total acidity with a large quantity of mesopores.