Biokerosene and green diesel from macauba oils via catalytic deoxygenation over Pd/C

Macauba is a palm tree with good oil productivity (6.2 ton/ha), is native to Central and South America and is not exploited for food purposes. Its oils have been noted as an important alternative for the production of biofuels, especially for aviation. This study investigated deoxygenation catalysed by 5% w/w of palladium on charcoal (Pd/C) reduced in situ using crude and previously hydrolysed macauba pulp and almond oils with different compositions and acidity values. The effect of the fatty composition and nature of the feedstock, reaction pressure, atmosphere, presence of stirring and use of the Pd/C catalyst were studied. The results indicated high selectivity, with a predominance of saturated linear hydrocarbons that correspond to green diesel, followed by biojet fuel hydrocarbons. Oxygen removal was favoured for free fatty acids with long carbon chains, for which decarbonylation and/or decarboxylation predominates. The highest content of hydrocarbons (85% w/w) was obtained in the reaction of hydrolysed macauba almond oil at 10 bar of H-2, 300 degrees C, 5 h of reaction and stirring at 700 rpm. This green product has potential applications as a drop-in substitute for fossil fuels. (C) 2015 Elsevier Ltd. All rights reserved.