Deoxygenation of vegetable oils over sulfided Ni, Mo and NiMo catalysts

Deoxygenation of vegetable oils has a potential to become an important process for production of biofuels. The present work focuses on investigation of Ni, Mo, and NiMo sulfided catalysts prepared by impregnation in deoxygenation of rapeseed oil at 260-280 degrees C, 3.5 MPa and 0.25-4 h(-1) in a fixed-bed reactor. The activity of the catalysts decreased in the order NiMo/Al2O3 > Mo/Al2O3 > Ni/Al2O3. The catalysts exhibited significantly different product distributions. The bimetallic NiMo catalysts showed higher yields of hydrocarbons than the monometallic catalysts at a given conversion. Apart from the various oxygenated product intermediates, NiMo/Al2O3 yielded a mixture of decarboxylation and hydrodeoxygenation hydrocarbon products while Ni/Al2O3 yielded only decarboxylation hydrocarbon products and Mo/Al2O3 yielded almost exclusively hydrodeoxygenation hydrocarbon products. The effect of Ni/(Ni + Mo) atomic ratio in the range 0.2-0.4 on the activity and selectivity was not significant. (C) 2009 Elsevier B.V. All rights reserved.