Catalytic cracking in the presence of guaiacol

The use of renewable fuels is expected to grow in the coming years. A possibility to achieve this consists in blending renewable bio-oils with conventional refining streams to further process in existing refineries. A key aspect of bio-oils is the presence of oxygenate molecules in significant amounts. To shed light into the effect of these compounds on Fluid Catalytic Cracking (FCC), guaiacol was chosen as model compound. Data on the transformation of n-heptane in the presence of small quantities of guaiacol over pure HY and HZSM-5 zeolites at 450 degrees C is presented and compared to gasoil + guaiacol blend tests using an industrial FCC equilibrium catalyst (E-CAT) pure and blended with a commercial ZSM-5 additive. Guaiacol has a negative influence on both n-heptane and gasoil conversions, since it is responsible for an increase of the coke retained on the catalysts. In the presence of n-heptane and with pure zeolites, guaiacol increases the methane yield, in line with its transformation into phenol. With industrial FCC E-CAT, the presence of guaiacol increases gasoline yield and reduces coke yield, however, increases coke on catalyst. Detailed GC analysis of the liquid product shows presence of phenols in the gasoline cut, suggesting the partial conversion of guaiacol (with methane and water formation). HZSM-5 zeolite was more severely deactivated than HY zeolite in the n-heptane transformation, which agrees with the observed reduction of the ZSM-5 additive effect on the transformation of gasoil. (C) 2010 Elsevier B.V. All rights reserved.