TY - JOUR
T1 - N-Heptane cracking over mixtures of HY and HZSM-5 zeolites
T2 - Influence of the presence of phenol
AU - Graa, I.
AU - Lopes, J. M.
AU - Ribeiro, M. F.
AU - Badawi, M.
AU - Laforge, S.
AU - Magnoux, P.
AU - Ramôa Ribeiro, F.
N1 - Acknowledgements
I. Graça thanks the Fundação para a Ciência e Tecnologia (FCT) for her PhD Grant (SFRH/BD/37270/2007) and the Project PTDC/QUE-ERQ/103912/2008.
PY - 2012/4/1
Y1 - 2012/4/1
N2 - Fluid Catalytic Cracking (FCC) catalysts are based on combinations of two main active phases, the HY and the HZSM-5 (additive) zeolites, but previous studies only concerned the phenol influence on these pure zeolites. Therefore, n-heptane was transformed in presence of phenol over mechanical mixtures of HY and HZSM-5 zeolites, at 450°C, to evaluate the FCC catalysts behaviour during phenolic-rich bio-oils/conventional FCC feedstocks co-processing. Phenol induces an additional deactivation of the zeolites mixtures from the beginning of the reaction because increases the carbon deposition, as for pure zeolites. However, mixing the zeolites, the impact of phenol on HZSM-5 seems to not be as strong as for HZSM-5 alone due to an initial preferential adsorption of phenol on HY, as suggested by the adsorption energies of phenol on these catalysts calculated by Density Functional Theory (DFT), -80 kJ mol -1 for HY and -60 kJ mol -1 for HZSM-5. This agrees with the initial products distribution, which points out an enhancement of 14-20% in the paraffins/olefins molar ratio and of about 40% in the amount of branched species on the effluent in presence of phenol, as for pure HY. The HZSM-5 further resistance against phenol, when mixed with HY, decreases by increasing phenol content from 1.2 wt.% to 4 wt.%. Hence, at an industrial level, the FCC catalyst should suffer a lower effect of phenol on the ZSM-5 additive function than expected, which would be certainly dependent on the amount of each zeolite in the FCC catalysts formulations and on the fraction of phenolic species in the FCC feedstock.
AB - Fluid Catalytic Cracking (FCC) catalysts are based on combinations of two main active phases, the HY and the HZSM-5 (additive) zeolites, but previous studies only concerned the phenol influence on these pure zeolites. Therefore, n-heptane was transformed in presence of phenol over mechanical mixtures of HY and HZSM-5 zeolites, at 450°C, to evaluate the FCC catalysts behaviour during phenolic-rich bio-oils/conventional FCC feedstocks co-processing. Phenol induces an additional deactivation of the zeolites mixtures from the beginning of the reaction because increases the carbon deposition, as for pure zeolites. However, mixing the zeolites, the impact of phenol on HZSM-5 seems to not be as strong as for HZSM-5 alone due to an initial preferential adsorption of phenol on HY, as suggested by the adsorption energies of phenol on these catalysts calculated by Density Functional Theory (DFT), -80 kJ mol -1 for HY and -60 kJ mol -1 for HZSM-5. This agrees with the initial products distribution, which points out an enhancement of 14-20% in the paraffins/olefins molar ratio and of about 40% in the amount of branched species on the effluent in presence of phenol, as for pure HY. The HZSM-5 further resistance against phenol, when mixed with HY, decreases by increasing phenol content from 1.2 wt.% to 4 wt.%. Hence, at an industrial level, the FCC catalyst should suffer a lower effect of phenol on the ZSM-5 additive function than expected, which would be certainly dependent on the amount of each zeolite in the FCC catalysts formulations and on the fraction of phenolic species in the FCC feedstock.
KW - Bio-oils
KW - Catalytic cracking
KW - Deactivating effect
KW - HY + HZSM-5 mixtures
KW - n-Heptane
UR - http://www.scopus.com/inward/record.url?scp=84856716069&partnerID=8YFLogxK
U2 - 10.1016/j.fuel.2011.11.033
DO - 10.1016/j.fuel.2011.11.033
M3 - Article
AN - SCOPUS:84856716069
VL - 94
SP - 571
EP - 577
JO - Fuel
JF - Fuel
SN - 0016-2361
ER -