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Impact of petroleum coke characteristics on the adsorption of the organic fractions from oil sands process-affected water
Pourrezaei, P.; Alpatova, A.; Chelme-Ayala, P.; Perez-Estrada, L.A.; Jensen-Fontaine, M.; Le, X.C. & Gamal El-Din, M.
Abstract
Petroleum coke (PC) is a waste by-product
generated during the oil upgrading processes by the
petroleum industry. The continuing accumulation of large
quantities of PC requires the development of innovative
strategies for the effective utilization of this carbon-rich
material. In this study, PC was used for the removal of
naphthenic acids (NAs) and acid-extractable fraction
(AEF) from oil sands process-affected water (OSPW),
generated during the oil refining process. A systematic
study on the adsorption of organic fractions, vanadium
leaching from PC, adsorption mechanisms, and the effect
of physico-chemical characteristics of the PC on adsorption
process was performed. Physico-chemical properties of PC
were determined by Fourier transform infrared spectroscopy
(FT-IR), X-ray photoelectron spectroscopy, thermogravimetric
analysis (TGA), scanning electron microscopy,
and Brunauer–Emmett–Teller surface area analysis. AEF
and NAs removals of 60 and 75 %, respectively, were
achieved at PC dose of 200 g/L after 16 h of contact. FTIR
and TGA analysis of PC suggested the physisorption of
organic compounds onto the surface of PC. The calculated
mean free energy of adsorption (E < 8 kJ/mol) also indicated
the physisorption of organics to the PC surface. The
hydrophobic interactions between the NAs and the PC were
suggested as the dominant adsorption mechanisms. The
vanadium release occurred when PC was mixed with
OSPW and vanadium concentration increased with an
increase in the PC dose. Speciation analysis indicated that
the vanadium leached was predominantly vanadium
(V) and insignificant amount of vanadium (IV) was also
detected.
Keywords
Adsorption; Petroleum coke; Naphthenic acids; Vanadium; Oil sands process-affected water
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