Adsorption kinetics of vanadyl etioporphyrin on Dagang asphaltene in pentane

The adsorption kinetics of vanadyl etioporphyrins on Dagang (DG) asphaltene in n-pentane solvent was investigated. The FT-ICR MS and C/H/N/O element analysis results indicated that a certain amount of vanadyl porphyrins can be adsorbed by the DG asphaltene, proving the interactions present between vanadium porphyrins and DG asphaltene. The adsorption process is influenced by the dosage of asphaltene (0.010 0 and 0.020 0 g), the concentration of vanadyl porphyrins in n-pentane (10 and 15 μg/mL), and the adsorption temperature (15、20 and 25 ℃). The overall adsorption rates are fitted by the pseudo-first order, pseudo-second order, Elovich, and diffusion kinetic models, which suggests that the adsorption process can be well described by the pseudo-second order equation.