Process Equilibrium, Kinetics, and Mechanisms of Ionic-Liquid Induced Dephenolation of Petroleum Effluent

Abstract

This study focuses on the effectiveness of ionic liquid (1-ethyl-3-methyl imidazolium bromide, EMIB) and chemically modified (EMIB impregnated) clay (CMC) as adsorbents for dephenolation of petroleum effluent. Process equilibrium and kinetics (including mechanistic modeling) of the adsorption were investigated. The results showed uptake efficiencies of 91.7 and 85% for CMC and EMIB, respectively, at equilibrium time of 25 min. The linear and non-linear isotherm and kinetic models were best fitted to Langmuir and pseudo-second-order model for both adsorbents. The CMC and EMIB had their monolayer adsorption capacity equal to 3.487 and 0.989 mg/g, respectively. Seven mechanistic models were proposed, with mechanism IV and its corresponding model equation IV (shifting rate order model) emerging as the best fitting to the adsorption data. The thermodynamic studies showed that the process was physical (ΔH < 84 kJ mol−1), spontaneous, and exothermic.