Performance of packed and fluidized bed columns for the removal of unconventional oil using modified dolomite

Abstract The performance of modified dolomite for removing oil from laboratory synthetic oil-in-water (o/w) emulsions in packed bed (PB) and fluidized bed (FB) modes was investigated. The conditions (i.e., surfactant concentration, mixing stirring rate, and mixing time) at which the emulsion stability was found to be maximum were studied to increase the resistance of the dispersed oil droplets against coalescence. For the most stable emulsions, a series of experiments were performed to investigate the effect of parameters, such as influent oil concentration (400–650 ppm), flow rate (10–26 mL/min), and particle radii (0.08–0.15 cm) on the oil removal efficiency of the modified dolomite in a fixed bed treatment column. The breakthrough experiments were accomplished, and several aspects such as process operating conditions, mass transfer characteristics, and hydraulic characteristics of the columns were determined. Scaling up to 600 cm column with a diameter of 200 cm showed that with the same breakpoint criteria a large increase in the degree of utilization and a large decrease in average concentration in the outlet has been observed. To circumvent the occurrence of coalescence and flow rate limits for a fixed-bed column, a fluidized bed of hydrophobic dolomite was applied. A model was developed to predict the fixed and fluidized bed experimental results based on kinetic and equilibrium batch measurements of the modified dolomite and the stabilized o/w emulsion. The breakthrough curves in fluidized bed adsorbent were different than those obtained from fixed bed adsorbent due to axial mixing occurring in the solid and liquid phase.