Dynamic Adsorption of Enzyme on Sand Surfaces- An Experimental Study

Abstract

Enzyme can reduce interfacial tension between oil and water thereby mobilising more oil than would originally be produced but its adsorption on the porous rock surfaces reduces its efficiency. This study presents experimental investigation of dynamic adsorption of enzyme on sand surfaces. The experiment was carried out at varied brine salinities and enzyme concentrations on different sand grain sizes. The concentration depletion method that accounts for the difference in enzyme concentrations in solution before and after its contact with the sand was used to determine the enzyme adsorption on relevant surfaces. The effluent sample from the adsorption process was collected after every three minutes until equilibrium was reached and the final concentration of the enzyme in the effluent solutions was measured and used to determine its adsorbed concentration on the sand surfaces. The results of this study show that increase in concentration of enzyme results in increase in its adsorption on sand surfaces. Also, increase in brine salinity increased enzyme adsorption on the sand surfaces but increase in sand grain size however reduced its adsorption. The result of this study is relevant in the design of enzyme enhanced oil recovery process.