Novel Barite Crystallization and Inhibition Model Based on Surface Adsorption

Abstract

Summary Inorganic mineral crystallization is a critical process for numerous industrial and geoengineering processes, including oil and gas production and transportation, geothermal energy exploitation, membrane filtration, cooling tower, heat exchanger, to mention a few. Its unexpected formation can cause significant engineering, economic, and safety issues. Scale inhibitors have been widely used in various geoengineering projects as one of the most efficient and economic methods for mineral scale control. However, after decades of research, the inhibition mechanisms still remain unknown. This study applied a newly developed mechanistic mineral crystallization and inhibition model to barite, one of the most difficult mineral scales to be remediated. This new model assumes that inhibitors prolong the crystallization induction time by adsorbing onto the nucleus surface following a Langmuir-type adsorption isotherm and increasing the surface tension. The new model accurately predicts the barite crystallization induction time without or with 10 commonly used scale inhibitors. More importantly, the adsorption affinity constants (i.e., KL) fitted with the new model from the barite crystallization induction time matched well with those fitted from the direct inhibitor adsorption testing and from measuring barite crystal growth rate changes due to various inhibitors. A good correlation was also observed between the KL values of various inhibitors with barite from this study and those with other minerals (i.e., hydroxyapatite and calcite) from the literature. Such good agreements and correlations validated the adsorption mechanism adopted in the new mechanistic model. This study will deepen the understanding of mineral crystallization and inhibition mechanisms and improve scale management in various industrial and geoengineering processes.