(318b) Irreversible Inhibition of Barite Crystallization: A Unique Mechanism for Treating Scale Formation

The mineralization of sparingly soluble compounds in process equipment may result in corrosion, equipment damage, and cause reduction or loss of finished product for oil and gas production, wastewater treatment, and manufacturing processes. Conventional treatments rely on the use of caustic solutions that pose a negative environmental impact. Designing effective biodegradable chemical treatments to reduce or eliminate scale formation requires an understanding of the molecular-scale interactions of chemical additives in supersaturated environments at the crystal interface. Here we implement a cooperative approach to design and test environmentally friendly chemical treatments for scale formation using a combination of surface science techniques and microfluidic technology. Crystallization can be suppressed in highly supersaturated solutions using dilute quantities of modifiers. These studies focus on barium sulfate (barite), a highly insoluble and common scaling mineral. In this presentation we will describe the effect of organic acids on barite crystallization in bulk assays under flow and in quiescent conditions. Using in situ scanning probe microscopy, we explore the interfacial interactions between the modifiers and different surfaces of barite over a range of supersaturated conditions to elucidate the role of these inhibitors during crystal growth. Our findings identify unique crystal-modifier interactions that suppress barite crystallization via an irreversible inhibition mechanism. Collectively, these studies provide new fundamental understanding of crystal growth modifier action towards the design of improved scale treatments.