(538i) Demulsification of Oil in Water Emulsions Using Silane Modified Silica Nanoparticles

The separation of oil and water poses challenges to several major industries. Industries that deal with water purification and petroleum refining routinely deal with emulsions that are difficult to separate into individual phases. The presence of natural emulsifiers in crude oils and wastewater further complicates the separation of the phases. Produced water is an effluent that is considered to be a waste product of the petroleum industry. Produced water contains organics that have the potential of forming emulsions. Produced water is usually disposed off by re-injecting into formations. If oil in water (O/W) emulsions are contained in this produced water then, oil droplets plug the pore space in the near-wellbore or near-fracture region, resulting in rapid declines in the performance of water injection wells where the remediation processes can be expensive Although produced water is usually considered a waste product, it contains a variety of valuable elements like Lithium. The efficient separation of contaminants and valuables depends on the demulsification of produced water. There is evidence that silica nanoparticles can be potential demulsifiers for emulsions. This study focuses on two parameters, wettability, and physical structure, that influence the ability of silica nanoparticles in their separation capacity. Fumed silica and spherical silica of two different geometries were used for the investigation. Wettability alterations were brought about by silane modifications of the silica nanoparticles. Silane chains of various lengths can be impregnated to influence the wettability of a silica particle. Silane chains are inherently hydrophobic by nature while silica is hydrophilic by nature. A longer silane chain impregnation corresponds to a decreased hydrophilicity. Hydrophilicity was measured with respect to the percentage of hydroxyl groups present in the matrix of silica particles. Contact angle measurements were made to verify the hydrophilicity of the produced silica particles. Demulsification experiments were conducted for (O/W) emulsions using the silica nanoparticles produced. Microscopic analysis was done on the emulsions before and after demulsification experiments to understand the coalescing behavior of the emulsions in the presence of silica nanoparticles. The presentation will highlight the influence of physical structure and the wettability of demulsifiers on demulsification efficiency.