Novel Biosurfactants Improve Efficiency and Selectivity in Iron Chelation Applications

Abstract Glycolipid biosurfactants such as rhamnolipids (RL) and sophorolipids (SL) are manufactured via low energy fermentation and are versatile molecules that can be tailored to fit a wide range of industrial applications. Among many attributes such as small micelle sizes of 1 nm, they display a high level of interfacial activity as well as biodegradability. The biodegradability and the variety of their functionality make them suitable for environmental remediation and oilfield activities ranging from drilling to production. In this study, rhamnolipids have been found to selectively bond with trivalent iron species in the produced water from the Permian basin, in the presence of other divalent cations. RL appears to be much more efficient than conventional or bio-based iron chelating agents, because of its one-of-a-kind umbrella molecular structure and specific complex with iron. Additionally, RL eliminates scale formation in typical produced water containing Ca, Mg and Fe and enhances oil recovery in nanometer-sized microfluidic tests, indicating its potential as next-generation surfactants in oilfield applications