Separating Oil-Water Mixtures Using Bump Arrays

Particle separation is an important process step across many fields. One technique being applied for separating solids such as blood components or sand particles from carrier fluids is the use of arrays of aligned posts called deterministic lateral arrays to bump particles to one side in the flow stream to induce separation. This technique may be useful for separation of deformable particles including oil droplets. The ability to efficiently separate two-phase industrial (oil/water) mixtures is key for future use of valuable resources. The ability to reclaim petroleum production water may be critical for the Central High Plains (Colorado, Kansas, New Mexico, Oklahoma, and Texas). Current drawdown trends in the High Plains alone suggest loss of up to 40% of the aquifer area by 2100 that will cause the switch from irrigated to dryland farming. Proving this technology is key to reuse of petroleum production water for crop irrigation or to replace water from currently failing aquifers in rich agricultural lands of the Central High Plains. We conducted experiments applying mesofluidic separation for flowing two-phase (oil/water) mixtures. Experiments were conducted using oil with water as the carrier fluid; separation was achieved over a range of oil-water concentrations. We describe the results of these experiments in this paper.