Rethink your liquid-liquid separations

Efficient liquid-liquid separations are an integral part of many industrial processes. Water entrained in oil and other hydrocarbon products can impede quality specifications. Entrained oil in process water streams puts additional demands on effluent treatment systems. Under the present economic environment, processing production demands push plants and existing equipment beyond the original design capacity. Equipment that formerly made clean-phase separations can no longer do so. And for new plants, strong economic incentives push process designers to incorporate equipment with smaller footprints to minimize weight, plot space and capital costs. Several examples highlight typical issues encountered with liquid-liquid separation operations and equipment applied in the hydrocarbon processing industry (HPI). Some general principles on design for liquid-liquid (and some vapor–liquid-liquid) separators will also be discussed Plant operators have found that efficient liquid-liquid separations are critical to achieve optimum plant performance But, how does one achieve this goal? What are the critical process parameters to be analyzed? What plant data need to be collected? What equipment options are available? How do you choose between these options? To begin the process of answering these questions, we must ask the fundamental question: