Portal de Periódicos da CAPES

Use coalescing methods to solve emulsion problems

1995; Gulf Publishing Company LLC; Volume: 74; Issue: 11 Linguagem: Inglês

0887-0284

P. Hennessey, Mark Neuman, B. A. Kalis, G. Hellinx,

Electrohydrodynamics and Fluid Dynamics

What are efficient and cost-effective ways to separate the dispersion of two immiscible liquids? A common result from processing hydrocarbons, dispersions exist when the droplets of one liquid become dispersed into another. Because the droplets are small [down to 1 {micro}m (micron)], molecular forces such as interfacial tension, viscosity, density, temperature, pH, etc., control the required time for the two liquids to separate. Old methods used large settler vessels and allowed gravity to merge the droplets into sufficient size for separation. To be more competitive, operators are increasing process capacity and consequently, incurring more problems with dispersions from higher throughputs. Thus, many operators must find process methods that accelerate the dispersion separation process and/or prevent dispersion formation. Using methods such as liquid-liquid coalescing media is one way to convert small droplets into large ones that quickly settle. The presented case histories show how coalescers were effectively used in refining and gas-processing applications. Dispersions can be expensive problems that affect product quality such as haze in jet fuel; they can be an environmental problem such as hydrocarbon emulsions present in wastewater; and they can be an operations problem such as solvent losses in an amine unit. However, by using these examples,more » operators can focus on how to cut operating costs, improve product quality and reduce process wastes especially when handling dispersions.« less