The Processes and Benefits of Demulsification

Demulsification, or mechanical separation, is a process of mechanical pressure that removes hydrophobic contaminants from oil. These include oils from the ground, as well as seawater, coal and other types of liquids that have high water content. Many demulsifiers resemble small steam boilers; they use mechanical forces to force heated oil and water to separate from each other.

A demulsifier is not the same as a solid state separation system. A demulsifier, or mechanical divider, is a group of specialized chemicals used to separating liquids, such as, water from oil. They are most commonly used in the production of crude oil, and large amounts of seawater, that is usually formed with other materials. Commonly used chemical ingredients in these programs include calcium thioglycolate, magnesium sulfate, and calcium carbonate. Many common industrial chemicals such as chlorine, sulfuric acid, glycol, and naphthalene may be contained in a demulsifier.

There are several different types of demulsification. The most common technique for breaking down materials is known as emulsification. In emulsification, wastewater is passed through a series of porous materials. In the process, tiny bubbles or droplets form which are later collected on a pipe or other collection device. In this type of demulsification, very coarse materials such as oil are separated from very fine ones.

An advanced form of demulsification is known as flocculation. In flocculation, wastewater is passed through a layer of extremely fine materials. Many times, these layers are made of highly conductive material such as graphite, which would allow for the escape of larger liquid molecules. These processes result in separation of substances with a density that is much lower than that of water, with the end product being water.

There are various types of flocculation. One method, known as mechanical flocculation, requires stationary machinery to drive fluid droplets into a medium of fine gravel. This leaves behind a coarse gravel along with the fluid, which then settles and forms tiny droplets. Another method called hydraulic flocculation, involves passing wastewater through a nozzle at very high pressure, inducing large volumes of water to spray into a settling pool, which causes the water to coagulate, or solidify, into droplets.

While many of these methods have their uses, some scientists have proposed a newer method of demulsification called cohesive gel filtration. By using fine sized particles, these researchers have been able to demonstrate that it is possible to use granular debris, rather than oil, to effectively remove contaminants from drinking water. By slowing down the rate at which granular debris combines with other particles, and forcing them to adhere to tiny barrier surfaces called micro-granules, this technique makes it impossible for particles to escape from the final water vessel. Because of its efficiency, this method may be able to reduce the risk of waterborne illnesses that have both contaminated and become a cause of death in drinking water reserves around the world.