Extraction is also called solvent extraction or liquid-liquid extraction (to distinguish it from solid-liquid extraction, that is, leaching), also known as extraction (commonly used in the petroleum refining industry). It is a widely used unit operation for component or multi-component solutions to realize the mass transfer separation process of component separation.


Solvent extraction is a process in which compounds are separated based on their relative solubilities.


This treatment method involves using a solvent - a fluid that has the ability to dissolve another substance.


Solvent extraction is used across multiple industries, including during the processing of perfumes and vegetable oil. It’s also commonly used in petrochemical refining industries. In the processing of waste diesel oil, solvent extraction can also be used to convert waste diesel into water-color oil that can be reused. In the recovery of waste oil, the extraction method is used to extract the reusable oil, which requires the use of a solvent extraction machine.


Solvent extraction is used to separate hazardous contaminants from sludge and sediments as well. This can be especially beneficial for hazardous waste generators since solvent extraction ultimately reduces the amount of hazardous waste that must be treated.


Solvent extraction does not destroy a compound. It instead separates it, a process that can provide several valuable benefits depending on the industry in which the process is used.


What Is Solvent Extraction?

Solvent extraction is the act of removing something or separating it. This must be done through force and this process occurs over the course of two different immiscible phases.


Immiscible liquids (liquids that do not dissolve in one another) form layers when put together. This is because each liquid differs in polarity, or orientations. The order of the phases, whether a particular liquid is on top or on the bottom, is determined by its density.


For example, if you use ether and water during the extraction process, water has a higher density than ether. Therefore, water will be the bottom phase.


Your method for extraction may vary depending on your equipment, but in its most simplistic form, extractions often use some kind of separatory funnel. The liquid mixture that is to be separated is first added to the funnel. When the two extraction solvents are then added to the funnel, they should separate into two phases.


After forcibly shaking the funnel and allowing it to stand for several minutes, the two layers can be collected. In the end, the target molecule for extraction will be located in one of the solvents.


More recently, according to a ScienceDirect report, new separation techniques are combining the solvent extraction process with additional technologies to enhance genetic engineering techniques. These include liquid membrane extraction and super critical fluid extraction.