LIQUID-LIQUID EXTRACTION AND STRIPPING
a) Liquid-Liquid Extraction Process
PSC S.r.l. Engineering & Contracting (PSC) is expert in Liquid-liquid extraction (LLE) also known as solvent extraction and partitioning: a method to separate constituents (solutes) of homogeneous liquid solutions. In this separation process, second liquid solvent is added which is immiscible or partially miscible with the feed and the solutes of the mixture are distributed between the two phases based on their relative solubilities. There is a net transfer of one or more species from one liquid into another liquid phase, generally from aqueous to organic. The solvent that is enriched in solute(s) is called extract; the feed solution that is depleted in solute(s) is called the raffinate.
This type of process is commonly used:
(LLE) require a large consumption of possibly toxic solvent, which also when recycled in the system requires costly equipment. Thus, right selection of the solvent in achieving a sustainable process is required and it creates challenges to the large-scale industry implementation of the process.
If the aim of the process is to achieve a pure extract, the LLE as a downstream process is most often only the initial step. Further purification, such as distillation, crystallization or second extraction might be needed.
(LLE) has several industrial applications:
Type of liquid-liquid extraction process can be performed by means following methods:
ENCYCLOPEDIA OF CHEMICAL ENGINEERING
b) Stripping Process
The stripping process is a physical separation process where one or more components are removed from a liquid stream by a vapor stream. In industrial applications the liquid and vapor streams can have co-current or countercurrent flows. Stripping is usually carried out in either a packed or trayed column.