Solvents are involved in numerous manufacturing and chemical processes, releasing large volumes of volatile compounds. These are harmful to the environment but are easily recovered and recycled through the use of appropriate technology. The use of activated carbons is one of the best methods for optimum extraction/recovery ratio of solvents and also for the control of operating costs on sites.
Extracting solvents
Issues:
Optimal coupling extraction/solvents recovery
Solutions:
The technique consists of passing solvents though a bed of specific granular activated carbons. Their granulometry is defined on the basis of the flow and form of the filter. When carbon grains are saturated, they may under certain conditions enter a desorption phase through heating. This is accomplished by passing solvents from a condensed liquid phase to a gase phase. Solvents may then be recondensed upon their exit for the purpose of reuse.
Three case scenarios are possible:
- The solvent is not miscible in water. It is recovered through decanting.
- The solvent is miscible in water and of high value . It is recovered through distillation.
- The solvent is miscible but of low value. The mixture is incinerated.