Solvent Recovery By Solvent Extraction

Our liquid liquid centrifugal extractors are widely used for recovering the organic solvent from the waste water by solvent extraction, such as DMF/DMAC , TCE , ChloroForm , EA/EAC , Et2O , IPA , P-Xylene etc...

Solvent extraction refers to the the method of transferring solutes from one solvent to another by utilizing the different solubility or distribution coefficients of substances in two immiscible or slightly soluble solvents; It is commonly used for extracting the organic solvent from low concentration organic waste water that are difficult to burn or contain water; The common extractants include volatile solvents such as chloroform, dichloromethane , n-hexane and petroleum ether etc.

The waste water which used for our liquid liquid centrifugal extractor can be :

1. DMF/DMAC wastewater
2. Phenolic wastewater
3. Amine wastewater
4. Naphthyl sulfonic acid wastewater
5. Carboxylic acid wastewater
6. Phosphorus and nitrogen containing wastewater etc.

For example, the steps to recover the DMF from waste water:

1. Aqueous heavy phase(A phase) : 15% DMF waste water
2. Organic light phase(O phase) : chloroform ( or CH2Cl2)

Step 1: Dichloromethane(CH2Cl2) is used as an extractant to enter from the light phase feed port of the centrifugal extractor, while DMF waste liquid enters from the heavy phase feed port of CWL-M centrifugal extractor, with a ratio of 1:2.

Step 2: Under the temperature of 25C, the A phase and O phase were mixed and separated by 2-3 stages counter current centrifugal extractor. DMF/DMAC dissolved in dichloromethane(CH2Cl2).

Step 3: The CH2Cl2 which containing the DMA/DMAC will come out from the outlet of CWL-M centrifugal extractor. Then go to distillation process to get high-purity DMF products.

Attention: DMF and DMAC have certain toxicity, so safety should be taken into consideration during operation. In addition, specific extraction conditions (such as temperature, O/A ratio etc.) need to be adjusted according to the actual situation.

Applications