Experimental principle of liquid-liquid extraction of phenol

Principle of phenol extraction Working principle and operation of centrifugal extractor

Working principle of centrifugal extractor At present, the treatment methods of printing and dyeing wastewater mainly include coagulation and sedimentation, adsorption, extraction, membrane separation, advanced oxidation and biochemical methods. Through a large number of data research, it is concluded that the extraction method is effective in treating printing and dyeing wastewater. Aiming at the treatment of printing and dyeing wastewater, the centrifugal extractor is used for tianyi extraction, and the application of centrifugal extractor in printing and dyeing wastewater treatment is introduced in detail in combination with composite extractant.

Working principle of centrifugal extractor in extraction process;

Firstly, the two-phase solution enters the mixing zone formed between the drum and the shell from two feed nozzles according to a certain proportion. With the rotation of the drum, the two phases are rapidly mixed and dispersed through the turbine, disc and impeller, and the two-phase solution is fully mass-transferred, thus completing the mixed mass-transfer process. The mixed two-phase liquid enters the drum under the action of the scroll, and the two-phase separation process is completed under the action of centrifugal force.

After extraction, the loaded organic phase needs to be back-extracted, and the alkali solution is used as the back-extraction agent for back-extraction. The regenerated extractant after back-extraction can be used many times without affecting the extraction effect.

Working principle of centrifugal extractor N, N- dimethylformamide (DMF) is a colorless and transparent liquid with strong polarity, which can be mixed with water, ether, ketone, fat and unsaturated hydrocarbon. Known as "universal solvent", it is widely used in petrochemical, organic synthesis, inorganic chemical, agricultural medicine, manufacturing medicine and other fields. DMF can damage human health through breathing and skin contact, and damage eyes many times. Long-term exposure or inhalation of DMF will hinder the blood machine and cause liver and visceral obstruction. In water, biochemical oxygen consumption and nitrogen content will increase. When the pH value of wastewater is adjusted to about 0.5, the COD value of wastewater after extraction is reduced to below 1000mg/L, and the H acid content is below 0. 1%. The treated wastewater is almost colorless and can be directly treated in the next section. After stripping with 10% alkali solution (NaOH solution), the residual H acid in the organic phase after stripping is less than 0.5%, which can be recycled. H-acid wastewater from a chemical plant in Ningxia.

Application example of centrifugal extractor working principle: design of phenol-containing wastewater treatment process: extraction stage: phenol-containing wastewater enters the centrifugal extractor, and the extractant also enters the centrifugal extractor in proportion. After 2-3 times of extraction and dephenolization, the wastewater is discharged from the centrifugal extractor. Back-extraction stage: the phenol-containing extractant (loaded with organic phase) enters the back-extractor, and at the same time, the liquid alkali enters the back-extractor in proportion, and the phenol-containing extractant is back-extracted and alkali-washed for two or three times, and the alkali-washed extractant can be recycled. The sodium phenolate solution produced after stripping is discharged from the stripper, and the sodium phenolate is recovered.

The working principle of centrifugal extractor In the compartment formed by the blessing plate, the mixed liquid and the drum rotate synchronously and rapidly. Under the action of centrifugal force, the heavier liquid gradually moves away from the center of the drum and leans against the wall of the drum in the upward flow process. The light-phase liquid with small specific gravity gradually moves away from the cylinder wall to the center, and the clarified two-phase liquid finally enters the collection chamber through their respective weir plates, and is led out of the machine through conduits respectively to complete the two-phase separation process. With the continuous development of chemical industry, the amount of wastewater produced in the production process of enterprises is also increasing. Among them, the coking plant will produce a large amount of phenol-containing wastewater, which is toxic, biochemical and complex in composition. If discharged directly, it will do harm to the environment and human body. Therefore, the treatment of phenol-containing wastewater in coking plant is one of the key points of wastewater treatment at present. At present, the treatment methods of phenol-containing wastewater mainly include biological method, chemical method and physical method, and the common method is solvent extraction. Solvent extraction has the advantages of high recovery rate, reusable solvent and low cost.