Solvent extraction technology application in the field of various industries
Say again extraction, solvent extraction or liquid-liquid extraction, which is also called extraction, is to use the system components have different solubility in the solvent to separate mixtures of unit operations.
That is, is to use the material in two mutually soluble (
Or slightly soluble)
Solubility in solvent or the distribution coefficient of the different, to solute movement of material from a solvent to methods in another solvent.
Widely used in chemical, metallurgy, food industry, such as universal in the oil refining industry.
In addition to two kinds of each phase after extraction soluble liquid separate operation, called liquid.
because can request according to the separation of objects, and select the appropriate extraction agent and process.
Thus has high selectivity, good separation effect and strong adaptability, etc.
Solvent extraction is usually carried out under normal temperature or low temperature, low energy consumption, especially suitable for the separation of heat sensitive material, and easy to realize large-scale continuous production.
Significant industrial application for the first time was in the early 20th century aromatics extraction in the oil industry.
Then used for vegetable oil extraction and purification of penicillin, etc.
During the second world war in the atomic energy industry has been successfully used in extraction, plutonium and radioactive isotope separation axis, promote the research and application of solvent extraction.
Since the 60 s, the solvent extraction for large-scale industrial production, such as lubricating oil refining of petroleum and chemical, propane deasphalting, aromatics extraction and hydrometallurgy industrial extraction of copper, nickel and cobalt separation and in the separation of rare earth elements, etc.
It is wet metallurgy, atomic energy chemical industry, petroleum chemical industry in areas such as an irreplaceable important separation technologies.
With the development of high-tech.
Liquid extraction in the energy and resource utilization, biological and medical engineering, environmental engineering and the development of high and new materials is faced with new opportunities and challenges.
due to solvent extraction has a long history and wide application, some call it 'mature technology'.
But, in the process of solvent extraction and large viscosity of continuous phase difference in density between, severe back-mixing, two phase flow and phase international mass transfer is very complex, and two phase has a certain degree of solubility, thereby causing loss to the solvent and secondary pollution, solvent regeneration is important impact on the economy and reliability of the process.
With distillation gas, etc
Liquid mass transfer process, extraction process and equipment design is difficult.
As an important branch of chemical separation science, solvent extraction has the characteristics of multidisciplinary cross, there is the need of further research and development and potential.
extraction technology application in environmental engineering, with the development of industrial technology and the improvement of people environmental consciousness, all kinds of industrial wastewater,
Such as organic and acid, containing metal ions, waste water containing radioactive substances and other toxic substances, etc. )
Processing becomes more important.
In view of the solvent extraction has the advantage in dilute solution recycling (
Especially in 10 - concentration range
3 orders of magnitude of waste water)
And many related research work.
Therefore, screening of high efficiency, low toxicity, low price and is available for long-term recycled solvent and composite solvent is very important.
Also in urgent need of development of high efficiency, high flux and less solvent entrainment extraction equipment to overcome the secondary pollution problem of residual solvents.
Efficient extraction tower packing and hollow fiber extractor and other new extraction equipment could be widely used.
Study effectively removal from aqueous solution of sugar, starch and other high solvent polarity material is also an urgent task.
Another potential advantage is solvent extraction wastewater treatment waste water in solving some difficult problems, can recovery of valuable material or material recycle, and not simply as biochemical treatment, the oxidation and burning destruction of these materials.
The development process of solvent extraction in green technology will play an important role.
extraction technology application in the food chemistry food materials is a variety of ingredients, including water, carbohydrates, proteins, lipids, vitamins, minerals, etc. , most of these substances are polar molecules, they can be heated in the microwave field, heating up, due to the different materials have different dielectric constants, so the extraction technique in food application is feasible.
Since extractive technology applied in the organic compounds, many scholars at home and abroad to participate in the prompt extraction technique in food chemistry, the application of the extraction technology is mainly used in the extraction of natural ingredients and food in the plant tissue analysis.