Steam permeation is a new membrane separation technology. The separation process of steam mixture or steam mixture is different from that of non condensable gas mixture in terms of solubility and diffusion rate of dense membrane. The organic solvent vapor phase feed is introduced on the side of the vapor permeation membrane, while the other side is evacuated in a vacuum suction way to get the pure organic solvent in time.
Principle of separation
During the process of steam permeation membrane dehydration, the steam components of water vapor enter the feed side of membrane module after preheating, while the permeating side adopts vacuum to maintain a low pressure environment. At the feeding side, the water molecules first adsorb on the surface of the membrane, and the membrane is permeated by the difference of water vapor pressure difference between the two sides of the membrane. After the separation operation, the waterless products are obtained at the exit side of the membrane feed side, and the osmosis side components are treated by the waste water after condensation.
The steam permeation membrane experimental device is a laboratory steam permeable membrane system, which is used to test the permeation flux of steam permeable membrane under certain temperature and pressure difference, it mainly includes material liquid system, steam permeable membrane, osmotic liquid collection system, evaporation system, etc.. The feed liquid enters the steam permeable membrane, and the latter maintains low partial pressure. The components move away from the membrane through the membrane to the back side of the membrane, it is driven by the partial pressure difference of components on both sides of the membrane. Among them, the components with fast diffusion are mostly passing through the membrane into the back side of the membrane, and the slower diffusion component has less permeable membrane into the rear side of the membrane, so that we can achieve the purpose of separating the different components in the liquid.
Organic solvent dehydration is made by pervaporation membrane separation technology, in this way, traditional separation methods such as distillation, extraction and adsorption can be replaced. It can achieve high quality products with low energy consumption and achieve separation requirements which are difficult or unable to achieve by conventional methods. It has a more obvious advantage in removing organic matter or mixed organic matter from small or micro amounts of water.
A. High efficiency and energy saving: yield 99% energy saving 50%
The core of the pervaporation technology is to use the selective permeability of the pervaporation membrane to make a small amount of water through the separation membrane in the organic solvent, while most of the materials are kept on the other side of the membrane. The separation process shows high energy saving effect, especially suitable for separation of azeotrope and near boiling mixture. Compared with traditional rectification and adsorption technology, the separation process can save more than 50% energy, and the yield is >99%.
B. Environmentally friendly: no third components are introduced or produced, and the quality of the product is high.
Pervaporation technology is applied to remove water from organic solvents. It does not need to introduce third components to avoid pollution to environment or products. At the same time, a small amount of permeation liquid can be recycled, processed and recycled, which is also good for environmental protection.
C. Space saving: compact structure, small area covering.
The pervaporation equipment has compact structure, small area covering and high utilization rate of resources. Compared with the distillation separation equipment, it can save more than 4/5 of space.
D. Easy and safe: easy to operate, high safety
The process of pervaporation membrane separation is simple, the operating conditions is mild, the degree of automation is high, therefore, the operation process has high safety and is more suitable for the dehydration of flammable and explosive solvent system.