Volatile Organic Compounds Treatment Technology
Adsorption recycling technology
Absorption method
The principle of similar compatibility between absorbing liquid and organic waste gas to achieve the purpose of treating organic waste gas.
Common absorbents can be divided into mineral oils (such as diesel oil, non-polar mineral oils), water composite absorbents (such as water-washing oil, water-surfactant-auxiliaries and other composite absorbents) and high-boiling organic absorbents. Solvents (eg DBO, DEHA, DEHP, etc.).
The absorption method has the advantages of mature processing technology, simple equipment and good absorption effect. It can handle most volatile organic compounds and is widely used in industrial fields.
Condensation technology
It is a process in which the volatile organic compounds in the vapor state are condensed and separated by changing the temperature or pressure of the system.
The operating system must have lower temperature and higher pressure to achieve high recovery efficiency, so equipment performance requirements and operating costs are higher.
Condensation technology is generally used in organic waste gas with high concentration and high boiling point, and is usually used in combination with absorption, adsorption and other methods.
Membrane separation technology
Membrane separation technology
Taking the gaseous membrane separation method as an example, the organic waste gas is pressurized by a compressor and then enters the condensation system, and the condensed liquid VOCs can be recycled or processed in the next step.
The membrane separation system is selective to the uncondensed gas so that it can be enriched by VOCs. The gas that cannot permeate the membrane can be directly discharged as the purified gas, and the exhaust gas that permeates the membrane is returned to the compressor for continuous recycling.
Compared with the traditional VOCs treatment technology, the membrane separation method has the advantages of high mass transfer efficiency, low energy consumption, small device size and simple operation.
The key to this technology is the choice of membrane. The choice of membrane material should consider the stability, mechanical properties, hydrophobicity and economy of the membrane. If the temperature of the treated exhaust gas is high, the high temperature resistance should also be considered.