Organic tail gas treatment, solvent resource recovery by condensing membrane method

Volatile organic compounds in organic tail gas,activated charcoalAdsorption orRTOAfter the combustion treatment to meet the emission standards, the solvent will disappear. The starting point of the condensed membrane recovery process is different-it converts the organic matter in the tail gas into a reusable liquid solvent, which can meet the environmental protection requirements and realize the reuse of resources.

The process is completed by two units, condensation and membrane separation.

The condensing unit completes the body recovery. After compression and pressurization, the tail gas enters the condensation system, and most of the organic matter is changed from gaseous to liquid through graded cooling, and the purity of the recovered solvent can reach more than 90%, which can be directly reused for production. The condensation temperature is set according to the boiling point of the target component, and is usually in the range of -10°C to 15°C.

The membrane separation unit is responsible for the cycle check. The condensed tail gas still carries a small amount of organic matter that is not liquefied, and this part of the gas enters the membrane separation unit. Taking advantage of the difference in the permeation rate between organic molecules and air molecules in the membrane material, VOCs preferentially permeate through the membrane layer to form concentrated gas, which is sent back to the compressor inlet and re-enters the condensation process for circulation treatment. Through this cycle design, the overall recovery rate of the system can reach more than 95%.

Why is it more cost effective?

Compared with activated carbon adsorption, the condensation film method has no replacement of consumables such as activated carbon and does not produce hazardous waste. Compared with RTO combustion, it does not need to consume natural gas, does not involve combustion, no open flame, and has good applicability in explosion-proof places. The process is driven by electricity, and the long-term economy is more controllable in terms of operating cost structure.

The process is suitable for organic tail gas with a concentration of more than 1000mg/m³ and a solvent with recovery value, covering common solvents such as hydrocarbons, halogenated hydrocarbons, alcohols, esters, ketones, etc. Before selecting equipment, it is recommended to first conduct a process condition assessment to determine the concentration, composition, and airflow rate, and then match the equipment specifications accordingly.