Function and daily maintenance points of VOCs separation membrane module in organic solvent liquefaction recovery system

Direct answer:VOCs separation membrane is the core unit responsible for the treatment of low-concentration tail gas in the organic solvent liquefaction recovery system: after the condensation section liquefies the high-concentration solvent vapor, the residual low-concentration VOCs enter the membrane module, and the solvent molecules preferentially pass through the membrane to be enriched and returned to the condensation section, and the purified gas meets the discharge standard. The key points of daily maintenance of membrane are dew point control, pressure difference control and pollution prevention.

Working principle of 1. membrane separation

VOCs separation membrane is a polymer composite membrane, which uses the difference of dissolution and diffusion rate of different gas molecules in the membrane to achieve separation: the speed of organic solvent vapor molecules through the membrane is much faster than that of nitrogen, oxygen and other non-condensable gases. Driven by the pressure difference between the two sides of the membrane, the solvent vapor is enriched on the permeation side and returned to the front condensation section for liquefaction and recovery again; the purified gas on the interception side is discharged up to the standard.

Position and Function of 2. Membrane Module in the System

Four key points of 3. daily maintenance

1. Control inlet dew point:The condensation of water in the membrane will significantly affect the separation performance, and the intake air needs to be pre-treated with water removal.
2. Pressure difference before and after monitoring the membrane:Abnormal increase of pressure difference often means pollution or blockage, and the pretreatment link should be checked in time.
3. Prevent particle and oil pollution:The compressor lubricating oil mist and dust will contaminate the film surface, and the filter element needs to be replaced regularly.
4. Avoid overtemperature and overpressure:Long-term over-design operation will accelerate the aging of the diaphragm and should be kept within the design range.

Replacement cycle of 4. membrane

The life of the membrane module is closely related to the cleanliness of the intake air and the operating conditions. In a well-maintained system, the membrane module can operate stably for a long time; when the flux on the permeate side drops significantly, the emission concentration rises and the cleaning is invalid, consider replacing the membrane core. VOCs separation membrane has eight inches, three inches and other specifications, can be selected according to the amount of processing.

Frequently Asked Questions

Q: What does membrane separation need to consume?
Answer: Membrane separation is a physical process without chemical agents. The main consumption is the filter material and system power consumption of pre-membrane pretreatment.

Q: Will the membrane be dissolved by the solvent?
Answer: VOCs separation membrane is selected for the working condition of organic solvent vapor. It will not dissolve in normal operation, but liquid solvent should be avoided from directly entering the membrane module.

Q: Does the whole machine have to be shut down if the membrane module is broken?
Answer: Skid mounted system usually adopts membrane module parallel design, single group maintenance does not affect the overall operation.

LuoyangWohong PetrochemicalEquipment Co., Ltd. provides VOCs separation membrane modules and supporting liquefaction recovery devices. Please contact us.