Compressed condensation membrane separation, combined process of VOCs treatment

Compressed condensation membrane separation, combined process of VOCs treatment

Single VOCs treatment technology is often short board: condensation method to deal with high concentration of waste gas energy consumption, low concentration of exhaust gas treatment efficiency is low and difficult to meet the standard;activated charcoalFast adsorption saturation and frequent carbon exchange;RTOBurning is dependent on natural gas, high operating costs. Compressed and condensed membrane separation combined process is a system solution to these problems.

Process principle: three stages of cooperation, each performing its own duties

The process couples the two technical gradients of compression condensation and membrane separation, forming a division of labor mode of "condensation is responsible for recovery and membrane separation is responsible for gatekeeping.

The first stage: compression condensation. The exhaust gas enters the multi-stage condensing unit after being pressurized by the compressor, and most of the organic matter is changed from gaseous to liquid by gradual cooling. The purity of the recovered solvent can reach more than 90% and can be directly reused in production.

Second stage: membrane separation cycle. After condensation, the tail gas still contains a small amount of unliquefied organic matter.gas separation membraneTaking advantage of the difference in the permeation rate between organic molecules and air molecules, VOCs preferentially permeate through the membrane layer to form concentrated gas, which is sent back to the compressor inlet to re-enter the condensation process for recycling treatment. Unpenetrated air is discharged up to standard.

This closed cycle design, the system of organic matter capture efficiency significantly improved. Compared with a single condensation process, membrane separation solves the problem of "not clean"; compared with a single membrane separation, the condensation unit solves the short board of "not directly liquefied.

Technical advantage: Recycling and compliance

Recovery and compliance are unified. The process integrates recovery and compliance in the same system: the first half of the process creates value by condensing the recovered solvent, and the second half of the process ensures compliance with the discharge by membrane separation. After treatment, the concentration of VOCs can be reduced to less than 50mg/m³.

Energy consumption is controllable. The membrane separation pre-concentration reduces the processing load of the condensation unit. Compared with cryogenic technology, the comprehensive energy consumption of the combined process can be reduced by more than 60%.

Low operating costs. It is driven by electric power, does not consume natural gas, does not replace consumables such as activated carbon, and does not produce hazardous waste. Pure physical separation, no open flame, good applicability in explosion-proof places.

Applicable scenarios

The combined process is suitable for VOCs waste gas with medium and high concentration (above 1000 mg/m) and solvent with recovery value, covering common solvents such as ketones, esters, hydrocarbons, halogenated hydrocarbons, alcohols, etc. Application scenarios include waste gas recovery in chemical storage tank areas, pharmaceutical dichloromethane exhaust gas treatment, printing plant ethyl acetate recovery, etc.

Before selecting equipment, it is recommended to first conduct a process condition assessment and match the equipment specifications based on concentration, composition, and airflow rate.