How to recycle acetone waste gas? Condensation and membrane separation liquefaction recovery process and configuration points

Acetone is a commonly used ketone solvent in coating, medicine, electronic cleaning and other industries, with moderate boiling point, strong volatility, high concentration of waste gas and obvious recovery value. The acetone waste gas recovery adopts the liquefaction recovery process of condensation and membrane separation: the condensation section liquefies most of the acetone vapor for direct reuse, and the membrane separation section intercepts the residual vapor and forms an internal circulation to purify the tail gas for external discharge. The whole device has good adaptability to intermittent and fluctuating working conditions, and is suitable for the workshop with acetone as the main solvent.

Characteristics and recovery ideas of acetone waste gas

The boiling point of acetone is around 56 degrees Celsius, which is easier to volatilize than most esters and aromatic solvents, and the vapor pressure is high at room temperature, which means that the enthalpy load of acetone exhaust gas is greater at the same concentration, and the temperature required for the condensation section is lower. Special attention should be paid to two points in the recovery design: first, acetone is miscible with water, and if water vapor condensate is entrained in the condensate, subsequent separation methods should be considered; Second, the flash point of acetone is low, and the anti-static and safety configuration of the device should be in place.

Configuration points

1. Condensation temperature level is determined according to exhaust gas temperature and acetone concentration, high concentration gas source is equipped with low temperature condensation, and conventional gas source freezing water condensation can be effective;
2. The condensate is provided with a settling separation unit or sent to a rectification unit to control the water content of the reuse acetone;
3. The membrane separation unit is arranged after the condensation, and the permeate side gas returns to the condensation inlet to form an internal circulation;
4. The whole set of equipment shall be equipped with electrostatic grounding, explosion-proof electrical and fire retardant according to the standard of low flash point solvent;
5. The design quantity of recovered acetone and sampling port shall be reused after inspection according to the reuse standard of workshop.

Division of labor between condensation and membrane separation

The condensing section bears the main recovery load, and the acetone is directly reused after liquefaction; the residual low-concentration acetone vapor enters the membrane separation section, the membrane module selectively permeates the organic vapor, and the enrichment side returns to the front end for recondensation. This internal circulation design makes the overall recovery degree of the system significantly better than that of single condensation, and the tail gas concentration is more stable.

Comparison of Single Condensation and Condensation Membrane Separation

Operation management suggestions

After the device is put into operation, the three indicators of condensation outlet temperature, pre-membrane pressure and recovery amount are paid attention to daily. Acetone is volatile, and the breathing loss of storage tank and pipeline cannot be ignored. It is recommended to connect the breathing exhaust to the recovery system. Solvent ledger and recovery measurement linkage, monthly check solvent consumption, recovery effect with data.

Frequently Asked Questions

Does acetone waste gas containing a large amount of water vapor affect recovery?

It will affect the selection of condensation temperature and the separation of condensate. The latent heat load is calculated according to the humidity of the air source during the design. The separation link is set for the condensate, and the moisture content of the reuse acetone is controllable.

Is acetone tail gas suitable for cleaning process in electronic industry?

Applicable. The concentration of acetone in the tail gas of the cleaning process is relatively high and the gas volume is not large, which can be covered by a small condensation and membrane separation skid-mounted device, and the recovered acetone can be reused for cleaning.

Can the purity of recovered acetone meet the production and reuse?

The purity of acetone recovered by condensation is usually good, which is checked and confirmed according to the workshop reuse standard. For scenes with high purity requirements, distillation purification can be added.

This article by LuoyangWohong PetrochemicalEquipment Co., Ltd. arranges that the company provides design, manufacturing and operation and maintenance services for condensation recovery, membrane separation recovery and complete solvent recovery devices for chemical and pharmaceutical enterprises. If you need process evaluation or scheme configuration, please contact and exchange.