How to treat DMF waste gas recovery? Dimethylformamide solvent recovery plan and precautions

DMF (dimethylformamide) is widely used as a reaction solvent for chemical and pharmaceutical intermediates. Its waste gas concentration is high and it is easy to absorb water. When processing, it is necessary to consider the recovery rate and pay attention to the quality of the recovered liquid. The condensation membrane separation combination process has good adaptability to DMF working conditions: high-concentration DMF vapor is directly liquefied and recovered by compression condensation, low-concentration tail gas is purified by membrane separation, and the recovered liquid is reused after dehydration quality management.

Sources and Characteristics of DMF Waste Gas in 1.

DMF vapor will be produced in the process of distillation and recovery of DMF waste liquid, vacuum desolubility and reactor respiration. DMF vapor pressure is moderate, condensation liquefaction is easy, but it is miscible with water, if the waste gas entrainment moisture into the condensation unit, the water content in the recovery liquid will rise, affecting the quality of reuse, which is the DMF recovery process to focus on management of the link.

2. recovery process

1. Sealed collection and dehumidification prediction

The discharge point is collected in a closed manner, and the moisture content of the exhaust gas is evaluated in the scheme design stage, and the gas-liquid separation is pre-arranged if necessary.

2. Compression and condensation

DMF vapor liquefaction recovery, the condensation temperature is determined according to the component characteristics, taking into account the recovery rate and energy consumption.

3. Membrane separation purification

The residual tail gas is treated by the membrane module, and the enriched gas is recirculated.

4. Recovery liquid management

The condensate is temporarily stored, moisture and purity are detected, and directly recycled or returned to the refining unit according to the quality.

3. DMF vs. Other High Boiling Solvents

Recommendations for 4. implementation

1. The temperature and humidity information are recorded synchronously when the discharge point is found out, which is used as the basis for dehumidification design;
2. Recycled liquid to establish batch testing system, reuse quality in mind;
3. DMF is selective for partial sealing and pipe materials, and the compatibility is confirmed one by one at the material selection stage;
4. With the linkage design of the refining device, the recovered liquid can be directly returned to the closed loop for refining and recycling.

FAQ

Q: What if the water content of DMF recovery liquid exceeds the standard?
Answer: First check the source of moisture (waste gas entrainment or equipment leakage), control from the source, and return the recovered liquid to the refining unit for treatment.

Q: Is DMF corrosive?
Answer: DMF itself is not corrosive, but it is selective to some materials under the condition of water or impurities. Wo Hong will make compatibility confirmation at the material selection stage.

Q: Is small batch multi-batch workshop applicable?
Answer: It applies. The device is designed according to fluctuating conditions, and the operating parameters can be checked according to the components during batch switching.

LuoyangWohong PetrochemicalEquipment Co., Ltd. provides customized services for liquefaction recovery devices of various solvent varieties such as DMF.