Condensation

In case of condensation the VOC containing exhaust air is cooled below the dew point of the VOC until a change from gas to liquid takes place. Typically a cryogenic temperature is required. Therefore the condenser consists of multiple steps and in some cases also redundant.

A common design cools the air down close to the melting point of water. After that the water condenses and is separated. Then the air is led to a redundant and alternating operated heat exchanger. One heat exchanger is always in operation and frozen. The other is defrosted at the same time. The freezing of the heat exchanger cannot be avoided in the cryogenic area because with the VOC there is always some water after the first cooling step in the exhaust air.

The VOC condense in the second cooling step and can be removed afterwards. Typically a further treatment of the liquid solvent is required to remove the water fraction via phase separation and distillation.