|
LENZING Technik
>
Engineering & Contracting
>
Environmental Technology
>
Chem./Phys. Waste Gas Treatment
>
CS2-Condensation
CS2 CONDENSATION
For the recovery of CS2 from viscose staple fiber processing.
Features
- Efficient recovery of up to 98% of released CS2 vapour.
- Lowest operation cost for CS2 recovery.
- Simple and reliable process and operation.
- Cleaning required only once every two years due to vapour condenser design.
In Detail
A mixture of steam vapour, CS2 and air with a temperature of approx. 95 °C is sucked off from the fleece forming unit (CS2 -box). Most of the vapour is condensed in the vapour condenser by mixing with water. The water temperature at the outlet of the condenser is approximately 70 to 75 °C, and the same water flows back into the acid water circulation system, to compensate for the water carried out of the system by the fleece. The feed temperature of the water to the vapour condenser should not be lower than 50 °C to avoid condensation of CS2 inside the vapour condenser.
CS2 and steam-saturated air pass through the condenser where the gases are extracted by a water jet, in which more CS2 is condensed by the cold water.
The gaseous phase is then separated from the liquid phase by means of an air separator.
The gaseous phase contains air and all the non-condensed gases, whereas the liquid phase consists of process water and condensed CS2, which are then separated in the CS2-settler.
The flow rate out of the CS2 box has be controlled properly: If the actual flow rate were too low, there would be overpressure in the box causing CS2 to be discharged into the aftertreatment. In the case of too high flow rates there would be underpressure in the box leading to excess air being sucked into the condenser causing higher CS2 - losses in the tail gas and thus lower recovery efficiency.
The recovered CS2 is of high purity, so can be used in the viscose process again without an extra cleaning procedure. The water overflow of the settler is nearly CS2 free, and can be circulated after the batch addition of caustic soda to remove remaining H2S.
Support
For further details about this product group please contact:
environmental-tech@lenzing.com
|
