Membrane degasification is mainly used for the removal of dissolved carbon dioxide and / or oxygen.
For membrane degasification, hydrophobic pore membranes are used, which are opaque for water, but permeable for gases. For this purpose, mostly hollow fiber modules with a high packaging density are used. The gasified water flows along the fibers.
Because of the partial pressure gradient, the dissolved gas diffuses through the membrane. However, the water is retained by the membrane. To generate the necessary partial pressure drop, a vaccum can be applied on the membranes or strip gas (nitrogen or pure air) can be used, which flows continuously through the fibers and carries off the removed gases.
Membrane degasification offers the following advantages:
- low operation costs
- low pressure drop
- no chemicals required
- Reduction of the chemicals for regeneration of a downstream ion exchanger unit
- Compact design
- Uninterruptible operation