Membrane Technology Degassification
Oxygen removal from clean water via membrane contactors system
Introduction of oxygen and dioxide carbon removal via gas transfer membrane (membrane contactor) Dissolved gases such as O2,H2S,NH3,NOx,CO2 etc in water/ wastewater lead to contamination in the water/wastewater system and high treatment costs for wastewater/water treatment plants. Since membrane based technology has been developing ,removal of dissloved oxygen via membrane contactors is a innovation process in many chemical/microelectric plants .
As a traditional process like gas striper ,extraction,vacuum tower and forced draft deaerator can be lead to several problems or issues such as high cost building or running ,high energy consumption .Those issues can be solve by membrane technology .Membrane contactors can remove oxygen from water and recover it to a usable form in a single step .
- You can benefit advantages from membrane contactors:
- Single and simple step processing
- Low energy demand
- Minimum oxygen concentration effluent/outlet
- No chemicals comsupation
- Up to 99% removal
- efficiency to 5 ppb
Principle of removal of oxygen via gas transfer membrane
The technology behind Microna membrane contactors is based on Henry’s Law, which states that gasses will dissolve in water relative to their partial pressure above the liquid. The solubility constant (Henry’s Constant), which is different for each gas, also depends on temperature. Water below atmospheric standard conditions (20°C, 1bar) and in contact with ambient air contains up to 6-9 ppm (mg/L) of oxygen.
Water flows through the contactor on the outside (shellside or liquid side) of the hollow fiber membrane. Because the membrane is microporous and hydrophobic, only gas molecules are able to pass through the membrane. Applying a vacuum or using an inert sweep gas on the inside (lumenside) of the hollow fiber membrane lowers the partial pressure of the gas that needs to be removed, carrying excess gasses away into the vacuum.
Gas transfer hollow fiber wall from outside into inside This process is shown in the left .Where the water flows at the outside or shell ,while an vacuum phase in the inside(lumen) .