Anaerobic Chambers
APPLICATION
Anaerobic chambers / atmospheres are used in microbiological applications.
Hospital laboratories and research institutes use anaerobic chambers to provide an oxygen free atmospheres which is the optimum environment for bacterial growth.
Anco Catalyst has been supplying palladium catalysts for over 40 years to remove O2 from H2 bearing gases. The palladium catalyst is normally wrapped in a perforated foil inside a woven plastic sachets to remove O2 from bell jars, glove boxes, anaerobic gas chambers or anaerobic jar systems. Anco Catalysts usually provides the catalyst only. The manufacturer of the anaerobic chambers produce the sachets incorporating our catalysts.
PALLADIUM CATALYST USED
Anco Catalyst provides the following 3 catalysts for this application.
Type DK : 0.5% Palladium on alumina pellets. Dimensions 3mm diameter x 3mm length.
Type DK3: 0.3% Palladium on alumina pellets. Dimensions 3mm diameter x 3mm length
Type DS2: 0.2% Palladium on alumina pellets. Dimensions 2 to 5 mm spheres.
Type DK has a high structural strength and it is less prone to dusting.
QUANTITY OF CATALYST
We recommend a space velocity of approx. 5,000hr-1 for circulated gas flows.
For jar systems we recommend:-
1 to 3 grams of catalyst for each 1.0 litre of gas jar volume
2 to 5 grams of catalyst for each 2.0 litre of gas jar volume
OPERATING DETAILS
The catalyst operates at room temperature.
The catalyst eliminates the O2 to less than 1 ppm (parts per million).
Usually a N2/H2 mixture is circulated in the chamber(maximum 5% H2)through the catalyst which reacts the O2 with the H2 to form H20.
The H2/O2 catalyst reaction is exothermic so the O2 removed has to be limited.
The exothermic temperature rise for each 1% O2 removal is 160°C
CATALYST POISONS
Sulphur is a strong catalyst poison.
Sulphur compounds such as H2S and SO2 gases are produced by degradation of organic materials.
A carbon guard bed is usually installed to remove these poisons and extend the catalyst life in anaerobic chamber applications.
The catalyst life is based on time or cycles in operation.