Carbon Dioxide (CO₂) Absorbent for Removal of CO₂ from Breathable and Industrial Gases

Many industrial applications require carbon dioxide (CO₂) absorbents for the safe removal of carbon dioxide from gas streams, most of which relate to breathable air.
Premier Chemicals supplies high quality industrial and diving grade soda lime CO₂ absorbents for carbon dioxide removal including:-

• Intersorb^® 408
• Intersorb^® 812
• Spherasorb^® 408

Ambient air generally contains approximately 350ppm (parts per million) of CO₂ and the exhaled breath of a person contains around 4% (40,000ppm). Therefore, in a confined space with little or no ventilation, the presence of people can cause the carbon dioxide level to rise quickly to unsafe levels.

It is generally recognised that a safe level of carbon dioxide should be below 1%. Soda lime can be used to maintain a low CO₂ level by re-circulating the air within a confined space through a bed of soda lime. Typically those applications include saturation dive chambers (see commercial subsea applications), mine refuge chambers or submarines.

Chemical reaction for carbon dioxide (CO₂) removal.

Soda lime CO₂ absorbents contain Calcium Hydroxide, Sodium Hydroxide and a carefully controlled level of water which aids in the exothermic, water facilitated catalytic chemical reaction to eliminate carbon dioxide and other acidic contaminants from gas streams. Water is also formed in the reaction as a by-product.

The reaction proceeds in 3 stages:-

(i) CO₂ + H₂O → H₂CO₃

(ii) H₂CO₃ + 2NaOH → Na₂CO₃ + 2H₂O

(iii) Na₂CO₃ + Ca(OH)₂ → CaCO₃ + 2NaOH