Soda lime is very effective and efficient in absorbing CO₂ which is very useful in medical facilities and industries. 

Soda Lime vs. Other Absorbents

Soda Lime or Lime that is Calcium Oxide

There is a difference in the chemical composition and use of soda lime and lime which is known as calcium oxide, CaO. Lime and soda lime are both used to remove carbon dioxide from air and water. Lime functions well only when heated to high temperatures while soda lime functions at the environment temperature. Soda lime is even more reactive and readily available for the absorption of CO₂. It is widely used in anesthesia machines and closed circuits in which high level of CO₂ removal is highly desirable. Lime on the other hand is used extensively in cement manufacturing where high temperature reactivity is desirable. 

Soda Lime vs. Silica Gel

Another material which explores the property of abiding gases particularly water vapor and some organic compounds is silica gel. Although both soda lime and silica gel are types of desiccants (substances that help in absorbing moisture), the use and operation of both differ greatly. Compared to Soda Lime, which mainly deals with CO2, the main function of silica gel is the removal of moisture. Soda lime in general with its structure provides the means for it not to capture gases such as CO₂ but to trap water molecules instead. Therefore, soda lime products are ideal for use in applications that include gas absorption like medical anaesthesia circuits and silica gel ideal in moisture regulation in packaging and preservation. 

Soda Lime and Activated Carbon

Another extensively employed substance that undergoes gas absorption is activated carbon or activated charcoal but these two are not similar to that of soda lime. Whereas activated carbon is considered for adsorbing gases, such as VOCs, odors and other pollutants, soda lime is tailored for the purpose of absorbing CO₂ only. The key difference between the two substances is their adsorption mechanism. Carbon activates molecules through its structural surface thereby physically trapping CO₂, soda lime on the other hand interacts with the CO₂ chemically through a process of forming a stable compound known as calcium carbonate. Soda lime products make excellent scrubbers when CO₂ is needed to be removed as in the medical anesthesia machines or submarines; activated carbon is more suitable for the air purification and filtration. 

Soda lime and sodium bicarbonate

These are two of the most commonly used absorbents in operating theatres; each have their characteristics that set them apart from the other. Other reagents that can neutralise the acids include Sodium bicarbonate (NaHCO₃) which-more or less-works in a different way from that of soda lime. Even though both substances can react with CO₂ sodium bicarbonate fails to do the absorption as effectively and in a short time as soda lime does. Alkaline component of the soda lime, sodium hydroxide, and calcium hydroxide reacts chemically with CO₂ and creates a stable compound calcium carbonate. On the other hand sodium bicarbonate readily reacts with CO₂ to form sodium carbonate, a less stable product and therefore needs to be replaced often. Thus, to maintain a continuous and highly effervescent CO(2) absorption in medical and industrial applications, soda lime finds more application.

 

Conclusion

Soda lime is a very unique reagent that, in fact, cannot be compared with any other materials used for the absorption of gaseous mixtures. The fact that it can act as a chemical, operate well at room temperature, and selectively bind to CO 2 makes it a valuable product in medical, industrial, and even environmental domains.