Why Does Super Dry Calcium Chloride Desiccant Absorb More Water

Desiccants are materials that absorb moisture from their surroundings, helping to protect goods from humidity and moisture damage. Among the various types of desiccants available, calcium chloride stands out for its exceptional moisture-absorbing capacity. But why does calcium chloride absorb more water compared to other desiccants? Let's delve into the science behind it.

The Science Behind Calcium Chloride

Calcium chloride is a type of salt, known as a hygroscopic substance, which means it attracts and absorbs water molecules from its surroundings. This property makes it an excellent desiccant. But what sets calcium chloride apart from other desiccants is its ability to absorb water in two ways: physical absorption and chemical absorption.

Calcium chloride cacl2 water absorption principle

Anhydrous calcium chloride can absorb water by utilizing its chemical properties (calcium chloride can react with water), chemical equation: CaCl2+6H2O==CaCl2·6H2O, but it can form unknown crystal water at different temperatures. Compound (can be 1, 2, 3, 6 crystal water).
    Anhydrous calcium chloride is generally in the form of white lumps. Its appearance will change after absorbing water. Its changing forms are: 1. Absorb a small amount of water: the appearance does not change much and remains lumpy; 2. Continue to absorb water: the surface begins to change. It becomes moist and soft, with the potential to melt; 3. Continue to absorb water: it changes from a moist block to a liquid, and then is completely dissolved by water.

Physical Absorption

Like other desiccants, calcium chloride can physically absorb water. This process is similar to how a sponge soaks up water. The water molecules are attracted to the calcium chloride and adhere to its surface. This type of absorption is common to many desiccants, including silica gel.

Chemical Absorption

What sets calcium chloride apart is its ability to chemically absorb water. When calcium chloride comes into contact with water, it undergoes a chemical reaction known as hydration. During this reaction, the calcium chloride dissolves, and in the process, it absorbs a significant amount of heat. This reaction not only allows calcium chloride to absorb water but also to do so very efficiently, absorbing several times its weight in water.

The Result: Superior Moisture Absorption

The combination of physical and chemical absorption allows calcium chloride to absorb more water than many other desiccants. This makes it particularly useful in situations where high levels of moisture need to be controlled, such as in shipping containers or storage facilities.

Thank you for reading, if you need super dry desiccant, please contact Absorb King.