What is a desiccant and what is its moisture absorption principle?

Desiccant is a dehumidifier that absorbs moisture from the atmosphere. Its drying principle is to physically adsorb water molecules into its own structure or chemically absorb water molecules and change its chemical structure to another substance.

What are the main types of desiccant?

There are many types of desiccant. Currently, there are three typical desiccant products in the desiccant industry: silica gel, clay (montmorillonite) and molecular sieves.

1) Silica gel desiccant - the main component is silicon dioxide, which is purified and processed from natural minerals into granular or beaded form. As a desiccant, its microporous structure (average 2A.) has a good affinity for water molecules. The most suitable moisture absorption environment for silica gel is room temperature (20~32) and high humidity (60~90%), which can reduce the relative humidity of the environment to about 40%.

2) Mineral desiccant - the appearance is a gray ball, which is most suitable for moisture absorption in an environment below 50℃. When the temperature is higher than 50℃, the degree of 'water release' of clay is greater than the degree of 'water absorption'. But the advantage of clay is that it is cheap.

3) Molecular sieve desiccant - It is a synthetic desiccant product with strong adsorption to water molecules. The pore size of the molecular sieve can be controlled by different processing techniques. In addition to adsorbing water vapor, it can also adsorb other gases. Under high temperatures above 230°C, it can still accommodate water molecules well. Advantages: strong adaptability. Disadvantages: low moisture absorption rate, poor environmental protection (non-degradable).