TYPES OF DESICCANT
Silica gel, calcium sulfate, calcium chloride, montmorillonite clay, and molecular sieves are commonly used as desiccants.
1. Silica Gel Moisture Absorber
Some silica gel, such as colored silica gel, is dangerous for human. It is toxic and can cause cancer.
That’s why it is an obligation for any silica gel producer to put label “do not eat” on the packaging of silica gel. Silica gel should not be ingested, as it is a poisonous substance, and to ensure that the product does not get eaten, manufacturers usually place a warning on the silica gel’s plastic container.
This moisture absorber is made from sodium silicate. Its name may be misleading because this form of silica is actually solid, produced in a beaded or granular form. Silica gel has a very strong attractive effect on water molecules. The material is usually placed in a vapor-permeable plastic and placed inside airtight containers to prevent moisture from destroying the other contents.
Silica gel has a very strong absorbing quality when in room temperature. However, it may give up the water it holds when exposed to temperatures near or higher than 40 degrees Celsius. These moisture absorbers are usually only used in products that are placed in room temperature. Since silica gels are quite expensive, they are not recommended for larger areas such as basements and kitchens.
2. Clay Moisture Absorber
Clay is also popular base material for packaged desiccant, because it is quite effective in absorbing moisture and the cost of production is quite low. The down side of clay as desiccant is that clay absorbs moisture but it will release it once it gets its saturation level or when we heating it. The same feature is exit in silica gel. That’s why both clay and silica gel can be recycled by thermally induced drying, for example, in a conventional kitchen oven, or with solar energy.
Clay absorbers offer a cheap alternative to absorbing moisture in a home or in any other space where moisture leads to molds. Some homes that make use of clay bricks often do not get moldy because the moisture absorbent qualities of the clay remove the dampness that increases mold growth. There is one disadvantage to using clay absorbers, though. Its moisture absorption property is very low as compared to the other two types. For heavily humid areas, clay absorbers are not recommended. Other alternatives to clay absorbers include coal, charcoal, rocks, and rough gravel.
3. Calcium Chloride Moisture Absorber
Calcium chloride or commonly known as salt has a natural antibiotic and anti-fungal effect and is not harmful to humans when consumed in moderate quantities, hence its popular use as drying agent.
For very humid basements, kitchens, cabinets, closets, and other spaces, calcium chloride does provide effective moisture absorption. Sometimes, an electric fan can make the dehumidifying effect of the compound a lot faster and more widespread. Place the fan over a bucket of calcium chloride, and the motion of air will allow the moisture to circulate above the compound.
As an alternative, rock salt can also be used in place of calcium chloride. Although rock salt is not as powerful, it does provide an effective alternative that is both cheap and easy to access.
Perhaps the best moisture absorber is calcium chloride, a mixture of chlorine and calcium. It has a very strong moisture absorbent property that makes it an ideal candidate for high humidity moisture absorption projects. Calcium chloride is usually used in shipping goods and does a good job in keeping these goods dry during the whole duration of the trip.