Uses of Silica Gel

Here we can discuss about the uses of silica gel in Edible Oil Refining. Silica gel is an adsorbent. Adsorbent means a substance that can adsorb another substance. Adsorption is a phenomena that the adhesion of atoms, ions or molecules from liquid, solid, or gas to a surface.

To remove contaminants from the oil, an important step in the refining process involves the use of an adsorbent material. Here as an adsorbent we can use silica gel or silica hydrogel. Adsorption process creates a layer of the adsorbate on the surface of the adsorbent. Adsorption is different from absorption.

The adsorbent agent silica gel is added into the oil as a free-flowing powder. To allow the contaminants to be adsorbed by the surface of the adsorbent particles, this mixture is agitated at the required temperature for a period of time necessary. When the contaminants are surfaced to the surface of the adsorbent particles, the mixture is filtered to remove the spent adsorbent.

Desiccants are a type of absorbents. Generally, the step of adsorbent treatment in edible oil processing is referred to as Bleaching. It involves treatment of the oil with a clay-based adsorbent called bleaching earth or bleaching clay.

As the name suggests, the main function of the bleaching step is to filter color bodies from the oil, for example chlorophyll and carotene. Like desiccants, the bleaching step is responsible for removal of a number of other contaminants including trace levels of phospholipids, metals and oxidation products, together with soaps which are generated upstream in the refining process.

Silica gel desiccants are widely using as an absorbent to avoid moisture damages. For commercial purposes, it is a good substance. Its not harmful to other substances as it is an inactive agent to others.