The effect of temperature on the adsorption of clay

Writer： Kaiqian Oil Purifier Release time：2022-09-15 13:57 Clicks：

Decolorization effect of activated clay on transformer oil at different adsorption temperatures

When the adsorption temperature is lower than 90°C, the decolorization effect of the clay increases gradually with the increase of the adsorption temperature. When the adsorption temperature is 90°C, the decolorization effect reaches the best, and the color number of the oil can be reduced from No. 9 before treatment. After treatment No. 3, the light transmittance reached 87.76%; however, when the adsorption temperature was further increased, the decolorization effect of the clay decreased significantly. This is because the decolorization of oil by activated clay is mainly carried out by van der Waals force in a physical way, adsorbing organic matter and impurities in the oil, which can also be classified as agglomeration phenomenon.

There are three types of adsorption active centers in the clay, which provide favorable conditions for this physical adsorption method:

① Oxygen atoms on the silicon-oxygen tetrahedron;

② Coordinated water molecules with magnesium ions on the octahedron;

③ On the tetrahedron, the Si-O ion group generated by the breakage of the Si-O-Si bond.

The adsorption mainly occurred on the solid surface, and the main factors affecting the adsorption were the specific surface area of the clay and the internal diffusion of the adsorbate in the clay. 

Therefore, appropriate temperature can reduce the diffusion resistance of oil products, and can increase the diffusion degree of impurities such as colored substances and micelles in the oil to the surface and internal structure of activated clay, which is beneficial to the adsorption of colored substances in the oil by active sites in the activated clay. 

However, when the temperature is too high, due to the violent thermal motion of the molecules, the adsorbed colored substances will be desorbed, and the excessively high temperature will also aggravate the oxidation of the oil, thereby making the color of the oil darker and the light transmittance. drop back, affecting the electrical properties of the oil.