(1) The surface adsorption of the adsorbent
Adsorption is mainly owe to the surface free energy of the adsorbent with accidented surface. After a good contact with oil and adsorbent, pigment will be adsorpted, and eventually to reach adsorption balance. The temperature is high when decolorizing, fast adsorption, achieve the adsorption equilibrium time is short. Due to the adsorption is exothermic process, temperature is too high, the adsorption amount was worse instead.
(2) Pressure filtration decoloring
After the pigment and adsorbent reaching the adsorption equilibrium, then use pressure filter to separate the slurry. When oil through a filter inside the adsorbent layer, adsorbent for oil is a high effective concentration, the concentration effect caused a new balance between decoloring agent and pigment. Namely, in the process of pressure filtration, oil can be further decoloring.
(3) A chemical reaction
In the process of bleaching, the adsorption activity not only on the white surface, but also in chemical reactions. Under the condition of vacuum, the oil oxidation products of decomposition, dehydration. Also called false neutralization, and that will lower the oil peroxide value obviously.
