Vegetable Oil Ghee Refinery and Pollution Sources

Crude triglyceride oils and fats from a wide range of vegetable or animal sources undergo a refining process in order to remove contaminants which may negatively impact the appearance, taste or stability of the final product. Such contaminants include free fatty acids, trace metals, phosholipids, color bodies and oxidation products.

The edible oil refinery process involves several steps

Adsorbent treatment

An adsorbent material is added to the oil to remove contaminants. The mixture is agitated and then filtered to remove the spent adsorbent.


The oil is treated with a clay-based adsorbent called bleaching earth or bleaching clay to remove color bodies and other contaminants. Bleaching earth clay removes the color of crude oil for good looking cooking oil or vegetable ghee.

Chemical refining

The oil is treated with caustic soda to remove free fatty acids and other impurities. The soap and phospholipid contaminants are then separated from the oil phase by centrifugation. This method is used for removal of fats by centrifugation process. After this the process oil is feed to washing tanks.


The oil is washed with water to remove any remaining impurities. For the removal of impurities by physical methods are as washing of foreign or unwanted particles.


The oil is treated with an adsorbent to remove any remaining color bodies and impurities. The earth clay is used for this purpose for the better look of oil as yellow and red color color of oil is analysed on LoviBond Tinto meter. Yellow and red color are settled as 1.8 yellow and 2.5 red color.


The oil is heated to remove any remaining impurities and improve its flavor and aroma. The method is used to remove free Fatty acids by applying vacuum as soap or fats. In this step odor and remaining fats are removed by low pressure vacuum.

The edible oil refinery process generates various environmental pollutants, including


The process generates large amounts of wastewater, which can contain high levels of oil, grease, and other pollutants. Their should be a wastewater treatment plant or oil recovery plant to remove oil from wastewater.

Solid waste

The process generates solid waste, including spent adsorbents, filter cakes, and other materials. Waste material should always be disposed to incineration service provider, or reused.

Air emissions

The process generates air emissions, including particulate matter, sulfur dioxide, and nitrogen oxides. By product carbon dioxide is wasted in atmosphere that increase the amount GHGs in atmosphere and increases the temperature. The carbon dioxide can be absorbed in water and used for pH of waste water treatment.


The process uses various chemicals, including caustic soda, acid, and bleaching agents, which can be harmful to the environment if not handled and disposed of properly. All these chemicals should always be incinerated by industry or given to incineration facility.

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