Castor oil production:

Castor seeds generally contain 30 to 50% oil, so in order to extract as much oil as possible, mechanical pressing (also known as pre-pressing) with an oil expeller must usually be followed by solvent extraction.

Castor seeds need to go through a number of preparation stages in order to produce castor oil with a high quality product.

Drying & Hulling of castor seeds-

After the castor seeds are dried to allow the seed hull to split apart, the seeds are cleaned using seed cleanser to get rid of any unwanted foreign particles.

Cooking of castor seeds-

The castor seeds are then heated in order to remove as much moisture as possible.

Oil expelling & Decantataion of castor seeds-

The initial stage in starting to remove the oil from the seeds is mechanical extraction. While the expelled oil proceeds to the decantation process to remove the solid particles or sludge. It is a kind of filtration process for castor oil.

Solvent Extraction of Castor Cake-

The remaining cake from expeller moves to the solvent extraction process, in this hexane is used to procure even more oil from the seeds.  A filtration device, often a filter press, is used to remove obvious physical contaminants from the extracted oil before all of it is sent to a castor oil refining factory.

Castor oil refining

Now comes the most critical part of producing clean and clarified castor oil. In a refinery for castor oil, contaminants are eliminated using procedures like degumming, bleaching, and/or deodorisation. Phospholipids, excess free fatty acids, colloidal debris, and substances that give castor oil its unique colour are some of these contaminants. Refining prolongs the shelf life of the final oil produced in addition to making it more suitable for use by other businesses.

Castor Oil Degumming & Neutralizing section–

As the name implies, degumming involves removing gums from the oil. Due to the hydratable gums in castor oil, water must be added at a high temperature and allowed to sit before an aqueous layer forms and can be removed. After degumming, some castor oil refining facilities would use a neutralisation stage to remove further contaminants using substances like sodium hydroxide.

Castor oil bleaching-

After the oil has been degummed, its colour is lightened using bleaching earth and activated carbon. After being combined with earth and oil, the mixture is filtered using a vertical pressure leaf filter before being transferred to the deodorising portion. Colour, phospholipids, and oxidation products are removed through bleaching.

Castor Oil Deodorizing-

Bleached oil is passed through deodorizing section to remove the smell & fats from the oil. In this section oil is being heated under controlled condition with help of thermic fluid.