Solvent Extraction is the process used for extraction of oil from Oil Cakes of Oilseeds after primary processing in Oil Mill. It is also used for Oilseeds / Oil bearing materials with relatively lower percentage of Oil, after preparing such materials in suitable preparatory equipments like seed cracker, cooker, flakers and extruder cooker. Commonly processed Oilseeds and Oil bearing materials in Solvent extraction includes oil cakes of Groundnut, Rape / mustard seeds, Sunflower, Coconut and Castor seeds, Soybean, Cotton seed, Rice bran, Maize Germs and Safflower are processed in Solvent extraction plant, after preparing them in suitable preparatory plant.


End products from Solvent Extraction plant are Solvent Extracted Vegetable oils and Deoiled cakes. Solvent extracted Oils are further processed in Vegetable oil refineries to make them suitable for human consumption. De-oil cakes are reach source of protein, and hence it is used largely as Animal feed and manufacture of protein based products, including extruded snacks after suitable processing.

The entire process is largely divided into three main sections as follows:


A good seed preparation is very critical to good extraction. Oil seeds are first cleaned and the destoned before processing. The cleaned seeds are then cracked in cracking mills having specially designed rolls. The rolls are grooved and have surface hardness. The cracked beans are then carefully cooked and flaked in hydraulic flakers to produce uniform flakes. These flakes are then transported to the extraction plant for further processing.


The prepared material as described above is received into the extraction plant by a conveyor. The transport speed through the solvent spraying chamber can be varied easily.

This chamber contains of a number of solvent sprayer which spray a solvent over the entire bed of raw material. To view the distribution of spray, a light and sight glasses are provided

The wet meal is coming out of the spraying chamber is de- oiled material and absorbed solvent which is to be recovered in the desolventising section. The mixture of the oil and solvent called “miscella” is pumped into the miscella tank, from where it will be transported by means of special conveyor to the desolventiser. Desolventisation The wet meal content 20% to 35% solvent. The basic principle involved in desolventisation is direct and indirect heating of the wet meal with steam to a temperature well above boiling point of the solvent to ensure that no solvent is left over in the meal. Solvent vapors are sent to the condenser via a scrubber where the solvent is washed from any fines.

The de- oiled and desolventised meal is transported to the bagging section with the help of conveyor. Miscella content 12% to 18% solvent in the case of oil cake or rice bran but 25% to 35% in the case of sunflower seed, during distillation solvent evaporates first due to its lower boiling point (64 to 67 0c) leaving clean oil behind.

Distillation is performed in three stages under vacuum to ensure that no oxygen is present when the oil is heated to high temperature. Presence of oxygen will make the oil rancid. First evaporation takes place in an economizer and is followed by a Flasher leaving practically only oil behind. This oil is further treated with open steam to ensure that no solvent stays behind.

The solvent vapors thus produced passes through an oil vapor separator to separate out any oil particles trapped with the solvent vapors before passing on to a Condenser. Condensation Solvent vapors are formed both in the Desolventisation section as well as in the Distillation section and need to be condensed. Special floating head types help quickly and easy removal of tubular for periodical cleaning. In Final solvent recovery the air that is being ejected out of the system contains traces of solvent. In order to recover these traces, a special final vent air stripping column has been provided. It comprises of main Absorber to give a large contact surface. It is partly filled with Groundnut oil to absorb the solvent vapors from the air. The oil and solvent mixture is Distilled later to recover the solvent. The extracted and desolventised meal is transported to the Meal finishing section by means of a Conveyor.


Meal finishing section contains drier cooler, lumps separator, lumps breaker & bagging section.

The Dryer-Cooler (DC) will dry and cool almost any solvent-extracted, vegetable-oil- bearing meal. The drying and cooling is accomplished by injecting heated air in the drying section and using ambient- temperature air to cool the meal in the cooling section. The evenly distributed flow of hot air and cool air in a true counter-current system is highly efficient and reduces energy costs while producing a meal with the desired characteristics for sale and storage.


Manufacturers of custom fabricated agricultural process equipments and heat exchangers which include desolventiser toaster, soya bean cooker, redler conveyor, economizer, industrial condensers, drier cooler, evaporator & all other solvent extraction plant machineries.