Products

SOLVENT EXTRACTION PROCESS

Solvent extraction is a common form of chemical extraction using solvent to extract the residual oil from oil bearing seeds & cakes. Vegetable oil has been the main source of fat for human consumption. Most edible oils & fats are soluble in liquid hydrocarbons and hexane is commonly used hydrocarbon fraction for solvent extraction.

Nowdays solvent extraction plants commonly used worldwide due to less maintenance and low power consumption. The main objective of the process is to reduce hexane losses during the oil extraction process and to separate hexane and oil from Miscella.

Preparatory section is mandatory for solvent extraction plant for most of the oil bearing seeds & pressed cakes to make it free from foreign particles ,controlled sizes and moisture level.

EXTRACTION PLANT

The flakes received from the preparatory section will be transferred to the extractor by chain conveyor. Rotary valve is incorporated to regulate the flow of feed material to the extractor to avoid the entrance of the air in the system equipped with a level controller regulating the raw material level in feed hopper.

Horizontal type extractor with contact parts in SS304 construction with a band conveyor chain system. In the extractor, the fresh hexane will be pumped into these flakes/processed cakes to extract the oil. The oil called miscella means oil and hexane mixed together where miscella contains About 60% of hexane. To separate oil and hexane , this miscella will go through another process in distillation plant. After the oils were extracted from the flakes/pressed cakes,the by products from the second compartment will be produced.

This by product contains around 40%of hexane,to separate meal and hexane these by products will be sent to another plant Meal-desolventizing.

Salient Features

1.  Spray system to control flooding in extraction

2.  Automatic mesh cleaning system to avoid choking

3.  Loss power consumption

4.  Better quality oil and by product.

MISCELLA DISTILLATION

Distillation is the process to separate the Miscella into oil and solvent mixture. In this plant the miscella will be heated up in 3 different stages and temperature till capture all the hot hexane vapours and thin hot vapours will be vacuumed to different condensors to cool it and regain the hexane in liquid form and will be re-used.

The concentrated miscella is pumped to first evaporator where it is charged to tube side & heated by steam is shell side. By the use of indirect steam heating the miscella concentration will be increased to 90-95% and then pumped to stripping Column. Where by an addition of stripping steam &indirect heating the remaining hexane is removed. That’s all done under vacuum thus exposing solvent on surface for removal of oil from the stripper and transferred to oil holding tank.

HEXANE RECOVERY

There are still some traces of hexane present in the air by the medium of leakages in the extractor like hopper, seals, pump drive etc. This hexane also has to be recovered from air by the means of Recuperation/ Absorption system.

Air goes to absorption tower → Mineral oil absorbs hexane → heated mineral oil to 90-100⁰c → absorbed hexane in desorption tower→ recirculated to extractor.