Hexane extraction process

After cleaning, crushing, cooking and drying soybeans or other oilseeds, flake seed material is soaked in hexane at a solvent plant. Proper pretreatment helps destroy the oil-bearing cells and increases the surface area of the seed, allowing the solvent to fully penetrate the material and extract more fat. During extraction, hexane flows through a sheet soybean or soybean collets bed (if the material has been expanded in an Anderson Solvex expander), rapidly dissolving the oil in the solid seed material.

The hexane extraction process produces two by-products: one is a mixture of oil and hexane, called miscella, containing about 25-35% fat, and the other is the remaining solid, saturated in a 25-30% concentration of hexane. Both by-products undergo further heating and processing to recover as much hexane as possible. The deoiled cake goes into a desolver toaster, which heats the food enough to evaporate the hexane without spoiling other nutrients. At the same time, the distillation mixture is heated with steam to vaporize the hexane, which is then recaptured and condensed for reuse while the oil is further refined, bleached and deodorized.

While most hexane is recovered from the final product, the solvent extraction process results in an average hexane loss of between 1.5 and 2 liters per ton of treated seeds. These losses usually occur in trace amounts of crude oil and meals, or through vents, hot water, or other leaks.

Why is hexane (hexane sds) used in petroleum extraction?

There are many reasons why processors rely on hexane as a solvent in the extraction process, the first being "like a dissolve". Hexane, like oil, is a non-polar hydrophobic compound, which means that they do not bind to water, so they bind well together during extraction.

Processors often prefer hexane as an extraction solvent because:

Perfect physical properties. Hexane's high evaporation rate and low boiling point make it ideal for the extraction process. It is liquid at ambient temperatures, easy to use at almost any temperature, and boils easily at 69 degrees Celsius (about 156 degrees Fahrenheit). Hexane evaporates quickly and oil can be extracted at limited energy costs.