Process for recovery of high-grade lecithin and solvents from ternary solvent system containing crude vegetable oil

摘要

A method of recovering a high-grade lecithin and solvents from an oil- bearing full miscella which also contains lecithin and which results from an oilseed ternary solvent extraction process. The method may include a first step of phase separation of the oil-bearing miscella containing lecithin and the ternary solvents into a polar and a non-polar phase, and a second step of azeotropic distillation of the non-polar phase to recover a portion of the solvents, and to remove substantially all the water from the residual crude oil, thereby keeping the lecithin in solution. A commercial grade lecithin having good water dispersibility is subsequently recovered from the residual crude oil, and a small amount of highly water dispersible lecithin may be recovered from the polar phase by atmospheric distillation.P PIn another embodiment, when the full miscella containing crude oil ternary solvent and lecithin resulting from the above ternary solvent extraction is initially subjected to azeotropic distillation to recover solvent therefrom and remove substantially all the water, a highly water dispersible lecithin having a high choline chloride content is obtained. Premature degumming of this highly water dispersible lecithin is avoided by maintaining the solvent ratios above certain minimums.PPThe ternary solvents for the oilseed extraction include a lipophilic hydrocarbon, such as hexane; a water miscible lower alcohol, such as ethanol; and a minor amount of water. The recovery method is energy efficient, because the boiling temperature of the ternary azeotrope is lower than any other combination of the three solvents.