IMPROVED METHOD OF PRODUCING METHYL ETHER OF FATTY ACID (BIODIESEL) VIA REESTERIFICATION OF OIL TRIGLYCERIDES Russian patent published in 2010 - IPC C10L1/02 C11C3/10 C07C67/03 

FIELD: chemistry.

SUBSTANCE: method of producing methyl ether of fatty acid (biodiesel) from oil, containing triglycerides and obtained from plants involves: (i) squeezing out oil from seeds and separation of the residue for use as manure, (ii) neutralisation with an alkali of the excess free fatty acid contained in the oil, and separation of the soap residue, (iii) addition of an antioxidant and blowing the oil with dry air to reduce water content, (iv) treatment of the oil with the respective amount of methanol solution of KOH, dried over anhydrous sodium sulphate, (v) separation of the glycerin layer formed during the reaction, (vi) treating the methyl ether of fatty acid with glycerin in two steps to further reduce content of methanol, catalyst and other impurities in the layer of methyl ether of fatty acid, (vii) separation of glycerin, (viii) washing the layer of methyl ether of fatty acid with water in two steps to minimise content of impurities, (ix) separation of washing water, (x) addition of an additional amount of antioxidant to the methyl ether of fatty acid and with blowing dry air to minimise water content, (xi) combination of the glycerin layers and treatment with SO_x or flue gas to convert spent KOH catalyst to K₂SO₄ or K₂CO₃ respectively, (xii) setting the pH to approximately 7 and distillation of methanol from the glycerin layer, (xiii) hot centrifuging the remaining mass to separate potassium salts from glycerin, (xiv) washing the salt to remove impurities, (xv) separation of the required amount of crude glycerin for washing the layer of methyl ether of fatty acid in the next portion as well as for other uses where crude glycerin is used, and (xvi) distillation of the remaining crude glycerin with low content of water to obtain pure glycerin.

EFFECT: obtaining biodiesel which meets international standards with high output.

21 cl, 18 ex