The main methods used in the industry to prepare Eugenol Natural are isolation and chemical synthesis from natural essential oils. However, the isomers produced by chemical synthesis have very close boiling points and are extremely difficult to separate. In actual production, the isolation method is the main method. The natural essential oil isolation method uses the perennial subshrub clove basil as raw material, and the mixture of essential oil and water is obtained through steam distillation. Add 20% sodium hydroxide to the oil-water mixture, and then carry out steam distillation to remove non-acidic substances.
Add 30% sulfuric acid to the obtained sodium eugenol solution at 50°C and stir to neutralize to Ph=2~3 (water layer). After standing still, the crude clove oil in the lower layer was separated, and the finished product of eugenol was obtained by distillation under reduced pressure. Or use clove oil and other essential oils containing a large amount of eugenol, add 30% sodium hydroxide solution, add inorganic acid or pass in carbon dioxide gas to make it precipitate. Or add it with sodium acetate to free it and then distill it to obtain pure product.
A method for preparing eugenol from Eugenol, characterized in that:
(1), will be pulverized to 5-10 purpose clove raw material, add the extraction solvent of 10 times amount in extractor, temperature is controlled at 75-90 ℃, stirring and extracting 3 hours, totally 3 times;
(2), merging the extracts, after decompression and vacuum concentration and recovery of the solvent, dark brown clove oil is obtained;
(3), add 5 times the alkaline aqueous solution of content 3-15% in clove oil, after constant temperature 65-85 ℃ of stirring for 3 hours, leave standstill layering, remove alkali aqueous phase oil layer and collect for subsequent use;
(4), alkaline water layer adds the activated clay of total volume 5%, after stirring 30 minutes, filter and separate activated clay, add acidic solvent gradually in the filtrate, adjust pH value 6-7, eugenol separates out in the solution, and the lower floor is Eugenol oil layer;
(5), the collected eugenol oil layer is washed with deionized water, the washed eugenol is distilled, and the collected distillate is slightly yellowish, which is pure eugenol oil product;
(6) The eugenol oil product is dehydrated and dried to obtain a slightly yellowish Eugenol Natural product.