Preparation methods are isopropyl alcohol and acetone.
(1) Isopropanol method Isopropanol is used as a raw material, and is passed through an aluminum-copper catalyst at atmospheric pressure and a temperature of 180 to 220° C. to dehydrogenate isopropyl alcohol to acetone and then dehydrate with isopropanol to obtain a product.
(2) Acetone method Acetone is heated and the vapor is passed through a sodium hydroxide catalyst and reacted under normal pressure to obtain bipropanol ketone. Dipropanolone was dehydrated in the presence of a phosphoric acid catalyst to obtain isopropenylacetone, and isopropenylacetone was catalytically hydrogenated in the presence of a copper catalyst. The temperature was 170-200°C to obtain a product.
Purification method: 4-methyl-2-pentanone is prepared by hydrogenation of isopropylideneacetone solution, and thus contains impurities such as water, isopropylideneacetone, 4-methyl-2-pentanol, and acidic substances. . The refining method can be referred to the butanone refining method. It can also be refluxed with a small amount of potassium permanganate, washed with aqueous sodium bicarbonate solution, dried over anhydrous calcium sulfate and then distilled. Acidic impurities can be removed by a column containing a small amount of activated alumina.
(3) Acetone is heated and vaporized, and the reaction is carried out at 20°C and atmospheric pressure under the catalysis of sodium hydroxide. When the temperature rises to ,
After the reaction is completed, diacetone alcohol is obtained. Under the action of phosphoric acid, diacetone alcohol is dehydrated to obtain isopropylideneacetone. After gasification, the mixture is mixed with hydrogen and then fed into the reactor. Under copper catalysis, the temperature is 170-200° C. and 0.3- The hydrogenation reaction is carried out at 1 MPa and then distilled to collect 115.5 to 116.5°C distillate (atmospheric pressure), which is a finished product, and the final product is obtained by vacuum distillation using 2666 to 6665 Pa.