Preparation of 2-Methyl-2,4-pentanediol

2-Methyl-2,4-pentanediol (MPD), isohexanediol, is a colorless, transparent, slightly viscous liquid with a slightly fresh and sweet smell. As a fine chemical product with a wide range of uses, isohexanediol is widely used in the fields of building materials, cosmetics, textiles, pesticides, coatings, biochemical engineering, organic synthesis, etc. It is mainly used as a solvent, coupling agent, emulsifier, penetrant, and stabilizer etc.

Preparation

Mix 10.0g of nickel nitrate and 1.0g of cobalt nitrate with 150ml of deionized water and 10.0g of white carbon black to prepare a mixed solution; take a certain amount of concentrated ammonia at room temperature and add dropwise to the above mixed solution until the pH is 12.0; stir at room temperature Treat the mixed solution for 10 hours; then heat up to 100°C at a rate of 1°C/min and stir for 2 hours; filter and wash the resulting solid product, and then dry it at 100°C for 24 hours; then transfer to a muffle furnace and calcine at 600°C After 8 hours, the catalyst was Ni-Co/SiO2.

Take 1.0 g (about 2 ml) of the above Ni-Co/SiO2 catalyst and put it into a fixed bed reactor. Before use, it undergoes an in-situ reduction and activation treatment, and the conditions of the reduction and activation treatment are a temperature of 450° C., a pressure of 0.3 MPa, a hydrogen volumetric space velocity of 1000 h-1, and a treatment time of 12 h. When the temperature in the reactor naturally drops to 120°C, the pressure is increased to 2.0 MPa, and the system is waited for stability. Inject diacetone alcohol into the mixer through a high-pressure pump to fully mix with hydrogen, adjust the liquid volumetric space velocity of diacetone alcohol to 0.5 diacetone alcohol g/catalyst·g·h, and control the H2 flow rate in the reaction system at 50 mL/min. For the reaction, the reaction time was 60 hours, and samples were taken from the collecting tank and analyzed by gas chromatography. In the hydrogenation reaction of diacetone alcohol, the conversion rate of diacetone alcohol was 99.8%, and the selectivity of isohexanediol was 98.8%.