In the 40's, the industrial production of cyclohexanone used phenol as raw material to hydrogenate cyclohexanol, and then dehydrogenated to cyclohexanone.
In the 1960s, with the development of petrochemicals, the cyclohexanone oxidation process for producing cyclohexanone gradually took a dominant position in the industry.
In 1967, the Dutch National Mining Company (DSM) studied the method of hydrogenation of phenol to produce cyclohexanone in one step and achieved industrialization. This method has a short production process, good product quality, and high yield, but the raw material phenol and the catalyst are expensive, so most of the industry still uses cyclohexane oxidation.
1. The phenol method uses nickel as a catalyst and hydrogenates phenol to cyclohexanol, and then uses zinc as a catalyst to dehydrogenate cyclohexanone.
2. Cyclohexane oxidation method Cyclohexane is used as raw material, without catalyst, it is oxidized to cyclohexyl hydroperoxide with oxygen-enriched air, then decomposed into cyclohexanol and cyclohexanone and alcohol in the presence of tert-butyl chromate catalyst. The ketone mixture is refined through a series of distillations to obtain a qualified product. Raw material consumption quota: Cyclohexane (99.6%) 1040 kg/t.
3. Benzene-Hydrogenation Process Benzene and hydrogen are hydrogenated in the presence of a nickel catalyst at 120-180°C to cyclohexane, and cyclohexane and air are oxidized at 150-160°C and 0.908MPa to form a ring. A mixture of hexanol and cyclohexanone separates the cyclohexanone product. Cyclohexanol is dehydrogenated at 350-400°C in the presence of zinc-calcium catalyst to cyclohexanone. Raw material consumption quota: benzene (99.5%) 1144kg/t, hydrogen (97.0%) 1108kg/t, liquid caustic (42.0%) 230kg/t.