New process for synthesizing nylon raw materials from phenol hydrogenation

The Japan Institute of Advanced Industrial Science and Technology (hereinafter referred to as "Synergy Research Institute) Supercritical Fluid Research Center has successfully developed supercritical carbon dioxide and antimony catalysts to efficiently synthesize nylon raw materials such as cyclohexanol and cyclohexanone from phenol with high efficiency. At present, cyclohexanol and cyclohexanone are produced. In addition to hydrogenation of phenol, partial oxidation of benzene gives rise to cyclohexene re-derivatization, or cyclohexane air oxidation and other methods. However, because the new synthesis method does not use organic solvents and the reaction conditions are mild, there is a characteristic that the catalyst is not aged, and carbon dioxide is easily recycled and used, which greatly reduces the environmental load.
The new process developed by ZTE employs supercritical CO2 extraction solvent at 55°C, hydrogenation of phenol under the control of a supported ruthenium catalyst, 100% conversion of phenol to KA oil (cyclohexanol, cyclohexanone mixture). As the pressure of carbon dioxide and hydrogen changes, the composition ratio of cyclohexanol to cyclohexanone can be freely controlled.
The process of obtaining cyclohexanol by phenol hydrogenation has the disadvantage that the reaction temperature is 130-180° C., and the surface area of ​​the palladium catalyst is carbon, which inevitably results in a decrease in the activity of the catalyst and a shortened lifetime. In contrast, when the new synthesis method is reacted at 55° C., the reaction temperature is greatly reduced, and even if the catalyst is continuously operated for a long period of time, the catalyst activity does not decrease, and the catalyst can be repeatedly used to greatly increase the catalyst life. In addition to significantly lowering the reaction temperature to save energy, organic solvents are not used, and supercritical carbon dioxide is easily recovered in the gaseous state. This process is environmentally friendly.