Pyromellitic Acid → 1,2,4,5-Cyclohexanetetracarboxylic Acid

Participants

Reaction Conditions

Reaction Steps

22.08 kg (86.88 mol) of pyromellitic acid, 8 kg of a catalyst containing rhodium supported on activated carbon (produced by N.E. Chemcat Corporation) and 80 kg of water were charged in a reactor made of Hastelloy (HC22) having a capacity of 200 L, and the interior of the reactor was replaced by nitrogen gas under stirring. The interior of the reactor was then replaced by hydrogen gas, and the temperature was increased to 50° C. under a hydrogen pressure in the reactor of 3.3 MPa. The reaction was performed for 2 hours while maintaining the hydrogen pressure to 3.3 MPa. The hydrogen gas in the reactor was replaced by nitrogen gas, the reaction liquid was taken out from the autoclave, and the reaction liquid was filtered in a hot state to separate the catalyst. The filtrate was concentrated by evaporating water under reduced pressure with a rotary evaporator to deposit crystals. The crystals thus deposited were separated by solid-liquid separation at room temperature and dried to provide 19.24 kg (73.94 mol, yield: 85.1%) of 1,2,4,5-cyclohexanetetracarboxylic acid.

Provenance & Evidence