公开(公告)号：US20210179527A1

公开(公告)日：2021-06-17

申请号：US17123004

申请日：2020-12-15

申请人： Evonik Fibres GmbH

发明人： Harald RÖGL

IPC分类号： C07C51/275 ,  C07C51/43 ,  C01B21/40 ,  B01J3/02 ,  B01J19/00

摘要： In a method for oxidizing 1,1-bis-(3,4-dimethylphenyl)-alkane with nitric acid in a pressure vessel to produce 3,3′,4,4′-benzophenone tetracarboxylic acid with concurrent formation of nitric oxide, passing nitric oxide from the pressure vessel into an absorption vessel and reacting nitric oxide in the absorption vessel with molecular oxygen and water to produce an aqueous nitric acid solution prevents discharge of nitric oxide, avoids the risk of oxygen inhibiting the nitric acid oxidation and reduces nitric acid consumption when the nitric acid from the absorption vessel is used for oxidizing the 1,1-bis-(3,4-dimethylphenyl)-alkane.