METHOD OF LIQUID-PHASE REDUCTION OF AROMATIC NITROCOMPOUNDS IN REACTOR WITH RIGID CELLULAR CATALYST Russian patent published in 2001 - IPC

FIELD: manufacture of polyurethanes and other polymeric materials and also dyes and medicinal compounds. SUBSTANCE: method comprises reducing nitrocompounds with hydrogen which is dispersed in liquid phase including organic solvent and nitrocompounds and reaction products dissolved therein, in closed reaction system with continuously recycling stream of reaction mixture created without using pump due to difference in densities in descending gas-liquid stream passing through reaction zone and in descending stream (recycling zone). Some product is taken off in the form of solution from separation zone and larger portion of reaction mixture is directed from separation zone into lower part of reaction column into which solution of nitrocompounds is simultaneously admitted. In this case all of reaction zone is filled throughout entire volume with rigid catalyst elements with porosity of at least 35% made of porous aluminium oxide-based material onto surface of which group VII metal is applied. Reducing is carried out at pressure of 0.1-5 MPa and at temperature which should be by at least 10 C lower than boiling temperature of solvent at process pressure. Method makes it possible to increase period of activity of catalyst and to eliminate losses thereof without deterioration of quality of the resulting product. EFFECT: more efficient liquid-phase reducing method.