METHOD OF CATALYTIC LIQUID-PHASE REDUCTION OF AROMATIC NITRO COMPOUNDS Russian patent published in 2001 - IPC

FIELD: chemical industry. SUBSTANCE: described is method of catalytic liquid phase reduction of aromatic nitrocompounds with hydrogen into amines; in order to reduce wear of catalyst under conditions of great flow rates (more than 1m/s), active metal includes VIII group elements (e.g. nickel, palladium) applied onto granular aluminium oxide with particle size of 20-200 mcm and bulk density of 0.6-0.3 g/cubic cm. Reduction is carried out at pressure of 0.1- 5.0 Mpa and temperature by at least 10 C lower than solvent boiling temperature. Process is carried out in closed system consisting of reaction, separation and recirculation zones. Hydrogen is fed into lower portion of reaction zone into which nitrocompound solution and catalyst recirculating in reaction products are weighted simultaneously. Recirculation is made possible due to difference of densitier of ascending gas-filled flow in reaction zone, and reaction products, in recirculation zone. EFFECT: smaller amount of catalyst and longer service life thereof. 1 tbl