Nitro Toluene Catalytic Hydrogenation Toluidine Process

M-toluidine is an organic chemical raw material and intermediate,which can be widely used as medicines,dye products and other chemical industries.In this paper,gas phase catalytic hydrogenation technology to the preparation of m-toluidine from m-nitrotoluene was studied.In the gas phase catalytic hydrogenation of m-nitrotoluene,the fixed-bed reactor was used as the reaction device.Two different particle size of Cu/SiO₂ catalyst was prepared.The effect of different contents of copper and supports, such as Ni,Co and Cr in Cu/SiO₂ catalyst was examined.It has been found the optimum catalyst was composed of 20%of copper and 0.8%Cr in the larger particle size of silica.And then we study the technological conditions of gas phase catalytic hydrogenation,The better technological conditions was obtained by orthogonal experiment.The optimum technology was as follows,under of 0.1Mpa,activation temperature 240℃,reaction temperature 270℃, oil-hydrogen ratio 11:1,LHSV 1.0 mL/h·mL-cat,conversion of m-nitrotoluene was 98.5%.The structure of the synthetic products were characterized by Infrared Spectroscopy(IR), GC-MS and 1H NMR.The structure and performance indexes of the products conformed to the design requirement.Based on the small pilot study,pilot enlarge which including production program, technology program,selection and calculation of equipmen had been accomplished.In the end,economic analysis about pilot enlarge manufacture was calculated.