Device and method for production of o-chloroaniline through continuous catalytic hydrogenation reduction of o-nitro chloro benzene

Abstract

The invention discloses a device and method for production of o-chloroaniline through continuous catalytic hydrogenation reduction of o-nitro chloro benzene. The method comprises the following steps: o-nitro chloro benzene, a catalyst and a dechlorination inhibitor are put into a hydrogenation reactor, and bottom materials are distributed well; nitrogen and hydrogen are sequentially used for displacing a system completely; a feed valve is opened, the o-nitro chloro benzene and the dechlorination inhibitor are continuously fed into the hydrogenation reactor, wherein the mass ratio of the o-nitro chloro benzene to the catalyst to the dechlorination inhibitor is 1:(0.001-0.005):(0.001-0.005); hydrogen is fed into the hydrogenation reactor for hydrogenation reaction, wherein the reaction temperature is 60-100 DEG C and the pressure is 0.5-1.5 MPa; hydrogenated liquid enters a heat exchanger firstly through a circulating pump and then passes through a cross-flow filter; the catalyst and part of hydrogenated liquid as well as fresh raw materials together enter an ejector for circulation, and the other part of the hydrogenated liquid is extracted out continuously, and o-chloroaniline is obtained after treatment. The device and the method disclosed by the invention have advantages that the production cycle is short, the catalyst selectivity is high, the dechlorination rate is low, the yield is high, the quality is stable, the equipment efficiency is high and continuous production is realized.

Description

technical field [0001] The invention relates to an o-chloroaniline production device and method, in particular to a device and method for producing o-chloroaniline through continuous catalytic hydrogenation reduction of o-nitrochlorobenzene. Background technique [0002] O-chloroaniline is an important organic chemical intermediate, widely used in polyurethane, pesticide, medicine and dye industries. O-chloroaniline is produced by reduction of o-nitrochlorobenzene. Traditional reduction methods include iron powder reduction, alkali sulfide reduction, electrolytic reduction and catalytic hydrogenation reduction. Due to heavy pollution and high energy consumption, the iron powder reduction method and the alkali sulfide reduction method have been included in the list of eliminated processes in my country; the electrolytic reduction method has a large investment in equipment and high energy consumption; the catalytic hydrogenation reduction method has a short process flow and lo...

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Problems solved by technology

The method has poor catalyst selectivity, high dechlorination rate, poor product yield, large consumption of catalyst and dechlorination inhibitor, need to recycle dechlorination inhibitor and solvent, and inconvenient catalyst regeneration and replacement

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