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Aminophenol is important fine chemical raw materials and pharmaceutical intermediates , mainly used in medicine , rubber , dyes and photosensitive materials industries . Medicine high product purity requirements aminophenol nitrobenzene electrolysis can be used to produce high purity aminophenol . Nitrobenzene electrolytic reaction will generate the intermediate hydroxy - aniline, hydroxyaniline can be transferred to the rearrangement to p-aminophenol, it is also possible on the electrode further reduction generated aniline solution . In order to improve the selectivity of the aminophenol , the paper examines the different acid catalyzed rearrangement reaction effect . Reduction of nitrobenzene with zinc powder to prepare hydroxyaniline temperature at 62 ℃ -66 ℃, the reaction 60min , resulting hydroxyaniline yield is the highest, reaching 74.49% . A neutral aqueous solution , the ion exchange resin has a good catalytic effect . Temperature of 80 ° C under acidic conditions , the optimal reaction conditions : H concentration 0.5mol/L-2mol/L reaction time of 15min using phosphoric acid , inorganic acid . Cyclic voltammetry scan found celite , sulfuric acid, zirconium oxide , the beta zeolite having a more significant catalytic effect . Hydroxyaniline in hydrochloric acid will generate the p-chloroaniline , Cl - concentration of 0.3mol / L , and p-aminophenol can maintain the selectivity of 80% . An anode chamber and a cathode chamber , respectively, using hydrochloric acid and sulfuric acid as an electrolyte, separated using cationic membranes chlorine evolution , can be realized , and to extend the lifetime of the electrode . The CMV membrane investigated the Cl - < / sup > through the cation exchange membrane behavior : 60 ℃ 5% hydrochloric acid 10h through spread to the other side of the Cl - concentration of only 0.14 mol / L, then Cl - diffusion coefficient of 1.54 × 10 -6 cm 2 / s , the diffusion coefficient of the CMV membrane approximately 10 -7 cm 2 / s. Product separation , adjusting the acidity to pH = 4.5 , p-chloro aniline and aniline is separated from the system , to increase the pH = 6.5 , to achieve separation of p-aminophenol . The vacuum distillation separation of aniline and chloroaniline , aniline purity of 98 % . The the diffusion dialysis recovery of sulfuric acid electrolyte electrolysis process . APS the AHT and AAV the acid recovery effect of the three films , the flow of acid recoveries effect of 0.003ml/min when APS film the best, can reach 68% . PAP and AN content in the recovered acid obtained in less than 1g / L , the sulfuric acid can be to achieve recycling.
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