The packed bed cell was used in the preparation of p-aminophenol from the electrochemical reduction of nitrobenzene.The effects of current density

flow rate of catholyte

reactor thickness and temperature on electrolysis were studied.The results showed that under the conditions of 10 mm thickness of copper mesh as cathode

DSA as anode

current density 1000 A·m-2

flow rate of catholyte 4.28 cm·s-1 and temperature 85℃

current efficiency for nitrobenzene reduction was almost 100%

and selectivity of p-aminophenol could reach 83%.The catholyte could be reused five times for electrolysis

which resulted in that the lowered consumptions of sulfuric acid and ammonia approximately to 25% of the original value

and reduced discharge amounts of ammonia sulfate and effluent by 75%.Diffusion dialysis was used to recycle sulfuric acid from the spent catholyte.The results showed that under the conditions of APS as anion exchange membrane

flow rate of simulated solution 0.01 ml·min-1 and temperature 20℃

recovery of sulfuric acid was up to 61%

and transmissivities for p-aminophenol and aniline were only 1.4% and 1.6%

respectively.