Preparation Of New Regenerating Catalyst For Working Solution Of Hydrogen Peroxide And Analysis Of Working Liquid Components

Anthraquinone was the main measures to obtain the hydrogen peroxide.Lots of side reactions occur during the full process.Without regeneration process,with the content of 2-ethylanthraquinone and tetrahydro-2-ethylanthraquinone(EAQ and H4 EAQ effective anthraquinone)would be decreased,the content of degradation products would be increased,the physical properties of working solution would be changed,the quality of the product would be decreased and eventually resulting in a production of hydrogen peroxide would be reduced.To solve these problems,the preparation method of new regenerating catalyst for anthraquinone degradation products and the qualitative analysis method of H4 EAQ,EAQ and degradation products in working solution of hydrogen peroxide had been researched in this paper.Firstly,new regenerating catalyst for anthraquinone degradation products in working solution of hydrogen peroxide was prepared by adopting apseudo-boehmite and MgO as raw materials.The effects of the type and concentration of new regenerant kneading alkali medium,the time of hydrothermal treatment and the content of MgO on the regeneration efficiency of the regenerant had been investigated.At the same time,it was compared with original working solution of hydrogen peroxide and the working solution of factory currently by using alumina material ball regenerant.The results showed that new regenerant regeneration of kneading with 5% nitric acid solution,hydrothermal treatment time of 12 h and 10% MgO was best.The relative contents of effective anthraquinone could reached approximately 97.55%.This results also suggested that the relative contents of effective anthraquinone has increased 0.53%,0.28% respectively which compared with original working solution of hydrogen peroxide and the factory alumina ball.Secondly,a normal-phase high-performance chromatography qualitative analysis method for H4 EAQ,EAQ and degradation products in working solution of hydrogen peroxide had been established.The conditions of chromatography were Shimadzu SPD20 A liquid chromate-graphy equipped with Agilent ZORBAX SIL chromatography column,hexane-dichloro-methane-ethyl acetate as the mobile phase.This method used nitrobenzene as internal standard substance,benzene as solvent of internal standard.The area ratios of EAQ and H4 EAQ standards and the internal standard substance with the standard concentration in 30~140mg/L showed a good linear correlation coefficients above 0.9999.In the case of retention time drift and peak area change,the content of EAQ and H4 EAQ in the hydrogen peroxide working solution were measured.The relative standard deviations of quantitative results were less than 1% and the recoveries were 99~102%.As for the contents of the degradation products,using the following formula to calculate,ie.(degradation products)/(AEAQ+AH4EAQ)?(XEAQ+XH4EAQ),calculated the content of degradation products.Finally,the influence factors and solutions for retention time drift in the normal phase liquid chromatography were studied.The effects of mobile phase composition and temperature changes on the retention time drift had been investigated by single factor experiment.In the analysis process,hexane-dichloromethane-ethyl acetate and hexanedioxane as mobile phase was selected to research hydrogen peroxide working solution.It was obviously for the retention time drift when the mobile phase have contained volatile solvents components.The variety of the environment temperature and column temperature could cause significant effects on the retention time drift,when the mobile phase with volatile solvents were used.And the corresponding solutions were proposed according to the factors that affected the retention time drift.