Process Research On Synthesis And Process Design Of 2,7-Dihydroxy-9-Fluorenone

Fluorene, as a product of coal chemical industry, has the advantages of large domestic production, wide use and low price. 2,7-hydroxy-9-fluorenone, as an important derivative of fluorene, has been widely used in medicine, agriculture, dyes, plastics industry, liquid crystal material, catalyst, etc., which all show its good and broad application prospects in recent years.In this paper, synthetic methods of 2,7-dihydroxy-9-fluorenone were studied, and synthetic routes were obtained by sulfonation using concentrated sulfuric acid, oxygen oxidation, alkli fusion using sodium hydroxide, and acylation using zinc chloride. The synthetic technology was optimized to obtain the process conditions of final product yield of 65.66 % by single factor experiment. A novel method of methylene carbonylation reaction of 9-oxo-9H-fluorene-2,7-disulfonic acid dipotassium salt which used O2-H2O-KOH as catalyst system and produced less solid wastes and highly toxic waste than current production process has been proposed. Also, an improved acylation process has been proposed which increased the yield and purity of the product of acylation reaction. The single factor process optimization experiment results are as follows:1. The optimum process conditions of sulfonation were as follows: 1)The ratio of reactants was n(I):n(H2SO4)=1:7; 2) The sulfonation reaction temperature was 100 ?; 3) The fluorene sulfonation reaction time was 10 min. The yield of sulfonation process was 88.78%;2. Through the better oxidation of fluorene salt containing methylene by oxygen in alkaline liquor, the optimum process conditions of oxidation were as follows: 1) The catalytic system was H2O-KOH-O2; 2) The amount of catalyst was 20 %; 3) The reaction temperature was 80 ?; 4) The reaction time was 16 h. The yield of oxidation process was 91.25 %;3. The optimum process conditions of alkali fusion were as follows: 1) The reaction time was 5 min; 2) The ratio of reactants was n(?):n(NaOH)=1:20. The yield of alkali fusion process was 90.10 %;4. The optimum process conditions of acylation were as follows: 1) Lewis acid catalyst was ZnCl2; 2) The amount of catalyst was n(ZnCl2):n(?)=3:1; 3) The reaction temperature was 200 ?; 4) The reaction time was 30 min. The acylate obtained by this process conditions had such advantages as high yield(89.95 %), high purity(99.32 %), less catalyst amount, lower production costs.Based on the above process conditions, industrial production flow diagram of 2,7-hydroxy-9-fluorenone was designed. By amplification of laboratory scale test, material balance calculation, energy balance calculation, and equipment selection and design were carried out, the material flow diagram and process flow diagram were drawn, and also the workshop plane and elevation layout design, economic accounting and preliminary design scheme of “three wastes” treatment were carried out.