Study On The Catalytic Synthesis Of 2-amylanthraquinone Over Solid Acid

Alkyl anthraquinone is important chemical intermediates,and it is the main building block for the synthesis of anthraquinone dyes,also used as catalyst for the synthesis of hydrogen peroxide,which has an important position in national economy with great industrial value.2-amylanthraquinone?2-AAQ?,with high stability,good compatibility of the work fluid,and high catalytic efficiency,shows better performance.2-AAQ is also the main intermediates for the synthesis of pure hydrogen peroxide?H₂O₂?,degradable resin,dye and photographic compounds.The traditional process of 2-AAQ is to catalyze diamylbenzene and o-Phthalic anhydride over AlCl₃ for synthesizing intermediate 2-?4'-pentyl-benzoyl?benzoic acid?ABB?by Friedel-Crafts acylation reaction.ABB is catalyzed with concentrated sulfuric acid or fuming sulfuric acid and to synthesize 2-AAQ in the cyclodehydration reaction.This process produces a large amount of waste acid,not only corroding the equipment but also polluting the environment.Thus,developing a new green synthesing route of 2-AAQ has found a wide application prospect.This paper uses environmental-friendly solid acid catalysts-zeolite molecular sieve as a substitute for AlCl₃ to produce 2-AAQ by catalyzing ABB in the cyclodehydration reaction.By selecting different types of solid acid catalyst catalytic property H-Beta zeolite molecular sieves,it shows a better performance for reaction.Though modifying and improving the process conditions,the selectivity of 2-AAQ is up to 99.2%,the conversion rate of ABB reaches 98.5%.All the above solve such problems that the catalyst cannot be re-used,and that catalyst and product is difficult to separate after reaction.In addition,an attempt is made to use the immobilized catalyst instead of the traditional Lewis acid catalyst to castalyze diamylbenzene and o-Phthalic anhydride in an acylation reaction for synthesis of ABB.The result shows that yield rate of ABB is low,the process has yet to be further optimized.The specific work is as follows:1.Using cheap diatomite as silicon and aluminum sources,the catalyst Beta zeolite molecular sieve is synthesized in a hydrothermal reaction.A study is about the influence of gel composition,the amount of H2 O,crystallizing time,crystallizing temperature on Beta zeolite,which is applied as catalyst to catalyze ABB in the cyclodehydration reaction to synthesize 2-AAQ.2.By comparing properties of such solid acid catalysts as HY,HZSM-5,Hbeta,phosphotungstic acid,phosphomolybdic acid,montmorillonite,the result suggests the better catalystic performance of Hbeta zeolite in the cyclodehydration process to synthesize 2-AAQ with the conversion rate ABB and the selectivity of 2-AAQ better than the other solid acid catalysts.3.The catalytic effect of using the modified H-Beta zeolite molecular sieve used as catalyst by organic acid?citric acid?to catalyze ABB in the cyclodehydration reaction to synthesize 2-AAQ is better than that of using CeCl₃·7H₂O or ZrOCl₂·8H₂O.The catalytic performance of H-Beta molecular sieve modified by citric acid is influenced by ion exchange number of times.Along with the increase in the times of ion exchange,the total volume of acid is reduced,the relative content of weak acid is decreased,the relative content of strong acid is increased,and catalytic performance is improved,with two times of the ion exchange being the best effect.Through the single factor experiment process,the optimal reaction process conditions are: the amount of the catalyst used is 28.6% of the raw material,reaction temperature is 280?,reaction time is 1.5 hrs.The area normalization method of high performance liquid chromatography?HPLC?is used to calculate the conversion rate,which reaches 98.5%,and the selectivity of 2-AAQ,which is up to 99.2%.4.The activity and stability of the catalyst test show that the catalytic effect significantly declines after the catalyst is used for three times.After the catalyst is roasted and regenerated by high temperature,the conversion rate of ABB reaches 97.7%,and the selectivity of 2-AAQ reaches over 84.3%.5.The modified Beta zeolite molecular sieve is characterized by XRD,SEM,TG,IR,NH3-TPD and BET.6.The intermediate ABB was obtained by water washing and acid pickling process,and 2-AAQ is separated by column chromatography isolation.Furthermore,the intermediate ABB and target product of 2-AAQ were determined by IR,1H NMR and 13 C NMR...