Study On Catalyst For Synthesis Of 2-methyl Anthraquinone By Phthalic Anhydride

2-methyl anthraquinone is a very important chemical intermediates,not only be used in dye synthesis and papermaking,but also be widely used in medicine,pesticides and many other aspects.In the traditional synthesis process of 2-methyl anthraquinone from phthalic anhydride,used a lot of aluminum trichloride and concentrated sulfuric acid,aluminum chloride can not be recycled,will form a lot of waste water and waste.Zeolite molecular sieve is a substitute for traditional acylation reagent catalyst,with adjustable acidity and can be recycled.In this experiment,screening zeolite molecular sieve and modified it to prepare a catalyst with good catalytic performance and recyclable.HZSM-5,Hβ,HMOR,HY,HZSM-35 and MCM-49 were screened in high pressure reactor,and the catalytic performance of Hβ zeolite was better.The catalytic performance of Hβ zeolite modified by alkaline earth metal was investigated by using alkaline earth metal modified Hβ zeolite molecular sieves and calcined at five different temperatures.The catalytic performance of Hβ molecular sieves modified by alkaline earth metal was investigated.The molecular sieve is poor,the amount of acid is reduced and the decrease of specific surface area is the main reason for the decrease of catalytic performance.The catalytic properties of the transition metals were silver,cobalt,chromium,zinc,iron,copper and zirconium at different temperatures by a series of transition metal modified Hβ molecular sieves.Compared with copper,other metal modified Hβ zeolites have better catalytic performance.Among them,the catalytic effect of chromium modified Hβzeolite is the best,the conversion rate of the catalyst is 17.34%,Selectivity was 93.68%.In the characterization of molecular sieves,it was found that the catalytic performance was positively correlated with the amount of acid and acid,and the content of weak acid was not found directly.The catalytic properties of the transition metal modified Hβmolecular sieves are related to the specific elements,and the overall law of the modification of the molecular sieves is not found.The catalytic performance of the modified H(3 zeolite was better than that of the unmodified Hβ zeolite,and the conversion rate of the catalyst was 14.56.The catalytic performance of the modified Hβ zeolite was better than that of the unmodified Hβ molecular sieve.The catalytic conversion was 14.56%,Selectivity is 95.31%.The characterization data show that cerium modification has little effect on the structure and specific surface area of Hβ molecular sieve,but it improves the strong acid content of Hβ molecular sieve and further confirms the conclusion that the amount of strong acid is the decisive factor of reaction.The Hβ zeolite was modified by HCl,H2SO4 and H3PO4 in the modification of inorganic acid.The catalytic performance investigated at different temperatures.From the conversion and selectivity,the hydrochloric acid modified Hβ zeolite molecular sieve has the best catalytic performance.The characterization data show that the acidity of strong acid is still the decisive factor of catalytic activity.The catalytic activity of H2SO4 and H3PO4 modified Hβ zeolite molecular sieve is decreased due to excessive delamination.In this experiment,Cr(NO3)3 modified Hβ zeolite molecular sieve was used as catalyst,and the reaction conditions were optimized by single factor experiment.The catalytic activity of Cr(NO3)3 modified Hβ zeolite molecular sieves after recycle and regeneration was investigated.It was found that the catalytic activity of Cr(NO3)3 was very serious in the process of recycle.The data showed that the specific surface area decreased,decrease of acidity is the main reason for the decline in catalytic performance.