The Study On Friedel-crafts Acylation Reaction Of Thiophene By Zeolite Molecular Sieves

Friedel-Crafts acylation reaction of aromatic compounds and heterocycliccompounds is one of the most important reactions in organic chemistry forsynthesizing aromatic ketone, which has some advantages, such as mild reactioncondition, high selectivity. The aromatic ketone, which is important intermediate forthe synthesis of fine chemicals and pharmaceutical intermediates, is now being widelyused in a broad range of fields such as fuel, pharmaceuticals, plastic and cosmetic.At present, the traditional catalyzer is homogeneous acid catalyst, such asinorganic phosphate acid by85%and metal chloride; in the reaction process, thephosphate acid brings into waste acid, which not only seriously erodes equipment, butalso takes severe environmental pollution problems. Metal chloride has corrosive, themost important is that the traditional catalysts cannot be reused, low selectivity, andpollutions, so that, they are not the ideal catalyzers for the green chemical industry.The article is aimed for the application of2-acetyl thiophene, by using C25zeolite as catalyst in magnetic stirred tank, trick bed and fixed bed reactor to researchthe acylation reaction of thiophene at atmospheric in order to provide the theoreticalprovinces for the industry produced2-acetyl thiophene. The effects of reactivetemperature, time and the dosage, and molar ratio on the Friedel-Crafts acylationreaction were investigated in batch experiment to get the proper reactive conditions,the reaction kinetic of thiophene was studied in magnetic stirred tank; The effects ofacetic acid as the solvent on acylation reaction were investigated also; In trickle bedreactor, based on the proper conditions from the batch experiment, the effects of C25zeolites, modified C25with different acids and regeneration times on the reaction werestudied; Meanwhile, the gas phase reaction in fixed bed reactor was investigated, anda large number of experimental data for the thiophene acylation reaction for largescale processes had been accumulated.By using several analysis methods, such as BET, XRD, NMR MAS, FT-IR andTGA, the zeolites were characterized. The comparison between the deactivated andregenerated zeolites showed that the carbon deposit was one of the main causes ofdeactivation. Finally, the reactive products were refined to get the purity2-acetylthiophene up to99.90%.