Abstract:

Aromatization is one of the key development directions of processing technology of coal based methanol in China. At present,the aromatics selectivity and yield of methanol-to-aromatics catalysts are relatively low. In view of this,a series of modified ZnO and NiO catalysts were prepared by an incipient-wetness impregnation method,then these catalysts were char-acterized by X-ray fluorescence spectrum（XRF）,physical adsorption desorption of nitrogen and temperature programmed desorption of ammonia（NH₃-TPD）,and were systematically investigated in a fixed bed reactor to discover the influence of the ratio and loading of bimetal on the reaction performance.A 300 t/a fixed-bed pilot plant was used to investigate the reaction performance of the best catalyst.The small scale experiment results showed that when the ratio of ZnO and NiO（mass ratio） was 2.0 and the total loading（mass fraction） was 6.2%,the catalyst achieved the best synergistic effect,while the aromatics selectivity was 62.98% and the aromatics yield was 19.46%.The medium scale experiment results showed that the methanol conversion rate remained 100% within 180 h,while the aromatics selectivity remained above 73% and the aromatics yield was higher than 32%.Using domestic abundant methanol in China as raw material to produce domestic shortage of aromatics,on the one hand,it can improve the industrial chain and optimize the product structure of coal chemical industry,on the other hand,it can alleviate the shortage of petroleum based aromatics.

Key words: modified ZnO, modified NiO, methanol aromatization, benzene/toluene/xylene BTX