Research on ethylbenzene dehydrogenation over the Fe-Al-based catalysts in a circulating fluidized-bed unit

Background In the traditional ethylbenzene dehydrogenation process, much superheated steam is needed to ensure the activity and stability of the catalyst, inevitably leading to high energy consumption. Methods A novel ethylbenzene dehydrogenation process based on a circulating fluidized bed (CFB) reactor was used for the ethylbenzene dehydrogenation reaction under a low steam-to-oil ratio. In this work, a series of Fe-Al-based catalysts were prepared by a sol-gel method and the effect of alumina content on the catalytic performance of Fe-Al-based catalyst for ethylbenzene dehydrogenation was investigated. Significant findings Among a series of Fe-Al-based catalysts, the FeAl40 catalyst (the Fe-Al-based catalyst with 40 wt. % alumina) had the highest dehydrogenation activity and suitable attrition resistance for the CFB reactor. Further investigation found that the adding alumina could inhabit the formation of KFe 11 O 17 , leading to poor stability. Interestingly, the high activity of the FeAl40 catalyst could be completely recovered through a reaction-regeneration operation. Compared with the conventional ethylbenzene dehydrogenation process, the CFB process benefits from high activity, low steam-to-oil ratio and no induction period. Consequently, the FeAl40 catalyst had high dehydrogenation activity (∼51 wt. % yield of styrene) and low preparation cost, showing an extraordinary potential for industrial application.