SiC foam based structured catalyst for process intensification in oxidative dehydrogenation of 1-butene to butadiene

Oxidative dehydrogenation of butenes to butadiene is a highly exothermic and diffusion-controlled reaction. The problems of high adiabatic temperature rise and pressure drop, low gas velocity and conversion, as well as high consumption of water exist in the conventional reactors. In order to ease these problems, SiC foam supporting ZnFe2O4-alpha-Fe2O3 (ZnFe2O4-alpha-Fe2O3/SiC foam) structured catalyst was prepared by a slurry-coating method. Its performance was systematically studied with varied reaction temperature, oxygen/1-butene molar ratio, steam/1-butene molar ratio and 1-butene gaseous hourly space velocity (GHSV), respectively. The results showed that the 1-butene conversion and butadiene selectivity over the structured catalyst could reach about 87% and 91%, respectively, at a 1-butene GHSV of 300 h(-1), and even at a 1-butene GHSV of 600 h(-1), the conversion could still maintain at 78%, which was much better than that of the particulate catalysts. In addition, compared to the particle packed bed, the structured bed showed lower temperature rise and nearly isothermic, could lower the consumption of water and allowed to be operated with a wider range of O-2/1-butene molar ratio and a much higher 1-butene GHSV, due to its better process intensification capacity.