ZrO2-impregnated red mud as a novel catalyst for steam catalytic cracking of vacuum residue. (1st February 2016) - Lee, Hak Sung
Graphical abstract: Highlights: ZrO2 -impregnated red mud were used for steam catalytic cracking of vacuum residue. 3 wt% ZrO2 -impregnated red mud exhibited the best performance. 3 wt% ZrO2 -impregnated red mud shows a high surface area and good catalyst stability. 3 wt% ZrO2 -impregnated red mud improves hydrogenation activity. ZrO2 -impregnated red mud has good durability for steam catalytic cracking. Abstract: ZrO2 -impregnated red mud catalysts were employed as a novel catalyst for catalytic cracking of vacuum residue with steam. Under the batch reaction condition at 470 °C for 2 h with superheated steam, 3 wt% ZrO2 -impregnated red mud exhibited the best performance for catalytic cracking of vacuum residue. Furthermore, under the same reaction conditions, the conversion and liquid yield of 3 wt% ZrO2 -impregnated red mud were higher than those of 3 wt% ZrO2 -supporting Al–FeOx, a well-known catalyst for catalytic cracking of heavy oil with steam. 3 wt% ZrO2 -impregnated red mud also showed better catalytic performance than 3 wt% ZrO2 -supporting Al–FeOx under the fixed-bed reaction conditions at 500 °C for 2 h with steam atmosphere, resulting in higher conversion as well as liquid yield. The better catalytic performance of 3 wt% ZrO2 -impregnated red mud was due to large surface area and high catalyst stability. The large surface area of 3 wt% ZrO2 -impregnated red mud could generate more active sites for hydrogenation, which induced higher H/C ratio in liquid product. X-ray diffraction data of the spent catalysts showed that iron oxide phase in 3 wt% ZrO2 -impregnated red mud maintained a hematite structure while it in 3 wt% ZrO2 -supporting Al–FeOx was transformed to magnetite, inactive phase for catalytic cracking.