Role of alkali sodium on the catalytic performance of red mud during coal pyrolysis

Abstract Red mud (RM) as large quantity of industrial wastes could serve as a low-cost catalyst for catalytic upgrading of coal pyrolysis volatiles. However, the catalytic performance of raw RM for improving the quality of tar was limited because of its composition and structure. In this paper, the RM-based catalyst (RMC) for coal pyrolysis was prepared by using acid-alkali treatment. It was found that changing sodium content could modify the characteristics of RMC. The BET and NH 3 -TPD showed that the surface area and acid strength of RMC increased evidently with the reduction of sodium content. The pyrolysis characteristics of samples by mix shaping of coal and RMC with different sodium contents were evaluated in a fixed-bed reactor. The addition of RMC into coal could upgrade tar quality, thus increasing the yield of light tar (boiling point