Rapid Regeneration of Spent FCC Catalysts through Selective Bioleaching by the Spent Medium Process

Fluid catalytic cracking (FCC) catalysts play an important role in modern industrial production and are capable of converting heavy oils into light oils. However, in the process of long-term use, the FCC catalyst will reduce its activity due to internal wear and external factors, and it will become a spent catalyst after failing to meet the requirements of use. Approximately one million tons of spent FCC catalysts are generated annually, and improper disposal of this hazardous waste can pose significant harm. In this study, the spent catalyst is treated by the bioleaching method, which restored its activity to some extent, allowing for its reuse in industrial production. This study found that at 58 °C, the biological cleaning of spent catalyst with 5.6% pulp density can increase its activity by about 10%, whereas the corresponding treatment with a mixed acid only achieved a 2% increase. This demonstrates the feasibility of the bioleaching method and provides insights into further enhancing the activity of spent catalysts.