China Petroleum Processing & Petrochemical Technology ›› 2022, Vol. 24 ›› Issue (1): 100-110.

• Process Research • Previous Articles     Next Articles

Preparation of solid waste-based activated carbon and its adsorption mechanism for toluene

  

  1. Taiyuan University of Technology
  • Received:2022-02-10 Revised:2021-10-07 Online:2022-03-30 Published:2022-03-30

Abstract: Regenerated activated carbon (RAC) samples were prepared by carbon activation using waste activated carbon from solid waste resources as the carbon source precursor, adding alkaline additives, and further modified by potassium ferrate to finally prepare high-performance VOCs adsorption carbon. At the same time, the samples before and after modification were systematically studied through characterization equipment such as SEM, RAMAN, FT-IR, XPS, and dynamic/static adsorption. The results showed that the specific surface area and pore volume of the RAC after modification by the strong oxidant potassium ferrate increased by 1.4 times; the degree of defects was enhanced and the content of oxygen-containing functional groups on the surface increased significantly. Among them, the sample modified with potassium ferrate for 24h had the best toluene dynamic adsorption performance (375.5 mg/g), and the dynamic adsorption capacity was twice that of the original sample (192.8 mg/g); The static adsorption test found that the maximum adsorption capacity of RAC-6%K2FeO4+H2SO4-24h was 796 mg/g, which indicated that potassium ferrate modification treatment can significantly increase the VOCs adsorption performance of RAC. In addition, through consecutive toluene adsorption-desorption cycle tests, it was found that the sample RAC-6%K2FeO4+H2SO4-24h still maintained 91% adsorption activity after the fifth regeneration. This indicates that RAC-6%K2FeO4+H2SO4-24h has good cycle stability and great application value for the efficient purification of industrial VOCs waste gas.

Key words: waste activated carbon, toluene adsorption, potassium ferrate modification, oxygen-containing functional groups, regeneration ability