Study on regeneration of spent activated carbon by using a clean technology

Abstract

Abstract In this paper, microwave regeneration of spent activated carbon saturated with organic compounds was investigated. It has been observed from the present experiments that the microwave regeneration temperature and time have significant influences on iodine adsorption value and yield of the regenerated activated carbon (RAC). The characteristics of the RAC were examined by Brunauer–Emmett–Teller (BET). The RAC has a greatly higher surface area (743.6~264.1 m 2 /g), total pore volume (0.54~0.22 cm 3 /g), and a relatively smaller average pore width (28.83~33.58 nm) compared to the spent catalyst. The separation mechanism for activated carbon and organic impurities was determined by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) equipped with an energy-dispersive spectrometer (EDS). It was a process in which the organic impurities were aggregated from the pore internal migration to the surface at low temperatures, and the organic impurities were completely decomposed as the temperature increased to 900°C for 40 min. Simultaneously, a hexagonal crystal structure material of ZnO was obtained.