关键词: 气化多联产杏壳活性炭, 改性, 乙烯, 吸附性能

Abstract:

The effects of modifiers(AgNO₃, Cu(NO₃)₂ and H₂O₂·Cu(NO₃)₂) and modification conditions(particle size of activated carbon, immersion time, roasting time and roasting temperature) on the ethylene adsorption properties of modified activated carbon were studied with apricot shell activated carbon(AC) as raw material. the structure and surface chemical composition of modified activated carbon were studied by means of ESEM-EDS, FT-IR, XPS and so on. The adsorption mechanism of ethylene on modified activated carbon was also discussed. The results showed that 15% H₂O₂ and 2% Cu(NO₃)₂ were the best modifier. The particle size, roasting time and temperature had greater influence on the adsorption properties than the immersion time. Under the conditions of 15% hydrogen peroxide and 2% copper nitrate as modifier, the particle size of activated carbon 0.83-0.38 mm, immersion time 6 h, roasting temperature 400℃ and the roasting time 4 h, the modified activated carbon had better ethylene adsorption properties, and the adsorptive capacity was 0.163 g/g, which increased by 136.23% than that of unmodified activated carbon(the adsorptive capacity was 0.069 g/g). The active component copper was uniformly dispersed on the surface and inside the pores of activated carbon. The pore structure and surface functional groups of activated carbon were changed by the modifier, the specific surface area decreased from 1 047.50 m²/g in AC to 1 012.65 m²/g, the total pore volume decreased from 0.467 1 cm³/g in AC to 0.434 7 cm³/g, and the pore diameter was distributed in a wider direction, among them, the pore diameter proportion of < 10 nm decreased from 58.16% to 53.95%, the pore diameter proportion of 10-20 nm increased from 18.01% to 19.10%, and the pore diameter proportion of >20 nm increased from 23.83% to 26.94%. The oxygen-containing functional groups increased, and the relative contents of C1, C3 and C5 decreased, the proportion of C1 peak area decreased from 77.468% to 76.827%, the proportion of C3 peak area decreased from 6.684% to 5.675%, and the peak area proportion of C5 decreased from 0.844% to 0.749%, the relative contents of C2 and C4 increased, and the proportion of C2 peak area increased from 13.514% to 15.225%, the proportion of C4 peak area increased from 1.490% to 1.524%.

Key words: apricot shell activated carbon by gasification poly-generation, modified, ethylene, adsorption properties