Preparation of high-performance toluene adsorbents by sugarcane bagasse carbonization combined with surface modification

Abstract

A series of activated carbons were prepared by carbonizing sugarcane bagasse combined with surface modification, which showed an excellent performance of adsorbing toluene (522 mg g⁻¹ at 30 °C). The results demonstrated that the enhancement of the activated temperature was benefit to promote the porosity and specific surface area (BET) of ACs. Thus, AC-800 showed optimal adsorption and its toluene adsorption performance was better than that of most ACs in the literature. Five consecutive adsorption–desorption cycles presented that AC-800's toluene adsorptive capacity was as high as 522 mg g⁻¹ (30 °C), and toluene adsorptive capacity was only decreased by 4.5%. According to the fraction of N-containing functional groups and the binding energy of toluene on N-containing functional groups, pyridinic-N (N-6) was believed to contribute more to toluene adsorption. Moreover, the Bangham model was considered as the best model of describing toluene adsorption on AC-800. Therefore, both surface adsorption and pore diffusion were the two mechanisms of toluene adsorption, and the diffusion of toluene molecules in the pores was considered as the key factor that affected the adsorption rate.