Application of high-gravity technology NaOH-modified activated carbon in rotating packed bed (RPB) to adsorb toluene

Abstract

In this paper, the adsorption of toluene by NaOH (sodium hydroxide)-modified AC (activated carbon) in a rotating packed bed was studied. In order to improve the adsorption capacity of AC, NaOH was used to modify AC. The modification ability of a rotating packed bed and magnetic stirrer was examined, and then, the capacity of a fixed bed and rotating bed to absorb toluene was compared. The functional groups and pore structure of the modified AC were characterised by using the Brurner-Emmett-Teller method, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, Bohem titration, scanning electron microscopy and transmission electron microscopy. The adsorption mechanism of modified AC and the adsorption capacity of the rotating bed were also studied. It was found that the basic functional group content of modified AC in the rotating packed bed was 1.25 times higher than in the magnetic stirrer under the same conditions. The modified AC still maintained a good pore structure at a suitable sodium hydroxide concentration. The absorption mechanism of the modified AC did not change, and the physical adsorption process occurred through the micropores. The adsorption capacity of the rotating bed was 1.3 times that of the fixed bed.