Optimal preparation of low-cost activated carbon: the enhanced mechanism of interaction and performance studies for volatile organic compounds (VOCs) capture

Abstract

The activated carbons developed using Phaseolus vulgaris L. (PVACs) were produced to enhance the benzene, toluene, ethylbenzene, and xylene (BTEX) adsorption. The PVACs chemically produced via phosphoric acid (H3PO4) from biomass waste and effectively found the adsorption capacity for multi-component BTEX. In accordance with the experiment protocols, a set of systematic operating parameters (temperature, residence time, and initial BTEX concentration) carried out to investigate the mechanism of multi-component BTEX adsorption on the PVACs (PVAC650, PVAC750, and PVAC850 named as carbonization temperature from 650 to 850 degrees C). The ambient temperature was kept constant at 22 degrees C, and the differences of BTEX adsorbed amount were clearly demonstrated in the experiments. The results indicate that (1) specific surface area is important for novel application in multi-component BTEX adsorption, and the surface area of PVAC650, PVAC750, and PVAC850 were 881, 1109, and 1007 mg/g; and (2) temperature and relative humidity have an important effect on the absolute BTEX adsorption, which BTEX adsorbed amount decreases at higher temperature and relative humidity. Under the condition of 15% relative humidity (RH), the maximum BTEX adsorption amounts for PVAC650, PVAC750, and PVAC850 were 189, 281, 217 mg/g at, respectively. The average multi-component of BTEX adsorption on PVAC750 is 235 mg/g, indicating that the dominant adsorption process of BTEX at room conditions may be physical adsorption.