Physicochemical properties of porous activated carbon prepared from palm kernel shell through a low-cost activation protocol

Abstract

Biomass-promoting routes for the synthesis of activated carbon (AC) have recently received considerable attention due to the advantages of this method: it is simple, cost-effective, and ecofriendly. This method is also an alternative way to avoid the unsafe practice of waste incineration. We describe the preparation of activated carbon from palm kernel shell (PKS) – an abundant biomass that is available in Africa and Asia. We investigated the effect of process variables such as impregnation ratio (ratio of H3PO4 to PKS) and carbonisation temperature (500–700 °C) on yield, microstructure, morphology, pore structure, and adsorption properties to optimise these parameters. Nitrogen adsorption isotherm analysis indicated that the AC was predominantly microporous in nature. Under optimal conditions, an AC with the highest surface area of 1560 m2/g was obtained. The aqueous adsorption test showed that the AC had significant removal capacity for methylene blue and iodine. The higher iodine value is consistent with the structural properties of the adsorbent, while the lower methylene blue value is consistent with the limited mesopore width. Considering the chemical and surface properties and adsorption properties of the AC produced, PKS has been shown to be an excellent precursor material for AC, thus solving the disposal problems associated with this biomass.

Effect of physical and chemical activation methods on the structure, optical absorbance, band gap and urbach energy of porous activated carbon

“…Zhang et al [30] developed an H 3 PO 4 activated hydrochar derived from peanut hull and showed that chemical modi cation greatly increases the adsorption capacity of hydrochar compared to acetone and cyclohexane. Pam et al [31] used palm kernel shell chemically to synthesize activated carbon and investigated the effect of process variables (ratio of H 3 PO 4 to PKS) and carbonization temperature on microstructure performance, morphology, pore structure and adsorption properties for methylene blue and iodine. Haghbin et al [32] prepared highly-porous activated carbon from date palm bark by chemical activation method with phosphoric acid and after characterization con rmed that date palm bark can be considered a cheap and promising precursor for the commercial preparation of activated carbon.…”