Stimulating Mesoporous Characteristics of Activated Carbon through Pyrolysis of Compacted Hydroxyethyl Cellulose—A Showcase for H2S Removal

Abstract

Activated carbon (AC) serves as extensively researched adsorbents, with numerous established methods for their preparation. This study originated from the hypothesis that compressing a hydrocarbon substance to create a densely compacted pellet, known as pelletizing, would enhance the development of porous features of the resulting AC. The anticipated enhancement is attributed to the rise in spatial proximity amidst HEC polymer chains within the bulk of the pellet, which facilitates aromatization both in extent and functionality. 2-Hydroxyethyl cellulose (HEC) pellets were prepared by adjusting the duration of load holding, aiming to increase the packing density of HEC polymer chains via creeping. The BET analysis of the resulting AC samples demonstrates the efficacy of compression on HEC pellets in enhancing their porous properties. The FE-SEM study revealed diverse AC surface morphologies that are associated with a set of specific pelletizing conditions. The 13C NMR spectroscopy for carbon skeletons, FT-IR spectroscopy for organic functionality, and XPS spectroscopy for surface composition collectively report the leverage of compression treatment before pyrolyzing HEC pellets. Furthermore, the assessment of hydrogen sulfide adsorption by the resulting AC samples revealed distinctive breakthrough curves, providing validation for the proposed compression effect.