• Applied Chemistry for Engineering
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• v.35 no.5
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• pp.404-409
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• 2024

Technologies that separate and capture CO₂ from landfill gas are attracting attention as a way to reduce CO₂ emitted into the atmosphere. In this study, we aimed to improve the gas separation ability of CO₂/CH₄ mixed gas by controlling the pores of activated carbon pellets (ACPs) through chemical vapor deposition of CH₄ and also investigated the adsorption characteristics as a function of reaction time. Both the specific surface area and the micropore volume increased up to a maximum of 997.8 m²/g and 0.392 cm³/g, respectively, following the carbon deposition through CH₄. In addition, the CO₂ adsorption quantity increased up to a maximum of 97.4 cm³/g as the deposition time increased. As a result, the pore structure of the ACPs could be controlled via the chemical vapor deposition of CH₄ and the ACPs' CO₂/CH₄ gas separation performance was improved. The improved CO₂ adsorption capacity was ascribed to an increase in specific surface area by heat treatment and an increase in the volume of below 0.61 nm micropores due to carbon deposition.

• Clean Technology
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• v.17 no.1
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• pp.48-55
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• 2011

The application of fibrous activated carbon (FAC)-titanium dioxide ($TiO_2$) hybrid system has not been reported yet for the control of malodorous dimethyl sulfide (DMS) at residential environmental levels. Accordingly, the current study was designed not only to characterize this hybrid system using x-ray diffraction method, particulate surface measurement and Fourier transform Infrared (FTIR) method, but also to evaluate its adsorptional photocatalytic activity (APA) for the DMS removal. The physical/surface characteristics of FAC-$TiO_2$ which was prepared in this study suggested that the hybrid material might have certain APA for DMS. The Brunauer-Emmett-Teller (BET) specific area, total pore volume, micropore volume and mesopore volume decreased all as the $TiO_2$ amounts coated on FAC increased, whereas the reverse was true for average pore diameter. $TiO_2$ coated onto FAC did not influence the adsorptional activity of FAC for the DMS input concentration of 0.5 ppm. The APA test of the hybrid material presented that the initial removal efficiencies of DMS were 93, 78, 71 and 57% for the flow rates of 0.5, 1.0, l.5 and 2.0 L/min, respectively, and they decreased somewhat 2 h after the experiment started and kept almost constant for the rest experimental period. Under this pseudo-equilibrium condition, the DMS removal efficiencies were 78, 58, 53 and 36% for the four flow rates, respectively. Meanwhile, there were no significant byproducts observed on the surfaces of the hybrid material. Consequently, this study suggests that, under the experimental conditions used in the present study, the hybrid material can be applied for DMS at residential environment levels without being interfered by any byproducts.