Development of a cost-effective CO₂ adsorbent from petroleum coke via KOH activation

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>The capture of CO<SUB>2</SUB> via adsorption is considered an effective technology for decreasing global warming issues; hence, adsorbents for CO<SUB>2</SUB> capture have been actively developed. Taking into account cost-effectiveness and environmental concerns, the development of CO<SUB>2</SUB> adsorbents from waste materials is attracting considerable attention. In this study, petroleum coke (PC), which is the carbon residue remaining after heavy oil upgrading, was used to produce high-value-added porous carbon for CO<SUB>2</SUB> capture. Porous carbon materials were prepared by KOH activation using different weight ratios of KOH/PC (1:1, 2:1, 3:1, and 4:1) and activation temperatures (600, 700, and 800°C). The specific surface area and total pore volume of resulting porous carbon materials increased with KOH amount, reaching up to 2433m<SUP>2</SUP>/g and 1.11cm<SUP>3</SUP>/g, respectively. The sample prepared under moderate conditions with a KOH/PC weight ratio of 2:1 and activation temperature of 700°C exhibited the highest CO<SUB>2</SUB> adsorption uptake of 3.68mmol/g at 25°C and 1bar. Interestingly, CO<SUB>2</SUB> adsorption uptake was linearly correlated with the volume of micropores less than 0.8nm, indicating that narrow micropore volume is crucial for CO<SUB>2</SUB> adsorption. The prepared porous carbon materials also exhibited good selectivity for CO<SUB>2</SUB> over N<SUB>2</SUB>, rapid adsorption, facile regeneration, and stable adsorption–desorption cyclic performance, demonstrating potential as a candidate for CO<SUB>2</SUB> capture.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cost effective CO<SUB>2</SUB> adsorbent could be prepared from petroleum coke. </LI> <LI> CO<SUB>2</SUB> uptakes have good correlation with narrow micropores (<0.8nm). </LI> <LI> The prepared microporous carbon showed excellent CO<SUB>2</SUB> adsorption performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>