Impact of KOH Activation on Rice Husk Derived Porous Activated Carbon for Carbon Capture at Flue Gas alike Temperatures with High CO₂/N₂ Selectivity

Abstract

Metal-free porous activated carbon is an effective alternative to capture CO2 due to its high surface area and textural advantages. In this regard, the present research work explores a suitable method for producing activated porous carbon with a high specific surface area through a two-step reaction involving rice husk and KOH at 600 °C for 1 h to capture CO2. By varying the ratio of rice husk biomass to KOH, the texture and specific surface area of the activated porous carbon has been altered. A high surface area of ∼755 m2/g and a micropore volume of 0.243 cm3/g have been observed in the porous carbon produced with a KOH/biomass weight ratio of 3 (PAC2). Nitrogen contents in PAC1 and PAC2 were approximately 2.27 and 2.71 atom %, respectively. When compared with other materials, PAC2 has the highest CO2 adsorption capability, reaching up to 3.13 mmol/g at 0 °C and 1.55 mmol/g at 50 °C. The isosteric heat of adsorption confirms the presence of both physisorption and chemisorption. The materials turn out to be highly CO2/N2 selective, with the highest selectivity of 131, proving that the samples are potential materials for capturing CO2 from flue gases. These findings unequivocally show that porous activated carbon can be used to make CO2 adsorption efficient, inexpensive, and, more importantly, extremely effective.

CuCl2-Activated Sustainable Microporous Carbons with Tailorable Multiscale Pores for Effective CO2 Capture

“…The selectivity of MC-3 still reaches 42 at 1 bar and 273 K. Notably, MC-2 exhibits a higher CO 2 /N 2 selectivity at 298 K in the low-pressure region below 0.4 bar (Figure d), which results in a higher CO 2 uptake at 0.15 bar and 298 K. Such results further confirm the dominant contribution of ultramicropores on CO 2 capture at low pressure and high temperature. The CO 2 /N 2 IAST selectivity of MC-2 is 78 at 0.15 bar and 298 K and still keeps 48 at 1.0 bar and 298 K, which is comparable or even much higher than those of most of reported porous carbonaceous adsorbents. − Importantly, the CO 2 /N 2 selectivity of MC- x at 298 K has no decrease and even shows an increase, which significantly favors the practical application in capturing CO 2 from the flue gases.…”

Sustainable Cow Hair Biocarbon‐Sulfur Cathodes with Enhanced Electrochemical Performance

“…The interaction between KOH and carbon instigates the generation of gasses that promote the development of pores, specifically small mesopores and micropores. During this activation process, carbon undergoes oxidation, yielding carbon dioxide, hydrogen, metallic potassium, water, and potassium carbonate [20,21] . Additional analysis included an examination of pore size distribution (Figure 1B).…”

“…During this activation process, carbon undergoes oxidation, yielding carbon dioxide, hydrogen, metallic potassium, water, and potassium carbonate. [20,21] Additional analysis included an examination of pore size distribution (Figure 1B). A comprehensive comparative assessment of the contribution of mesopores and micropores is provided in Figure S1.…”

Sustainable energy storage: Mangifera indica leaf waste-derived activated carbon for long-life, high-performance supercapacitors

“…The characteristics of these porous activated carbons can be regulated by adjusting the activator/carbon precursor ratio, activation pyrolysis temperature, and activating agents like ZnCl 2 , FeCl 3 , H 3 PO 4 , K 2 CO 3 , KOH, etc. 14,15…”

“…The characteristics of these porous activated carbons can be regulated by adjusting the activator/carbon precursor ratio, activation pyrolysis temperature, and activating agents like ZnCl 2 , FeCl 3 , H 3 PO 4 , K 2 CO 3 , KOH, etc. 14,15 In the current study, we thoroughly investigated how activating temperature affected the porous texture, surface characteristics, and electrochemical performance of activated carbon. Here, dead Mangifera indica leaves waste was employed as the feedstock, and porous activated carbon was synthesized using a two-step process with changing temperatures.…”