Computer Analysis of the Porous Structure of Activated Carbons Derived from Various Biomass Materials by Chemical Activation

Abstract

In this study, the preparation of activated carbons from various materials of biomass origin by activation with potassium hydroxide and a comprehensive computer analysis of their porous structure and adsorption properties based on benzene (C6H6) adsorption isotherms were carried out. In particular, the influence of the mass ratio of the activator’s dry mass to the char mass on the formation of the microporous structure of the obtained activated carbons was analysed. The summary of the analyses carried out based on benzene adsorption isotherms begged the conclusion that activated carbon with a maximum adsorption volume in the first adsorbed layer and homogeneous surface can be obtained from ebony wood at a mass ratio of the activator to the char of R = 3. The obtained results confirmed the superiority of the new numerical-clustering-based adsorption analysis (LBET) method over simple methods of porous structure analysis, such as the Brunauer–Emmett–Teller (BET) and Dubinin–Raduskevich (DR) methods. The LBET method is particularly useful in the evaluation of the influence of the methods and conditions of production of activated carbons on the formation of their porous structure. This method, together with an appropriate economic analysis, can help in the precise selection of methods and conditions for the process of obtaining activated carbons at specific manufacturing costs, and thus makes it possible to obtain materials that can successfully compete with those of other technologies used in industrial practice and everyday life.

Hydrothermal Pretreatment of KOH for the Preparation of PAC and Its Adsorption on TC

“…The specific surface area and pore size distribution of the PAC were measured using a fully automated specific surface area and pore size distribution analyzer [28], and the results are presented in Table 3. The findings indicate that the activated carbon obtained through the second pretreatment process had a greater specific surface area and a more developed micropore structure, which was attributed to the formation of micropores during the decomposition of KOH [29] in the PC and KOH impregnation pretreatment process followed by heating. In general, the adsorption efficiency of the adsorbent is strongly associated with its specific surface area, and as the specific surface area and micropore volume increase, the adsorption sites on the activated carbon surface increase as well, thus boosting the adsorption capacity [30].…”

Activated Carbon

“…The examination of the ACs' porous structure, therefore, revealed the substantial potential for producing ACs from waste biomass with a very high adsorption capacity and significant specific surface area by activation with KOH. 30…”

Porous Carbon Nanofibers Derived from Silk Fibroin through Electrospinning as N-Doped Metal-Free Catalysts for Hydrogen Evolution Reaction in Acidic and Alkaline Solutions

“…The Cl – ions can etch the carbon structure and create micro- and meso-pores . Besides, K + can react with the C and O atoms in the carbon framework involving the charge transfer from the electropositive potassium to the carbon and/or heteroatoms present, generating potassium carbonate which will further decompose under heat into CO 2 and K 2 O. Pores are formed when the gas escapes. , Although the specific mechanism of chemical activation that occurred during the initial carbonization and activation is hard to predict, our team has recently reported the successful application of KCl activation in the preparation of porous carbon derived from silk fibroin . After chemical activation, the specific surface area of the porous carbon increases by 45.41%, indicating that KCl is an effective activation reagent.…”