Structural and Electrochemical Characteristics of Activated Carbon Derived from Lignin-Rich Residue

Abstract

Lignin-rich residue was obtained by sequential acid pretreatment (sulfuric, oxalic, and maleic acid; H-ST, H-OT, and H-MT) and enzymatic hydrolysis (EH). Pretreatment using dicarboxylic acid (oxalic and maleic acid) showed a relatively low solid yield (72.55 and 69.27%) compared with sulfuric acid pretreatment (74.83%). In addition, the enzymatic hydrolysis yield of pretreated biomass differed significantly depending on the acid catalyst used. To investigate structural properties of lignin-rich residue, milled wood lignin (MWL) was extracted. H-MT-EH-MWL and H-OT-EH-MWL were found to have higher M w and polydispersity values than H-ST-EH-MWL, but the syringyl-to-guaiacyl (S/G) ratio of H-ST-EH-MWL was the highest. The lignin-rich residue was used to prepare activated carbons (ACs) to make commercially viable energy storage materials. These activated carbons showed commercially viable specific surface areas (SSAs) (>2000 m2/g) and high rate capabilities (>90% at 50 mA/cm2). H-ST-EH-AC had the highest BET SSA value (2182 m2/g). H-MT-EH-AC had a slightly lower value (2156 m2/g), but H-OT-EH-AC had the lowest value (2079 m2/g). The sp2/sp3 ratio of H-ST-EH-AC (3.8) is higher than the others (H-MT-EH-AC: 3.6 and H-OT-EH-AC: 3.1). On the basis of the lignin-rich residue structure, it is considered the high S-type lignin content of H-ST-EH can be attributed to the graphitic structure in H-ST-EH-AC.

Renewable Coffee Waste-Derived Porous Carbons as Anode Materials for High-Performance Sustainable Microbial Fuel Cells

“…As seen in Figure , the C 1s peak can be considered a contribution of several peaks. The dominant peaks at 284.4 ± 0.1 and 285 ± 0.2 eV can be attributed to the graphitic structure (sp 2 CC) and hybridized carbon (sp 3 C–C), respectively. , The small peaks centered at 286 ± 0.2, 287.4 ± 0.2, and 288.8 ± 0.2 eV are assigned to the phenolic groups (C–O), carbonyl groups (CO), and carboxyl or ester groups (OCO), respectively . From Table , sp 2 percentages for CWAC5 (68.19%) and CWAC10 (68.61%) are higher than those for CWAC0 (55.00%) and CWAC1 (48.39%), indicating that CWAC5 and CWAC10 possess higher proportions of the graphitic structure.…”

Biochar derived from corn stalk and polyethylene co-pyrolysis: characterization and Pb(ii) removal potential

“…However, the type I isotherm may also be mesoporous materials with pore sizes closing to that of the micropores. 35 When closed to the saturated vapor pressure, the adsorption reaction was similar to that of macropores due to the existence of gaps between the particles, and the isotherm raised rapidly. According to comprehensive analysis, the pore structures of biochar became micropores by modication.…”

Performance and Economic Analysis of Organosolv Softwood and Herbaceous Lignins to Activated Carbons as Electrode Materials in Supercapacitors

“…Selecting an appropriate lignin precursor is challenging due to lignin's highly complex structure that varies as a function of the biomass source and isolation methods adopted (Rowlandson et al, 2020). The basic constituent of lignin is phenylpropane (C6−C3), which tends to form a three-dimensional complex structure through ether or C−C bonds (Han et al, 2018). Lignin is composed of varying ratios of three aromatic monomers depending mainly on botanical origin, including p-coumaryl alcohol, coniferyl alcohol, and sinapyl alcohol (McKendry, 2002;Calvo-Flores and Dobado, 2010).…”