Microwave-assisted catalytic hydrothermal carbonization of Laminaria japonica for hydrochars catalyzed and activated by potassium compounds. (December 2021)

• Record Type: Journal Article
• Authors: Ding, Zhuhong; Zhang, Lianyi; Mo, Huijing; Chen, Yijun; Hu, Xin
• Is Part Of: Bioresource technology. Volume 341(2021)
• Publication Date: 2021-12
• Subjects: Algae biomass -- Catalytic effect -- Chemical activation -- Comprehensive characterization -- Adsorption; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2021.125835
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Algal hydrochar prepared successfully via microwave–assisted catalytic HTC. Great differences on catalytic decomposition effects posed by different catalysts. Synergetic activation revealed by significant improvement of adsorption capacities. Intraparticle and film diffusion were the rate-limiting step of Pb(II) sorption. Catalysts have different effects on properties and adsorption ability of hydrochar. Abstract: There are limited investigations describing preparation and application of alga-based hydrochars via microwave–assisted catalytic hydrothermal carbonization (MA-CHTC). Therefore, hydrochars were successfully prepared from macroalgae biomass Laminaria japonica impregnated with KH2 PO4, KCl, K2 CO3, and KOH as acidic, neutral salt, and alkaline catalysts, respectively, via the MA-CHTC. Comprehensive characterization of physicochemical properties of the hydrochars, including yields, elemental and phase composition, specific surface areas, functional groups, and morphology, confirmed different catalytic effects of these catalysts on hydrochar formation. Adsorption kinetics and isotherms of Pb(II) revealed significant improvement of adsorption capacities for Pb(II) due to synergetic chemical activation of the spiked catalysts. Therefore, the synergetic catalytic effects and chemical activation is benefic for tailored design of engineered hydrochars with different properties for special application through selection of catalysts during the MA-CHTC process.