Lignin recovery from cocoa bean shell using microwave-assisted extraction and deep eutectic solvents. (March 2023)

• Record Type: Journal Article
• Authors: Mao, Yujie; Gerrow, Alex; Ray, Ella; Perez, Nidia Diaz; Edler, Karen; Wolf, Bettina; Binner, Eleanor
• Is Part Of: Bioresource technology. Volume 372(2023)
• Publication Date: 2023-03
• Subjects: Lignin -- Deep eutectic solvents -- Waste valorisation -- Microwave-assisted extraction -- Dielectric properties; 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.2023.128680
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: A novel and sustainable lignin recovery method developed using DES and microwaves. DES susceptible to microwave heating, dielectric loss 3.4–12.0 from 20 to 80 °C. Extraction yield of 95.5% lignin from CBS was achieved at 130 °C and 30 min. DES-extracted lignin exhibits unique structural characteristics. DES extraction is promising in the development of higher value lignin products. Abstract: Lignin is the second most abundant natural polymer after cellulose, and valorisation of lignin-rich streams has attracted increasing attention recently. This paper presents a novel and sustainable method to recover lignin from Cocoa Bean Shells (CBS) using Deep Eutectic Solvents (DES) and microwaves. A DES containing p-toluenesulfonic acid, choline chloride and glycerol (2:1:1 M ratio) was selected based on its dielectric properties. Under 200 W microwave power, the optimum yield of 95.5 % lignin was achieved at 130 °C and 30 min. DES-extracted lignin exhibited unique structural characteristics including larger particle sizes (242.5 µm D50 size), structural diversity (410.4 µm D90-D10 size) and H/G sub-unit ratio (71.9 %) compared with commercial Kraft lignin (77.2 µm, 157.9 µm and 0.1 % respectively), indicating the potential of DES in the modification and upgrading of lignin for novel value-added products.