Lignin recovery from cocoa bean shell using microwave-assisted extraction and deep eutectic solvents

Mao, Yujie; Gerrow, Alex; Ray, Ella; Perez, Nidia Diaz; Edler, Karen; Wolf, Bettina; Binner, Eleanor

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.

Citation

Mao, Y., Gerrow, A., Ray, E., Perez, N. D., Edler, K., Wolf, B., & Binner, E. (2023). Lignin recovery from cocoa bean shell using microwave-assisted extraction and deep eutectic solvents. Bioresource Technology, 372, Article 128680. https://doi.org/10.1016/j.biortech.2023.128680

• Journal Article Type: Article
• Acceptance Date: Jan 23, 2023
• Online Publication Date: Jan 24, 2023
• Publication Date: 2023-03
• Deposit Date: Mar 9, 2023
• Publicly Available Date: Mar 9, 2023
• Journal: Bioresource Technology
• Print ISSN: 0960-8524
• Electronic ISSN: 1873-2976
• Publisher: Elsevier BV
• Peer Reviewed: Peer Reviewed
• Volume: 372
• Article Number: 128680
• DOI: https://doi.org/10.1016/j.biortech.2023.128680
• Keywords: Waste Management and Disposal; Renewable Energy, Sustainability and the Environment; General Medicine; Environmental Engineering; Bioengineering
• Public URL: https://nottingham-repository.worktribe.com/output/16506799
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0960852423001062?via%3Dihub