Evaluating the integration of olive tree pruning fractionation with ternary eutectic solvent after aqueous pre-extraction or dilute acid pre-treatment

abstract

Developing lignocellulosic biomass fractionation approaches that valorize lignin besides the conventional polysaccharide conversion routes have been a growing interest in achieving full biomass cascade processing. Additionally, integrating and designing technologies that use environmentally friendly and recyclable solvents following green chemistry is required. Within this context, the present work aims at investigating the integration of pre-treatments, such as aqueous pre-extraction or dilute acid pre-treatment, with the fractionation of the olive tree pruning biomass (OTP) assisted by ternary eutectic solvent (ES) composed of cholinium chloride, p-toluenesulfonic acid and ethylene glycol (ChCl:pTSA:EG; 1:1:9). The impact of both technological integrations on lignin isolation yield and on lignin physicochemical, thermal and antioxidant properties were the major parameters under evaluation. Overall, the most efficient integration was accomplished with aqueous pre-extraction plus ternary ES treatment. Around 64.3 % and 36.6 % delignification were achieved with ES, when using solid fractions obtained from aqueous pre-extraction and dilute acid pre-treatment, respectively. The lignin isolated after aqueous pre-extraction and ES treatment showed a remarkable aliphatic OH content (5.72 mmol center dot g-1). Finally, the integration of these processes enabled cellulose enrichment of remaining solid fractions that were accessible to enzymes (80.1-90.3 % hydrolysis yield).

keywords

ANTIOXIDANT ACTIVITY; ETHANOL-PRODUCTION; LIGNIN; BIOMASS; FERMENTATION; VALORIZATION; ALKALINE; POLYMER

subject category

Engineering

authors

Gómez-Cruz, I; Sosa, F; Alfieri, ML; Esposito, R; Panzella, L; Labidi, J; Goodfellow, B; Castro, E; Silvestre, AJD; Lopes, AMD

Groups

G4 - Renewable Materials and Circular Economy
G5 - Biomimetic, Biological and Living Materials

Projects

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)

acknowledgements

This work was developed within the scope of the project CICECO- Aveiro Institute of Materials, UIDB/50011/2020 (DOI 10.54499/ UIDB/50011/2020), UIDP/50011/2020 (DOI 10.54499/UIDP/50011/ 2020) & LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020), financed by national funds through the FCT/MCTES (PIDDAC) . I. Gomez-Cruz expresses her gratitude to the University of Jaen and the Ministry of Universities for the financial support of the Grants for the Recalibration of the Spanish University System for 2021-2023 in the Margarita Salas modality for the training of young doctors. Andre M. da Costa Lopes thanks his research contract funded by Fundacao para a Ciencia e Tec-nologia (FCT) and project CENTRO-04-3559-FSE-000095-Centro Portugal Regional Operational Programme (Centro2020) , under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) . Filipe H. B. Sosa acknowledges FCT, Fundaca o para a Ciencia e a Tecnologia, I.P. for the Researcher Contract CEECIND/07209/2022, under the Scientific Employment Stimulus, Individual Call. The work was also partially funded by the European Union Next GenerationEU (PIANO NAZIONALE DI RIPRESA E RESILIENZA (PNRR) within the project "ON Foods-Research and innovation network on food and nutrition Sustainability, Safety and Security - Working ON Foods" (PNRR-Mission 4, Component 2 Invest-ment 1.3-Call for tender No. 341 of 15 March 2022 PE00000003, Concession Decree No. 1550 of 11 October 2022) and This manuscript reflects only the authors' views and opinions, neither the European Union nor the European Commission can be considered responsible for them. This work was also supported by PRIN: Progetti di Ricerca di Rilevante Interesse Nazionale-Bando 2022, Prot. 2022NHBS9Z.