Novel ternary deep eutectic solvent fractionation for effective utilization of willow

Area of Science:

• Green Chemistry
• Biomass Valorization
• Materials Science

Background:

• Lignocellulosic biomass presents a sustainable feedstock for biofuels and biochemicals.
• Efficient fractionation of biomass components (cellulose, hemicellulose, lignin) is crucial for its effective utilization.
• Deep eutectic solvents (DES) offer tunable properties for biomass processing.

Purpose of the Study:

• To develop and evaluate a novel ternary deep eutectic solvent (TDES) for efficient fractionation and conversion of willow biomass.
• To investigate the performance of specific TDES compositions for biomass pretreatment.
• To assess the properties and reusability of the TDES and derived lignin.

Main Methods:

• Formulation of ternary deep eutectic solvents using zinc chloride, ethylene glycol, and alpha hydroxy carboxylic acids (glycolic, citric, malic acid).
• Fractionation of willow (Salix matsudana cv. Zhuliu) biomass using the optimized TDES at 130 °C for 1.5 h.
• Subsequent enzymatic hydrolysis of the pretreated biomass to determine glucose yield.
• Characterization of the regenerated lignin and evaluation of TDES recyclability.

Main Results:

• The ZnCl2/EG/MA TDES achieved high xylan (91.66%) and lignin (90.12%) removal.
• Pretreatment resulted in a 96.01% glucose yield after enzymatic hydrolysis.
• Regenerated lignin exhibited nanoparticle morphology and antioxidant properties.
• The TDES maintained significant delignification (70.16%) and glucose yield (83.70%) after four recycling cycles.

Conclusions:

• A novel ZnCl2/EG/MA TDES is highly effective for fractionating willow biomass under mild conditions.
• This approach maximizes lignocellulose utilization, yielding fermentable sugars and valuable lignin.
• The TDES demonstrates good stability and reusability, supporting sustainable biomass processing.