Polyol-assisted ternary deep eutectic solvent protective lignocellulose pretreatment for high-efficiency xylan...

Area of Science:

• Biomass Pretreatment
• Green Chemistry
• Biofuel Production

Background:

• Traditional lignocellulose pretreatment methods often use harsh conditions (acidic, alkaline, high temperature) leading to xylan degradation.
• This degradation reduces sugar yields for enzymatic hydrolysis and subsequent ethanol fermentation.
• Developing selective pretreatment methods is crucial for efficient biomass conversion.

Purpose of the Study:

• To design an effective deep eutectic solvent (DES) for selective lignin removal from lignocellulose.
• To prevent excessive xylan degradation during pretreatment.
• To enhance enzymatic digestibility and cellulosic ethanol production.

Main Methods:

• An ethylene glycol-assisted ternary DES was developed for corn straw pretreatment at 100 °C for 6 hours.
• Lignin removal, cellulose and xylan retention were quantified.
• Enzymatic digestibility and ethanol fermentation of pretreated biomass were evaluated.
• The method's universality was tested with other polyols.

Main Results:

• Achieved 65.51% lignin removal with over 93.46% cellulose and 50.22% xylan retention.
• Demonstrated excellent enzymatic digestibility with glucan and xylan conversion rates of 77.05% and 71.72%, respectively.
• Attained a high total sugar conversion of 75.93%.
• Proved the universality of lignin removal and xylan retention with other polyols.
• Achieved a high ethanol yield of 0.488 g/g total reducing sugar using a genetically engineered yeast strain.

Conclusions:

• The developed polyol-assisted ternary DES is effective for selective lignin removal while preserving carbohydrates in corn straw.
• This pretreatment strategy significantly enhances enzymatic digestibility and cellulosic ethanol production.
• The method shows promise for sustainable and efficient biofuel production from lignocellulosic biomass.