Dissolution and fractionation of nut shells in ionic liquids.

Area of Science:

• Biomass valorization
• Green chemistry
• Sustainable materials

Background:

• Nut shells (peanut, chestnut) are abundant lignocellulosic biomass.
• Efficient extraction of cellulose from biomass is crucial for biorefining.
• Ionic liquids offer tunable properties for biomass dissolution.

Purpose of the Study:

• To investigate the dissolution of raw peanut and chestnut shells using ionic liquids.
• To optimize conditions for maximum biomass dissolution and cellulose extraction.
• To assess the recovery of cellulosic material and ionic liquids.

Main Methods:

• Dissolution of raw biomass (peanut and chestnut shells) in selected ionic liquids.
• Optimization of dissolution parameters (e.g., temperature, time, concentration).
• Quantification of extracted polysaccharides using quantitative 13Cq NMR.
• Regeneration of cellulosic material and ionic liquid using an antisolvent mixture.

Main Results:

• Achieved biomass dissolution up to 7wt% under optimized conditions.
• Extracted up to 87% of cellulosic material into ionic liquids.
• Recovered 75% (peanut shells) and 95% (chestnut shells) of cellulosic material.
• Recovered over 95% of the ionic liquid in both cases with low mass loss (<8%).

Conclusions:

• Ionic liquids demonstrate high potential for the biorefining of nut shells.
• Efficient recovery of both cellulosic material and ionic liquids is feasible.
• The process is economically favorable due to high ionic liquid recovery.