Enhanced Conversion of Xylan into Furfural using Acidic Deep Eutectic Solvents with Dual Solvent and Catalyst...

Area of Science:

• Green Chemistry
• Biomass Conversion
• Catalysis

Background:

• Xylan is a key component of lignocellulosic biomass, a sustainable resource.
• Furfural production from xylan is crucial for various chemical industries.
• Current methods often involve harsh conditions or inefficient catalysts.

Purpose of the Study:

• To develop an efficient and sustainable process for furfural production from xylan.
• To utilize acidic deep eutectic solvents (DESs) as dual-purpose solvents and catalysts.
• To optimize reaction conditions for maximum furfural yield and facilitate recovery and recycling.

Main Methods:

• Utilized acidic deep eutectic solvents (DESs) composed of cholinium chloride and malic or glycolic acid.
• Investigated the effects of water content, γ-valerolactone (GVL), solid/liquid ratio, and microwave heating.
• Optimized reaction parameters including temperature, time, and solvent composition for furfural synthesis.

Main Results:

• Achieved a remarkable furfural yield of 75% under optimized conditions (1:3 [Ch]Cl:malic acid DES, 5 wt% water, 2.5 min microwave heating at 150°C, S/L ratio of 0.050, 2:1 GVL ratio).
• Demonstrated high furfural recovery (89%) via direct distillation or back-extraction into 2-methyltetrahydrofuran (2-MeTHF).
• Showcased successful recycling of the DES/GVL solvent system for at least three cycles with minimal yield loss (>69%).

Conclusions:

• Developed the fastest and highest-yielding process for furfural production using bio-based DESs.
• The process is efficient, sustainable, and amenable to scale-up.
• Acidic DESs offer a promising alternative to conventional catalysts and solvents in biomass valorization.