Cost of Deconstruction Depots for Diversified, Waste-Based Lignocellulosic Sugars Using Distillable Solvents

Area of Science:

• Biomass conversion and biorefining
• Sustainable chemistry and green solvents
• Bioeconomy feedstock development

Background:

• Transitioning to a bioeconomy necessitates adaptable biomass deconstruction methods to handle diverse, low-emission feedstocks and overcome storage challenges.
• Current biomass deconstruction technologies face limitations in efficiently processing a wide range of feedstocks, impacting cost-effectiveness and scalability.
• Long-term storage of biomass presents challenges like material loss and fire risk, emphasizing the need for rapid and efficient processing.

Purpose of the Study:

• To evaluate the cost-effectiveness of using butylamine, a distillable solvent, for deconstructing a variety of biomass feedstocks.
• To identify key process parameters influencing lignocellulosic sugar production costs and determine pathways for cost reduction.
• To assess the potential for butylamine-based deconstruction to support feedstock-flexible biorefineries.

Main Methods:

• Butylamine solvent-assisted deconstruction was applied to 22 diverse biomass feedstocks, including herbaceous, woody, and food processing residues.
• Lignocellulosic sugar production costs were calculated based on empirical data, with a focus on solvent loading as a critical parameter.
• Process optimization, including reduced solvent loading (down to 59 g/kg), was demonstrated in an L-scale reactor using poplar biomass.

Main Results:

• Initial lignocellulosic sugar production costs ranged from $1.3 to $6.1/kg, indicating a need for significant cost reduction.
• High solvent loading (850 g/kg) was identified as a major bottleneck; reducing it to 59 g/kg lowered the minimum sugar selling price by 33%.
• Achieving target sugar production costs of $0.45-0.79/kg is dependent on optimizing solvent loading, recovery, solid loading, sugar yield, enzyme use, and biomass cost.

Conclusions:

• Butylamine deconstruction offers a viable pathway for processing diverse biomass feedstocks, but process optimization is crucial for economic competitiveness.
• Reducing solvent loading and improving recovery are key strategies to lower the cost of bio-based sugars derived from lignocellulosic materials.
• Strategic feedstock blending, process optimization, and selection of low-cost feedstocks are essential for advancing feedstock-flexible biorefineries.