Integrated analysis of hydrothermal flow through pretreatment

Area of Science:

• Biomass Pretreatment
• Biochemical Engineering
• Renewable Energy

Background:

• Hydrothermal flowthrough (FT) pretreatment is a key step in biomass conversion.
• Evaluating FT pretreatment severity is crucial for optimizing performance.
• Comparing different feedstocks and conversion systems is essential for industrial application.

Purpose of the Study:

• To assess the impact of FT pretreatment severity on performance metrics.
• To compare FT pretreatment with batch pretreatment.
• To evaluate two distinct biomass conversion systems.

Main Methods:

• Utilized three milled feedstocks: corn stover, bagasse, and poplar.
• Employed two conversion systems: simultaneous saccharification and fermentation (SSF) and Clostridium thermocellum fermentation.
• Varied FT pretreatment severity to analyze its effects on XMG recovery, non-carbohydrate carbon removal, and glucan solubilization.

Main Results:

• FT pretreatment consistently outperformed batch pretreatment in XMG recovery, non-carbohydrate carbon removal, and glucan solubilization.
• Optimal FT conditions for poplar (16 min, 210°C) yielded 85% SSF glucan conversion.
• Clostridium thermocellum fermentation demonstrated faster and more complete conversion of FT-pretreated poplar than SSF at low solids concentration.

Conclusions:

• FT pretreatment effectiveness varies with feedstock, influencing glucan conversion differently.
• Non-carbohydrate carbon removal positively correlates with higher hydrolysis yields.
• Clostridium thermocellum offers a more efficient conversion pathway for FT-pretreated biomass compared to SSF.