Rheology of dilute acid hydrolyzed corn stover at high solids concentration

Area of Science:

• Biomass processing
• Rheology
• Chemical engineering

Background:

• Acid hydrolysis of lignocellulosic biomass like corn stover is a key step in biofuel production.
• Understanding the rheological properties of concentrated biomass slurries is crucial for efficient process design and operation.
• Previous studies have often focused on lower solids concentrations, leaving a gap in knowledge for high-concentration systems.

Purpose of the Study:

• To investigate the rheological properties of acid hydrolyzed corn stover at high solids concentrations (20-35 wt.%).
• To determine the applicability of the Bingham model for describing these materials.
• To elucidate the effects of solids concentration and hydrolysis reaction conditions on rheological parameters.

Main Methods:

• Torque rheometry was employed to measure the flow behavior of concentrated biomass slurries.
• The Bingham plastic model was used to characterize the yield stress and plastic viscosity.
• Systematic variations in solids concentration and reaction parameters (temperature, acid concentration) were analyzed.

Main Results:

• Acid hydrolyzed corn stover behaves as a yield stress fluid, accurately modeled by the Bingham model.
• Yield stress increases with solids concentration and decreases with higher reaction temperature and acid concentration.
• Plastic viscosity increases with solids concentration and generally decreases with increased reaction temperature and acid concentration.
• Observed changes in yield stress correlate with alterations in particle size, indicating its role in flow behavior.

Conclusions:

• Torque rheometry is an effective tool for characterizing the rheology of concentrated biomass.
• The rheological properties of acid hydrolyzed corn stover are highly dependent on process conditions.
• This understanding can inform the design of handling and processing equipment for lignocellulosic biomass at high concentrations.