A two-phase substrate model for enzymatic hydrolysis of lignocellulose: application to batch and continuous reactors

Area of Science:

• Biomass conversion
• Biochemical engineering
• Enzymatic hydrolysis modeling

Background:

• Enzymatic hydrolysis is crucial for biomass conversion but faces high production costs.
• Current models are often too complex or inflexible for process simulations.
• Accurate and accessible models are needed to reduce enzyme and equipment costs.

Purpose of the Study:

• To develop a computationally accessible phenomenological model for enzymatic hydrolysis.
• To represent rate slowdown due to substrate structure and feedback inhibition.
• To apply the model to continuous reactor systems.

Main Methods:

• Developed a phenomenological model incorporating substrate phases and feedback inhibition.
• Performed batch experiments to determine model parameters using nonlinear least-squares.
• Validated the model with continuous enzymatic hydrolysis experiments.

Main Results:

• The model accurately predicted glucose and solids concentrations in batch and continuous reactors.
• Achieved good fits for sugar yield, insoluble solids, and sugar production rates.
• Demonstrated quantitative agreement between model predictions and continuous reactor experiments without refitting.

Conclusions:

• The model offers a balance between complexity and computational efficiency.
• Applicable to novel reactor designs and computational fluid dynamics (CFD) simulations.
• Facilitates reactor design, scale-up, and process optimization in biomass conversion.