Countercurrent multistage fluidized bed reactor for immobilized biocatalysts: I. Modeling and simulation

Area of Science:

• Biochemical Engineering
• Chemical Reaction Engineering

Background:

• Fixed bed reactors are predominantly used for immobilized enzymes.
• These reactors face challenges with deactivating catalysts, impacting process efficiency.

Purpose of the Study:

• To investigate a novel reactor design for immobilized enzymes with continuous biocatalyst transport.
• To compare the performance of this new reactor against traditional fixed bed reactors.

Main Methods:

• A stagewise reactor with countercurrent flow of biocatalyst and substrate was designed.
• The reactor's performance was evaluated, focusing on biocatalyst transport and conversion.
• Comparison with fixed bed reactor configurations was performed.

Main Results:

• The novel reactor demonstrated limited back-mixing and near plug flow transport of biocatalyst.
• Constant flow rate and conversion were maintained due to stable catalytic activity holdup.
• For first-order reactions, enzyme requirements were slightly lower than in fixed bed reactors.

Conclusions:

• The multistage fluidized bed reactor is a promising design for efficient biocatalyst use, enabling low residual activity.
• Potential challenges include particle nonuniformity affecting plug flow characteristics.