Simultaneous Enzymatic Cellulose Hydrolysis and Product Separation in a Radial-Flow Membrane Bioreactor.

Area of Science:

• Biochemical Engineering
• Biomass Conversion
• Renewable Energy

Background:

• Enzymatic hydrolysis of lignocellulose is crucial for bioethanol production.
• Product inhibition and low enzyme reusability hinder economic viability.
• Previous studies showed promise with flat-sheet membrane bioreactors (MBRs) for cellulose hydrolysis.

Purpose of the Study:

• To compare the effectiveness of flat-sheet versus radial-flow MBR designs for lignocellulose hydrolysis.
• To assess MBR performance using complex lignocellulose biomass (date seeds).
• To address product inhibition and enhance enzyme reusability in bioethanol conversion.

Main Methods:

• Utilized pretreated date seeds as lignocellulose biomass.
• Employed a flat-sheet inverted dead-end filtration MBR system.
• Designed and tested a tubular radial-flow MBR with a larger membrane surface area.
• Simultaneously separated products during hydrolysis.

Main Results:

• The flat-sheet MBR achieved a 10.8% glucose yield from date seeds within 8 hours with product separation, a threefold increase compared to 3.5% without separation.
• The tubular radial-flow MBR demonstrated superior performance, achieving a 60% glucose yield within 8 hours.
• The radial-flow MBR design offers over a tenfold increase in membrane surface area compared to the flat-sheet design.

Conclusions:

• The tubular radial-flow MBR design is highly effective for hydrolyzing pretreated lignocellulose biomass.
• This novel MBR approach significantly enhances glucose yield and addresses key challenges in bioethanol production.
• The findings suggest a viable pathway towards economically feasible lignocellulose-to-bioethanol conversion.