Enzyme management in the Iotech process.

Area of Science:

• Biomass Conversion and Bioenergy
• Biochemical Engineering
• Enzymatic Hydrolysis

Background:

• The Iotech process utilizes steam explosion for wood chip pretreatment to enhance cellulose hydrolysis.
• Hemicellulose degradation during steam explosion produces inhibitory compounds, such as furfural, affecting enzymatic hydrolysis efficiency and enzyme stability.

Purpose of the Study:

• To investigate methods for improving enzymatic hydrolysis of steam-exploded wood chips.
• To enhance enzyme stability and hydrolysis rates by mitigating inhibitory factors.
• To explore enzyme recovery and recycling strategies for a more sustainable process.

Main Methods:

• Steam explosion of wood chips followed by enzymatic hydrolysis.
• Washing pretreated wood chips with water to remove inhibitory compounds.
• Enzyme recovery from hydrolysis residue and filtrate via pH adjustment and adsorption onto fresh substrate.

Main Results:

• Water washing of steam-exploded wood chips significantly improved hydrolysis rates and enzyme stability.
• Inhibitory factors, likely furfural-related, were effectively reduced by washing.
• Enzymes were successfully recovered and recycled, with mass balance calculations indicating efficient reuse.

Conclusions:

• Water washing is a simple yet effective method to overcome inhibition in enzymatic hydrolysis of steam-exploded wood.
• Enzyme recovery and recycling strategies enhance the economic viability and sustainability of biomass conversion processes.
• Optimized pretreatment and hydrolysis conditions are crucial for efficient cellulose-to-value product conversion.