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Agitation and pressure effects on acetone-butanol fermentation
M G Doremus1, J C Linden, A R Moreira
1Colorado State University, Department of Agricultural and Chemical Engineering, Fort Collins, Colorado 80523.
Biotechnology and Bioengineering
|June 1, 1985
Summary
Agitation and pressure significantly impact solvent production in acetone-butanol fermentation. Optimizing these parameters enhances butanol productivity, crucial for industrial applications.
Area of Science:
- Biotechnology
- Chemical Engineering
- Microbiology
Background:
- Acetone-butanol fermentation is a key bioprocess for solvent production.
- Understanding factors influencing solvent yield is critical for process optimization.
- Dissolved hydrogen gas levels are known to affect fermentation outcomes.
Purpose of the Study:
- To investigate the effects of agitation rate and pressure on solvent production in batch fermentations.
- To determine the influence of these parameters on butanol, butyric acid, and hydrogen productivity.
- To analyze the relationship between process conditions and product concentrations.
Main Methods:
- Batch fermentations were conducted under varying agitation rates and pressures (1 bar or nonpressurized).
- Dissolved hydrogen gas levels were monitored as a function of agitation and pressure.
- Productivity of butanol, butyric acid, and hydrogen was measured.
- Redox balance was used to determine the proportion of reducing equivalents utilized.
Main Results:
- In nonpressurized conditions, lower agitation increased butanol productivity.
- Pressurization enhanced overall butanol productivity, independent of agitation.
- Increased agitation led to earlier and higher butyric acid and hydrogen productivity.
- An inverse relationship was observed between acetone and acetoin concentrations.
Conclusions:
- Agitation and pressure are critical parameters for optimizing solvent productivity in acetone-butanol fermentation.
- Pressurization offers a significant advantage for increasing butanol yield.
- Controlling agitation can influence the production dynamics of different solvents and intermediates.
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