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Simultaneous acetic acid separation and monosaccharide concentration by reverse osmosis
Fanglei Zhou1, Cunwen Wang, Jiang Wei
1Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan Institute of Technology, Xiongchu Avenue 693, Wuhan 430073, China.
Bioresource Technology
|February 5, 2013
Summary
This study demonstrates reverse osmosis effectively concentrates sugars while separating acetic acid from lignocellulosic hydrolyzates. Optimal conditions achieved high sugar concentration and reduced acetic acid levels simultaneously.
Area of Science:
- Biochemical Engineering
- Separation Science
- Renewable Energy Technologies
Background:
- Lignocellulosic hydrolyzates contain valuable sugars but also inhibitory compounds like acetic acid.
- Efficient separation of sugars and inhibitors is crucial for biofuel and biochemical production.
- Reverse osmosis (RO) is a promising membrane technology for separation processes.
Purpose of the Study:
- To evaluate the feasibility of simultaneous acetic acid separation and sugar concentration using reverse osmosis.
- To investigate the impact of operational parameters (pH, temperature, pressure) on solute retention.
- To determine optimal conditions for maximizing separation factors and achieving desired concentrations.
Main Methods:
- Utilized a synthetic model solution of xylose, glucose, and acetic acid to simulate lignocellulosic hydrolyzates.
- Examined the effects of varying pH, temperature, pressure, and feed concentration on reverse osmosis performance.
- Employed concentration and diafiltration processes under optimized conditions.
Main Results:
- Monosaccharides (xylose, glucose) showed near-complete rejection above 20 bar.
- Acetic acid retention was enhanced by increasing pH and pressure, but decreased with higher temperatures.
- Maximum separation factors for acetic acid over sugars reached 211.5 (vs. xylose) and 228.4 (vs. glucose) at pH 2.93, 40°C, and 20 bar.
- Simultaneous achievement of high sugar concentration and low acetic acid concentration was demonstrated.
Conclusions:
- Reverse osmosis is a feasible and efficient method for simultaneous acetic acid removal and sugar concentration from lignocellulosic hydrolyzates.
- Operational parameters significantly influence separation efficiency, with specific conditions yielding high separation factors.
- This process offers a viable strategy for pre-treatment of hydrolyzates, improving downstream processing for biochemical production.
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