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Published on: December 25, 2015
Fermentative hydrogen production in packed-bed and packing-free upflow reactors
1Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR, China. h0295019@hkusua.hku.hk
Summary
This study compared two upflow reactors for fermentative hydrogen production from sucrose. Reactors with packing rings achieved higher hydrogen production rates and yields than packing-free reactors, indicating packing enhances efficiency.
Area of Science:
- Biotechnology
- Environmental Engineering
- Microbiology
Background:
- Sustainable hydrogen production is crucial for a clean energy future.
- Fermentative hydrogen production from wastewater offers a promising renewable energy source.
- Optimizing reactor design is key to maximizing hydrogen yield and production rates.
Purpose of the Study:
- To investigate the impact of reactor packing on fermentative hydrogen production from sucrose.
- To evaluate the effect of varying hydraulic retention times (HRT) on hydrogen production efficiency.
- To analyze the microbial community and structural characteristics of granular sludge.
Main Methods:
- Two upflow anaerobic reactors were operated for 400 days: one with packing rings (RP) and one packing-free (RF).
- Sucrose synthetic wastewater (10 g/L) was used at 26°C with HRTs ranging from 2 to 24 hours.
- Microbial community analysis using 16S rDNA and structural analysis of granules via fluorescence techniques were performed.
Main Results:
- The reactor with packing rings (RP) consistently showed higher hydrogen production rates and yields compared to the packing-free reactor (RF).
- Optimal HRTs for maximum hydrogen yield were identified as 14 h for RP and 8 h for RF.
- Granular sludge formation was observed in both reactors, with extracellular polysaccharides concentrated on the outer layer of granules in the RP.
Conclusions:
- Reactor packing significantly enhances fermentative hydrogen production efficiency from sucrose.
- Hydraulic retention time critically influences hydrogen yield, with optimal values dependent on reactor configuration.
- The structure of granular sludge, particularly extracellular polysaccharide distribution, plays a role in hydrogen production.
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