Technology
What is it?
Biomass is processed via dark fermentation, followed by anaerobic digestion, which leads to the production of hydrogen and methane. Methane can then be processed to produce further hydrogen, if required, via processes such as reforming or pyrolysis.
Why is it important?
Two-stage anaerobic digestion of biomass presents an opportunity to produce additional methane and hydrogen from biomass following dark fermentation.
Characteristics
- Inputs: Biomass, water
- By-products: Methane, carbon dioxide
- Operating temperature: Ambient, or elevated to approximately 50 to 70°C if thermophilic microbes are used
Benefits
- Low-to-net zero carbon
- Can be carried out at high organic loading rates
- Higher theoretical energy yield achievable compared to one-stage dark fermentation
- More effective for treatment of slurry than pyrolysis
Limitations
- Bacteria must be kept within survivable conditions
RD&D priorities
- Utilise biochar from biomass to enhance yield. Biochar can act as a buffer to maintain optimal pH conditions, and supply carbon, nutrients and minerals that support high bacterial growth
- Optimise operating temperature and pH of the system
- Optimise biomass pre-treatment
Known active organisations
- CSIRO
- Griffith University
- Queensland University of Technology
- The University of Western Australia
- Victoria University