Technology
What is it?
Biomass pyrolysis is the thermal decomposition of biomass in a non-oxidising environment to produce predominantly bio-char, pyrolysis liquid, and syngas. The composition is dependent on operating conditions and feedstock type. Catalyst choice alters the hydrogen yield in the gas component at different temperatures. When biomass-derived liquid reforming is employed, addition of steam or oxidation results in steam reforming and produces a stream of syngas.
Why is it important?
Biomass is plentiful, regenerative and removes carbon dioxide from the atmosphere, making this process carbon neutral. Coupling the process with CCUS has the potential to make it carbon negative. Simultaneous treatment of municipal waste is also possible.
Characteristics
- Inputs: Biomass, water
- By-products: Carbon dioxide, solid charcoal (biochar)
- Operating temperature: >500°C
- Energy efficiency: 35-50%
Benefits
- With upgrading and stabilisation, the pyrolysis liquid can be used as a substitute for fossil fuels, or used for biomass-derived liquid reforming
- Lower temperature requirements
- Biochar can be used in biomass gasification, or used for fertilising agricultural soil
Limitations
- Low thermal efficiency due to high moisture content of biomass that must be dried
- Produces a significant amount of tar in product gas
- Significant resource requirements to gather and transport biomass to plant for pyrolysis.
- Produces carbon dioxide (CCUS required)
- Note: The TRL of this technology varies based on feedstock: TRL 7-8 for woody biomass, and TRL 5-7 for municipal solid waste
RD&D priorities
- Improve modelling and simulations of the heat, mass and momentum effects in conjunction with kinetics
- Minimise pyrolysis oil formation and improve H2 production
- Process miniaturisation and mobilisation (development of portable units)
- Integrate renewable energy sources. For example, concentrated solar power can act as a thermal energy source for the process
Known active organisations
- CSIRO
- Curtin University
- Monash University
- Queensland University of Technology
- The University of Adelaide
- The University of Newcastle
- The University of Queensland
- The University of Western Australia