What is it?
Coal is reacted with controlled amounts of oxygen and/or steam at high temperatures to produce syngas (hydrogen and carbon monoxide) which also contains carbon dioxide, methane and water vapour. Gasification involves four stages: drying, pyrolysis, combustion, and gasification reactions.
Why is it important?
This process is well understood and established at industrial scale.
- Inputs: Coal, water, heat
- By-products: CO2, carbon, other hydrocarbons (temperature dependent)
- Operating temperature: >500°C
- Energy efficiency: ~63%
- Established industrial process
- Other chemicals generated can be useful by-products
- Higher hydrogen produced per unit of coal compared to coal pyrolysis
- Cleaner hydrogen product than that obtained from coal pyrolysis
- Impurities in syngas require further separation
- Low thermal efficiency
- Produces tar in product gas
- Requires CCUS to achieve low carbon emissions
- Remains a higher emitter of carbon dioxide than natural gas-based methods and renewable methods after CCUS is employed
- High water usage per kilogram hydrogen produced
- Develop and demonstrate effective means of integrating carbon capture, utilisation and storage (CCUS) to achieve zero-to-low carbon emissions
- Develop alternatives to the cryogenic process used to separate oxygen feedstock from air
- Improve appliance and plant design for greater flexibility in ramping up and ramping down
- Integrate renewable energy sources. For example, concentrated solar power can act as a thermal energy source for the process
- Establish environmentally suitable treatment of waste by-products
- Develop cheap and effective hydrogen separation systems to obtain appropriately pure hydrogen for specific applications
- Improve reactor design to accommodate highly exothermic or endothermic reactions (e.g. staged introduction of reagents, better designed heat transfer surfaces, process intensification, advanced materials, reaction monitoring/control, pre-treatment of waste streams)
Known active organisations
- Curtin University
- The University of Adelaide
- The University of Newcastle