Mineralisation
Industries that emit dilute CO2 streams, for example hard-to-abate processes with cement, iron and steel, bio-gas and liquefied natural gas, prioritise the safe capture and storage of carbon. Despite this, carbon capture and geological storage technologies face significant challenges, including high CO2 capture costs and uncertainty surrounding CO2 storage. This integrated process can capture CO2 from dilute sources and subsequently convert CO2 and alkaline solid wastes to construction materials.
Additionally, coal-fired power generation and many other industrial processes generate around two billion tonnes of alkaline residues each year and more than 90 billion tonnes in total since industrialisation. These wastes are frequently stored in waste piles or landfills and can pose an environmental risk. We’ve developed an integrated CO2 absorption and mineralisation process, which can capture CO2 from dilute sources and convert CO2 and alkaline solid wastes to construction materials such as cement and geopolymer.
Technology
Our technology uses chemical absorbents to capture CO2 from dilute streams to form a CO2-rich solution which reacts with Ca/Mg containing solid wastes. Carbonation reactions occur between wastes and the CO2-rich solution, from which CO2 is precipitated as carbonate and the chemical absorbent is regenerated. The technology is cost effective for emission reduction and utilisation of CO2 and solid wastes. Benefits of the technology include:
- The carbonation reaction is exothermic, and no additional energy is needed for the solvent regeneration and CO2 compression.
- The mineralisation process does not require steam extraction from the power station and can be carried out independently, having a high operational flexibility.
- Geological storage is not needed, and the CO2 captured is safely stored as the stable carbonate.
- Less absorbent degradation and equipment corrosion occurs at low temperatures, which will reduce costs for absorbent makeup, plant maintenance and treatment of waste generated, and produce less waste.
- The alkaline wastes are neutralised, and the resulting products have improved commercial values.
Applications
This integrated technology could be readily deployed in industries that produce both CO2 and alkaline wastes, for example:
- cement plants
- iron and steel mills
- fossil fuel-based power plants.
It could also be deployed in natural gas production, bi-gas industry, aluminium smelters and hydrogen production where alkaline wastes from other processes can be incorporated.
Featured in the media: A concrete step forward: Australia’s ambitious plan to cut cement and lime emissions.
Intellectual property
Know-how on materials selection and process assessment.
