Greenhouse gas removal

Small amounts of CO₂, methane and other fossil fuel emissions have an outsized impact on global warming. Although they exist at low concentrations in the atmosphere – around just 0.04% in the case of CO₂ and 0.00017% for methane – they are nevertheless exceptionally good at trapping heat. Yet the low concentrations and the chemical nature of these compounds makes them difficult to filter out of the atmosphere.

To address this challenge, we’re developing engineered approaches to carbon removal via Direct Air Capture (DAC) through the design of nanomaterials that selectively trap greenhouse gas molecules, such as CO₂. This will provide a sustainable source of CO₂, a key commodity for agriculture and horticulture, and as a valuable feedstock for renewable fuels.

The removal of CO₂ from the ambient air using renewable energy can be achieved using specially designed nanomaterials called Metal-Organic Frameworks (MOFs) which can be produced economically and at scale.

We're looking at new techniques to develop advanced MOFs with highly sought-after physicochemical properties such as ultrahigh selectivity for CO₂ combined with air and water stability.

We're also researching nanomaterials with outstanding efficiency for conversion of CO₂ to commodity chemicals.

Lead: Professor Deanna D'Alessandro

Team: Professor Timothy Langrish, Dr Gustavo Fimbres Weihs, Professor Anita Ho-Baillie, Professor Christopher Wright, Dr Gareth Bryant, Associate Professor Amanda Tattersall, Katie Moore

We’re developing engineered approaches to carbon removal via soil sequestration of carbon. As the largest body of terrestrial carbon, soils are widely recognised as an important sink for atmospheric carbon. Our work seeks to improve the persistence of soil carbon by advancing our understanding of carbon sequestration in soils and ultimately redesigning better soils that can maintain higher levels of carbon.

Research areas:

• Implementing methods to quantify soil carbon and thus verify increased CO₂sequestration by soils.
• Developing methods for increasing carbon in soil via DAC leading to high CO₂cropping (increasing biomass capture), understanding microbial processes and soil mediated by nanomaterials and improving the retention of carbon as microbial necromass adsorbed into nanomaterials.

Team: Professor Alex McBratney, Professor Budiman Minasny, Professor Deanna D'Alessandro

In many Australian industries CO₂ is a valuable commodity and essential to maintaining a robust supply chain. Examples include pH control in water treatment, protected cropping and microalgae cultivation for food production, as well as and Modified Atmosphere Packaging (MAP) to extend food shelf-life. Currently, these industries use CO₂ derived from non-renewable fossil fuel resources and face an immediate challenge in transitioning to sustainable sources of CO₂.

Sustainable CO₂ production via capture from the air rather than from fossil fuels enables the development of a ‘circular economy’ from which valuable commodity chemicals can be produced.

The processes involved in Direct Air Capture, concentration and purification of CO₂ can be powered by low-cost renewable energy and could displace the use of fossil fuels. Such sustainable CO₂ production will enable the development of a ‘circular economy’ from which valuable commodity chemicals can be produced.  Moreover, by designing these processes to operate intermittently in an efficient manner, they could also offer a way to stabilise electricity grids.

Research themes:

• Developing advanced nanomaterials such as Metal-Organic Frameworks (MOFs) for (i) electrochemical CO₂ reduction to high value-added products through standard intermediates such as ethanol and ethylene, and (ii) production of green methane and methanol. We would seek to utilise green hydrogen as a reactant.
• Integrating advanced nanomaterials into units for industrial-scale conversion including plasma-driven synthesis of hydrocarbons from CO₂.
• Developing viable separation/purification methods to yield valuable commercial-grade products.

Team: Professor PJ Cullen, Dr Fengwang Li, Dr Gustavo Fimbres Weihs, Associate Professor John Kavanagh, Professor Andrew Harris, Dr Li Wei

Sediment weathering is a natural process that sequesters carbon out of the atmosphere. Decades of laboratory research have shown that it may be possible to increase the rate of sediment weathering by intentionally mining, grinding, and spreading easily weatherable rocks and minerals on beaches where the increased surface area (from mechanical grinding) and tumbling action of waves results in dissolution rates thousands of times faster than is typically found in nature. This process is called Coastal Enhanced Weathering (CEW) and is an example of a negative emissions technology (NET) which may be capable of removing significant amounts of excess CO2 from Earth’s atmosphere if applied at scale (~ 108-109 metric tons per year). The challenge is to understand how olivine sand is transported by wave action, currents, and tides in coastal ecosystems, leading to uncertainty about how and whether olivine sand may be successfully incorporated into coastal engineering projects. 

Our research aims to understand how olivine-supplemented sediments will respond to coastal dynamics when deployed into a beach setting by using numerical modelling and flume tank experiments. 

Lead: Dr Sara Moron Polanco

Team: Associate Professor Eleanor Bruce, Associate Professor Ana Vila Concejo