Images

Flue gases pass through a solvent that preferentially absorbs carbon dioxide.

Carbon dioxide passes through the membrane more easily than other gases.

Carbon dioxide diffuses through a membrane and is absorbed by the solvent.

The gas is cooled and only carbon dioxide condenses. The rest of the gas is vented to the atmosphere.

Chilled water is passed through the flue gas. Water and carbon dioxide form hydrates.

Adsorbents preferentially attract molecules of carbon dioxide to their surface. A change in pressure or temperature releases the carbon dioxide.

In natural gas processing, CO₂ is separated in the gas sweetening stage.

Carbon dioxide is produced in the manufacture of ammonia from natural gas or other fossil fuels. It is separated as part of the process, so it is ready for compression and transport to storage.

The process of making iron and steel creates CO₂ emissions through the use of fuel for energy and the use of coke and limestone.

Schematic representation of CO₂ capture in natural gas processing.

Schematic representation of pre-combustion CO₂ capture.

Schematic representation of post-combustion CO₂ capture.

Multi-layer adsorption beds separate flue gases in stages.

Principle of adsorption capture.

Membrane gas absorption: hollow fibre module.

Gas separation membrane: flatsheet module.

CO₂ moves upwards to the top seal. Over time the CO₂ dissolves into the formation water. This makes it denser and it moves downwards.

Carbon dioxide can be reacted with minerals to form stable carbonates. The mineral needs to be crushed and research is underway to increase the rate of reaction.

CO₂ can be stored in mineral residues such as red muds produced by alumina refineries.

As more information about a potential storage site is obtained, uncertainty about the volume of carbon dioxide that can be stored is reduced.

Rock formations for geologic storage, such as deep saline formations, would be much deeper than any usable groundwater and separated from that groundwater by thick barriers of impervious rock.These formations generally already proved their effectiveness by keeping highly-salty saline water separate from usable groundwater for millions of years.

Geological storage options for CO₂. Several types of rock formations are suitable for CO₂ storage, including depleted oil and gas fields, deep saline formations and deep, unmineable coal seams. Other types of formations such as basalts and oil shales are being examined by scientists for possible future use.

Some CO₂ will be trapped between pores some will dissolve and sink in the formation and some will react to form stable minerals. The dissolved CO2 travels very slowly with the formation water, trapped in the formation.

A sealing fault can line up an impervious rock layer with the formation to prevent the CO₂ from moving upwards out of the formation

The buoyant CO₂ will collect under a curved layer of impermeable rock at the highest point, unable to move out of the formation.

CO₂ can become trapped when there is a change in the type of rock in the formation from a permeable rock to an impermeable rock.

The CO₂ is trapped when there is a sudden change in the rock formations, so that the CO₂ cannot move further upwards.

As time goes on, increasingly secure trapping mechanisms come into play and the overall security of storage increases

CO₂ will be injected at depths below 0.8 km (2600 feet ). CO₂ increases in density with depth and becomes a supercritical fluid below 0.8 km. Supercritical fluids take up much less space, as shown in this figure, and diffuse better than either gases or ordinary liquids through the tiny pore spaces in storage rocks. The blue numbers in this figure show the volume of CO2 at each depth compared to a volume of 100 at the surface

Carbon dioxide can be injected into oil reservoirs, making the oil easier to produce. Some of the carbon dioxide remains trapped in the rocks.

CRC-1 Injection Well

Preparing control lines to be lowered into the well

CO2CRC’s Otway project visitor centre

Martin Ferguson, CO2CRC Chairman, speaks to guests

Tania Constable, CO2CRC CEO, Martin Ferguson, CO2CRC Chairman, and Richard Riordan, Member for Polwarth, unveil the plaque

CO2CRC’s Rajindar Singh explains the important research untaken at the site

127m of core was recovered for the CRC-3 Well

The inside of the renovated visitors centre made possible by sponsorship from the GCCSI

Aerial view showing the CRC-3 Well at the CO2CRC Otway National Research Facility

Members of the local community and from further afield came to the Otway National Research Facility for the annual Open Day.