Annual global CCS capacity needed to meet IEA sustainable development scenario.
To meet global targets the IEA estimates the industry will have to scale up by some 60 times its current capacity.
GHG emitters will increasingly need to either minimise their emissions or acquire approved offsets, either by stand alone offset projects or the purchase of Australian Carbon Credit Units (ACCUs).
Carbon Capture and Storage (CCS) is an effective method for safely removing GHG emissions, particularly for large volumes / high rates.
Demand for GHG storage capacity is expected to grow exponentially.
What is Carbon Capture and Storage?
CO₂ is a powerful greenhouse gas (GHG) and rising concentrations in the atmosphere are contributing to climate change.
GHG emissions come from a variety of sources including agriculture, land use change, industrial processes such as cement and steel manufacture, but are primarily generated through the use of fossil fuels.
Carbon Capture and Storage (CCS) is a multi-stage process.
Capture
CO₂ can be captured from an emission source where the CO₂ is highly concentrated e.g. LNG gas processing plants, coal fired power stations, ammonia facilities, cement facilities. Historically this CO₂ has been emitted straight to the atmosphere but, with the adoption of net zero targets, companies and governments are imposing limits to hasten GHG emission reduction and lower atmospheric CO₂.
CO₂ can also be removed from the atmosphere where the CO₂ is present in a much lower concentration (0.04%) in a process called Direct Air Capture (DAC). DAC is effectively removing historic emissions but the lower concentration makes it more expensive to operate per tonne CO₂ captured.
Transport
Once captured the CO₂ is compressed and transported to a storage location by road, rail, pipeline or ships depending on the amount of CO₂ and the distance from GHG source to storage location
Storage
The compressed CO₂ is injected into suitable rocks more than 1km underground and permanently stored in tiny pore spaces. It is prevented from escaping by a combination of physical barriers and processes.
Not all locations are optimal for CO₂ injection and an in-depth understanding of the suitability of local conditions is needed for successful and cost effective long term geological storage of CO₂. This is GeoVault’s area of expertise.
Storage is the key.
CO₂ needs to be permanently stored in a geologically secure location; a “geological vault”. The process involves compression of CO₂ to a state known as supercritical (a highly dense fluid like state) which is injected into a suitable porous rock formation. Once injected, the CO₂ will move slowly through the rock, filling up the microscopic pore spaces that normally contain salty water. To be a good storage formation the rock layers must exhibit several characteristics including:
Have a large enough area and be thick enough to contain the required volume of CO₂ (capacity)
Have a connected network of spaces, called pores, which will allow the CO₂ to move away from the injection well and fill up the surrounding rock (continuity and injectivity)
Be deep enough (more 1km below the surface) and have a good impermeable sealing rock layer above the storage formation, to ensure the CO₂ remains permanently trapped in the supercritical state (containment).
The movement of CO₂ will be monitored by a number of different technologies to ensure it is moving through the rock as predicted.
Geological carbon storage imitates how nature has stored oil and gas for millions of years. It builds on decades of oil and gas industry expertise ensuring that CO₂ remains trapped below the surface just as oil and gas have naturally remained trapped.
