Carbon Capture and Storage
One of the most important technologies for addressing climate change is CO2 capture & sequestration (CCS).
CCS (carbon capture & sequestration)
Without CCS, global climate targets may not be obtainable, with the International Panel on Climate Change’s 5th Assessment report stating “many models could not limit likely warming to below 2°C if bioenergy, CCS and their combination (BECCS) are limited.”
CCS is a technology value chain which captures CO2 before it is emitted to the atmosphere and sequesters it safely – whether through incorporation into new useful products, or stored underground in expended oil and gas fields or aquifers.
While there are a number of large scale CCS projects in the world, one of the main reasons that CCS has not been widely adopted yet is due to the complexity and prohibitive costs of operating the additional equipment currently required to capture the CO2. This is a particular issue for the cement and lime industries which operate in a highly competitive sector; but the sectors urgently need viable CCS solutions. The majority of the CO2 emissions associated with the production of cement and lime are released directly, and unavoidably, from the chemical reaction in the process – not from the combustion of fossil fuels.
LEILAC aims to tackle this problem, by demonstrating a technology that could replace an existing part of the cement and lime making process, and capture the pure process CO2 emissions without significant energy or capital penalty. It can also work in conjunction with other capture and emissions reduction approaches such as oxy-fuel, maximising the options available.
LEILAC will contribute to providing the community with a technology that can address the dual challenges of enabling European industry to sustainably thrive while significantly lowering CO2 emissions.
In 2009, the European CCS Directive was created to establish a legal framework for the safe geological storage of CO2. Its provisions cover all geological storage sites in the European Union. This lays down extensive requirements for the selecting sites for CO2 storage. A site can only be selected if a prior analysis shows that, under the proposed conditions of use, there is no significant risk of leakage or damage to human health or the environment. No geological storage of CO2 will be possible without a storage permit.
Such permanent storage is also the only way that many industries can decarbonise: for example CO2 is unavoidably released by the processing of cement meal, and CCS is the only way of managing the majority of these emissions (see also the latest International Energy Agency report here). “Underground accumulation of carbon dioxide (CO2) is a widespread geological phenomenon, with natural trapping of CO2 in underground reservoirs…Injecting CO2 into deep geological formations at carefully selected sites can store it underground for long periods of time: it is considered likely that 99% or more of the injected CO2 will be retained for 1000 years” (IPCC report Chapter 5, and Nature)
The fact that geological storage CO2 is a very safe and proven method of ensuring that the CO2 does not get released into the atmosphere, is supported by many years of demonstrated experience. Norway has successfully prevented around 30million tonnes of CO2 from being emitted to the atmosphere by storing CO2 offshore for 22 years at Sleipner and then Snøhvit.
The IPCC, representing the scientific community, has a special report on CO2 storage here www.ipcc.ch/report/carbon-dioxide-capture-and-storage/ explaining what happens when CO2 is stored: “Carbon dioxide can remain trapped underground by virtue of a number of mechanisms, such as: trapping below an impermeable, confining layer (caprock); retention as an immobile phase trapped in the pore spaces of the storage formation; (and) dissolution in the in situ formation fluids. Additionally, it may be trapped by reacting with the minerals in the storage formation and caprock to produce carbonate minerals. Models are available to predict what happens when CO2 is injected underground… Moreover, CO2 becomes less mobile over time as a result of multiple trapping mechanisms, further lowering the prospect of leakage.” (IPCC report Chapter 5)
A recent summary about why CO2 storage is safe, explaining more about this trapping mechanism can be found here.
CCU (carbon capture and utilisation)
Carbon Capture and Utilisation consists of a range of technologies that use or convert captured CO2 to make valuable fuels, feed, chemicals, building materials or other products. Some technologies require a purified (concentrated) CO2 stream, whereas others can utilise the CO2-rich exhaust gas. The market of these products however is not large enough to cover all man-made CO2 emissions. Therefore, the cement and lime sectors consider CCS inevitable to reach the EU targets. (See the FAQ for more information).
The CCS technology is in principle ready to be applied, but it is currently not economically feasible for cement and lime while public support is weak in several countries.
Therefore it is clear that both CCS and CCU need to be developed in parallel as a whole range of solutions will have to be implemented by 2050.