CCS FAQ

CCS uses safe technologies based on more than a hundred years of experience in natural gas storage. In addition, CO₂ is not flammable, explosive or poisonous. This is evidenced by its everyday use in fire-fighting, decaffeination, dry ice, dry cleaning and, of course, carbonated beverages.

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What is CCS?

Storage in depleted fields is both permanent and reliable. The likelihood of accidental leakage is zero because these sites are naturally sealed - as evidenced by their ability to spontaneously store and hold vast quantities of natural gas for millennia without leakage. 

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What is CCS?

Eni and Snam's planned CCS projects have been carefully designed with seismic safety in mind. According to European guidelines, which are also followed by Italian regulations, it's forbidden to build storage sites in areas with high seismic risk (risk level 1). The storage sites selected for the Ravenna CCS project are outside these high-risk seismic areas. In addition, CCS uses a pressure that is not higher than the pressure of the original reservoir, when it contained natural gas. It is worth noting that in the long history of production in the areas off Ravenna and Liverpool Bay, there have been no recorded earthquakes associated with extraction activities.

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What is CCS?

The pressure with which CO₂ is injected underground is rather low. Depleted or near-depleted reservoirs have internal pressures (fluid layer pressure) that are often well below their initial levels (hydrostatic pressure). Therefore, there's no need to achieve higher pressures to inject CO₂. In addition, the volume of carbon dioxide to be injected will always be less than the volume of methane previously extracted, ensuring that we never approach the reservoir's initial pressure levels. 

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What is CCS?

To further enhance safety, the Ravenna CCS will use advanced microseismic monitoring tools and techniques for detecting ground motion that have already been used in the Ravenna area to monitor subsidence associated with gas extraction. These monitoring methods, whether continuous or periodic, use cutting-edge technologies ensuring great precision and reliability. With decades of experience, Eni has acquired considerable expertise both in the use of these tools and in the interpretation of the data obtained.

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What is CCS?

It's important not to equate CCS with Enhanced Oil Recovery (EOR), which is used in the US to increase oil recovery by injecting CO₂ into active reservoirs. In the context of the Ravenna CCS, storage will take place in depleted methane reservoirs that would be destined for definitive decommissioning. Once converted to carbon dioxide storage, these reservoirs will no longer be usable for production. 

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What is CCS?

CCS is a technically mature process based on proven technologies. Its effectiveness is demonstrated by plants that have been in operation for many years. There are currently 33 operational CCS initiatives around the world, with a cumulative capacity of around 40 million tonnes per annum (Mtpa). In Europe, particularly in Norway, plants such as Snohvit and Sleipner have been operational since 2008 and 1996 respectively. 

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The global context

Even after taking into account emissions from energy use during the carbon capture and compression process, the net reduction in emissions is between 70-80%. The exact percentage of reduction depends on the specific capture method and its industrial application. Today's methods can capture of over 90% of the CO₂ emitted from industrial chimneys, as widely demonstrated by plants currently in operation. As with most industrial processes, the capture of CO₂ and, to a lesser extent, its compression, requires energy and, depending on the source of this energy, may result in the release of CO₂. However, the effectiveness of current CCS methods, which is already impressive, will be further enhanced by technological advances and the predicted increase in renewable energy in the coming years, ensuring a supply of clean energy also for capture processes to be applied to “hard to abate” industries.

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The role of CCS in the decarbonization strategy

More and more governments are directly backing domestic CCS projects to contribute to the decarbonisation of entire production districts.

With the introduction of the Inflation Reduction Act in 2022 in the United States, CCS projects are granted tax benefits as well as funds for research and investment in technology.
In the United Kingdom, the government has outlined a decarbonisation strategy with the aim of capturing and storing 20-30 million tonnes of CO₂ per year by 2030, accompanied by supporting policies worth around £20B, to attract private investment and lower market risk.

Norway is directly participating in the investments that will be needed to bring the Longship CCS project to fruition, contributing about 2/3 of the total value of the costs.
The European Union is also allocating funds, such as the Innovation Fund and the Connecting Europe Facility, with an increasing share regularly being allocated to CCS projects.
In addition, some EU Member states, including the Netherlands and Denmark, have provided significant support tools for the development of CCS technology and projects that will be able to help in achieving national decarbonisation targets. 

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The global context