Carbon Capture and Storage: decarbonising systems during the energy transition

What is Carbon Capture?

Carbon capture is a broad term to apply to the reduction of CO₂ emissions in the atmosphere, with a variety of technologies and applications. 

Carbon capture is an important measure to reduce carbon emissions to the atmosphere by capturing CO₂, and either utilizing it or storing it several kilometers underground. Carbon capture has existed for many years already, but at a relatively small scale. Our current global systems will continue to produce too much CO₂, and solutions to handle it elsewise must be considered.

Industries with heavy CO₂ emissions from energy generation (power) or direct industrial processes (cement, chemicals, metals, waste refining, power, heat, hydrogen…etc.) are now turning to carbon capture to reduce their carbon footprints. 

Between sectors, options for CO₂ mitigation vary. For some processes, such as cement production and waste incineration with heat recovery, few mitigation options for deep emission reductions beyond carbon capture are identified, due to the nature of their processes (calcination processes for cement or incineration of waste).

Carbon Capture and Utilisation (CCU)

CCU is a broad term that covers all established and innovative industrial processes that aim at capturing CO₂ – either from industrial  sources or directly from the air – and at transforming the captured CO₂ into a variety of value-added products such as synthetic fuels, chemicals, enhanced oil recovery and building materials. 

Other terms such as CO₂ transformation, CO₂ conversion, CO₂ recycling, CO₂ valorization, or CO₂ upcycling are used to describe CCU. Carbon is integral to many products we use every day, and CCU is receiving increasing interest, partly due to climate change considerations and because using CO₂ as a feedstock can result in a cheaper or cleaner production process compared with using conventional hydrocarbons. 

Carbon Capture and Storage (CCS)

CCS is CO₂ capture, transport and storage; the CO₂ released by industrial plants is captured by separating it from other gases, then liquefied and/or compressed and transported by pipeline or by ship to the storage site. This may be the lithosphere, by geological sequestration into reservoirs such as saline aquifers or depleted oil and gas reservoirs, or by mineralization into rocks; the biosphere, in trees, soils and the human-built environment; or the hydrosphere, with storage in the deep oceans.

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Carbon Capture Export 

Carbon capture technologies are applied to industrial sites or power plants to capture CO₂ that would otherwise be released into the atmosphere.

The first carbon capture and storage projects underway in Norway with financing from the Norwegian government include Norcem and the joint Equinor/Shell/Total Northern Lights project exporting CO₂ in an offshore reservoir. These projects utilise technology and procedures from the existing commercial CO₂ distribution market and offshore energy sector. Therefore, the first vessels dedicated for carbon capture will be fitted with pressure tanks capable of handling 15 barg and -30 °C, such is standard in today’s CO₂ marine distribution industry.

However, in the future it is possible that vessels will adapt to optimum operating pressures closer to the triple point for CO₂ (-56 °C and 5.1 bar). Today’s vessels, with operating pressures around 15 bar, require heavy tanks (40mm-45mm wall thickness) which are expensive and difficult to manufacture. With lower pressures, one can allow for cheaper and lighter tank designs which can in turn reduce the CO₂ shipping cost.

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Carbon Capture Import 

There are two pathways for captured CO₂. The first is to feed the current and evolving commercial market that uses CO₂ in the manufacturing process of their end product (carbon utilization). The second is to remove the CO₂ from the value chain by permanently storing it in geological reservoirs (carbon storage). Both pathways will require an import facility with intermediate storage, if not already in place.

Today’s commercial market for carbon utilization will likely continue with small transport volumes and transport pressures in the vicinity of 15 barg with corresponding temperatures around -30 °C. The import to permanent storage facilities will follow the development of the carbon capture industry and will need to accommodate a larger span of pressures and be able to adapt to the emerging market.

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Carbon Capture for LNG, Blue Hydrogen and Ammonia

In countries where LNG, gas-based power generation and fuel production is likely to retain an important role due to available and suitable infrastructure or abundant domestic resources, including carbon capture in the portfolio of technology options can reduce the total cost of power system transformation, compared to renewable power. 

An IEA 2019 report that targeted regional studies found that the cost of decarbonizing the UK power system would be about 50% higher if carbon capture was not available. In Poland it would be 2.5 times higher, and in New South Wales in Australia it would be twice as high.

Similarly, blue hydrogen, or hydrogen produced with “blue” feedstocks such as natural gas and coal, set the low-cost benchmarks for low-carbon storable energy commodities. For production facilities that use blue feedstocks, carbon capture can enable the carbon-free production of ammonia and hydrogen, as well as enabling zero emissions from existing LNG powered plants. 

Floating Solutions for the Carbon Capture Value Chain 

ECONNECT Energy enables storage terminals by reducing the overall terminal payback time, lead time and flexibility for terminal owners. Already proven successful in the LNG market, ECONNECT Energy provides floating CO₂ liquid export and import terminal solutions. 

In areas where the geology suitable for underground storage is not available, new infrastructure is required to transport the captured CO₂ for utilization or storage elsewhere. Traditional CO₂ import and export shipping methods need to be substituted for smart and flexible infrastructure for profitable carbon capture projects.

For some clients, especially industrial sites looking towards capturing and temporarily storing CO₂  for export, space restriction can be a barrier. In such instances the use of ECONNECT Energy’s storage barge connected by the IQuay transfer system will be a key enabler as pairing the IQuay with floating storage tanks allows for increased flexibility. 

The IQuay jettyess solution can be scaled according to a project’s need, enabling the carbon capture and utilisation value chain. Benefits include:

• A floating transfer system allows for a high degree of flexibility and can be deployed quickly and without the environmental impact of building conventional marine infrastructure - the floating solution does not affix to the seabed and does not disturb marine biodiversity, so no negative consequences to seabed morphology, water quality, nor marine habitats. 
• Along with transportation through pipelines, CO₂ can be transported on ships either at high-pressure state or at liquid state by cooling the gas down to the liquefaction point.
• Loading and unloading ships with a jettyless system provides for a fast and flexible solution that lowers the risk because of its flexibility. Our systems have high safety standards from the LNG industry which will be valuable lessons learned for the management of CO₂.
• Minimal footprint: hoses can be reeled and platform moored close to shore while not in use.
• Cost Efficient: significant CAPEX reduction compared to fixed infrastructure
• Flexible to demand and easy to re-deploy in other CCS locations, thereby simplifying asset investment and increasing utilisation across several projects.

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This article was Co-written by Stian T. Magnusson and Danielle Murphy-Cannella