What is Carbon Capture and Storage
Carbon storage is a complex method, as it captures carbon dioxide emissions and stores them in coal seams, aquifers, depleted oil and gas reservoirs and other spaces deep under the surface of the Earth.
The emissions are captured either at the source of production, such as a power plant, or directly from the air. After that, arbon dioxide can be separated from other gases either before or after combusting fuel in a plant or industrial facility.
With this technology it is considered that up to 90% of the CO2 emissions pro duced from the use of fossil fuels can be captured. The CCS includes three parts:
- Capturing the carbon dioxide;
- Transporting the carbon dioxide;
- Securely storing the carbon dioxide emissions, underground in depleted oil and gas fields or deep saline aquifer formations.
At first, capture technologies separate the carbon dioxide from gases produced in electricity generation and industrial processes. After this process, the carbon dioxide is transported by pipeline or by ship for safe storage. Specifically, millions of tonnes of carbon dioxide are being transported annually for commercial purposes by road tanker, ship and pipelines. In fact, the US has already four decades of experience of transporting carbon dioxide.
Finally, the carbon dioxide is stored in carefully selected geological rock formation that are typically located several kilometres below the earth's surface.
Carbon capture in shipping
Currently, shipping finds itself at a critical crossroad regarding its green footprint. With IMO trying to reduce emission by 50% in comparison to 2008, the industry is considering ways to comply and become greener.
While alternative fuels, and slow steaming, seem to be winning the trust of shipowners, there are many saying that carbon storage is the future for shipping’s decarbonization.
More specifically, according to a recent Japanese study, onboard capture systems could reduce emissions by 85% and up to 90% depending on technological advancements.
Nevertheless, the study highlights that the resulting captured CO2 would be much heavier than the fuel, by as much as four times more than standard oil. As a result, extra energy would be necessary to propel vessels to their final destinations.
In addition, the authors noted that despite the fact that any fuel could potentially be used, it would require pre-treatment before its use. This process would ensure the removal of sulphur and nitrates. What is more, systems for unloading and processing captured carbon would also have to be created.
However, despite these problems, an innovative project focuses on the tremendous potential this technology has for almost full decarbonization. Namely, a group of shipping companies including NYK, Sovcomflot, Knutsen OAS, Ardmore and DSME, have joined forces with the Maritime Development Center to develop an on-board carbon capture and storage solution in a project named decarbonICE.
The decarbonICE project started in October 2019 and will run through 2020. Its aim is to prepare a feasibility study and begin the IMO approval process for the technology.
While decarbonICE mainly focuses on newbuilds, it also takes a look at retrofitting existing ships, providing the opportunity to accelerate the transition towards the IMO target.
In combination with future carbon neutral fuels like biofuels and electro fuels, the decarbonICE technology can create carbon negative shipping and thus contribute to atmospheric carbon reduction at a significantly lower cost than shore-based carbon capture
stated Chairman of the decarbonICE project, former DNVGL President and CEO Henrik O. Madsen.
What is more, Mitsubishi announced on August that it will build and test a carbon capture system for ships, aimed at significantly reducing the emissions of the maritime sector.
The company has already started work on developing the system for vessels, which promises to reduce ship emissions by up to 90% and even produce raw materials for new fuels to be produced.
The demonstration involves converting the design of an existing CO2 capture system for onshore power plants to a marine environment, and installing it on board an actual ship in service
Mitsubishi explained.
R&D and the testing phase are set to last two years, with Mitsubishi expecting to complete construction of the onboard capture system by mid-2021.
Pros and cons of carbon storage
When talking about the benefits of carbon storage, its environmental friendly character is the most significant one. With this technology, CO2 emissions will be prevented from spreading and exacerbate climate change.
Moreover, many advocates claim that carbon storage is actually cheaper than switching from fossil fuels to forms of renewable energy like solar power.
However, according to Mitsubishi’s calculations for its project, the system would add more than US$45M to the cost of a conventional VLCC.
What is more, return on investment is not the only obstacle. The size and weight of the carbon capture units also pose challenges. The system for MHI’s project uses the treatment method that has been deployed on land. The weight of the whole system would be over 4,500 tonnes, or nearly 2% of the vessel’s deadweight.
Another barrier is the fact that the carbon capture is not totally effective, with a capture rate of about 86%. Of course, the technology is expected to improve in the future, but at tis stage it seems that it cannot lead to a vessel that offers no carbon emissions.
Carbon storare is a really innovative solution for achieving shipping’s climate goals. While this technology is not new on land, applying it on ships would require different necessities. Should the shipping industry manages to solve these new requirements, carbon storage can truly be a great solution.
