CO2 is considered the main "culprit" causing global warming and climate change. Therefore, burying CO2 under the seabed is considered by many countries in the world as an effective measure to handle this toxic gas and deal with climate change.
In early 2023, Denmark officially launched a project to store CO2 emissions under the seabed. The project, called Greensand, uses an exploited oil field developed by British chemical group Ineos and German oil group Wintershall Dea, and is expected to store up to 8 million tons of CO2 emissions per year by 2030.
The Greensand project will capture and liquefy industrial CO2 and inject it into old oil wells. (Photo: Semco Maritime)
At the Greensand project, CO2 emissions are transported in specialized containers to the Nini West mine, where they are pumped into a storage tank 1.8 km below the seabed.
Denmark aims to be carbon neutral by 2045. Authorities say the approach is an essential tool in Denmark's climate change toolkit.
Before Denmark, Norway has also launched a number of CO2 burying projects. The country boasts the best prospects for CO2 storage on the European continent, especially in depleted North Sea oil fields. The government has funded 80% of the infrastructure, investing 1.7 billion euros to develop the technology.
Norwegian companies have even planned to build a giant pipeline to develop the world's first cross-border CO2 transport and storage service, scheduled to launch in 2024.
Accordingly, a pipeline will pump liquefied CO2 into geological pockets 2,600 meters deep under the ocean floor, where this CO2 will stay forever. This pipeline system has a capacity to transport 20 to 40 million tons of CO2 per year, equivalent to the emissions of 3 to 6 million people.
There are currently about 30 CO2 burying projects in operation in Europe. However, these projects can only handle a very small amount of the CO2 that European countries are currently emitting.
According to the European Environment Agency (EEA), European Union (EU) member states emitted 3.7 billion tonnes of CO2 emissions in 2020 alone - a year that saw economic activity decline due to the COVID-19 pandemic.
Construction of a facility to pump liquefied CO2 under the seabed in Norway. (Photo: AFP)
Not only do scientists "bury" CO2, they also hatch a plan to turn this toxic gas into stone. In 2016, an international team of scientists mixed CO2 with water, and then pumped this liquid mixture into a layer of basalt deep underground.The Hellisheidi power plant in Iceland, the world’s largest geothermal power plant, emits 40,000 tons of CO2 per year, just 5% of the emissions of a coal plant of similar size, but still a worrying figure.
Scientists were concerned that it would take hundreds, even thousands of years for the liquid mixture to turn into stone. However, after only two years, 95-98% of the mixture pumped down had turned into chalky white boulders.
The only problem with this type of CO2 storage technology is that it requires a lot of water, with each ton of CO2 needing to be dissolved in 25 tons of water. However, scientists say that in some places, seawater can be used.
CO2 capture and storage is currently the only technology capable of reducing greenhouse gas emissions at scale across a wide range of industries. It is seen as a viable solution for CO2-heavy industries as a way for them to continue operating in the face of increasingly stringent emissions reduction measures aimed at combating climate change.
CO2 is considered the main "culprit" causing global warming and climate change, and this is also the reason why scientists have long sought to develop solutions to capture and store CO2. Basalt has emerged as a prime candidate. Formed by magma that cools and erupts from volcanoes, it is dense, porous, and rich in calcium, iron, and magnesium. Basalt forms much of the Earth’s seafloor. |
Ngoc Chau
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