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CO2: Back from whence it came

How can we get back from the brink?

Carbon Capture and Storage (CCS) will necessitate trading, moving, and storing CO2. In part II of our series, we explore how CCS will bring about completely new economies, in which the climate is the ‘cost’, and the ‘profit’ is human existence

It is well-understood that excessively penalizing shipping for carbon emissions would provide perverse incentives to switch to less efficient transport modes. But at the moment heat and pressure are applied to hydrocarbons to convert them into propulsion, it is possible to sequester the waste CO2, and store it. Capturing CO2 at the funnel and offloading it directly may be possible, and if properly realized, could take place on a ship-to-ship basis, akin to STS bunkering today, and perhaps even via the same vessels.

But what to do with it? The original carbon capture and storage (CCS) technology is the tree, converting atmospheric CO2, through photosynthesis, into wood. Growing more trees is by far the best available carbon capture solution; unfortunately for trees, wood is useful, and so is the land on which it grows, meaning they are constantly under threat. Besides, for the maritime industry’s part, it encounters relatively few of them.

Nature’s solution, then, will have to be supplemented by man-made ones. While carbon credits and other initiatives only scratch the surface, they offer a hint at the entirely new types of economies saving the planet will likely bring about.

Under the carpet

Indeed, it may in fact be possible to put it right back into the Earth, where we found it. The Port of Rotterdam’s CO2 transport hub and offshore storage (‘Porthos’) project would harvest CO2 from industrial emitters in and around the port itself – who account for around 16% of the Netherlands’ CO2 emissions – compress it, and transport it along a pipeline linked to an offshore platform.  The system would bury the CO2 at the site of a depleted gas well off the Dutch coast, at a rate of 2.5m tonnes per year. Technical considerations include construction of gas collection systems, a compressor station, and the laying of new pipes from the port to the facility, a site 20km out to sea.

In January, the Port of Rotterdam reported that the project is on schedule, and, once the final investment decision is made in 2022, companies Air Liquide, Air Products, ExxonMobil and Shell will together they will seek to bury 37m tonnes of CO2 in a 15-year period.

The Net Zero Teesside project, a collaboration between BP, Eni, Equinor, Shell and Total, would compress some 6.61m metric tonnes of CO2 and bury it in used oil and gas wells at the bottom of the North Sea. This amount is equivalent to the energy needs of two million of the UK’s 29 million homes.

Meanwhile, the Norwegian Government has committed to the construction of a CO2 receiving terminal in Øygarden, on Norway’s west coast, which would enable the capture of some 1.5m tonnes of CO2 annually, storing it in a chamber 2,500m below the seabed. Due to come online during 2024, Phase I entails an investment of $673m, which is expected to be followed by others in series.

China Petroleum & Chemical Corp (Sinopec) is planning to capture 1m tonnes of CO2 per year, and inject it into 73 oil wells in the nearby Shengli oilfield. “According to IEA, CCUS will contribute about 14% of carbon dioxide emissions reduction by 2050, and the market application prospects are very promising,” said Zhang Yuzhuo, Chairman of Sinopec.

Further studies have taken place into the use of liquefied CO2 in geothermal systems, which already rely on pumping water into the Earth in order to extract heat as steam. A small percentage of the water used is lost to the surrounding rock; with this in mind, there is potential for CO2 to be ‘wasted’ into the deep rock, offering a slow but reliable CCS method whose costs are offset by power generation.

Building better

Besides burying it, a number of initiatives are underway to recycle CO2 for other purposes. Researchers Cambridge Carbon Capture and Carbicrete are examining the possibility of locking it up in concrete. This would be a one-two-punch, removing CO2 from the atmosphere while offsetting emissions from production – which by itself is responsible for 7% of global emissions.

In the coming decades, a large number of coastal and offshore concrete structures will be necessary to mitigate the effect of rising sea levels and more extreme weather events. Given the high carbon cost of such constructions at the moment, the possibility that construction vessels could be carrying blocks of carbon-negative concrete out to sea, to install breakwaters and other structures to mitigate the effects of climate change, is tantalizing indeed.

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