Large-scale CO2 collection terminals receiving CO2 from multiple emitters will have to address the impurities in vapour return, but says a leading expert on CCS, this is the ‘nature of the business’.
Building on its experience transporting oil from floating production, storage and offloading (FPSO) vessels to shore, Altera Infrastructure is planning the Stella Maris CCS, an ambitious carbon capture and storage project, with the goal of storing at least 10M tonnes of CO2 annually in a reservoir in the Norwegian North Sea.
For the massive CCS project, Altera Infrastructure, formerly Teekay Offshore, is working with the UK independent energy company Harbour Energy, which acquired the assets of Wintershall Dea’s asset portfolio in 2024.
“We have the Havstjerne Reservoir, which looks to be very promising,” said Altera Infrastructure project manager, new venture CCS, Frank Wettland.
Mr Wettland provided a deep dive on the project at Riviera’s CO2 Shipping, Terminals & CCS Conference, Americas 2024, held in Houston, 16 September, which was produced in association with Norton Fulbright Rose, and with the support of DNV.
He said Altera Infrastructure wants to be a carbon manager controlling the full value chain – from collecting the CO2 onshore to transporting the volumes on liquefied CO2 (LCO2) shuttle tankers to an offshore location where they will be directly injected into a reservoir for permanent storage. The CO2 would be collected from both large and small volume emitters in partnership with local stakeholders, who would transport the gas by pipeline, rail, truck or barge to a CO2 storage terminal onshore.
Altera Infrastructure’s CCS strategy was to design a full-scale value chain as its base case. Mr Wettland likened this approach to how the oil business developed in Europe in the 1960s and 1970s. The E&P companies had the control over the full value chain from the reservoir to the production to the oil transport to refineries and gas stations.
With complete control of the value chain, Altera can offer emitters a turnkey CO2 disposal solution. “Just pay us X amount of dollars per tonne, and you’ll get rid of it,” said Mr Wettland.
Economies of scale also factor into the designs for the LCO2 carriers, which will be some of the biggest yet. Samsung is working on two designs, 30,000- and 50,000-m3 shuttle tankers. “We will have a very low unit price per tonne of CO2 compared to the size of the ship,” he said.
German liquefied gas handling specialist TGE Marine is developing large CO2 tanks for these ships that will be 6,250 m3 each. To help delegates visualise the scale of these units, Mr Wettland said the tanks will be about 35 m long and 16 m in diameter.
“So, they are huge, but we want to standardise on a tank size to have better economics in the project.”
Commissioning of the Stella Maris CCS is planned for 2028 or 2029.
Dealing with vapour return
But one of the issues that will have to be approached “seriously” by ship operators and terminals is vapour return, noted Clarksons Norway, green transition group, senior technical advisor, Johan Tutturen.
“We would not be surprised if some of the storage facilities on shore did not accept vapour return,” said Mr Tutturen, highlighting the potential hazards of commingling CO2. “CO2 comes with the specification, and if there are some substances inside, for instance, at the offloading terminal, if this goes back into the cargo tank again, you may see… over time that commingling is something that you want to avoid because it will form new hazards, new impurities that will be damaging. CO2 with the impurities is extremely corrosive.” Added Mr Tutturen, high-pressure carriage of CO2 would make an LCO2 carrier “less prone to corrosion.”
But during a Q&A following the session, moderator Martin Cartwright, DNV global gas director, gas carriers and FSRUs, asked Mr Wettland to elaborate on the design of Altera’s LCO2 shuttle tankers, which would use low pressure. “The pressure discussion – medium pressure, low pressure – is not that interesting. It’s all about the volumes. We are not choosing low pressure. We are choosing large volume and low cost, giving us low pressure as the answer,” he said.
And Mr Wettland also responded to the issue of how vapour return would be handled by ships and terminals.
“There will be vapour return and there will be a mixture of impurities in the CO2,” he said. This is to be expected, given that there are multiple emitters delivering volumes to collection terminals and through pipelines, providing a mix of CO2. He said pipeline operators and the ship operators will have specifications for the CO2, but when the ship comes back to the terminal, or when there are large volumes of vapour return, “the CO2 terminals will have to take care of those impurities. That’s how it is.”
To address this, Altera is “collaborating with very large terminal operators in Europe and receiving CO2 of different qualities with different impurities is the nature of the business, and it has to be handled in the terminal.”
He said with new IMO requirements for CO2 capture on ships, there will be large volumes of CO2 coming back from merchant shipping to those same terminals, and there will be a lot of impurities in that CO2. “It has to be handled. So, yes, there will be vapour return from the CO2 carriers, and there will be mix of impurities that have to be handled on the terminals. That is solvable. We have the science for handling that,” he concluded.
source: riviera news
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