Plying the waters of the Baltic and the North Sea are four 7,500 tonne capacity bulk carriers with a special payload, liquefied CO₂, in a first of a kind project whose genesis can be traced back 20 years or more. Calling at a Swedish cement plant, Dutch ammonia plant and two Danish biomass power plants, the special fleet will head north to Øygarden, western Norway. There, their cargo will be stored for a day and then pumped 100 km north-west and 2.6 km down under the Norwegian Continental Shelf into a porous saline aquifer, where they will remain.

Including liquefaction, this is the scope of Norway’s huge, and mostly publicly-funded, Longship project for carbon capture and storage (CCS). Its total investment, including Northern Lights, Brevik and Celsio, is at least NKr25.1bn ($2.27bn), of which 10 years’ operation amounts to NKr8bn ($0.72bn). Total state investment is estimated at NKr16.8bn ($1.52bn). Within that massive scope is the Northern Lights transport and storage project, run by a consortium of Equinor, Shell and TotalEnergies.

In a 2020 press release announcing the Longship project, the Norwegian government pointed out decades of experience in CCUS, with a 1mn t/y project in the Sleipnir field (1996) and 700,000 t/y project in the Snøhvit (2008) field in Norwegian waters. Therefore, the safety and integrity of the CO₂ storage process was not at risk, but it admitted that project economics and the difficulty of technical integration of project elements would be a different story.

And so it has proved. Alongside Heidelberg Materials (whose contribution was at the Brevik, Norway, cement factory) was originally intended to be Hafslund Celsio, the Norwegian utility who would siphon off 350,000 t/y out of emissions of the Klemetsrud (Oslo) waste-to-energy plant.

Having made a final investment decision (FID) in June 2022, less than a year later, the organisation paused the project when costs began to rise, amounting to NKr3bn ($0.27bn). In summer 2024, the company is re-submitting its plan to the Norwegian government in hopes of agreeing a new support plan. If a deal can be reached by the end of the year, it says the CCUS plant could be commissioned in 2028.

Heidelberg Materials’ 400,000 t/y carbon capture project in Brevik has also suffered cost increases. But, following negotiations with the Norwegian government, the concrete supplier has agreed to cover those in exchange for a proportionately bigger stake of the project. In addition, Norway has agreed to provide up to NKr150mn ($13.59mn) of ‘start-up support’ once the project has reached the point of first CO₂ transport.

That project, which includes Heidelberg Materials and carbon capture technology provider Aker Carbon Capture, aims to complete mechanical works for commissioning in December 2024. Late last year the main process and six storage vessels were installed; in May, the 27-tonne compressor and compressor motor went in. Heidelberg is also developing a digital twin of the plant to run virtual operations and training scenarios before start-up.

Elsewhere, Northern Lights’ ships for CO₂ transport are nearing completion. South Korea-based shipbuilder Dailan Shipbuilding is reportedly 88.4% complete with the first two vessels. Two more have begun construction; one, like the first two, to be owned by Northern Lights and operated by K-Line, a fourth owned and operated by third-party shipper Bernhard Schulte under a long-term charter.

Faring even better, at a reported 94% completion, is the Northern Lights onshore reception terminal (with its twelve 700-tonne tanks), underwater pipeline, two injection wells and storage complex. The jetty and tanks are sized for phase two operations (5mn t/y).

Financial interest
In addition to Heidelberg and possibly Celsio, Yara and Ørsted have bought their way into the Longship project, negotiating for project capacity of 800,000 t/y from 2025 and 430,000 t/y of CO₂ from 2026. (The latter is partly subsidised by an offsetting deal with Microsoft for 2.67mn tonnes of CO₂).

Those transactions demonstrate the level of public- and private-sector market interest in the technology. In December 2023, the European Union’s Connecting Europe Facility awarded €131mn for construction of the second phase of Northern Lights (to reach 5mn tonnes).

More recently, in March 2024, oil and gas technology firm Schlumberger bought 80% of Aker Carbon Capture for NKr4.12bn ($1.29bn; plus up to an extra NKr1.36bn ($0.12bn) over the next three years in performance bonuses). The new joint venture will add Aker’s amine-based carbon capture technologies to Schlumberger’s own non-aqueous solvent and emerging sorbent-based offerings.

In March, Schlumberger CEO Olivier Le Peuch said: ‘For CCUS to have the expected impact on supporting global net zero ambitions, it will need to scale up 100–200 times in less than three decades. Crucial to this scale-up is the ability to lower capture costs, which often represent as much as 50–70% of the total spend of a CCUS project. We are excited to create this business with Aker Carbon Capture to accelerate the deployment of carbon capture technologies that will shift the economics of carbon capture across high-emitting industrial sectors.’

If we spend the next 10–15 years on R&D, not on implementation, unfortunately we won’t achieve net zero by 2050.
 

In the plant
Within the potential auspices of Longship, Hafslund Celsio is working with Aker Solutions on front-end engineering and design, and Aker Carbon Capture as technology provider of its Just Catch 400 modular CCS plant.

The waste-to-energy facility receives 1,000 t/d of sorted waste to power a district heating network. Two cranes feed three continuous incineration lines. The utility claims that the plant will capture 95% of CO₂ from the flue gas. To do so, it estimates it will consume 0.7–0.85 MWh/t of captured CO₂, with variation due to higher summer ambient temperatures. Other electricity requirements add up to an additional 400 kW/t, or 20 MWh for the expected 54 t/h of CO₂ planned to be captured.

To capture 54 t/h, the plant requires 40 MW of steam and 20 MW of electricity. To help improve efficiency, a heat pump using excess heat from the carbon capture process (and 17 MW of electricity) will contribute 60 MW to the district heating network.

The plant captures CO₂ using a closed-loop amine-based absorption process. Three main process vessels are required, according to Muhammad Ismail Shah, Managing Director of the Technology Centre Mongstad, where the Norway-developed ACC process was proven-out a decade ago.

The first step is for flue gas from the source to come in via a blower for pretreatment, to condition to the right temperature and level of impurities. Gas turbine exhaust gas temperature is ~110–160°C; it needs cooling to 30–40°C, so is showered with cold water in a closed loop process, and the gas rises. At this point, chemicals may be added to safeguard the process from impurities.

Second, the cooled gas enters the absorber vessel from the bottom. A few metres from the top, lean amine is inserted.  As the amine falls through the packing material and the gas rises, a chemical reaction occurs in the contact area and the CO₂ is absorbed by the amine. Because the reaction makes energy, the processed gas needs cooling again, from 60°C to 40°C, and is then washed to remove any amines or other volatile components, before being emitted from the stack.

Finally, the CO₂-rich amine enters the regenerator column. This is essentially a kettle, which boils the rich amine, raising its temperature to about 120°C. Doing so releases the CO₂, which then goes downstream for post-processing, compression or liquefaction. Heat recovery helps to reduce energy consumption.

Reflecting on the chemical basis of the process, Shah says: ‘All solvent amine technologies rely on absorption and are liquid-based. Some have high water content; some have almost no water. There are differences between the amine molecules. Some are more corrosive, some can use carbon steel, others need stainless steel, but the principal operational parameters and process conditions could be similar. It’s all closed-loop, but the chemistry is completely different.’

He adds: ‘Like Pepsi and Coca-Cola, the look and taste might be similar, but the formulae are highly confidential.’

At Mongstad, alongside the main large-scale generic amine test facility, and a much smaller emerging-technology test bed, sits a carbon capture plant that uses chilled ammonia. Built by Alstom, the patented technology was tested and proven-out technically in 2012–2014, and has sat idle for the most part since. In principle, the process it uses is similar to amine absorption, but instead of amine a cold liquid ammonia solution (at 5–15°C) is used to capture the CO₂. Another unit recovers and regenerates the ammonia slip from the CO₂ absorption unit.

When asked for his view about how expensive CCUS is as a process, Shah first replies that this information is considered confidential. However, he mentions that ‘the US Department of Energy has estimated $100–150/t, but that changes with size, location and many other details; there is no simple answer. Whatever the number is, we need to reduce it to deploy at a large scale.’

Shah continues: ‘There are two things we need to do... both in parallel. First, we need to continue to work on research, innovation and testing. We have technologies for deployment today, but we need to innovate more to make the process more cost-efficient.’

‘And we need to start building, to take final investment decisions and learn lessons from standardised construction and large-scale operation. If a vendor builds a plant, the fifth or sixth should be cheaper, so the overall process is more efficient. That should be done in parallel with R&D... If we only spend the next 10–15 years on R&D, not on implementation, unfortunately we won’t achieve net zero by 2050.’

• Further reading: ‘Designing the world’s first overground CO₂ pipeline for CCUS hub in Teesside’. Two industrial projects in Teesside will see approximately 4mn t/y of CO₂ collected from local emitters and safely transported for storage offshore via a new overground pipeline designed by Costain.
• Some claim CCUS is a promising bridge between fossil fuel dependence and a clean energy future, particularly in hard-to-abate industrial sectors. However, there are still numerous economic, technological, political and social issues to address.