Giving presentations about decarbonization is almost a full-time job for Mr Wijdeveld. Hardly surprising perhaps as – thanks to his work as Sales Director with Dutch marine system integrator VDL Carbon Capture and VDL AEC Maritime – he is on close terms with many companies active in the marine sector and can speak with authority about a whole range of strategies and technologies to reduce carbon dioxide emissions from ships’ funnels.
His most compelling PowerPoint slide shows little more than a simple graph but this illustration lays bare the real challenge as regards decarbonization in the shipping sector (see Figure 1). The X-axis shows the coming decades, whilst the Y-axis indicates expected fuel consumption of various fuel types, such as diesel, MDO, HFO, LNG, methanol, etc. Right now, diesel represents 99 per cent of all fuel consumed and – despite the attention given to biodiesel and other E-Fuels – is likely to account for the lion’s share for many decades to come.
“Everyone in the industry supports the concept of maritime decarbonization but we have to be pragmatic. Of course, ship owners can attempt to reduce fuel usage, such as by focusing on energy efficiency, by fitting wind propulsion systems, etc. Other strategies include using E-Fuels, offsetting carbon emissions and/or capturing carbon. There is no single best option: the choice depends on the area the ship is expected to operate, the local regulations, etc,” states Mr Wijdeveld.
He continues: “Smaller ships, requiring a power of under 2.5 MW, could run on alternatives like battery power or hydrogen. But such options are not practical for larger vessels which will continue to run on traditional fuels like diesel and perhaps at some point environmentally-friendly fuels such as ammonia and methanol. And here is the crux of the problem: the supply of such E-Fuels is practically zero right now. Realistically speaking, E-Fuels will probably only be able to meet 25% of the marine sector’s needs by 2040. This is why we strongly believe that ship-based carbon capture – SBCC for short – is the logical way to quickly accelerate maritime decarbonization.”
At the time of writing, carbon capture on board ships is a much-talked about subject but one which – as far as Mr Wijdeveld is aware – has yet to be applied outside of pilot tests. Nevertheless, Mr Wijdeveld says that ship owners he speaks to are very receptive to the idea. “Firstly, ship-based carbon capture systems use amine-based capture, which is a technique that has been proven in land-based installations over many decades. Moreover, many ship owners have seen for themselves how easily SOX scrubbers can be fitted to engine exhausts, so are much more willing to adopt carbon dioxide capture systems.”
Indeed, when discussing SBCC with ship owners, the first question he typically has to answer is nothing to do with technology or even price but is related to space. Comments Mr Wijdeveld: “space is always at a premium at sea so it is logical for ship owners to ask whether carbon capture systems can fit. My answer is always an emphatic ‘yes’, referring to the many compact SOx scrubbers that we have designed to neatly fit around existing systems and infrastructure on ships.”
The second question from ship owners tends to be ‘where can I offload the liquefied carbon dioxide?’ “That is a more complicated position and depends initially on the ship owner’s strategy – for example, whether they want to opt for long-term storage or to sell the CO2 as a commodity. As we speak, more and more options are emerging. For example, Northern Lights in Scandinavia as well as Porthos in the Netherlands are developing storage options. Moreover, as the CO2 captured by our system meets food-grade quality, it is attractive as a raw material for the greenhouse sector in the Northern Europe.”
As stated, ‘real-life’ carbon capture has yet to be applied on board a vessel. However, 2021 saw the start of a very relevant SBCC project, termed EverLoNG. By demonstrating ship-based carbon capture on board commercial shipping, EverLoNG aims to take the technology through its paces and speed its deployment by the maritime sector. The project further aims to close knowledge gaps and tackle both the technical and economic challenges of SBCC.
VDL is a proud partner in the project, states Mr Wijdeveld. “This is a project with a wide scope. There are six separate work packages and we are operating to a ten-point check list. What I find particularly exciting is that the project involves developing and installing a prototype SBCC system on two separate LNG-fuelled vessels. During the first campaign the SBCC system will run for 3000 hours and capture twenty tonnes of CO2. The second campaign, a 500-hour test, will allow us to compare system performance on both ships.”
Looking ahead, Mr Wijdeveld sees real potential to sell the captured carbon dioxide as a raw material which could be used in the production of E-Fuels such as methanol and ethanol. However, he believes policymakers do need to offer clarity on what exactly would constitute an E-Fuel. “In principle, E-Fuels are made using green carbon dioxide, plus green hydrogen or green electricity. First problem: there simply isn’t enough green electricity right now. Second point: how do you define green carbon dioxide? Current rules indicate that carbon dioxide captured from the exhaust of a ship’s engine that runs on fossil fuel, should be termed ‘gray’. However, if the self-same carbon dioxide is released into the atmosphere and captured later via a DAC process, then it is deemed to be green. Many in the industry find this to be illogical and confusing, which hampers investment decisions. Therefore, I do hope politicians can straighten this out. After all, it is surely better all-round to capture the CO2 before it leaves the ship’s funnel and use that to create fuel? This would genuinely help the sustainability effort, as we could continually recapture and reuse the CO2.”
Another financial benefit of promoting the use of carbon dioxide as a raw material for green fuel is that it reduces the need for sequestration, which is a costly process and as yet unproven over the long term, states Mr Wijdeveld.
Tried and trusted
The basic principle of an SBCC system envisaged by VDL is as follows (see Figure 2): first the hot exhaust gases are cooled from around 350 °C to 40 °C using seawater quenching, following which they pass into an absorption system. Here, an amine solution is sprayed into the cooled exhaust fumes to capture the CO2. The CO2-rich amine then passes to a stripper where it is heated to release the CO2 as a gas. The amine can then be reused. Meanwhile, the separated CO2 passes to a liquefaction unit where it is cooled, cleaned and liquefied. Finally, the CO2 is transferred to a storage tank.
This process, used for decades in various industrial sectors, relies on tried and trusted technology. The marine setting, however, does raise a couple of challenges which Mr Wijdeveld and his colleagues are working hard to address. “Land-based carbon capture units are optimized for performance at a steady state, ie, for a set flow rate. However, on a ship the system will have to accommodate fluctuations in the exhaust gas flow rate, depending for example on the ship’s speed. One avenue we are addressing in this respect is to run tests on the new amines currently being developed which offer superior process flexibility.”
Another challenge is to improve the overall efficiency. Mr Wijdeveld: “amine-based carbon capture is an energy intensive process. On land that is not so much of a problem, but at sea we believe it makes economic sense to aim to capture perhaps 50% of the total CO2 emissions. Over time, I am sure that capture rates will improve rapidly.”
Nevertheless, Mr Wijdeveld is adamant about the immediate benefits of deploying SBCC and stresses that VDL and its supply chain partners providing items like valves, pressure vessels, compressors, etc, are fully ready to respond to inquiries from ship owners. “If a client – be it for a new build or an existing ship – signs an order with us today, we could have a tailor-made SBCC system designed, engineered, manufactured, installed and commissioned with ten to twelve months. Looking ahead, I am confident that we can bring that timeframe down to say three to six months.”
About VDL Carbon Capture
- VDL Groep, headquartered in Eindhoven, the Netherlands, is an international industrial family business with more than 100 operating companies, spread throughout 19 countries, with over 15,000 employees.
- The VDL companies break down into four divisions: Subcontracting, Car Assembly, Buses & Coaches and Finished products.
- VDL AEC Maritime B.V. boasts a reference list of over 120 SOx scrubbing systems. The acquired know-how plus the intention to help in decarbonizing the marine sector prompted VDL’s owners to invest carbon capture and storage systems for ships.
- VDL Carbon Capture B.V. was formally established in 2023 and provides a full suite of services for the carbon capture sector, including design, engineering, fabrication, installation, commissioning, training, maintenance, servicing, etc.
- VDL Carbon Capture’s initial focus lay on systems for LNG-powered vessels and the company was selected as a partner for the EverLoNG project. The company is currently developing SBCC systems for diesel-powered ships.