Decarbonising shipping: Developing sustainable fuels and CO₂ capture solutions

International shipping is the backbone of global trade. It is also a highly carbon-intensive and hard-to-abate sector, responsible for over 2% of global CO₂. What’s more, the shipping industry has a critical role to play in a future low-carbon economy; enabling other industries to reach net zero through the clean transportation of low-carbon minerals, fuels and other exports.

Cargo Ship

The International Maritime Organization’s revised strategy to reduce greenhouse gas emissions from international shipping states an ambition to reach net zero by or around 2050. The strategy also includes targets to reduce the carbon intensity of international shipping by at least 40% by 2030 compared with 2008, and for uptake of zero or near-zero greenhouse gas emission technologies, fuels and/or energy sources to represent 5%, striving for 10%, of the energy used by international shipping by 2030.

Calix is committed to applying its core technology to develop solutions to help decarbonise shipping. These include the production of sustainable transport fuels from captured industrial CO₂ and the use of zero emissions lime for shipborne carbon capture.

Sustainable fuels from captured CO₂

Sustainable alternative transport fuels may enable low carbon fuels for the shipping industry. Capturing CO₂ that is an unavoidable byproduct of other industrial processes, such as cement and lime production, and using that as a feedstock for synthetic fuels offers one potential solution. As well as helping to reduce the carbon intensity of shipping, this approach can aid the decarbonisation of other industries by providing offtake solutions for their process emissions, creating synergies across the carbon value chain.

The use of captured industrial CO₂ and the production of synthetic fuels, such as methanol, continues to gather momentum from both industry and policy makers. As part of its net zero by 2040 strategy, global shipping giant Maersk now has 25 methanol enabled container vessels on order. In the US, the Department of Energy recently announced a US$100m funding program to support the procurement of products derived from converted carbon dioxide emissions.

Closer to home, the Solar Methanol Project, of which Calix is a consortium member, aims to develop the production of sustainable fuels from renewable energy, green hydrogen and captured process CO₂ emissions. The project intends to use the Leilac technology for CO₂ capture and is supported by ~$40m in funding from the German-Australian HyGATE Initiative.

Cargo Ship

An onboard carbon capture solution for shipping

While more sustainable transport fuel solutions are being developed and scaled, the use of diesel is expected to continue for several decades. For the existing international shipping fleet, carbon capture offers an alternative, near-term decarbonisation solution.

Lime is a highly effective sorbent for the capture of CO₂ and can be used in a carbon capture system for the abatement of emissions from conventional diesel engines. For this solution to provide a net reduction or elimination of emissions, the lime used for capture must be produced with low or zero carbon emissions, using shore-based decarbonisation of the lime. If methanol produced using captured CO₂ from industry is used as a fuel, its combination with a carbon capture solution could deliver net negative emissions from shipping.

Windship withdraws from UK Clean Maritime Demonstration Competition

Calix’s participation in a zero-emissions shipping project led by Windship Technology Limited has been paused while Windship explores funding options. Windship advised The UK Department of Transport and Innovate UK, part of UK Research and Innovation, that it does not have the required funding to commence the project in July 2023. As a result, the project and associated grant funding of around £5m (of which Leilac was to be allocated around £1m to help develop CO₂ sorbent systems) will be withdrawn from the UK Government’s Clean Maritime Demonstration Competition (“CMDC3”).

Calix looks forward to continuing its collaboration with Windship to develop and demonstrate decarbonisation solutions in the future. Leilac continues to develop its CO₂ sorbent technologies through other projects, including with Heirloom for Direct Air Capture.

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