Who Needs Fossil Fuels When You Have Seaweed?

A company based in Cape Town is garnering attention for its innovative initiative to offset emissions in the shipping industry by creating bio-LNG liquefied natural gas and e-methanol from seaweed.

The concept has been in development for several years but has gained significant momentum over the past four years, becoming more financially viable, says Johannes Bochdalofsky , founder of SeaH4.

Interest in developing fuel from seaweed is growing within the maritime sector in particular, he says. The company has been collaborating closely with an international shipping line, the South African Department of Transport and the International Maritime Organization IMO. The IMO commissioned GreenFuelHub GFH to independently evaluate the greenhouse gas emissions savings potential of SeaH4s liquefied biomethane LBM and e-methanol production. The evaluation covered all stages of the production chain, from algae cultivation to final fuel synthesis. The products have undergone pre-audits for certification under the International Sustainable Carbon Certification ISCC European Union standards, indicating compliance and readiness for the market.

SeaH4 is currently building a test facility in Pepper Bay in Saldanha. The seaweed used is not sourced from the sea but rather grown on non-arable land near the coastline in small man-made ponds, says Bochdalofsky. South Africa already has an established seaweed-growing industry, thanks to its abalone farms. We have the know-how now its about scaling up significantly. None of the seaweed used is imported or genetically modified, and we have no impact on the indigenous biotome.

Plans are underway to construct a pilot plant, with construction slated to begin next year. Bochdalofsky anticipates having a full-scale facility operational by as early as 2028.

The company initially kept its production calculations conservative to ensure financial feasibility. However, with the emergence of alternative fuels at much higher prices, the possibility of scaling up to higher quantities of production has now become a reality.

We have a very solid case study, and our product competes on par with the best in the world, says Bochdalofsky.

Explaining the process further, he says seaweed was transformed into a biogas, which in turn was upgraded into bio-LNG and even liquified e-methanol with the final emergence of green hydrogen.

We are confident in our ability to produce LBM and e-methanol at scale, which is why we have prioritised the maritime industry over road transport. At this stage, it is easier and more profitable to produce bio-LNG and e-methanol than e-diesel, says Bochdalofsky.

However, the company has plans to expand its product range in the long term to include e-diesel. We view Africa as an ideal market and believe our products can contribute to delivering carbon-neutral fuels across the continent.

Electrification of road transport in Africa is not expected to happen soon, and the affordability of purchasing new vehicles makes our product highly viable, he says.

SeaH4 is also exploring the production of compressed gas for use in tugboats and near-shore fishing vessels. We are already in discussions with a port authority in Africa to develop a solution where compressed natural gas can be used in tugs as old as 40 years.

He describes the solution as involving the installation of a dual-fuel kit on the existing engine of the tug, with compressed gas cylinders strapped to the wheelhouse. This approach allows us to decarbonise even older vessels, he says.

While it took time for the entire concept to get off the ground, this delay has been beneficial, says Bochdalofsky. With the focus on sustainability over the past four years, we have seen a dramatic change in perception around our product. Initially, we were planning for a commercial facility capable of producing around 15 000 tons of LBM per year, along with the equivalent amount of e-methanol. However, shipping lines have indicated they would require at least four times that amount.