‘Waste’ oxygen from offshore hydrogen production could revive dying Baltic waters

‘Waste’ oxygen from offshore hydrogen production could revive dying Baltic waters

Marine environments are dying around the world. Sea grasses and corals are withering, destroying vital habitats. Fish are reproducing and growing less, and dying from disease more. Others are migrating away, leaving coastal areas that once teemed with multi-coloured life empty and grey.

The cause is not the widely published issues of plastic pollution and overfishing, but a less visible phenomena – ocean deoxygenation.

Physical oceanographer Patricia Handmann, says :

Our oceans are losing oxygen,

“Since the 1950s, they have lost already 2% and they are predicted to lose 7% in the future, in the next 100 years – which is, of course, a challenge for all [animals and plants] living in the ocean.”

In 1960, there were 45 coastal areas with dangerously low oxygen levels, known as hypoxia. Almost 60 years later, a 2018 research paper found there were more than 700 worldwide.

The main cause, as with many other environmental issues, is climate change. As the surface of the ocean warms, it holds less oxygen. It is also more buoyant, so it distributes less oxygen to lower levels, which naturally contain less of it.

Other culprits include sewage and fertiliser run-off, which cause nutrient pollution known as eutrophication. This leads to algal blooms, which further deplete oxygen levels, killing fish and seagrass. Bacteria that decomposes the algae also uses oxygen before mobilising other substances in the sediment, such as phosphorus, which feeds new algae.

It is a “vicious cycle”, Handmann says, which can continue until environments are unable to sustain underwater life. That is bad news not just for plants and animals, but also the humans that rely on them for food and livelihoods.  

Handmann, oxygen adviser for French green hydrogen firm Lhyfe, says:

There are large parts of the population that live within coastal areas and they are directly affected by this,

“The sad news is that, until now, there were no real mitigation measures for that, apart from limiting nutrient import and also limiting, of course, greenhouse gas emissions.” These are both slow processes, however.

This led Lhyfe to consider the opportunities presented by offshore hydrogen production, which it has successfully trialled off the coast of Western France.

Electrolysis of water generates not just hydrogen but oxygen, which is normally seen as a ‘waste’ byproduct. Lhyfe hopes it could instead be used to combat some of the worst effects of climate change in marine environments.

Breathing new life into coastal areas

Aiming to replace ‘grey’ hydrogen produced from fossil fuels, the Nantes-headquartered company plans to use wind turbines to generate green hydrogen offshore. It will further test offshore production technology in the upcoming Hope project in Belgium, which could eventually produce up to four tonnes of hydrogen per day.

Until now, electrolyser engineering has focused on maximising hydrogen production, with oxygen usually vented into the atmosphere. Lhyfe’s upcoming BoxIn project, which it is seeking funding for, aims to find out what would happen if it was instead captured and pumped underwater to reoxygenate depleted areas.

READ the latest news shaping the hydrogen market at Hydrogen Central

‘Waste’ oxygen from offshore hydrogen production could revive dying Baltic waters, source

The post ‘Waste’ oxygen from offshore hydrogen production could revive dying Baltic waters appeared first on Hydrogen Central.