Desalination in California
As usual with these types of experiment, nothing can be assumed unless or until the tests of economic and industrial viability have been passed. They say the electrode ‘is able to go more than a thousand hours’ but that’s still only a few weeks. Storage and management of hydrogen is known to be tricky and expensive compared to most other fuels.
Stanford researchers have devised a way to generate hydrogen fuel using solar power, electrodes and saltwater from San Francisco Bay, reports Phys.org.
The findings, published March 18 in Proceedings of the National Academy of Sciences, demonstrate a new way of separating hydrogen and oxygen gas from seawater via electricity.
Existing water-splitting methods rely on highly purified water, which is a precious resource and costly to produce.
Theoretically, to power cities and cars, “you need so much hydrogen it is not conceivable to use purified water,” said Hongjie Dai, J.G. Jackson and C.J. Wood professor in chemistry at Stanford and co-senior author on the paper. “We barely have enough water for our current needs in California.”
Hydrogen is an appealing option for fuel because it doesn’t emit carbon dioxide, Dai said. Burning hydrogen produces only water and should ease worsening climate change problems.
Dai said his lab showed proof-of-concept with a demo, but the researchers will leave it up to manufacturers to scale and mass produce the design.
Tackling corrosion
As a concept, splitting water into hydrogen and oxygen with electricity—called electrolysis—is a simple and old idea: a power source connects to two electrodes placed in water. When power turns on, hydrogen gas bubbles out of the negative end—called the cathode—and breathable oxygen emerges at the positive end—the anode.
But negatively charged chloride in seawater salt can corrode the positive end, limiting the system’s lifespan. Dai and his team wanted to find a way to stop those seawater components from breaking down the submerged anodes.
The researchers discovered that if they coated the anode with layers that were rich in negative charges, the layers repelled chloride and slowed down the decay of the underlying metal.
Continued here.
via Tallbloke’s Talkshop
March 19, 2019 at 05:51AM
Iowa Climate Science Education 