Hydrogen is a dream fuel because it does not generate climate change causing emissions when burned, thus a promising alternative to fossil fuels or CO2 emitting energy sources.
The Economist article describes how a research team based in Germany has found an ingenious way to store and carry hydrogen energy by creating a chemical compound called hydrogen goop.
At Fraunhofer Institute for Manufacturing Technology and Advanced Materials in Germany, Dr. Marcus Vogt and his team created a magnesium hydride-based “power paste” that stores hydrogen in a chemical form and ready for release on demand.
Supplying hydrogen as a paste is a way to get around its storage limitation and challenges. According to the article, keeping meaningful amounts of hydrogen gas requires compressing it several hundred times, and liquefying hydrogen requires a temperature drop of -235C for this to happen.
Storing hydrogen is very tricky because hydrogen can infiltrate metals, causing them to weaken and crack over time, requiring storage made from special materials to withstand its effects.
How Hydrogen goop works
According to a New Atlas article, hydrogen goop is made from heating hydrogen with magnesium and stabilizers so hydrogen can be store in cartridges even at room temperatures. The result is a stable medium that is, according to its makers, ten times more energy-dense than lithium-ion batteries.
The article describes how it works:
“When it comes time to release the energy, a plunger mechanism extrudes the paste into a chamber where it reacts with water to release hydrogen at a dynamically controlled rate, which then feeds a fuel cell to create electrical power with which to run an EV powertrain or other device. Part of the paste’s impressive energy density comes from the fact that half of the hydrogen released comes from the water it reacts with.”
According to the Economist article:
Hydrogen goop good can be pumped into a cartridge and release hydrogen gas when needed because its main ingredient is magnesium hydroxide. This compound reacts to water and forms hydrogen and magnesium hydroxide.
Hydrogen produced can then be guided into the fuel cell where it reacts with oxygen from the air to produce electricity. The magnesium hydroxide waste is then emptied from the reactor automatically.
Hydrogen goop’s advantages over batteries and petrol
- First, hydrogen goop’s stores more energy per litter and per kilogram compared to petrol or batteries.
- Second, the ease of refilling the goop is just a matter of swapping an empty cartridge of the paste with a new one and then refilling water stored on a separate tank.
- Third, unlike the battery, the paste does not lose its stored energy when it sits on the shelf.
- Fourth, the paste is non-toxic, as is the reaction’s by-product.
With all these advantages, Dr. Vogt’s team still has some tiny details to work through. On its own, magnesium hydroxide reacts with water slowly because of a chemical reaction that forms a barrier.
However, Dr. Vogt’s and his team found a way to accelerate the reaction and control the reaction in a precise manner that would supply just the right amount of hydrogen needed at any given moment.
The researchers hope that the application of this technology will find a niche in the market. It is ideal for small vehicles like scooters or flying drones where weight is a premium and can also extend its range and use. Another use of the power paste is the miniature stoves that campers use.
Disadvantages of Hydron goop
Apart from hydrogen’s obvious problem of being both chemically and financially expensive to separate into a usable form, there are huge logistical steps involved in preparing the paste, manufacturing the cartridges.
Then there is also the infrastructure needed for refuelling, disposal and recycling for spent cartridges and magnesium.
Today’s hydrogen is processed using carbon-emitting fossil fuels. Clean hydrogen that is hydrogen processed using clean and renewable energy is rare.
Clean energy production has to substantially grow first before hydrogen goop becomes a serious contender in the renewable energy market.
PHOTO CREDIT: GPA Photo Archive via Flickr Creative Commons