The idea that the world could run on clean hydrogen fuel is alluring. And why not? A hydrogen fuel cell has no waste products other than heat and water vapor. Why, a person could hold a cup under the tailpipe of a fuel cell powered vehicle and drink what comes out. No carbon or particulate emissions, no oxides of nitrogen — what’s not to love?
Actually, most CleanTechnica readers are well aware of the downside. There are two principal ways of making pure hydrogen. You can start with natural gas — which in America comes primarily from fracking — or you can pass an electric current through water to break it into its component parts. The first involves massive pollution of the environment. The other involves massive amounts of electricity.
Hydrogen is the most reactive element in the periodic table. It bonds like crazy with just about every other element and can only be tamed by storing it under very high pressure — up to 900 psi. Unlike battery packs which are mostly flat and rectangular, hydrogen tanks have to be cylindrical in order to withstand such ultra-high pressures. Regardless of what they are made of, cylindrical tanks do not fit conveniently with the footprint of a typical automobile chassis.
New Hydrogen Storage Medium
Researchers at Northwestern University say they have devised a way to store hydrogen at much lower pressures using a metal organic framework, popularly known among scientists as an MOF. They say the new material has much greater porosity. One gram — about the weight of 6 M&Ms — has enough surface area to cover 1.3 football fields. It could store hydrogen at much lower pressures than normal and at greatly reduced cost.
“We’ve developed a better onboard storage method for hydrogen and methane gas for next-generation clean energy vehicles,” said Omar K. Farha, who led the research. “To do this, we used chemical principles to design porous materials with precise atomic arrangement, thereby achieving ultrahigh porosity.” The new materials also could be a breakthrough for the gas storage industry at large, Farha said, because many industries and applications require the use of compressed gases such as oxygen, hydrogen, methane and others, according to Science Daily.
The ultraporous MOFs, named NU-1501, are built from organic molecules and metal ions which self-assemble to form multidimensional, highly crystalline, porous frameworks. To picture the structure of a MOF, Farha says, think of a set of Tinkertoys. (Younger readers should Google “tinkertoys” to learn more.) The metal ions are the nodes and the organic molecules are the rods holding the nodes together.
“We can store tremendous amounts of hydrogen and methane within the pores of the MOFs and deliver them to the engine of the vehicle at lower pressures than needed for current fuel cell vehicles,” Farha says.
The study, combining experiment and molecular simulation, was published April 17 by the journal Science. Farha and his team collaborated with scientists at the Colorado School of Mines and the National Institute for Standards and Testing.
South Australia As Hydrogen Export Hub
The government of Australia is committed to extracting every lump of coal on the entire continent because coal equals jobs and it cannot think of any other way to keep the national economy going. One alternative is to produce hydrogen gas and export it to the world. But a new report by The Australia Institute finds residents of South Australia only support such a plan if the hydrogen is made from renewable energy sources.
Here are the key findings of the report:
- Four in five South Australians (79%) would prefer that South Australian hydrogen fuel is generated from renewable sources. Only 6% would prefer that it is generated from fossil fuel sources.
- Three in four South Australians (73%) also say that South Australia should only pursue a hydrogen fuel industry if it uses renewable energy. Only 13% disagree.
“South Australia has the potential to be a global hydrogen fuel exporter, but our research shows the concept will only receive public support if it uses renewable sources of energy,” says Noah Schultz-Byard, SA Director at The Australia Institute.
“The South Australian government has already taken steps towards establishing a renewable hydrogen energy industry. Considering how popular green hydrogen appears to be in South Australia, that is likely to be a well-supported move. On the other hand, creating hydrogen using fossil fuels is deeply unpopular with just 6% of South Australians supporting the idea.
“Other Australian states are pursuing hydrogen fuel research using a mixture of energy sources but South Australians want our state to lead the way on clean, green hydrogen for the future. Many people are excited about the potential of hydrogen energy but it is only green hydrogen, made from renewable energy sources, which will help us to tackle global warming.”
The interesting thing here is that there would need to be enormous amounts of excess renewable electricity available to hydrolyze water into hydrogen and oxygen and then to compress it for storage and shipping. The question becomes what is more efficient, storing excess electricity in pumped hydro installations or batteries, or using it to make hydrogen and then using the hydrogen to make electricity again.
The dream of a hydrogen economy refuses to go away. Someday, in the far distant future, there may be so much renewable energy available that using it to making hydrogen will be a good idea. That day is not likely to arrive any time soon.