Automotive

Sandia Labs looks to the liquid hydrogen filling stations of the future

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Rendering of First Element Fuel’s liquid hydrogen retail fuel pump, showing the pump and storage tank
SNL
Rendering of First Element Fuel’s liquid hydrogen retail fuel pump, showing the pump and storage tank
SNL
Sandia National Laboratories’ hydrogen safety modeling team, from left to right, risk analyst Brian Ehrhart, project co-leader Chris LaFleur and co-leader Alice Muna
SNL

Hydrogen-powered vehicles are here, but we're still a long way from having widespread infrastructure to support them. In anticipation of the hydrogen economy of the future, Sandia National Laboratories (SNL) is working on software models that will help hydrogen refueling stations switch from hydrogen gas to liquid hydrogen while implementing new, easier to follow safety standards.

As an alternative to gasoline and diesel, hydrogen has a lot going for it. It can not only be burned directly in properly designed engines, but it can also power fuel cells for hybrid vehicles. It's the most abundant element in the universe, leaves behind only water as an emission, can be dispensed as fast as conventional fuels and, with the right adjustments, can be handled and transported like natural gas.

The problem is that hydrogen isn't a very dense fuel source – especially in a gaseous state – and there are still very few hydrogen filling stations, with most of those in the United States concentrated in San Francisco, Los Angeles, and San Diego. Worse, the current designs for stations allow for only one pump and not much hydrogen stored on site.

With an increasing number of hydrogen cars expected to be built in the near future to join the estimated 5,000 already on US roads today, a more widespread and efficient hydrogen infrastructure will be needed. To provide this, SNL and the largest American hydrogen retailer, First Element, have entered into a Cooperative Research and Development Agreement to find ways to better use liquid hydrogen, which is much denser than hydrogen gas, so more can be stored in one place.

Sandia National Laboratories’ hydrogen safety modeling team, from left to right, risk analyst Brian Ehrhart, project co-leader Chris LaFleur and co-leader Alice Muna
SNL

However, liquid hydrogen has to be kept at a temperature below -253° C (-423° F) and that causes all sorts of headaches. Not the least of these is that the current US National Fire Protection Association safety codes are decades out of date when it comes to handling liquid hydrogen.

Using a new software package, SNL is developing models to help it better understand how liquid hydrogen behaves, especially in cases of leaks. Unlike hydrogen gas, liquid hydrogen is so cold that it freezes the air around it when it escapes, which means it's hard to determine how a leak works, how much hydrogen is in the air, and how far away from a leak the combustion sources are. These are things that need to be solved before large numbers of hydrogen fueling points are established in built up areas with dense populations.

The new SNL models look at how hydrogen and oxygen interact in gaseous and liquid states. Since oxygen has a much higher boiling point, one element will warm as the other liquefies, and vice versa, so the computer model assumes a zone of initial hydrogen and air mixing that is far enough from the leak that the mixture is warm enough to accurately model. This allowed the SNL team a better understanding of how far from a leak will show a flammable concentration.

According to SNL, this modeling will provide First Element with an inexpensive scientific basis for designing and gaining local permits for the 12 fueling stations the company is planning to build in California. In addition, it will help in writing new fire safety codes that are performance based rather than prescriptive. That is, instead of laying out in painful detail how to meet safety standards, the codes will determine what a safe station will look like and it will be up to the supplier to meet those requirements.

The claim is that this will make it easier to build more stations in different states as well as encourage the wider application of hydrogen as an energy source in both the domestic and industrial spheres.

"Our mission has always been to foster the adoption of these cars, ensuring better air quality and energy security," says Tim Brown, COO of First Element Fuel. "That is the part of the project that will live on beyond the particular stations we're building right now."

Source: SNL

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6 comments
Gizmowiz
Hydrogen as a fuel is as stupid today as it was for the Hindenburg as a lifting agent in the days of Hitler.
Hydrogen is very difficult to handle safely--leaks are atrociously hard to prevent--far more so than natural gas (but less so than Helium).
In most commercial situations hydrogen is stored as a liquid in huge tanks. That's all we need is tens of thousands of hydrogen storage tanks just sitting their for terrorists -- who hate Americans but love the Japanese--to blow them up.
In addition, hydrogen is created by the disassociation of water and this takes a huge amount of energy so currently it's being done by extracting hydrogen from natural gas--meaning will still be hooked on fossil fuels.
No thanks.
Solar with battery storage is the way to go. Forget FCEVs.
Knut
Nothing match hydrogen when it comes to holding energy - but it is very difficult to manage. There is something called "Absolute zero" or 0 Kelvin. Hydrogen is cryonic and solid as rock when the temperature and pressure is right. Then it can be held as a square box, and will not drain into a hole, and cannot be "tapped". You have to reduce the pressure and lift the temperature in small increments - valves. That make very low temperature hydrogen very cumbersome. For all practical applications, the hydrogen should be held as gas or liquid. Hydrogen tanks are these days made for liquid hydrogen at a pressure of 350 bar. This is then millions of hexagon cubes, so that the built can be shot through the tank without causing explosion. The tank can be thrown in the fire, and will not explode, but let out the hydrogen gradually. There is a combustion engine, Mazda holds the rights, that will burn hydrogen and this can be used as an engine to a car. But most use of hydrogen is by exposing this to an agent - usually nitrate, causing a reaction that produces electric power. The problem with fuel cells is that they require clean hydrogen, much cleaner than a rotary engine. But the fuel cells burn more of the hydrogen, the combustion is not that complete. The exhaust is as you say, clean water for both the fuel cells and the motor. Since the US will not take part in reducing the global heating, most of the hydrogen research is done outside the US. The storage technologies is in Europe, the infrastructure is in Europe, where special buses use hydrogen fuel. The fuel cell is South Africa, Japan and Europe. The experience from using hydrogen in buses is that the fuel cells technology behave very bad during he winter and sensitive to clean fuel. Hydrogen is produced a waste dumps using methane as catalyst.
Martin Winlow
'H2 is going to save the world!' tosh. It's relatively low specific energy is the least of the problems associated with it being used as a fuel in the same way petrol and/or diesel is used. It is simply too impractical and that is the reason dozens of massive auto companies have spent decades and billions (pick your currency) trying to develop H2-fueled cars... and given up. Some are still trying (eg Toyota) but it is a complete farce.
The 2 most glaringly obvious issues with the whole basic idea is overcoming the fact that H2 is basically a fossil fuel (as 98% of H2 currently made is steam-reformed from natural gas) and that even the most efficient engine 'burning' H2 is only about (*theoretically*) 50% efficient. Compare this to the real-world 90% or more efficient that a typical EV is and you begin to see the problem.
fb36
It is obvious (at least to me) that, some car companies keep pushing for hydrogen (instead of electric) vehicle future, because, switching their factories from producing gasoline vehicles to hydrogen vehicles would be a lot cheaper, compared to switching to producing electric vehicles!
But the real problem is, we would be replacing extreme fire hazard (during a collision) gasoline vehicles with MOVING BOMBs, quite literally! (And that does not even include the extreme danger hydrogen infrastructure would create everywhere in the world!)
Sorry to those car companies (that want hydrogen future), but hydrogen future should/must NEVER be allowed to happen, for the good of whole world/humanity!!!
guzmanchinky
I thought the REAL problem with Hydrogen was the efficiency when you take into account production losses, transportation losses, and Hydrogen to Electricity conversion losses. There is an excellent video out there by Real Engineering called "The Truth About Hydrogen". Or are they wrong?
Derek Howe
BEV's (Battery Electric Vehicle) killed the hydrogen fuel cell EV.
When I was a kid I remember reading Popular Science and thought for sure we would all be driving fuel cell in the future. But thankfully, the technology was slow to mature. So in comes the rise of pure EV's using batteries, and once you drive one, you never want anything other then that. It's that damn good.