Prototype hydrogen storage tank maintains extended thermal endurance

Jun 04, 2008
Prototype hydrogen storage tank maintains extended thermal endurance
Salvador Aceves (left) and Tim Ross check out the on-board hydrogen storage tank that powers a prototype hybrid vehicle. Photos by Jacqueline McBride/LLNL

A cryogenic pressure vessel developed and installed in an experimental hybrid vehicle by a Lawrence Livermore National Laboratory research team can hold liquid hydrogen for six days without venting any of the fuel.

Unlike conventional liquid hydrogen (LH2) tanks in prototype cars, the LLNL pressure vessel was parked for six days without venting evaporated hydrogen vapor.

The LLNL development has significantly increased the amount of time it takes to start releasing hydrogen during periods of long-term parking, as compared to today's liquid hydrogen tanks capable of holding hydrogen for merely two to four days.

LH2 tanks hold super-cold liquid hydrogen at around -420 Fahrenheit. Like water boiling in a tea kettle, pressure builds as heat from the environment warms the hydrogen inside. Current automotive LH2 tanks must vent evaporated hydrogen vapor after being parked three to four days, even when using the best thermal insulation available (200 times less conductive than Styrofoam insulation).

In recent testing of its prototype hydrogen tank onboard a liquid hydrogen (LH2) powered hybrid, LLNL's tank demonstrated a thermal endurance of six days and the potential for as much as 15 days, helping resolve a key challenge facing LH2 automobiles.

Today's automotive LH2 tanks operate at low pressure (2-10 atmospheres). The LLNL cryogenic capable pressure vessel is much stronger, and can operate at hydrogen pressures of up to 350 atmospheres (similar to scuba tanks), holding the hydrogen even as the pressure increases due to heat transfer from the environment. This high-pressure capability also means that a vehicle's thermal endurance improves as the tank is emptied, and is able to hold hydrogen fuel indefinitely when it is about one-third full.

Last year, the LLNL experimental hybrid vehicle demonstrated the longest driving distance on a single tank of hydrogen (650 miles). The recent thermal endurance experiments validate the key benefit of cryogenic pressure vessels: They deliver the high density of liquid hydrogen storage without the evaporative losses. These two advantages make LH2 vehicles far more practical in the search for a replacement to today's gasoline-powered automobiles.

Source: Lawrence Livermore National Laboratory

Explore further: Website shines light on renewable energy resources

add to favorites email to friend print save as pdf

Related Stories

Recommended for you

Website shines light on renewable energy resources

7 hours ago

A team from the University of Arizona and eight southwestern electric utility companies have built a pioneering web portal that provides insight into renewable energy sources and how they contribute to the ...

Better software cuts computer energy use

7 hours ago

An EU research project is developing tools to help software engineers create energy-efficient code, which could reduce electricity consumption at data centres by up to 50% and improve battery life in smart ...

Cook farm waste into energy

Dec 17, 2014

It takes some cooking, but turning farm waste into biofuels is now possible and makes economic sense, according to preliminary research from the University of Guelph.

Developing a reliable wind 'super grid' for Europe

Dec 17, 2014

EU researchers are involved in the development of a pan-European 'super grid' capable of dispersing wind power across Member States. This will bring more renewable energy into homes and businesses, help reduce ...

Boeing 737 factory to move to clean energy

Dec 16, 2014

Boeing said Tuesday it plans to buy renewable energy credits to replace fossil-fuel power at the factory in Washington state where it assembles its 737 commercial airplanes.

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

hudres
5 / 5 (3) Jun 04, 2008
Outstanding! This is a critical breakthrough for transitioning from the gasoline to the hydrogen transportation paradigm. 73
taliasrider
3 / 5 (3) Jun 05, 2008
It is wonderful to see positive activity toward solving our polution and dependence on fossil fuel, this technology could be here and accessible to everyone, at a reasonable cost, if only our government would see the benefit and get behind it as it has in getting us to Mars!
Lord_jag
not rated yet Jun 13, 2008
Now all we need are rooftop solar collectors and in-basement hydrogen cells with some good compressors. Free fuel anyone?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.