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: Power-generating urinal pioneered in Britain

add to favorites email to friend print save as pdf

Related Stories

Recommended for you

Power-generating urinal pioneered in Britain

2 hours ago

British scientists on Thursday unveiled a toilet that unlocks energy stored within urine to generate electricity, which they hope could be used to light remote places such as refugee camps.

Why your laptop battery won't kill you

Mar 03, 2015

News on Tuesday that major U.S. airlines are no longer going to ship powerful lithium-ion batteries might lead some to fret about the safety of their personal electronic devices.

New incubator network to help clean-energy entrepreneurs

Mar 03, 2015

The Energy Department's National Renewable Energy Laboratory (NREL) and the Electric Power Research Institute (EPRI) have launched the Clean Energy Incubator Network. The program, funded by the Energy Department, aims to ...

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.