When you join the military, there are certain risks you expect. Anything from enemy combatants to training accidents can strike in the blink of an eye.
What you don't expect is for the air you're breathing to spark an explosion.
Rudy Luck was presented with precisely this problem by the US military. The associate professor of chemistry at Michigan Tech was brought in when the military discovered R40—an unapproved coolant maintenance personnel were sold by local suppliers—in some of their armored vehicles. R40 reacts with aluminum to create the highly reactive gas trimethylaluminum, TMA. This is a problem in an environment like Iraq, where cooling is vital and continuous.
Making this more complicated is the fact that the impressively armored vehicles are not designed to open easily. With hydraulic doors that require additional time to open—preventing unwanted access from the outside—it's not like there's a margin of error when an explosive mix is washed in through the air vents.
"What they discovered was that vehicles would come back for refurbishing and the chloromethane (R40 coolant) could be reacting with the aluminum in the engine," says Luck. Chloromethane isn't supposed to be there. It's a cheap substitute that local suppliers use instead of the proper refrigerant, tetrafluoroethane.
The resulting mixture is explosive. "We brought two vehicles up here and demonstrated just how dangerous this can be," says Luck. "We shot a flask of this mixture at a test range to show what could happen. It was quite a bang."
The proper refrigerant, called R134a, works well, but the atmospheric effects are stark: more than 1300 times the warming effect as the greenhouse gas carbon dioxide. The European Union is now mandating a newer option referred to as HFO-1234yt. It's hard to make, however, and it may not work in the current generation of cooling systems.
Luck's team has devised a method to safely deactivate the TMA. They are also finding ways to test for the unapproved coolant in both combat vehicles and Apache helicopters. So far they've found traces in a few, though not enough to produce the explosive TMA.
Still, even that small chance is enough for Luck to keep his focus.
"My neighbor's son went to Iraq three times," Luck explains. "I've seen pictures of him in these same vehicles. This is personal. This is important."
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