by Bob Ciminel
I have some limited experience in the art of making hydrogen. On a small scale, I've watched it bubble out of my car battery when I've had to use a battery charger; on a larger scale, the oxygen generators on my nuclear submarines produced hydrogen as a byproduct. Simply put, you take demineralized water, stick it in a cell separated by a porous membrane, and introduce an electric current. Oxygen molecules will migrate to one side of the membrane and hydrogen molecules will move to the opposite side. Voila! You have oxygen - and hydrogen. The trick is keeping the oxygen and hydrogen separated or else you can have a nasty explosion. That's why we referred to our oxygen generators as "The Bombs."
Once, during a qualification board, I asked the candidate how we made oxygen on the ship. I was impressed with his knowledge of the electrolysis process. Then I asked him what we did with the two gases. He replied, "Well, we pump the oxygen into the ship's oxygen tanks for breathing air and we put the hydrogen in the missile warheads for hydrogen bombs." Without going into the technical details, thermonuclear warheads use tritium, which is a radioactive isotope of hydrogen, not something you want to carry in tanks aboard a submarine. Suffice to say, the candidate did not qualify on that go-round.
So, if, in the future, everyone drives a hydrogen-fueled car, what changes in society might occur?
Initially, there will be a huge increase in the number of Darwin Awards (http://www.darwinawards.com) given out. Hydrogen is very explosive, and, as with all emergent technologies, there will be the inevitable learning curve to surmount. Fortunately, in this new age of instant communication we will learn quickly from others' mistakes and minimize the time we spend on the curve. There will be that 10%, who will never learn, but they'll be easy to spot - no eyebrows are a dead giveaway - and we will learn to avoid them.
As we become more familiar with fueling our vehicles with hydrogen, we will begin to see a noticeable rise in the relative humidity. Folks along the Gulf Coast probably won't notice the change because the humidity there is always 100%, unless it's raining. Whether it's consumed in an internal combustion engine or a fuel cell, hydrogen becomes water vapor when it combines with oxygen. The hydrogen molecules in gasoline do that already, as evidenced by the white cloud that comes out of your exhaust pipe when you first start a cold engine. White smoke coming out of your exhaust pipe after your engine has warmed up is also water vapor, but it's probably coming from your cooling system because you have a cracked cylinder head. As the relative humidity increases, people will run their air conditioners longer, which will require more electricity, which causes more pollution and global warming, unless we build more nuclear power plants.
Therefore, from my perspective as a nuclear professional, switching to hydrogen fuel is a good thing. Of course, there will be some other downside issues, if we make the switchover, and I would be disingenuous not to mention them.
Hydrogen, like ammonium nitrate can be both good and bad. The good side of ammonium nitrate is its use as a fertilizer; the bad side of ammonium nitrate became apparent in Oklahoma City in April 1995. Hydrogen has a spotted history too.
In May of 1937, the zeppelin "Hindenburg" self-immolated at Lakehurst, New Jersey when the 7,600,000 cubic feet of hydrogen gas it used for buoyancy ignited. In January 1986, the "Challenger" space shuttle destroyed itself when a leak in a solid rocket booster burned through the shuttle's external tank and ignited 600 plus tons of liquid hydrogen. And, in April 1986, the Chernobyl nuclear power plant self-destructed when steam from ruptured pipes reacted with red hot graphite in the reactor core, producing hydrogen, which exploded, destroying the reactor building and ejecting 25% of the core.
If switching to hydrogen fuel
will reduce our dependence on oil, I'm all for it. However, I
think that before we switch to hydrogen, we ought to transition
from gasoline to liquid propane first. We know how to handle
propane safely. True, we still see some folks without eyebrows,
but they will always be with us. The point is, when learning
a new technology; you have to develop processes and procedures
to make it safe. We're not ready to go from gasoline to hydrogen
yet, but we can switch to propane safely. Our procedures for
refilling propane tanks seem to work well, with a few minor exceptions,
- they already have Darwin Awards to prove it - and the average
citizen is used to hooking up propane cylinders to grills and
infrared heaters. That puts us quite a ways out on the learning
curve already. Keep in mind, though, there is no such thing as
a free lunch, and for all of its pluses, we still will have to
learn to use hydrogen fuel the hard way.
Bob Ciminel lives in Roswell, Georgia, and works for the Institute of Nuclear Power Operations. Bob is also a conductor on the Blue Ridge Scenic Railway.