Green machines leave the lab and hit the highway.
Powering your car with water is a fantasy that ranks with turning tin to gold. But the next best thing — H2O without the O — isn’t so farfetched. Last month, California Governor Arnold Schwarzenegger beamed a radiant smile to news cameras while pumping his Hummer’s fuel tank full of hydrogen (H2) at a new Los Angeles International Airport station. “What?!,” you say. “Isn’t that the stuff that blew up the Hindenburg? Is this Terminator IV, Revenge of The Public Servants?”
|BMW’s H2R hydrogen racecar (under construction above) uses a non-boosted 282 hp, 6.0L V-12 to hit speeds over 186 mph. Nine records were set in a new hydrogen-fueled-vehicle class. |
Like a Hollywood porn queen cleansed by six weeks in a convent, hydrogen is back. This time safety measures are available to guard against catastrophe. In fact, prognosticators insist that what’s likely to go boom is a global hydrogen economy. In his 2003 State of the Union Address, President Bush kicked off a hydrogen initiative with a price tag over $1-billion. The U.S. government’s Department of Energy hopes H2 will handle ten percent of America’s energy needs by 2030. A growing number of experts believe this colorless, odorless gas is the silverbullet solution to our transportation, air-pollution, and energy-security concerns.
Governor Schwarzenegger seems serious about making hydrogen a star. Calling his specially modified Hummer “a vehicle of today capable of running on the fuel of tomorrow,” he’s ready to start his SUV’s big V-8 and motor on down California’s Hydrogen Highway, an initiative aimed at proving the viability of this brave new fuel.
Hydrogen is hot, and not just in California, for two reasons. It’s what we’ll be pumping into our squeaky-green fuel-cell electric vehicles when they hit the street in 15 or so years. But a growing throng of engineers, scientists and backyard tinkerers are unwilling to wait; this group insists that the engine under the hood of your car can be broken of its gasoline habit and reprogrammed to run just fine on hydrogen. They also contend that lessons learned accumulating, storing, transporting and consuming hydrogen will advance us several miles down the governor’s highway to the future.
|Ford’s hydrogen C-MAX demonstrates that hydrogen is a viable fuel for ICEs, but also shows the problems with packaging the large cumbersome tanks.|
BMW is hydrogen’s biggest corporate booster. In 1978 — when fuel cells were still the stuff of space travel — Bavarian engineers began modifying conventional engines to run on H2. The knowledge they learned will hit the road within five years in the form of production- line 7-series sedans capable of switching between gasoline and hydrogen fuels.
Hydrogen, which consists of one proton and one electron, is nature’s most elegant and abundant element. It accounts for three-quarters of the mass and 90-percent of the atoms in the universe. Jupiter is literally full of it. On Earth, hydrogen is the ninth most abundant element, though its tendency to wander off into space makes it a stranger (one part in a million) in our atmosphere. Combustion experiments began in the 16th century before hydrogen got its name. It burns nicely in air and makes a potent rocket fuel, but hydrogen also has a mean streak (H-bomb).
H2 is the current darling of internal combustion engine fuels for the same reason it’s so attractive for use in electric-car fuel cells: there’s no carbon to foul up the energy-conversion process. Burn gas, an amalgamation of hydrogen and carbon, in an engine and most of the by-products spewing out the exhaust contain what’s become the evil element (C): carbon monoxide (CO) is what kills you when you lock yourself in the garage with a car engine running. Partially burned hydrocarbons (HC) are a key constituent of smog. Carbon dioxide (CO2) is the greenhouse gas under attack for its presumed role in global warming. Hydrogen, the most potent fuel going, packs nearly three times the energy of gasoline. It’s easy to ignite and burns faster and hotter than high-octane gas. The exhaust consists mainly of steam (water in the vapor state). The only carbon by-products come from trace amounts of lubricating oil consumed during combustion.
Only minor changes are needed to switch engines from gasoline to hydrogen fuel. The make-up of some internal components, such as valve seats, must be altered to guard against a phenomenon called hydrogen embrittlement — the tendency of hydrogen atoms to infuse the surface of welded or heat-treated steel, causing a lack of ductility and cracking. Also, local hot spots must be avoided to forestall premature ignition.
Were it not for its drawbacks, we’d already be pumping hydrogen into our tanks instead of gasoline. Beyond cost and availability, the major hydrogen headache is that it’s a gas at room temperature. Its tiny little atoms slip right through clay, rubber and some metal containers. Condensing it into a liquid state requires cooling it to -423 degrees F, only 37 degrees above absolute zero. In spite of the bother associated with what’s called cryogenic (super-cooled) hydrogen, BMW is convinced this is the way to go. Others, such as General Motors in the aforementioned Hummer application, prefer compressing the gas to 5,000 psi to increase concentration, with hopes of doubling that pressure in the near future. Three expensive carbon-fiber-reinforced tanks built into Schwarzenegger’s Hummer carry 12 pounds of hydrogen, enough for a 60-mile cruise. In contrast, BMW’s cryogenic method allows carrying 24 pounds of liquid hydrogen inside a highly insulated, 80 psi, 45-gallon tank. That’s enough fuel to power a large BMW sedan nearly 200 miles.
No matter how it’s stored in a car’s fuel tank, hydrogen is metered into the engine’s intake manifold in gaseous form via electronically controlled injectors. While the ideal ratio for maximum power is 34 parts air to one part hydrogen, engineers steer clear of such mixtures because they’re prone to premature ignition and they trigger undesirable by-products. When combustion temperatures exceed 3,100 degrees F, nitrogen ingested with the air is partially burned creating the photochemical-smog constituent NOx.
The ready solution is upping the mix to at least 68 parts of air for each increment of hydrogen to cool combustion. Thanks to hydrogen’s ease of ignition and ready flammability, engines will run with up to 280 parts of air for each increment of hydrogen. (Gas engines run best on a 15:1 air:fuel ratio.) To help pump in all that air, GM added a supercharger to the 6.0L Vortec V-8 engine powering Governor Schwarzenegger’s Hummer H2H. The down side is that the lean mixtures sacrifice peak power. While the Hummer’s original gasoline V-8 produces 316 horsepower, the clean, lean hydrogen-fueled version yields only 180 horses.
To prove that engines fed hydrogen can be clean AND potent, BMW engineers goaded a 6.0L V-12 up to 282 horsepower (without supercharging or turbocharging) and installed it in a special single-seat streamliner dubbed H2R (Hydrogen Record Car). In September, three company drivers circulated a French proving grounds track at speeds over 186 mph. Nine records were set in a new hydrogenfueled- vehicle class.
Similar technology will be fitted to a few 7-series sedans that will be offered to retail customers within three to five years, according to BMW. A notable difference is that these cars will be tuned for both hydrogen and gasoline operation to stretch their operating distance. The anticipated driving range is 180 miles on hydrogen and another 375 miles of travel with gasoline.
So the chicken-egg race between hydrogen- powered cars and suitable means of refueling them is heading into the home stretch. The LAX station dedicated by Schwarzenegger last month is intended for public use within five to ten years. On November 12, the Clean Energy Pump of Berlin opened for business, ready and able to dispense hydrogen to German motorists. A few hydrogen-powered cars are on the road and more are coming. The age of H2 transportation has officially begun.
|Hydrogen Hit Parade: Ten large and small hydrogen fuel boosters.|
|BMW AG: |
|Began hydrogen research in 1978; plans sale of dual fuel (hydrogen or gasoline) 7-series sedans in 3-5 years.|
|Ford Motor Company:|
|Constructed 10 H2- powered vehicles during 7 years of research as a bridge to fuel cells. If sufficient progress is made, may offer hydrogen internal combustion engine vehicles for sale.|
|Prefers focusing attention on “the journey to a hydrogen economy.” Hydrogen storage, delivery and refueling experience with Hummer H2H expected to advance fuel cell cause.|
|Mazda Motor Corporation: |
|Has studied hydrogen-fueled rotary (Wankel) engines since 1991. Plans to offer dual fueled RX8 sports cars for lease to Japanese drivers within two years.|
|Hydrogen Car Company (of Los Angeles):|
|Has converted 50 cars to run on hydrogen fuel. Offers green pickups, SUVs, mediumduty trucks and Shelby sports cars costing up to $200,000.|
|Stuart Energy Systems Corporation:|
|Toronto-based enterprise working with Shell Hydrogen expects in 3-4 years to offer a $10,000 HomeFueler for producing residential hydrogen.|
|South Coast Air Quality Management District:|
|California Hydrogen Highway partner awarded a $2.3 million contract to Quantum Technologies to convert a fleet of 30 Toyota hybrid-electric Priuses to hydrogen- fuel operation.|
|GM’s strategic partner for development and manufacture of gaseous fuel storage and delivery equipment. Patented a 10,000-psi H2 storage tank.|
|Energy Conversion Devices Ovonics: |
|In partnership with ChevronTexaco, developed tank for storing hydrogen in solid form and converted a Toyota Prius hybrid to run on hydrogen fuel.|
|President Tai Robinson of Sandy, Utah, converted a Toyota Tacoma pickup truck to run on hydrogen and other fuels for a 2003 crosscountry drive.|