With the help of the American Hydrogen Association, they have modified a standard gasoline lawnmower engine to run on hydrogen fuel. The ubiquitous lawnmower engine produces disproportionately high levels of polluting gases, including unburned hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NOx) and carbon dioxide (CO2). HCs are considered carcinogenic and cause smog; CO is toxic; NOx and CO2 are powerful greenhouse gases that contribute in a big way to greenhouse warming. But when operated on clean-burning fuel, hydrogen fuel either dramatically lowers or entirely eliminates the pollutant levels produced by the gasoline-fueled lawnmower (see graph).
The news gets better. Not only was the exhaust from the lawnmower clean and drinkable (the product of hydrogen combustion is potable water), but the hydrogen combustion process reduced ambient air levels of hydrocarbons in the test facility by 70%. Where did the hydrocarbons in the ambient air go? The lean-burn process facilitated by the hydrogen turned them into water and trace amounts of carbon dioxide. If it can do that for lawnmowers, it can do the same for cars, trucks, buses, trains and airplanes.
Nearly 25% of CO2 emissions result from the 200 million plus vehicles on U.S. roads. Catalytic converters that were once considered a miracle response to air pollution are now implicated as major producers of nitrous oxide (N2O), a greenhouse gas 300 times more potent than CO2. The EPA has estimated that N2O emissionsÑproduced by catalytic converters when they combine oxygen with nitrogen monoxide (NO)Ñnow account for 7.2% of global warming.
Hydrogen powered engines require no catalytic converters and produce only trace amount of NO. Hydrogen is an inexhaustible resource which can be derived from organic matter, water or fossil fuels. Unlike fossil fuels, hydrogen is non-toxic, burns cleanly and recycles itself into water when burned in an internal combustion engine or a fuel cell. Hydrogen offers a safe, potent solution to the world's urgent environmental and energy problems. Because it can be made using locally available renewable resources, its use will greatly lessen the need to transport oil from distant sources or to spend billions of dollars annually for imported oil. It will render unnecessary our expensive military presence in the Middle East; in itself that's a multi-billion dollar cost savings.
Thank you, engineering students! Let the politicians make the noise, while you deliver the goods.
For more information: Charles Bensinger at the Southwest Renewable Energy Center, 505-989-4750 or E-mail at newworld@timewindow.com
Copyright Mendocino Environmental Center 1998
Permission granted to excerpt or use this article if source is cited