[Editor’s note: A “baghouse,” industry’s cheapest and most commonly used air-pollution-control device, is a box filled with conical or cylindrical filters — like giant vacuum-cleaner bags — that trap particulates in dirty air before it is sent out the smokestack.]
Natural gas burns much cleaner than regular gasoline — which is why the APCA is beginning to convert the cars in its fleet to run on natural gas. Such vehicles are now available from most major car manufacturers. (The fuel is stored on board as either a compressed gas — called CNG — or as a liquid, LNG.) But natural gas is far from being the only fuel being developed and produced as an alternative to smog-producing petroleum.
Methanol, a close cousin of natural gas, has been fueling Indy 500 race cars for decades. It can be readily produced from cellulose-rich biomass, such as hemp, cornstalks or even waste paper.
Although it’s still hard to find a methanol-powered passenger car or bus anywhere outside of California, federal mandates and grants are driving a rapid increase in conversions of government, private and mass-transit fleets to this and other Department of Energy-approved alternative fuels.
Another alcohol-based “biofuel” is ethanol, fermented and distilled from corn, barley or wheat mash — in other words, moonshine (but, in this case, with a finger or two of gasoline added to render it even less fit for human consumption). With a lot more gasoline, it becomes “gasohol.”
Within a few years, several million FFV’s — “flexible-fuel vehicles,” capable of running on gasoline, ethanol, methanol, or any combination of these from the same tank — are expected to be in use on U.S. roads, including sedans, minivans and compact pickup trucks.
But what about all those semis and buses that are still belching old-fashioned soot?
Well, they could be running their diesel engines just as effectively — and far more cleanly– on vegetable oil or animal fat! Though Rudolph Diesel invented his engine to run on a wide variety of oils — even used frying-oil (known as “fellow-grease”) — it’s only now that “biodiesel” fuel is being revived, particularly by soybean farmers who are marketing SoyDiesel, in an effort to find yet another product for their versatile but heavily overproduced crop. (Rapeseed and hempseed are also gaining attention as excellent sources of biodiesel oil.)
And, on the electric-car front, many major auto companies are now manufacturing them and experimenting with a variety of exotic fuel cells and batteries (such as nickel-cadmium, lithium and aluminum-air).
Unfortunately, electric cars’ clean, low-maintenance operation is counterbalanced by their dependence on not-so-clean electric-power plants.
A truly futuristic alternative, the hydrogen-fueled engine, uses a small electric charge to crack molecules of water into oxygen and hydrogen, the latter an extremely clean source of energy — but autos running on a tankful of water apparently have yet to leave the lab. Keep wishing for that 100-percent renewable, emissions-free, solar-powered car, and maybe one day, Detroit will begin producing this cleanest (but rarest) of all AFVs.
For more information, visit the Alternative Fuels Data Center Web site at: www.afdc.nrel.gov/altfuels.html.