Water as fuel?

Dear EarthTalk: I’ve heard that cars can be modified to run on water. How is this possible?

Diane McMorris

Rockport, Maine

There are a number of online marketing offers of kits that will convert your car to “run on water,†but these should be viewed skeptically. These kits, which attach to the car’s engine, use electrolysis to split the water (H2O) into its component molecules — hydrogen and oxygen — and then inject the resulting hydrogen into the engine’s combustion process to power the car along with the gasoline. Doing this, they say, makes the gasoline burn cleaner and more completely, thus making the engine more efficient.

But experts say the energy equation on this type of system is not, in reality, efficient at all. For one, the electrolysis process uses energy, such as electricity in the home or the on-board car battery, to operate. By the laws of nature, then, the system uses more energy making hydrogen than the resulting hydrogen itself can supply, according to Dr. Fabio Chiara, research scientist in alternative combustion at the Center for Automotive Research at Ohio State University.

Moreover, Chiara says, the amount of greenhouse gases produced by the vehicle “would be much larger, because two combustion processes [gasoline and hydrogen] are involved.†Finally, there is a safety consideration for consumers who add these devices to their cars. “H2 is a highly flammable and explosive gas,†he says, and would require special care in installation and use.

The electrolysis process could be viable in saving energy if a renewable, non-polluting energy source such as solar or wind could be harnessed to power it, although capturing enough of that energy source on board the car would be another hurdle.

Researchers today put more focus on using hydrogen to power fuel cells, which can replace internal combustion engines to power cars and emit only water from the tailpipe. And though hydrogen is combustible and can power an internal combustion engine, to use hydrogen in that way would squander its best potential: to power a fuel cell.

Hydrogen fuel cell cars are gaining traction, but commercialization of hydrogen fuel has not yet been accomplished. “The potential benefits of fuel cells are significant,†say researchers at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL). “[H]owever, many challenges must be overcome before fuel cell systems will be a competitive alternative for consumers.â€

The state of California operates a “Hydrogen Highway†program that supports development of hydrogen fuel cell technology and infrastructure. And many companies are working on ways to produce, store and dispense hydrogen. Cars powered by fuel cells are in prototype stages now, nearing production.

While we all wait to see how that shakes out, the best choice today for high mileage and low emissions is still the gasoline/electric hybrid car.

CONTACTS: Center for Automotive Research, car.eng.ohio-state.edu; NREL, nrel.gov; California Hydrogen Highway, hydrogenhighway.ca.gov.

Dear EarthTalk: I’ve heard so much about using Borax for green housecleaning.  But if this mineral has to be mined, doesn’t that negate some of its “green-ness?â€

Elsa

Lincoln, Neb.

Mining for minerals such as boron (the key ingredient in the “Borax†we use for cleaning, pest control and other household tasks) is an activity that typically leaves behind a big environmental footprint. Mining degrades the local landscape and destroys wildlife habitat, while polluting both air and water. It also usually consumes large amounts of water, which can be taxing in already arid regions, such as the Mojave Desert, one of two regions of the world (along with parts of Turkey) with large boron deposits.

Typically, boron is extracted in open-pit mines by drilling, blasting, crushing and hauling — all activities fueled by petrochemicals. The refining process then uses a significant amount of water. Finally, the waste product — known in the industry as “tailings†— is deposited in man-made ponds where further refining is done before the water is then discharged into the local watershed.

The mining industry has long been criticized as an environmental baddie, but the leading company that mines Borax, Rio Tinto, has actually been given high marks for environmental stewardship. Jared Diamond’s 2005 book, “Collapse: How Societies Choose to Fail or Succeed,†called the British mining giant the exception in its industry. Due to “a strongly supportive CEO and British stockholders,†he wrote, the company moved forward with the 2002 environmental recommendations of the mining industry’s Mining Minerals and Sustainable Development project that were for the most part ignored by the rest of the industry.

“Rio Tinto foresaw business advantages to being seen as an industry leader in social responsibility,†said Diamond. “Its Borax mine in Death Valley, Calif., is now perhaps the most cleanly operated mine in the U.S.â€

Boron, oxygen and sodium make up sodium tetraborate, which is sold as “20 Mule Team Borax†(the name comes from the teams of 18 mules and two horses that would haul large wagons of processed borax from mines in the late 1800s to the nearest railroad spur). The powdered detergent is considered a least-toxic recipe as a natural disinfectant and household cleaner. Beyond cleaning formulations, boron is also used in a wide variety of other products, including the manufacture of fiberglass and Pyrex.

Pest control is another use. One boron compound is used to treat wood to prevent fungal decay and repel carpenter ants, roaches and termites. Boric acid is included on the national list of allowed substances for structural pest control in organic food production (as long as there is no direct contact with food or crops). The U.S. Environmental Protection Agency has determined that pesticide products containing boric acid and its salts are of low toxicity. (However, ingesting it or applying large amounts to the skin can cause acute poisoning, so parents should be vigilant about where they store and use products containing Borax.)

Emerging uses of boron, and new ways to recycle its waste, may make this mineral even more valuable. A Turkish researcher notes that borax waste added to red bricks and cement products increases strength and lifespan. And at the National Boron Research Institute in Turkey, it is being studied as an element to produce fuel cells and to aid in cancer treatment.

CONTACTS: Rio Tinto, riotinto.com, U.S. Environmental Protection Agency, epa.gov; Turkey’s National Boron Research Institute, boren.gov.tr/en.

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