Switch to ethanol may be harmful to health, scientist says
03
June
2007

Switching from gasoline to ethanol – touted as a green alternative at the pump – may create dirtier air, causing slightly more smog-related deaths, a new study says.

Nearly 200 more people would die yearly from respiratory problems if all vehicles in the United States were to run on a fuel blend made mostly of ethanol by 2020, the research concludes. The author of the study acknowledges that such a quick and monumental shift to plant-based fuels is next to impossible.

Each year, about 4,700 people, according to the author of the study, die from respiratory problems related to ozone, the unseen component of smog, combined with small particles. Ethanol would raise ozone levels, particularly in certain regions of the country.

“It’s not green in terms of air pollution,” said Mark Jacobson, a Stanford University civil and environmental engineering professor and author of the study. “If you want to use ethanol, fine, but don’t do it based on health grounds. It’s no better than gasoline, apparently slightly worse.”

His study, based on a computer model, was published Wednesday in the online edition of the peer-reviewed journal Environmental Science and Technology. It added to the messy debate over ethanol.

Farmers, politicians, industry leaders and environmentalists have clashed over just how much ethanol can be produced, how much land it would take to grow the crops to make it and how much it would cost. They also disagree on the benefits of ethanol in cutting back fuel consumption and in fighting pollution, especially of the gases linked to global warming.

In January, President George W. Bush announced a push to reduce gas consumption by 20 percent over 10 years by substituting alternative fuels, mainly ethanol. Scientists with the Environmental Protection Agency estimated that such a change could mean approximately a 1 percent increase in smog.

Jacobson’s study troubles some environmentalists, even those who work with him. Roland Hwang of the Natural Resources Defense Council, said that ethanol, which cuts one of the key ingredients of smog and produces fewer greenhouse gases, is an important part of reducing all kinds of air pollution.

Jacobson’s conclusion “is a provocative concept that is not workable,” said Hwang, an engineer who used to work for the California pollution control agency. “There’s nothing in here that means we should throw away ethanol.”

And Matt Hartwig, spokesman for the Renewable Fuels Association, the largest Washington ethanol lobby group, said other research and real-life data show that “ethanol is a greener fuel than gasoline.”

But Jacobson found that it all depended on where you lived, with ethanol worsening the ozone problem in most urban areas. Based on computer models of pollution and air flow, Jacobson predicted that the increase in ozone – and the diseases it causes – would be worst in areas where smog already is a serious problem: Los Angeles and the Northeast.

Most of those projected 200 deaths would be in Los Angeles, he said, and the only place where ozone would fall was in the Southeast, because of the unique blend of chemicals in the air and the heavy vegetation.

The science behind why ethanol might increase smog is complicated, but according to Jacobson, part of the explanation is that ethanol produces more hydrocarbons than gasoline. And ozone is the product of hydrocarbons and nitrogen oxide cooking in the sun.

While praising Jacobson as one of the top atmospheric chemists in the nation, Hwang said that he had problems with some of Jacobson’s assumptions, like that of an entire switch to ethanol by 2020.

Jacobson is also ignoring that ethanol reduces greenhouse gases, which cause global warming, and that global warming will increase smog and smog-related deaths, according to an international scientific panel, Hwang said.

By Seth Borenstein source: IHT

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    3 Comments to "Switch to ethanol may be harmful to health, scientist says"
    1. I really am impressed with this blog. we really need to get away from fossil based fuels. Love the green stuff!

    2. Brian Mott says:

      One way to help cut down on the amount of emissions coming from vehicles is to use a re-formulator. There is a product called ethos fr which cuts emissions by 30% or more. The data and some of the users can be found at usaethosfr.com

      Brian Mott
      Dallas, Texas

    3. Russell McLean says:

      After carefull thought of your article, I firmly believe ethanol wouldn’t have to cause more smog related harm, actually it should be less. Ethanol has diffirent properties to normal petrol so if a car is optmised to run on ethanol it won’t produce any more pollutants. Flexi fuel vehicles (vehicles that work on either ethanol or petrol) are designed to work as a compromise. E85 is a an 85% ethanol blend that is commonly used in Europe and has an octane rating of 113 meaning that it withstands harmful detonation far more than petrol and the motor actually runs cooler. If the compresion ratio is simply increased and the motor gets tuned properly then the burning becomes far more efficient.
      There are 4 main types of pollutants that are legislated against -unburnt hydrocarbons, carbon monoxide, carbon particles (smoke) and nitrates. The first three are caused by incomplete burning, i.e the wrong compresion ratio, poor timing, or a poor air fuel mixture. Nitrates are created by how long and how hot the burning takes place and can be negated by engine design and by catolytic converters. Nitrates DO NOT go hand in hand with hydrocarbons and they can be greatly reduced with catolytic converters. All of the other pollutants are problems with an engine not optimised for use with that fuel. I must also add that a big reason diesel engines are more efficient than more eco-friendly than petrol are because they have higher compresion ratios.
      Another cool thing about optimising a motor for ethanol is a large power increase (Swedish supercar manufacturer Koenisgegg increased the power output from 806 bhp to 1018 bhp with the same motor by just a few minor changes). Isn’t it strange that flexi fuel vehicles have less power when run on ethanol than pertol, surely this is a sure indication of a poor coprimise
      There should be advantages or better economy, power with less pollution.
      I also noticed some other flaws with the original post. The smog problem isn’t worsened by heavy vegetation. Vegetation takes up nitrates, carbon dioxide and even reduces smoke. The real problem about the smog is the combination of the pollutants created in the area combined with landscape and weather in the area. Petrol is also mixed with other environmentally unfriendy additives that add to the smog toxicity that Mark Jacobson just happened to leave out (probably on purpose), and the fact that ethanol is a renewable fuel that has a very small carbon footprint in comparisin. When I can afford the initial cost, I will definately convert to ethanol because there are no disadvantages in ethanol where I live and I’ll have a clean concience about my carbon footprint.

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