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Thread: An alternative fuels artice from FoMoCo.

  1. #1
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    An alternative fuels artice from FoMoCo.

    http://www.fordboldmoves.com/Article...2-21e1adcbc876
    It’s everywhere—newspapers, magazines, movies and political speeches—we are addicted to oil, and that the addiction has dire consequences.

    Obviously, the logical solution would be to discover or develop an alternative fuel—that is, one not derived from oil. Unfortunately, finding an alternative that is abundant or renewable, economical to produce, and environmentally safe is a very difficult and complex challenge.

    Let’s take a step back to provide some perspective on the tremendous challenge that we face. The dominant source of our oil addiction is transportation. Transportation, unlike the other major energy-consuming segments of the global economy, is almost singularly dependent upon gasoline and diesel fuels derived from oil.

    Fuel is, broadly speaking, something that is consumed to produce power or heat. Currently, 99.9% of the cars and trucks that we drive are powered by a combustion engine. The fuel—gasoline or diesel—is burned to release the energy that pushes the pistons that make the wheels go round.

    There are a wide variety of alternative fuels including:

    (1) Liquid fuels—biofuels such as ethanol or biodiesel, or synthetic fuels such as coal-to-liquids or gas-to-liquids;
    (2) Gaseous fuels—natural gas, bio-methane (methane produced by waste), propane, hydrogen; and
    (3) Electricity—when used by an electric motor to drive the wheels.

    Just because it is possible to devise an alternative fuel doesn’t necessarily mean it is a good idea to use it. An assessment of the total emissions and energy profile of a fuel from its production through its use is called a “Lifecycle Analysis” (LCA). An LCA consists of two main parts.

    The first is “well-to-tank”—or what is required to produce and deliver the fuel to the filling station pump. The second is “tank-to-wheels”—or what is produced by the actual consumption of the fuel in the operation of the vehicle. Some alternative fuels can be extremely clean-burning in the car (tank-to-wheels) but so costly in their use energy and production of emissions in their production that widespread use doesn’t make sense.

    By far the alternative fuel with the greatest immediate reach and potential for further expansion in the US is the biofuel ethanol, which can be blended with gasoline. Ethanol is an alcohol, produced by the fermentation of sugars from plants. As an alternative fuel, ethanol offers three immediate benefits.

    First, it doesn’t require major changes to the predominant engine platform in the US. Modern cars in the US can run on an E10 (10% ethanol, 90% gasoline) blend with no changes. A car that burns an E85 blend (85% ethanol, 15% gasoline) or gasoline interchangeably is called a flexible-fuel (flex-fuel) vehicle—and there are already about 4 million of these on US roads.

    Second, ethanol is produced from plants or plant waste, reducing dependence on imported oil. Third, it reduces net carbon dioxide emissions.

    Anytime a hydrocarbon fuel burns, it releases carbon dioxide, the dominant greenhouse gas associated with global warming. Accordingly, when ethanol burns, it releases carbon dioxide; but, because the carbon in ethanol comes from plants, and the plants pulled the carbon out of the atmosphere, it is considered a wash.

    Fossil fuels, on the other hand, release carbon that had been sequestered underground for eons. That results in a net addition of carbon dioxide in the air.

    Ethanol can help us to overcome our oil addiction, but it poses high hurdles of its own. As a fuel, it contains less energy than gasoline. That means that the same engine will use more ethanol than gasoline to produce the same amount of power. (Put another way, fuel economy drops when using E85.)

    Furthermore, it requires a separate distribution and pumping infrastructure. There are only about 600 E85 pumps in the US right now, compared to about 170,000 petroleum fuel pumps.

    Third, given the size of the automotive fleet in the US, we simply can’t make enough ethanol to replace our gasoline.

    Ethanol has some clear emissions benefits in tank-to-wheels. But a number of opponents to the use of ethanol have argued over the years that the emissions and energy costs for producing the fuel are too high.

    Whether or not this is accurate depends on a number of factors: the type of crop (feedstock), the energy and emissions required for the production of the crop, the exact process for producing the fuel, transportation costs and so on.

    The production of ethanol from corn in particular has stirred decades of debate over the environmental value of its use. After an assessment of the major claims and counterclaims, Dan Kammen, co-director of the Berkeley Institute of the Environment and UC Berkeley’s Class of 1935 Distinguished Chair of Energy, recently concluded:

    “It is better to use various inputs to grow corn and make ethanol and use that in your cars than it is to use the gasoline and fossil fuels directly. The people who are saying ethanol is bad are just plain wrong.

    But it isn’t a huge victory—you wouldn’t go out and rebuild our economy around corn-based ethanol.”

    New production methods under development—such as the ability to produce ethanol from other plant material (called cellulosic ethanol)—can make ethanol use a more compelling proposition, however.

    Synthetic liquid fuels produced from coal, natural gas or biomass—called Fischer-Tropsch fuels after the German scientists who invented the process—are another class of alternative fuel rapidly gaining serious reconsideration by the government and by industry.

    The Fischer-Tropsch process essentially rearranges the chemical structure of feedstocks that contain hydrogen and carbon (hydrocarbons) into a more usable set of liquid hydrocarbons (synthetic diesel, for example).

    The resulting fuels are much cleaner-burning (tank-to-wheels) than conventional diesel. Their production, however, is extremely energy-intensive and depending upon the feedstock, can emit much more carbon dioxide than the production of regular diesel.

    For example, a recent major European study on alternative fuels found that the production of coal-to-liquids fuels emits almost twice as much carbon dioxide as the production of petroleum diesel; the production of natural gas-to-liquids fuels emits about the same amount as that for petroleum diesel; and the production of biomass-to-liquids synthetics emits substantially less.

    At a time when the US is considering policies to encourage coal-to-liquids production, that’s important to keep in mind.

    No other alternative fuel highlights the full range of outcomes (positive and negative) for different production pathways as well as hydrogen does.

    Hydrogen is the alternative fuel that some consider to be the fuel of the future, the foundation of a coming hydrogen economy that could supplant the fossil-fuel economy of today.

    Hydrogen is found within all organic compounds, water, and many other chemical compounds. In its gaseous form it is a fuel that can be burned in an engine, or combined with oxygen in a fuel cell to produce electricity. A fuel cell is a device similar to a battery, but one that is continuously replenished as the reactants (hydrogen and oxygen) are consumed.

    One of the main reasons that hydrogen is so appealing is that it contains no carbon. Therefore, burning it produces no carbon dioxide, nor any of the other pollutants associated with combustion engines. Using it in a fuel cell produces clean electricity, the only emission being water.

    However, hydrogen gas only occurs naturally in trace amounts. It must be extracted from other compounds such as hydrocarbons or water. Since it is not a pre-existing source of energy like a fossil fuel, it can’t be mined or pumped—it must be manufactured.

    There are a number of ways to produce hydrogen; all are energy-intensive, and some produce large amounts of carbon dioxide as a byproduct. Natural gas is the predominant feedstock in use in the US; coal is considered by many to be a likely source for the future. Again, the downside of such production pathways is the large amount of carbon dioxide produced.

    The problem, then, is to find a sustainable way to produce a sufficient amount of hydrogen—and that likely means the use of renewable electricity for electrolysis, the production of hydrogen by organisms (bio-hydrogen), or the use of solar energy to split water directly.

    Another significant challenge for hydrogen is that it is very light—that is, it contains very little energy per unit volume. To be useful in a car, a lot of hydrogen must be packed into a relatively small area, either through compression, liquefaction, or chemical storage. Without enough hydrogen on board, the range of the vehicle would be too limited. Storage is one of the main obstacles to wider use of hydrogen as an alternative fuel for vehicles.

    Electricity has three primary applications as an alternative fuel. First is as a component in a hybrid system. Second is as power for a battery electric vehicle. And third is as the power produced by a fuel-cell in a vehicle. In all three applications the purpose of the electricity is to power an electric motor.
    Part 1 of 2.
    Last edited by Quiggs; 08-15-2006 at 04:10 PM.
    [O o)O=\x/=O(o O]

    The things we do for girls who won't sleep with us.

    Patrick says:
    dads is too long so it wont fit
    so i took hers out
    and put mine in

  2. #2
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    A hybrid, by definition, provides two sources of power to move the car. Typically a hybrid car pairs a combustion engine with an electric motor, although other power sources are possible and being explored. Hybrids cut down on fuel consumption by reducing the work the engine has to do, relying instead on the motor, which is powered by a battery that recharges during driving and braking.

    Plug-in hybrids represent a more advanced application of the hybrid architecture. Plug-ins use much larger batteries than conventional hybrids—batteries that can be recharged by plugging in to the electric grid. The result is a longer all-electric range, and correspondingly, a greatly reduced use of the engine.

    Battery-powered electric vehicles are currently constrained by the capability of battery technology. Current batteries just can’t hold enough electricity to provide sufficient range for widespread adoption. (That’s one of the major rationales for a hydrogen fuel-cell vehicle—you make your electricity as you go.)

    If there were a major breakthrough in battery technology that could provide that sort of long range and power, then one of the major rationales for fuel-cell vehicles would disappear.

    With power from the electric grid, the primary considerations then become how that power is made. Is it from coal? Natural gas? Nuclear? Or renewable wind, solar, geothermal, biomass or tidal?

    Generally speaking, alternative fuels for engines are less energy-efficient than conventional fuels, although they also tend (with a few coal-based exceptions) to produce fewer greenhouse gas emissions than conventional fuels. Balanced against that is the energy-efficiency of gasoline and diesel, coupled with the need to reduce their use for both emissions reductions and concerns over the stability of the oil supply.

    One viable approach to trying to resolve this situation is to use a hybrid architecture that significantly decreases the size of the engine in favor of a very robust battery/motor capability, and then to fuel that engine with an alternative fuel.

    Examples of this would be a flex-fuel E85 hybrid or a biodiesel hybrid.

    To protect against the risk of disruption in the oil supply, blending of alternatives with conventional fuel is possible. E85 is a prime example of that. But Gas-to-Liquids diesel, with a greenhouse gas profile comparable to that of regular diesel, can be blended with that diesel in relatively low amounts with good results from an emissions point of view, and from an extension of the oil supply point of view.

    Furthermore, gaseous fuels can be blended with each other (hydrogen and natural gas) or used with liquid fuels as combustion enhancers—again, resulting in improved efficiency and decreased emissions.

    In essence, by using alternative fuels now, we are trying to buy the time—via reductions in petroleum use and associated emissions—to develop a long-term sustainable solution. Alternative fuels can thus play an important role right now—and some may even end up part of the long-term solution.
    Discuss.
    Last edited by Quiggs; 08-15-2006 at 04:12 PM.
    [O o)O=\x/=O(o O]

    The things we do for girls who won't sleep with us.

    Patrick says:
    dads is too long so it wont fit
    so i took hers out
    and put mine in

  3. #3
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    Audi's diesel fuel for the R10 is made from biomass

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