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Hybrid Vehicles Ethanol - E85 FlexFuel Is Ethanol good for the environment?
165 messages, Last post on Sep 24, 2008 at 5:25 AM
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Has any one run into info regarding the sensor used in the fuel line? I'd read on another forum the sensor was optical? TNX Paul Why is there Air? |
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Ethanol made from surplus biomass can be beneficial for the environment. Our forests are overstocked with small trees and trees that can't be sold for timber because they are the wrong species or have poor form. Harvesting these trees and using them for biomass has these benefits: (1) Reduced wildfire risk because dense, small trees are much more flammable than larger, older trees in the early stages of wildfire. Uncontrolled open-air burning is horribly polluting. Combustion is incomplete so everything from carbon monoxide to methane and formaldeyde are vented into the atmosphere, along with particulates in the most unhealthy sizes. The energy content of the burnt matter is utterly wasted, and burnt-over land will have problems like hardened soil, humus depletion and years of erosion until groundcover is re-established. (2) forests become more productive by channeling their finite potential to grow biomass into the most valuable trees, according to management goals for the forest which could be anything from supporting wildlife or growing timber to improving soil chemistry. Agricultural and municipal waste are other major potential sources of biomass. Currently waste is burned (with the same air pollution problems as with forest fires) or put in landfills (where some of it decomposes to methane which is a powerful greenhouse gas). Although there are natural processes for decomposing biomass, they work at finite rates. Waste buried in landfills decomposes very slowly and will be with us for centuries. Using these waste streams as biomass energy sources turns a huge problem into a resource that will be used up to provide useful products. Energy plantations of perennial plants such as fast-growing trees or switchgrass can be located immediately downstream from tilled fields to absorb silt and excess fertilizer runoff instead of these ending up in the Gulf of Mexico etc. In short, it is often better to harvest surplus biomass and use it for energy than to dispose of it through open air burning or by dumping it into the environment. Also we can use biological processes to clean up certain types of pollution and then harvest biomass. This will be greenhouse-neutral energy that can replace fossil fuels. Energy pathways that convert biomass into ethanol are valuable because biomass is mostly cellulose, and cellulose is a carbohydrate that can be broken down into fermentable starches and sugars, or possibly fermented directly with the development of suitable microbial organisms. It is difficult to find good substitutes for liquid hydrocarbons, particularly for intercity or longer transportation. The opportunity to convert waste biomass into such a valuable product is a rare opportunity.
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Replying to: ladave (Sep 21, 2005 10:55 am) I agree with everything that you say, but I have a question that you may be able to answer. You speak of 'biomass ethanol' made from small trees and such. The name that used to be applied to methanol was 'wood alcohol'. Was that a misnomer? Can you derive either form from wood? This is more than idle curiosity, because all of the discussion of this alternative fuel is around ethanol. I wondered why methanol was not considered, for exactly the reasons that you state; there is a whole bunch of scrub wood out there for the taking. I wondered whether the absence of methanol in the alcohol discussion was because methanol was poisonous or whether it was just that there was a lot more money to be made by pushing ethanol. Any insight?
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Replying to: bhill2 (Sep 23, 2005 11:47 am) As a fuel, methanol is slightly less energy-dense than ethanol, but perfectly viable; in fact some race cars burn it. It is *not* true that they produce fewer horsepower, in fact both fuels are higher octane than gasolene and can be burned with ignition further advanced and higher compression ratios. Also with more fuel per pound of air, so the net result is more horsepower output for a given engine size and RPM. Methanol's biggest drawbacks are (1) it can decompose into methane, a powerful greenhouse gas and (2) it is more bio-toxic than ethanol. Ethanol occurs naturally whenever yeast cells meet carbohydrates, so most organisms have evolved tolerance to ethanol in moderate doses. Nevertheless methanol is less toxic than gasolene, so it can't be dismissed out of hand on grounds of toxicity. Ethanol has certainly been a good thing for farmers who grow corn, but we can't possibly grow enough corn to stop importing oil. If we are going to convert biomass into liquid fuels, the choice between ethanol and methanol should be based on cost, efficiency, and the two environmental issues just mentioned. |
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Forgive me if this has already been mentioned, but USDOE and USDA released a major report on biomass supply back in April. It is online at feedstockreview.ornl.gov/billion_ton_vision.pdf The gist is that between waste (forest, agricultural and municipal) and energy crops, the USA could produce over a billion dry tons of biomass annually. The cellulose in biomass is basically sugar molecules joined into long chains, so technology is under development to change cellulose back into sugar. Throw in some yeast and set up a still, and say sayonara to the Saudis. With forseeable efficiency improvements, a billion dry tons should yield about 100 billion gallons of ethanol, nearly one gallon per capita per day. The gross energy content of a billion dry tons is about 20% of current energy consumption, including coal, nuclear, natural gas, hydro, wind, etc. etc. |
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For those interested in using E85 you may want to read the hazards. This study is from LSU. Ethanol is not real safe to handle. http://www.camd.lsu.edu/msds/e/ethanol.htm#Health |
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"The ALA [American Lung Association] and many environmental groups supported a 2% oxygen requirement for RFG [reformulated gasoline] in the Clean Air Act Amendments of 1990 based on the assumption at the time such requirement would guarantee reductions of VOCs, and toxics. We now know we were wrong. .... The volatility increases that ethanol causes in summertime can overwhelm any benefit it provides in reducing CO tailpipe emissions, sulfur dilution or aromatics dilution. That is why the ethanol industry only talks about tailpipe emissions benefit from ethanol in RFG. The ethanol industry often quotes last year's National Research Council study of reformulated gasoline as finding that CO reduction credit should be included for ethanol in EPA's complex model for RFG because CO tailpipe emissions contribute to ozone formation. But they fail to acknowledge what we believe to be a more important finding. The NRC report stated, '...the increase in the evaporative emissions from the ethanol-containing fuels was significantly larger than the slight benefit obtained from the lowering of the CO exhaust emissions using the ethanol-containing fuel.' .... The bottom line: the reduction in CO tailpipe emissions obtained by using ethanol in summertime gasoline are not worth the increase in evaporation and the increases in NOX emissions from a smog contribution point of view. Incidentally, the increases in evaporation do not just contribute to ozone formation. Since the gasoline also contains toxic aromatics, such as benzene, these will evaporate more readily along with the ethanol. While ethanol may dilute the amount of benzene in a gallon of gasoline, the amount of benzene that ends up in the ambient air due to increase evaporation from the fuel may be greater than if the ethanol were not added at all." The National Research Council study referred to above is regarded as the definitive scientific study of ethanol. The title of their news release says it all "Commonly Available Ethanol and MTBE Gasoline Blends Do Little to Reduce Smog". Even the Minnesota Office of the Legislative Auditor, who tries as hard as possible to put a happy face on their state's aggressive ethanol policy, admits "we think the NRC report is currently the most independent, authoritative document available to policy makers." Very recent evidence suggests even more serious cause for alarm regarding ethanol use. Professor James Garvey of SUNY-Buffalo has discovered that nitric oxide, a common air pollutant, combines readily with ethanol to form highly reactive gas-phase clusters. The implication of this discovery is that the sum of NO and ethanol emissions is more dangerous than its parts. Of course the EPA is well aware of the pollution problems caused by ethanol, especially the fact that it increases serious hydrocarbon evaporative emissions during warm weather. http://www.powerweb.net/heisey/dirtyair.htm |
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According to report from IEA (International Energy Agency). This year, more Flex fuel vehicles than Gasolene vehicles were sold in Brazil. In Nov, 71 % of the vehicles sold were FFV. Brazil is expecte to export the fuel to other countries as well. |
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Ethanol, a fuel that's backed by state and federal governments and viewed as a boon to corn farmers in the Midwest and South, may make it harder to breathe in Louisville this summer. While governors in more than 25 states, including Kentucky and Indiana, tout it as a way to make gasoline burn cleaner, there's new evidence ethanol can worsen some types of pollution linked to damaging health effects -- namely ozone and fine particles. And that could make it harder for cities like Louisville, where it already is being used, to meet air standards. "There is growing evidence that when used in the summer with reformulated gasoline, ethanol actually creates more smog and fine-particle soot," said Frank O'Donnell, a longtime clean air advocate in Washington, D.C. http://www.courier-journal.com/apps/pbcs.dll/article?AID=/20050421/NEWS01/504210- 377/1008 |
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"The bottom line is that both the motor vehicle industry and the refining industry have evolved since the early 1990s, when these requirements went into effect," remarks Frank O'Donnell, director of the Clean Air Trust, an air-quality-defense group put together nine years ago by former U.S. senators Edmund Muskie of Maine and Robert Stafford of Vermont. "Oxygenates aren't necessary anymore. Modern cars have oxygen sensors that adjust the air-to-fuel ratio, which is one of the things that oxygenates were supposed to do. And we have better fuels." Ethanol Not so good |
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