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Biodiesel is an alternative fuel source

  1. Aug 30, 2005 #1
    Okay, so I was watching Trucks! on spike tv last week, and he did an episode on biodiesel, even made some right before our very eyes. For those of you who don't know, biodiesel is an alternative fuel source for diesel powered enginens. It is a mixture of old used vegitable oil or fried food grease, methanol, and lye. It looks like pretty good stuff. You get better gas mileage, better for your engine, and almost superior to petroleum diesel in every way. Plus it smells like a big french fry cooker going down the road! It is also better for the environment and our health. It reduces risk of cancer by quite a bit. And you can get it for a whopping 70 cents per gallon!

    what do you think?
     
  2. jcsd
  3. Aug 30, 2005 #2

    russ_watters

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    I think this claim, in particular:
    ...is highly dubius.
     
  4. Aug 30, 2005 #3

    Pengwuino

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    Yah I also remember an article saying it breaks down engines faster then 87 gasoline. I wonder how much an engine overhaul costs vs. savings with biodiesel. I hear they are very helpful in heavy machinery applications where the engines are very powerful and well built.
     
  5. Aug 30, 2005 #4

    Ivan Seeking

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  6. Sep 6, 2005 #5
    It is for diesel engines not gasoline.
     
  7. Sep 6, 2005 #6
    I know a diesel mechanic who has run into problems with SVO. (straight vegetable oil) He is withholding recommending bio-diesel until he knows more.

    Bio-diesel is cleaner, and bio-degradable, however methanol is will eat some rubbers and is hard on the fuel line. There is an process where they use ethanol instead, I don't have any experience with bio-diesel using ethyl esters as opposed to methyl esters, so I don't know how well they perform.

    You can run bio-diesel in any diesel engine, the only concern is make sure you don't have natural rubber fuel lines. You will need to change your filter after the first tank because the bio-diesel will clean out any deposits left by the diesel fuel and clog up the fuel filter. Some stations are adding bio-diesel to diesel fuel, if you see B10 or B20 diesel that is 10% and 20% bio-diesel.

    Here is a good link for bio-fuels, lots of recipes.

    http://journeytoforever.org/edu.html#biofuel
     
  8. Sep 6, 2005 #7

    Pengwuino

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    man.... i need a memory transplant. Mine doesn't seem to work
     
  9. Sep 6, 2005 #8
    There's a guy who I see driving around the area where my school is located sometimes (his daughter goes to another school nearby) in a Hummer. Now that's not a very cool story, but the thing is, this hummer is entirely run on what the guy calls "veggie-gas" and is a biodiesel fuel.
     
    Last edited by a moderator: Mar 4, 2015
  10. Nov 13, 2008 #9

    Astronuc

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    Re: Biodiesel

    While the thread is dated - biodiesel has been advancing in the past couple of years.

    Specifically, researchers are looking at 'jotropha' plants as a source of fuel.

    http://en.wikipedia.org/wiki/Jatropha

    [1] Fairless D. (2007). "Biofuel: The little shrub that could - maybe". Nature 449: 652–655.
    [2] "Poison plant could help to cure the planet". The Times (2007-07-08) - http://www.timesonline.co.uk/tol/news/world/article2155351.ece
    [3] Jatropha Plant Gains Steam In Global Race for Biofuels - http://online.wsj.com/article/SB118788662080906716.html (subscription required)


    And jatropha-based fuel is being tested for use in commercial aircraft.

     
  11. Nov 13, 2008 #10
    Re: Biodiesel

    The problem with using crops for biofuel would always be that it requires domestication of the land, cutting rainforests, and it competes with growing crop for food. Biodiesel from algeae can be produced in unproductive desert areas with higher insolation due to the lack of clouds. That's a big difference.
     
  12. Nov 13, 2008 #11

    chemisttree

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    Re: Biodiesel

    Harvesting Jatropha requires one man per acre. I wonder if that is a full time job? If so, Jatropha oil is likely to be quite expensive in developed countries.

    Jatropha produces roughly 900 Kg per hectare in poor soils and 1600 Kg in average ones. This is a range of roughly 360 to 650 Kg per acre. At roughly 4 Kg per gallon, the crude oil yields are about 100 to 150 gallons per acre man year.

    http://www.svlele.com/jatropha_plant.htm
     
  13. Nov 14, 2008 #12
    Re: Biodiesel

    The only thing that is holding alternative fuels back is the engines.

    Currently the engine has been designed for 2 primary fuel sources, Gasoline and Diesel.

    What we need is a brand new engine designed that is specifically run on biodiesel, ethanol, etc.
     
  14. Nov 14, 2008 #13

    uart

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    Re: Biodiesel

    Here's a quick calculation that really illustrates the problem with biofuels created from food crops. One litre of diesel contains about 36 MJ of energy and in developed countries we use an average of over 20L (diesel or gas equive) per week per person (averaged over everyone, even those that don’t drive). That's an energy equivalent of over 100MJ per day per person for the entire population. But for our food needs we only need about 8MJ per person per day!

    So one days supply of energy for fuel is equivalent to about 12 days supply of food. Its completely unsustainable, we'd need to increase our agricultural output by 1200% to supply our current fuel needs from crops. This so far out of the feasibility ballpark that it’s a joke.

    This is why everybody is finally waking up to the fact that current biofuels options (like ethanol from corn) are not an environmental saviour but rather an ecological disaster. The only future for biofuels will be if new technologies can efficiently produce biofuels (esp alcohol) from non-food waste parts of the crops.
     
  15. Nov 14, 2008 #14

    mheslep

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    Re: Biodiesel

    It appears a prerequisite for making biofuels work as a large scale energy source is energy efficiency, and I don't mean lecturing people to wear sweaters. I believe the current gasoline/diesel usage has room to be cut nearly in half by efficiency increases and moving some transportation to electric power. Then, other factors can come in to play. Switchgrass and other non food source crops could be grown on otherwise untenable land, of which there's plenty, and thus should not significantly displace food crops. As mentioned up thread, algae has a 10-30x greater energy output than vascular biomass.
     
  16. Nov 14, 2008 #15
    Re: Biodiesel

    and AFAIK, there's nothing wrong with 87 octane either, unless you're running a high-compression engine (supercharger, turbo, high-compression heads). i've gotten over 200k on a V8 so far with 87.
     
  17. Nov 16, 2008 #16

    brewnog

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    Re: Biodiesel

    That is not the "only concern" at all. Many synthetic 'rubbers' (such as PVC) aren't resistant to biofuel either. Biodiesel can also have an adverse effect on many metal components commonly found in fuel systems, such as copper and zinc. Biodiesel also begins to gel at much higher temperatures than petrochemical diesel, and this can cause problems with fuel injection equipment. Biodiesel is hygroscopic, so if left for periods of time, the fuel can cause premature failure of FIE, corrode the fuel transfer system, and damage pistons.

    I'm not against biodiesel in any way, but you need to get some facts straight if you want to consider it for serious use in a vehicle.
     
  18. Nov 16, 2008 #17

    brewnog

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    Re: Biodiesel

    Not true. A conventional diesel engine will run happily on biodiesel with certain modifications/design characteristics, just as a conventional spark ignition engine will run on ethanol.

    The problem is creating a sustainable source of second generation feedstocks sufficient to meet demand.
     
  19. Nov 16, 2008 #18

    brewnog

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    Re: Biodiesel

    These are tall claims.
    I think I would like to see you back up these claims with a source.
     
  20. Oct 18, 2010 #19
    Re: Biodiesel

    I have been running a Volve 740 turbodiesel and a Ford Transit diesel van on biodiesel made from waste veggie oil
    Both vehicles have done at least 80,000 miles with no modifications.
    All diesel engines will happily run on well made biodiesel.
    The methanol caustic and soaps are washed out during the manufacture process and all that is left is pure biodiesel.
    The biodiesel does have an effect on rubber and eventually will rot said rubber.
    I find it best to be reactive and fix the perished rubber as and when.
    Most if not all vehicles manufactured since the early nineties have Viton rubbers and seals this is not affected by the bio.

    Incidentally I manufacture my own biodiesel on a small scale
     
  21. Oct 18, 2010 #20

    mheslep

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    Re: Biodiesel

    Its not clear from the above if you are using your own BD for a substantial portion of that 80k miles. If you buy, who do you buy from?
     
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