Fuel choices, Global Warming & Polution

Discussion in 'Science & Society' started by Billy T, Nov 25, 2005.

  1. DaleSpam TANSTAAFL Registered Senior Member

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    I am not a pilot, but my understanding is that aviation gasoline is very different from jet fuel. Aviation gasoline is for an internal combustion engine and jet fuel is for a gas turbine engine. I believe you are correct that jet fuel is kerosene and I am pretty sure that it is much cheaper than aviation gasoline.

    -Dale
     
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  3. CANGAS Registered Senior Member

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    Too many pilots have crashed and died or been terribly injured because some idiot, or in some other manner, aviation gasoline has been confused with jet fuel(s).

    Kerosene and jet fuel(s) are similar but are not the same thing. If you feel like it is your lucky day, pump kerosene into one of the tanks of your Lear and switch tanks on takeoff.

    Have fun.
     
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  5. DaleSpam TANSTAAFL Registered Senior Member

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    Now that is a pleasant thought!

    I think I would probably trade it for a yacht. Of course, all of the other yachters would make fun of me since I would immediately rig my yacht for deep-sea fishing. As they say, "You can take the redneck out of the bass boat but you can't take the bass boat out of the redneck". Or something like that.

    -Dale
     
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  7. CANGAS Registered Senior Member

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    Just be sure to trade BEFORE the lucky day take off.

    Trading vehicles is a game of timing.
     
  8. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Alcohol fuel production in Barrels / day:
    Brazil 260,209
    US 230,594
    China 62,883
    India 30,137
    Rest of World 118,721
    Total 702,544

    data from slide 31 of:
    http://fairway.ecn.purdue.edu/~lorre/16/research/Countrymark_Presentation_at_Purdue_feb_15_06.pdf

    Note Predue University held 23 Feb 2006 interesting conference on their efforts at bio fuels. (When the above page appears, in the address line it will be different. Cut off the "Countrymark ...." end sight in address box and see other presentation slides. Then go to bottom of that page form many interesting links. and sub links. Seems to be relatively trustworthy University filtered set of links.)
     
    Last edited by a moderator: Mar 15, 2006
  9. Carcano Valued Senior Member

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    Question: Why can't the US produce more ethanol from the sugar cane produced in the southern states like Louisiana. Why is corn the number one source for ethanol in America?
     
  10. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Good question. I do not know answer. Perhaps it is economics, as most things are. I.e. cotton or some other crop grown in Louisiana, gives better profit than sugar production. (Hard to believe this is true now as sugar is at all time high on world market, more than double the price of a year ago. - This has made alcohol for my car almost as expensive as gas per mile driven.)

    I looked, but could not find, in newspapers of recent days for actual numbers I read about the profit per acre of cane vs. soybeans. Cane is now several times more profitable, so fields that did grow soybeans are converting to cane. Today I read that the official estimate for Brazil's 2006 grain production was reduced by 1.5%, but the official reason given was the "dry weather." In same issue of paper was article noting Feb 2006 was wettest on record!

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    I think conversion of soybean fields to cane, where US does not compete, and global demand for both sugar and alcohol is rising rapidly is more likely true than the "official reason." Fact that Brazilian Real is very strong, is making prices in dollars convert to less profit for farmers paying help in Real etc, but sugar/alcohol and OJ prices are increasing more rapidly than grain prices, so this also drives conversion of soy fields to cane, but few will cut down orange trees in the short term, so OJ production should remain high.

    I also noticed that the FDA, projects continued decline in the production of OJ in Florida (due to some extent to hurricanes damage in recent years). OJ traded yesterday at $1.465/Lb in US markets - a 14 year high. Brazil is worlds largest producer of OJ. To protect the profits of the few, especially in state GWB's brother governs, US still prevents Brazil from exporting to US as it would like to. (I recall that tariff is $1008/ ton, plus extra fees imposed by state of Florida, if off loaded at closest port (Miami) - that is about $0.50/lb.)

    If US really believed in "free trade" your glass of OJ would cost about half what you are currently paying to aid the rich, who make big campaign contributions in exchange for this "protection". The ignorance and/or stupidity of the average US voter never ceases to amaze me!

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    Last edited by a moderator: Mar 23, 2006
  11. Carcano Valued Senior Member

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    Ok, so why is OJ so much more expensive to produce in the US than Brazil? Is it the labour costs, which I imagine are much less in Brazil? Maybe the same economics applies to Sugar Cane as well???

    Actually, I doubt it because Australia has developed its own cane production using mechanical combines, instead of cutting the stalks by hand, as its done in Brazil. A sugar cane combine (invented in Australia) can harvest 30 tons of cane in one hour. The US could implement the same production tech in States like Florida, Alabama, and Louisiana. http://www.austehc.unimelb.edu.au/tia/052.html

    Sugar Cane fields in Childers Australia:

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    Last edited: Mar 23, 2006
  12. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    yes I am sure for OJ that is a big factor, but more sunshine per year surelymust help too. On cane, much of it in Brazil is mechanically harvested also. I think the cheap labor may be slightlymore cost effective, but the cane field needs to be set fire first to burn off the leaves (cut up workers too badly if not done) leaving only the sap rich stocks. This also greatly increases the density of sap in the wagon hauling the cane also if no bulky leaves. Burning cane fields has come under a lot of environmental pressure and is rapidly ceasing. Also some workers die while cuting cane. Hours are long, sun is hot. No one just sure why, but I suspect it is some serious metaboic problem. - all that work and some Na/Cl/K imbalance stops heart, I bet. This is also less acceptable than it once was.

    Just today in Sao Paulo newspaper was article about Cosan S.A., world's largest producer of "sugaralcool." They will expand production 25% with investment of US400,000 - to 50 million tons/ per year. Currently they produce 9% of sugaralcool produced in Brazil. Currently they have stored:200 million liters of alcohol and 550 thousand tons of sugar. Since their IPO in november of 1005, their stock is up 132%! Partially because sugar price is up 95% in last 12 months, but mainly I think because of their planned expansion and the expanding exports. Unfortunately, I did not even hear of the IPO.
     
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  13. Carcano Valued Senior Member

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  14. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    very interesting, perhaps even true.

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    If true, I too am surprized, and have no certain explaination. Perhaps too much of the solar energy is used to make the tall cane stocks that feed cows or make power at the crushing plant etc. I.e. sugar beets put more of their effort into making sugar than cane which puts relatively more into making animal food (stocks). - Sugar maple trees must be very low sugar producers / acre as they are making a lot of wood with their sunshine. Thus sugar maple trees and sugar beets may be two extremes and sugar cane falls in between.

    I assume that if this is true, then the sugar beet industry most use some source fo energy other than the sugar beet to distill the alcohol, but not so the sugar cane industry. The cane stock is more than and adequate energy source for distillation. Some feds cows or generates electricity for the grid at the larger alcohol plants.

    A more fair comparison is the net energy produced per acre, not the sugar produced per acre. Here you reference states that cane yields more than 8 times more energy than is used to prdouce it (and essentially none used is fossil energy) while the beet gives less than a factor of two gain and does use fossil energy to get this gain. From your source:

    "But, Brazilians get over 8 times the energy from sugar cane than they invest in growing it. France's energy yield from sugar beets is just 1.9, and America's energy yield from corn is 1.5...and some controversial research shows that it costs us more energy to make ethanol from corn than it produces."

    I do not think this net yield is counting the energy content of the cow food or electric power. I think any fair accounting will show that cane makes approximately 20 units of energy and requires one or two at most be used at the plant for distillation - even this could be reduced if counter flow heat exchangers were used to transfer the heat of the hot liquid from which the alcohol has been distilled to the new fermented liquid containing the alcohol before it enters the still.
     
    Last edited by a moderator: Mar 28, 2006
  15. Carcano Valued Senior Member

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    Ethanol production from Brazilian Cane is still a lot cheaper though, not just because of the labour and currency issues, but also because they burn the cane stalks to provide heat for the distillation. Beet producers have to buy natural gas for the same purpose.

    Of course, it doesn't have to be that way - western producers could burn rice straw for distillation instead. Straw is currently considered a waste product and much of it is burned in the field.
     
    Last edited: Mar 28, 2006
  16. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    The cane stocks are already delivered to the plant. I doubt it would pay, either in energy or dollar terms, to collect and transport rice straw for its fuel / heating value. If it did, we would be heating buildings with it instead of oil, I think.

    They burn pastures in rural Brazil to get rid of insects, but the agricultural PH.D.s are trying to get the simple farmers to stop this wide spread policy. (My bet is the simple farmers know what they are doing from years of practice and the PH.D.s are working from theory.) However, US has insect killing freezes and Brazil does not, so:

    Why is it burned in US fields? I would think it better to plow it into ground and let worms eat it (and microorganism process it) to improve the soil as Brazil's Agricultural professors tell the simple farmers.
     
    Last edited by a moderator: Apr 1, 2006
  17. Carcano Valued Senior Member

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    There are actually a few power plants in Poland which burn waste straw, and the ash is recycled back to the farmers as fertilizer.

    I doubt its as energy dense as cane stalks, but in the case of companies like Iogen, which already use straw as the cellulose base for ethanol production, it would simply be a matter of using a portion of their incoming straw shipment to fuel the distillation process.
    www.calricestraw.org/library/abstracts/energy0021.html
     
  18. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    I bet the straw comes in a horse drawn cart, or at least leaves the farm in one for some "collection point." (correct?)
    I also hope that soon (perhaps in only a decade, if all goes well) any cellulose can be broken down into simple surgars and that microbes can be engineered for each of the resulting sugars to convert the to some liquid fuel (perhaps not alcohol?).

    It will take quite a few years to adapt and even with a decade, US may not have time to convert its suburban infrastructure to one more suited to post peak oil conditions. Rest of world has better infrastructure for that world, and corresponding less need for liquid fuel, than the US for the world that is coming in less than a decade.

    Thanks for the reference, but it only was abstract telling that rice straw can be feed in partial replacement for crushed sugar cane stocks (bagasse). Nothing about Polish plants - any more on that?
     
    Last edited by a moderator: Apr 2, 2006
  19. 2inquisitive The Devil is in the details Registered Senior Member

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    There are several problems for the farmers in the disposal of rice straw. Simply chopping the straw up and plowing it back into the fields is not cost effective and can lead to diseased crops. Burning cost the farmer about $2 per acre, plowing it back into the fields costs about $60 to $80 per acre. California rice farmers have individually invested up to hundreds of thousands of dollars in straw bailing equipment only to find no market for the bailed staw. Only 2% to 5% has found a market, the rest is still accumilating in fields, stacked and just taking up space that could be used for farming.
    No cost effective outlets for rice straw have been found to date, despite intense study by many groups.

    By the way, California passed a law against burning rice straw in 1991, requiring a permit for that which is approved to be burned. Only a maximum of 25% of deseased fields are permitted to be burned.

    Of course, the high cost of alternate straw disposal puts the farmer at a disadvantage in the world market when competing against rice from countries that have no laws against burning. Answers are not simple in the real world.

    Here is a link with some of the real world problems of straw disposal discussed:
    http://ricenetwork.com/talk/messages/2/419.html?1062549090
     
  20. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Thanks for much more informative reference than Carcano's. I knew nothing about the problems of rice straw. Why can they not do what is done in Brazil with the bagasse not needed as fuel for alcohol distillation at alcohol distillories too small to use the excess bagasse in generation of electricity? I.e. Why not return it to the farms with the trucks going back for the next load of cane? The farmer may ferment a little more and then feed it to pigs and cows, who at no cost transform it to a "soil enriching product" and even distribute this "soil additive" about in the fields also "for free".
     
    Last edited by a moderator: Apr 2, 2006
  21. Carcano Valued Senior Member

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    Heres the link on the projects in Poland:
    http://www.energie-cities.org/db/luban_140_en.pdf

    Theres a haystack of interesting links to be found just by googling the words 'straw' 'fuel'. Heres another one:
    http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/eng3127
     
  22. 2inquisitive The Devil is in the details Registered Senior Member

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    I'm not clear about what you are suggesting. Billy T. What are you referring to when speaking of 'returning it to the farms'? The rice straw never leaves the farms when harvested. And I don't know about feeding fermented straw to livestock. There are health risks unless you mean from some specific type of alcohol production facility the farmer would have to construct and operate on his farm, seemingly a very expensive endeavor to place upon a grain farmer. Don't forget, about 3 TONS of straw are produced per acre.

    Straw that ferments naturally from rainwater and heat make the straw unusable as feed. Cows don't like the taste, and the mold that is likely to grow in moist straw can produce over 200 mycotoxins. One of them is aflatoxin, which can be transferred to the milk of dairy cows. Aflatoxin has toxic and carcinogenic effects in humans.
     
  23. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Much better reference. Thanks. My impression is that relatively local use of (rice?) straw is both economically sound and environmentally beneficial. That is in your reference, the distance it is transported (24Km =15miles) to the small village (24,000 people) and used for district heating system is what makes this true. I doubt if it can scale up by even a factor of 4 (Transport 60 miles and small city, still less than 100 thousand people). I.e. I doubt it can still remain economically viable, but its environmental benefits would remain and perhaps justify some subsidy to make it viable for small cities.

    For modest and large cities, coal fired district heating is a good idea, widely used in Sweden and some other northern European countries, including part of Germany. It is little used in the USA, and when it is, it is usually the very local distribution of the "spent steam" exhaust of a electric power plant. Hot water district heating can serve a wider area.

    I know a little about all this because for a couple of years I lead a study team investigating CASES, Community Annual Storage Energy System. (CASES, used ice making machines to economically extract heat from water in winter during peak heating requirements and the surplus heat of the larger buildings of the community* and stored the ice (or chilled water produced from it in local aquifer if available, and more economical) for cooling need the next summer. Large, efficient, ice machine making flake ice, not cubes, can have a COP = 4. I.e. get four times as much heat out as electric power in but the real saving is the reduction of electric power consumption in summer air conditioning requirements. Can think of their winter heating as free.)

    The idea of annual storage is now being used in some places, but mainly in colder locations with two aquifers, and no ice machines. One aquifer is warmed by the heat removed from buildings in summer and the other naturally chilled in winter, perhaps by spraying its water into the cold air and reinjection into the aquifer at a different, but not too distant location. (Not very efficient the first year or two as the ground mass of aqufer is being charged with "cold.")

    Unfortunately, the psychological orientation of most Americans against anything that resembles "socialism" or "community cooperative systems" is too strong for these more efficient systems to be accepted. When oil is too expensive for them to use for heating their home and they are sitting in cold houses under blankets, perhaps they will think differently.
    --------------------------------
    *Few realize that modest and large cities typically produce net surplus heat in their larger buildings, even on cold winter days, than the city requires. (Cold outside is taken in and the heat is just dumped to the environment - why city air is warmer than the suburban air.) This heat is too low a quality (temperature) to be used directly but if feed to locally distributed ice making machines or other heat pumps serving individual homes, it is a much better heat source than the cold winter air that the typical home heating heat pump extracts heat from. I.e. with it, their COP can be much higher, reducing electricity requirements for the same heating.
     
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