" From: Frank Swygert <farna@xxxxxxx> " " The real problem here is that none of the guys doing the talking are " farmers. Certain plants are easier to produce alcohol from and would " be much easier than corn -- sugar cane and sugar beets are probably " the most efficient as far as amount of product produced and ease of " extraction. Corn takes more energy to produce alcohol from, but is " more widely frown. Can't grow sugar cane just anywhere, needs to be " near tropical. I'm not sure about sugar beets, but they have certain " environmental needs too, and then there is harvesting -- big " investment in mechanical harvesters that only work for the beets. good point. too many studies depend on oversimplified statistics. btw the best biodiesel source is also tropical, oil palms, and jungle deforestation to make way for palm plantations is becoming a problem already. " As far as I know most of the studies are based on corn production as " that's the most commonly used plant. Why? The US grows a lot and " often has a surplus. In the past the surplus has offset the " production costs, and not that much was used. Now that there is a " higher demand the extraction process has been improved, but sugar " beets and sugar cane are still better. Brazil often had a surplus in " sugar cane, one of their main cash crops, so using alcohol as an " alternative fuel works real good for them! Still took 10+ years to " build a fairly decent infrastructure, and lots of government " encouragement (subsidies... tax money...). ...and afaik they still struggle to make it better than a break-even energy production. they were happy to re-embrace oil when it was discovered off their shore. the biggest barrier is that these are all food crops and the alcohol fermentation starch-based, and no plant is efficient at producing starch. imho the focus has been on ethanol from starch only because it's off-the-shelf technology, familiar, well known and well characterized, but this doesn't yield much per acre. alcohol is a high-value food product so this doesn't matter much for food production, but fuel is a very different game with different needs and rules. cellulose and starch are both polymers of glucose, linked at different places and needing different enzymes to break down. all plants are mostly cellulose... ...and there are other alcohols than ethanol, which bring the subject of butanol up again - if someone can only develop a good production method. butylfuel's two-step fermentation looks good on paper but afaik they haven't shown it in practice and haven't done anything in a couple of years. http://en.wikipedia.org/wiki/Butanol_fuel footnote: the #16 dyson racing car in the american lemans series ran most of last year on butanol as an experiment, not just petit lemans. it's now an approved alms race fuel and they're still running on it. the #99 team gunnar car also in alms uses bio-oil from green earth technologies - www.getg.com - comparable to synthetic oils like mobil1 but biodegradable when disposed of. my local hardware store can get it; i'll be using it in my next oil change. http://en.wikipedia.org/wiki/Biodiesel they note that the world market for glycerol [glycerine] has already crashed thanks to rising biodiesel production. every 10 gallons of biodiesel has 1 gallon of glycerol byproduct. " ------------- " " The real problem is (1) there simply isn't ever going to be enough of the " " stuff for more than a few thousand cars even in Los Angeles. I think the " " rule of thumb is, if every single acre of arable land in the United States " " was 100% converted over to vegetable oil plant production, it would meet 15% " " of U.S. passenger car fuel consumption! " " i've heard the reverse, that all our motor fuel needs could be " supplied with a [large] fraction of farmland production. " " a lot depends on crop productivity... ________________________________________________________________________ Andrew Hay the genius nature internet rambler is to see what all have seen adh@xxxxxxxxxxxxxxxxx and think what none thought _______________________________________________ AMC-list mailing list AMC-list@xxxxxxxxxxxx http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com