I've looked into sugar beets. They potentially make a very high yield of ethanol per acre of crop. But beets only store for a few months. So economically, they are difficult because beets would require a high capital investment. Beets require either an ethanol plant 6X the size of a comparable grain plant or a sugar mill and tank farm to produce and store syrup for year around operation of a smaller ethanol plant. A big advantage of grain feedstocks is their ability to survive years of storage.
Though I don't know as much about cane, I suspect it has the same storge problems as beets. And cane is obviously very climate dependent. I once saw a world map of crops. All cane is grown within a certain distance from the equator. Maybe it can be grown in other climates, but probably not very effectively. For the last 15 to 20 years, fuel ethanol is no longer dehydrated by azeotropic distillation using benzene or hexane (or whatever). Ethanol is now dehydrated by molecular sieves that use a lot less energy and are a lot less toxic and dangerous. Modern plants are also much more thermally efficient. Ethanol plants from 20 to 30 years ago required maybe 80 lbs of steam to distill a gallon of product. That number is now down in 20's. So it now takes maybe 20k BTU's of steam to distill 80k BTU's of ethanol (order of magnitude only YMMV). Ned Kleinhenz '95 E300D _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
