Luis R. Calzadilla wrote: >Dear Steve: > >The financial success of a cane juice-to-ethanol project will depend >on a few key variables, such as: > >1- Total fermentable sugars produced yearly per unit of land >2- Number of ratoons that can be harvested from each planting >3- Sugar cane production cost per unit of land >4- Capital cost of the distillery >5- Efficiency of Yeast and the Fermentation Process > >A few comments follow on the above:
Luis, I've wanted to say so a few times in response to your posts - IMO the big hole in your scheme is your exclusive concentration on sugar. It's no use telling me that it's the best crop for this or that reason or scores of reasons: THERE IS NO BEST CROP. Which crop is "best" depends entirely on the local circumstances, which vary widely: a higher-yielding crop might not in the end produce better results - better overall results - than a lower-yielding one which local farmers grow, are familiar with and which has other benefits for them and their farming systems and their communities. Yield is not everything, and too often it's claimed to be everything while the adverse effects on other parts of the system (it's a system) of achieving that high yield are concealed, or not even noticed. Unless you diversify your scheme to include other crops and other possibilities, you'll only be making the classic top-down, centralist mistake of fitting the project to the technology instead of the other way round - a mistake that has cost many millions of people most dearly, while the technology promoters often remain unaware of that and go right on promoting their technology and its "benefits". >The best site in the world to produce sugar cane for direct fermentation to >ethanol is Colombia, for the following reasons: There is no "best site in the world" either - the best site is the local site. >a) In Colombia we can harvest cane all 365 days of the year, therefore, the >distillery and harvesting equipment could run the year round without any >interruption for lack of cane thus using the capital investment more >efficiently than in a situation where you have a short harvest season. >Therefore, depreciation cost/unit of ethanol product will be lower than in >almost any other country of the world. > >b) By the implementation of the GADA Sugar Cane Production System, developed >by our Research Foundation, we can produce >around 38,000 kilograms of fermentable sugars/Hectare/Year >that translate into some 20,000 liters fuel ethanol/Ha/Year. This >yield seems to be, by far, the highest in the world. > >c) Under the GADA System, the productive life of sugar cane fields >can be extended up to 20 years and more...Right now we can show >30 (thirty) year-old fields yielding more than 150 MT sugar cane/Ha/Year of >cane planted for high sucrose content intended for sugar production. > >d) The GADA System affords the best way to lower production costs >while simultaneously doing it in a sustainable fashion; Soil fertility is >increased with each crop; It permits to minimize input of irrigation >water; Application of N-K-P fertilizers are reduced to around 2 (two) kgs >per MT of harvested cane. Best best best, eh? There is no need for NPK fertilizers. Why do you want to use unnecessary and costly inputs derived from fossil fuels and part of an unsustainable agricultural production system to produce biofuels you claim are sustainable? <snip> >e) All Saccharomyces Serevisiae yeasts have an "ethanol inhibiting point" or >ethanol concentration tolerance. That is, as the ethanol concentration >rises in the substrate being fermented, the yeast will >react by inhibiting (not producing any more alcohol) when it reaches >its cncentration limit. Common yeasts usually stop producing >alcohol when the ethanol concentration reaches 5-6% in the broth >(substrate). A yeast that possesses a higher ethanol concentration >tolerance, for example 12% ethanol tolerance, will be more >desirable for two important reasons: This seems to be wrong. Common yeasts usually stop producing at 5-6%? More like 15% I think. A higher ethanol concentration tolerance would be 12%? Turbo yeasts produce clean alcohol up to 21%. Here's one example, but there are quite a few of them. http://www.stillspirits.com/webfiles/StillSpirits/files/tb2turbonotes.pdf Best Keith <sip> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/index.php?list=biofuel Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/biofuel/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
