Dear list experts,
I note a good deal of information in the list about using Jatropha (J. curcas) for biodiesel, and, mindful of repeated admonitions, I've looked for information about the questions I have in the archives, but I've not yet seen answers directly to my questions. My own background is in biogas, and I have only recently started learning about biodiesel and ethanol, so I'm an admixture of knowing and novice. May I ask a few questions? (And Kieth, no doubt there are many gems in the archives which of which you know, yet which I missed. Please feel free to educate me regarding their nature and location.) I've been contacted about a project in south Asia which would involve planting 600 ha to Jatropha, to produce 3,500 tonnes of biodiesel annually. (Based on what I've seen about Jatropha, that may be optimistic for yield, but I'm just presenting the information as given to me.) Obviously then that also means either the use of a good deal of methanol (as presently planned), or (as I have suggested), producing either ethanol or butanol through fermentation and using one or more than one together for separation. The oil cake resulting from oil extraction would be feedstock for a biogas plant. The biodiesel plant is presently being considered as a prototype for a number of such plants, and among the key goals of the project are social and economic development, not merely the production of fuel, and although the project expects a profit, my impression is that things would be operated to produce a balance of outcomes. So, first question: Although I've reviewed the project overview, which mentions that the biodiesel mixer will be batch loaded, as yet I have no information about the size of the unit. What size would/should it be to produce that much biodiesel annually? Second, am I near the mark with suggesting that the project consider producing ethanol (or butanol) rather than purchasing methanol? Certainly it will provide increased challenges to use ethanol, and perhaps even more to use butanol (in either case including adding complexity to the process), but I would think for a plant this large, with good access to land (albeit perhaps marginal land) and given the low labor costs in the area, it may make sense, although one problem may be training personnel. Yes? No? The Jatropha will almost certainly be planted in rows, ~3x2m per plant, and it appears that the project developers are not considering using irrigation. The area in which the plants will be growing has a rainy season (June-September; 130cm rainfall), and a hot, usually dry season (April-May, sometimes 40 deg C). What plants might be considered to assist in producing ethanol/butanol, if they were interplanted with the Jatropha? Glycerol/glycerine would be one by-product at perhaps 10% of the amount of biodiesel (i.e. ~350 tonnes/yr?). I know that depending on how one handles this waste stream, it can be burned (at high temp), composted, used in soap-making, used to supplement the oil cake for biogas production, used in Clostridium fermentation to produce ABE, used to dry ethanol (and butanol?), et al. Are there other options? Among those possibilities, which might best serve the mix of goals? Lastly, the information I have says that "Furthermore, the process to manufacture biodiesel... has no waste at all [excepting the oil cake and glycerol]. The process employed has no emissions and absolutely no effluent treatment." I don't see how that can be correct. Can that be the case? d. -- David William House "The Complete Biogas Handbook" |www.completebiogas.com| "Make no search for water. But find thirst, And water from the very ground will burst." (Rumi, a Persian mystic poet, quoted in /Delight of Hearts/, p. 77) -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/attachments/20090101/00e0f327/attachment.html _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/sustainablelorgbiofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (70,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
