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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Alexander,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I believe Dr. Karve might be referring to using dehydrated dung as a feedstock for heating water. Or, perhaps he is referring to biomass gasification.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Regardless, I think it is important to measure total energy of a given system. In the case of AD, it’s hard to measure the positive effect the nutrient slurry has on biomass production. Surely that fertilizer provides some measure of growth for plants, trees, and/or crops. Can this be measured? If so, I would venture a guess that the total positive effect of AD would outweigh burning dehydrated dung.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Let me illustrate… <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Suppose that the nutrient effluent was used to grow cattails (Typha Latifolia) in a shallow pond. Cattails spread in the rhizome layer, forming large interconnected stands. Routine harvesting of a small amount of roots – preferably at the same rate of propagation – would yield a very starchy feedstock to use WITH dung, as a blend.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Nutritional value per 100 g (3.5 oz)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Energy = 106 kJ (25 kcal)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Carbohydrates = 5.14 g<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Sugars = 0.22 g<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>This is just speculation on my part, but I would think that a system such as this might be surprisingly efficient. Cattails are far more starchy and prolific than, say, potatoes. Additionally, the bagasse could be used as fodder (more future dung), and/or used for compost.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Troy<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Digestion [mailto:digestion-bounces@lists.bioenergylists.org] <b>On Behalf Of </b>Alexander Eaton<br><b>Sent:</b> Thursday, June 27, 2013 7:58 PM<br><b>To:</b> For Discussion of Anaerobic Digestion<br><b>Subject:</b> Re: [Digestion] Biogas plant at Zoo<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Dr. Karve,<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>You have held this stance in many past posts, comparing starch to waste, and arguing waste as not an ideal feedstock for AD. I have always thought that your point is valid, but a bit academic and missing the fact that AD systems can be seen as an extension of the animal digestive system, treating waste further and extracting energy that has not been used. Clearly starch creates more gas, but the questions posed here is not about choosing starch or animal dung for a digester, it is about whether a zoo would be wise to consider a digester to treat animal waste and recover energy. Is dedicating space and time at a zoo to dehydrating animal dung and then developing a system to burn it and recover the energy really a better alternative than an AD system? From an energy and process balance, can you explain a system that would perform better than a digester in this context? <o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Best, <o:p></o:p></p></div><div><p class=MsoNormal><br>A<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div></div><div><p class=MsoNormal style='margin-bottom:12.0pt'><o:p> </o:p></p><div><p class=MsoNormal>On Thu, Jun 27, 2013 at 2:28 PM, Anand Karve <<a href="mailto:adkarve@gmail.com" target="_blank">adkarve@gmail.com</a>> wrote:<o:p></o:p></p><div><p class=MsoNormal>Dear Rabin,<o:p></o:p></p></div><div><p class=MsoNormal>all animals, including humans, function as live biogas plants. The fecal matter represents slurry coming out of a biogas plant. Using animal dung as feedstock in a biogas plant is a highly inefficient way of producing biogas. You get about 800 litres biogas from just 1 kg starch. To get the same amount of biogas from cattle dung, you need 40 kg of it. One gets much more energy from dung if it can be dehydrated and burned directly<br>Yours<o:p></o:p></p></div><div><p class=MsoNormal>A.D.Karve<o:p></o:p></p></div><div><div><div><p class=MsoNormal>On Wed, Jun 26, 2013 at 11:35 AM, Rabin Shrestha <<a href="mailto:rshrestha@winrock.org.np" target="_blank">rshrestha@winrock.org.np</a>> wrote:<o:p></o:p></p></div></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in'><div><div><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Hello,<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Will it be a good idea to install biogas plant at zoo to manage and generate energy from the animal waste in the zoo???<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Regards,<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Rabin<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p></div></div><div><p class=MsoNormal style='margin-bottom:12.0pt'>_______________________________________________<br>Digestion mailing list<br><br>to Send a Message to the list, use the email address<br><a href="mailto:Digestion@bioenergylists.org" target="_blank">Digestion@bioenergylists.org</a><br><br>to UNSUBSCRIBE or Change your List Settings use the web page<br><a href="http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org" target="_blank">http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org</a><br><br>for more information about digestion, see<br>Beginner's Guide to Biogas<br><a href="http://www.adelaide.edu.au/biogas/" target="_blank">http://www.adelaide.edu.au/biogas/</a><br>and the Biogas Wiki <a href="http://biogas.wikispaces.com/" target="_blank">http://biogas.wikispaces.com/</a><br><br><o:p></o:p></p></div></blockquote></div><p class=MsoNormal style='margin-bottom:12.0pt'><span style='color:#888888'><br><br clear=all><br><span class=hoenzb>-- </span><br><span class=hoenzb>***</span><br><span class=hoenzb>Dr. A.D. Karve</span><br><span class=hoenzb>Trustee & Founder President, Appropriate Rural Technology Institute (ARTI)</span><br><br></span><br>_______________________________________________<br>Digestion mailing list<br><br>to Send a Message to the list, use the email address<br><a href="mailto:Digestion@bioenergylists.org">Digestion@bioenergylists.org</a><br><br>to UNSUBSCRIBE or Change your List Settings use the web page<br><a href="http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org" target="_blank">http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org</a><br><br>for more information about digestion, see<br>Beginner's Guide to Biogas<br><a href="http://www.adelaide.edu.au/biogas/" target="_blank">http://www.adelaide.edu.au/biogas/</a><br>and the Biogas Wiki <a href="http://biogas.wikispaces.com/" target="_blank">http://biogas.wikispaces.com/</a><br><br><o:p></o:p></p></div><p class=MsoNormal><br><br clear=all><o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><p class=MsoNormal>-- <br>Alexander Eaton<br>Sistema Biobolsa<br>IRRI-Mexico<br>RedBioLAC<br><br>Mex cel: (55) 11522786<br>US cel: 970 275 4505<br><br><a href="mailto:alex@irrimexico.org" target="_blank">alex@irrimexico.org</a><br><a href="mailto:alex@sistemabiobolsa.com" target="_blank">alex@sistemabiobolsa.com</a><br><br><a href="http://sistemabiobolsa.com" target="_blank">sistemabiobolsa.com</a><br><a href="http://www.irrimexico.org" target="_blank">www.irrimexico.org</a><br><a href="http://www.redbiolac.org" target="_blank">www.redbiolac.org</a><o:p></o:p></p></div></div></body></html>