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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal>Interesting conclusions. There are now many peer reviewed papers on biochar addition to digesters. Result vary according to biochar feedstock, processing conditions, and likely with digester feed such as food waste or biosolids. Positive results in solids removal, COD removal, methane production and ammonia nitrogen reduction have stimulated further research. <o:p></o:p></p><p class=MsoNormal><br>Tom<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b>From:</b> Digestion <digestion-bounces@lists.bioenergylists.org> <b>On Behalf Of </b>Anand Karve<br><b>Sent:</b> Sunday, November 07, 2021 8:31 AM<br><b>To:</b> For Discussion of Anaerobic Digestion <digestion@lists.bioenergylists.org><br><b>Subject:</b> Re: [Digestion] Test Message<o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>We had filled the biochar into a nylon net-bag and placed the bag into the digester. In this way, the biochar remained in the digester as long as we wanted it to be there. The bag was removed from the digester only after we found that the biochar was no longer effective. We do not recommend application of biochar to a biogas digester. The experiment was conducted only to find out how the biochar affected the performance of a biogas plant. Now that I know the role played by biochar as a donor of minerals, we are using ordinary field soil instead of biochar. The universal presence of green plants in nature shows that all soils in the world have all the minerals that living beings need.<o:p></o:p></p><div><p class=MsoNormal>Yours<o:p></o:p></p></div><div><p class=MsoNormal>A.D.Karve<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Sun 7 Nov, 2021, 1:55 PM , <<a href="mailto:tmiles@trmiles.com">tmiles@trmiles.com</a>> wrote:<o:p></o:p></p></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><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>AD, <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'>It is great to hear from you. Many thanks for your observations and experience with biochar. The digesters that we know of that are adding biochar to food waste find that there are a number of benefits as you have experienced. They feed the biochar to the digester continuously along with the food waste and remove it with the digestate. They probably benefit from the minerals as well as pH buffering. As far as I know the biochar does not accumulate in the digester. What we have seen so far are results from experiments at the lab scale and reports from some industrial scale use. We haven’t heard of biochar being used on the household scale. I wonder if others on the list have added biochar to digesters. <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'>Kind regards, <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><br>Tom <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b>From:</b> Digestion <<a href="mailto:digestion-bounces@lists.bioenergylists.org" target="_blank">digestion-bounces@lists.bioenergylists.org</a>> <b>On Behalf Of </b>Anand Karve<br><b>Sent:</b> Saturday, November 06, 2021 10:33 PM<br><b>To:</b> For Discussion of Anaerobic Digestion <<a href="mailto:digestion@lists.bioenergylists.org" target="_blank">digestion@lists.bioenergylists.org</a>><br><b>Subject:</b> Re: [Digestion] Test Message<o:p></o:p></p></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Glad to hear from you and also glad to know that the list is still surviving. I am still working on food waste and kitchen waste as feedstock. One of the drawbacks of this feedstock was that one could load the digester with only a small quantity of feedstock at a time. But with our new design, we have overcome this problem. Now we load all the feedstock into a predigester. Because of overloading, the pH of the material in the predigester becomes acidic, but the new design is such, that the digester draws in only so much of the acid, as can be converted by it into biogas.<o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Adding bichar certainly works, but only temporarily. The digester filled with biochar produced three times as much biogas as was possible without the biochar, but only for three months,. After 3 months we had to open the digester and load it again with fresh biochar. This indicated that food waste does not have enough minerals and that the ash in the biochar served the bacteria as a source of minerals. One can as well add chemical fertilizers to the digester to achieve the same results.<o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Yours<o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>A.D.Karve<o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>On Sun 7 Nov, 2021, 3:31 AM , <<a href="mailto:tmiles@trmiles.com" target="_blank">tmiles@trmiles.com</a>> wrote:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Thanks! A lot has happened in anaerobic digestion since the list was last active last Spring. <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><ol start=1 type=1><li class=m-7172047680366109882m4540393590755396650msolistparagraph style='mso-list:l0 level1 lfo1'>RNG. While we only have a small number of commercial digesters in the US compared with Europe there is a lot of excitement about Renewable Natural Gas, especially from the American Biogas Council. They report that there are 161 digesters that are now selling RNG and that there is a potential for something like 2000. The contracts for RNG appear attractive but it is not yet clear what the net benefit is to the owner after complex transaction fees are subtracted. <a href="https://americanbiogascouncil.org/" target="_blank">https://americanbiogascouncil.org/</a><o:p></o:p></li></ol><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><ol start=2 type=1><li class=m-7172047680366109882m4540393590755396650msolistparagraph style='mso-list:l1 level1 lfo2'>Food wastes are another emerging feedstock for AD in the US, almost as a pre-treatment for composting the digestate. <o:p></o:p></li></ol><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><ol start=3 type=1><li class=m-7172047680366109882m4540393590755396650msolistparagraph style='mso-list:l2 level1 lfo3'>Research has demonstrated the value of adding biochar to AD feedstock with a variety of benefits but we don’t see commercial use of biochar yet in AD either as a digester additive or as an additive to digestate prior to composting. <o:p></o:p></li></ol><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'>Tom <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b>From:</b> Bruno M. <<a href="mailto:brunom1@telenet.be" target="_blank">brunom1@telenet.be</a>> <br><b>Sent:</b> Saturday, November 06, 2021 2:31 PM<br><b>To:</b> For Discussion of Anaerobic Digestion <<a href="mailto:digestion@lists.bioenergylists.org" target="_blank">digestion@lists.bioenergylists.org</a>>; <a href="mailto:tmiles@trmiles.com" target="_blank">tmiles@trmiles.com</a><br><b>Subject:</b> Re: [Digestion] Test Message<o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>yep, works perfect Tom.<o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>================================<o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Op 6-11-2021 om 21:02 schreef <a href="mailto:tmiles@trmiles.com" target="_blank">tmiles@trmiles.com</a>:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>This is a test to see if the list is still available<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'>Tom Miles<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Digestion list Owner<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;margin-bottom:12.0pt'> <o:p></o:p></p><pre>_______________________________________________<o:p></o:p></pre><pre>Digestion mailing list<o:p></o:p></pre><pre> <o:p></o:p></pre></blockquote><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;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 the Biogas Wiki <a href="http://biogas.wikispaces.com/" target="_blank">http://biogas.wikispaces.com/</a><o:p></o:p></p></blockquote></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 the Biogas Wiki <a href="http://biogas.wikispaces.com/" target="_blank">http://biogas.wikispaces.com/</a><o:p></o:p></p></blockquote></div></div></body></html>