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</o:shapelayout></xml><![endif]--></head><body bgcolor=white 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'>Dear Edward,<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 may be off here with my comments, so please forget me for chiming in without looking at the email thread. It is hard to answer your question # 3 correctly without having all the facts about your anaerobic digester system and the waste management practices at the mill. >From my experience one of the biggest culprits for low or not ideal biogas/methane production in POME ADs, and a lot of time missed during the design stage, is the seasonal fluctuation of FFB processed at the mill. If the digester was not designed to handle the high season POME flow rates, your biogas/methane production will suffer. In some cases I discovered the high season FFB processed were as high as double as the average but digesters were designed for the average.<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 comes from someone that was in charge of the performance improvement programs (increasing biogas/methane production) of around 600 ADs including 50 POME ADs located in Indonesia, Malaysia, and Colombia. We increased the biogas/methane production by 50% on the POME ADs but to be fair their biogas/methane production were low before we intervened.<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'>Best of luck increasing the biogas/methane production.<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><div><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Arial Black","sans-serif";color:green'>Charlie Ramos</span></b><b><span style='font-family:"Arial Black","sans-serif";color:green'><o:p></o:p></span></b></p><p class=MsoNormal><a href="blocked::http://www.biogreenengineering.com/" title="blocked::http://www.biogreenengineering.com/"><b><span style='font-size:11.0pt;font-family:"Arial Black","sans-serif";color:green;text-decoration:none'>BioGreen Engineering LLC</span></b></a><b><span style='font-size:10.0pt;font-family:"Arial Black","sans-serif";color:green'><o:p></o:p></span></b></p><p class=MsoNormal><a href="blocked::mailto:cramos@biogreenengineering.com" title="blocked::mailto:cramos@biogreenengineering.com"><b><span style='font-size:11.0pt;font-family:"Arial Black","sans-serif";color:green;text-decoration:none'>cramos@biogreenengineering.com</span></b></a><b><span style='font-size:10.0pt;font-family:"Arial Black","sans-serif";color:green'><o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Arial Black","sans-serif";color:green'>+1-407-459-7806 (office)</span></b><b><span style='font-size:10.0pt;font-family:"Arial Black","sans-serif";color:green'><o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Arial Black","sans-serif";color:green'>+1-407-412-0165 (cell)</span></b><b><span style='font-family:"Arial Black","sans-serif";color:green'><o:p></o:p></span></b></p></div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'> Digestion [<a href="mailto:digestion-bounces@lists.bioenergylists.org">mailto:digestion-bounces@lists.bioenergylists.org</a>] <b>On Behalf Of </b>David<br><b>Sent:</b> Monday, June 24, 2013 8:29 PM<br><b>To:</b> For Discussion of Anaerobic Digestion<br><b>Subject:</b> Re: [Digestion] Digestion Digest, Vol 34, Issue 8<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='margin-bottom:12.0pt'><br><br>Edward,<o:p></o:p></p><div><p class=MsoNormal>On 6/24/2013 1:08 AM, Edward Silalahi (Medan) wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><pre>Dear David, [...]<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>3. Our waste are Palm Oil Mill Effluent (POME) with COD approximate<o:p></o:p></pre><pre>70.000 to 80.000 ppm, my question how could I raise the efficiency of my<o:p></o:p></pre><pre>bio gas production?<o:p></o:p></pre></blockquote><p class=MsoNormal><br>This is a different David.<br><br>I did a little work on POME in the Dominican Republic. As you may know, the effluent from palm oil processing is relatively dilute, and digesters using it are subject to wash-out, which means that the slow-growing biogas microbes-- the methanogens-- may not have time to multiply and become numerous before the effluent exits the digester. One way to handle this is to provide increased surface area-- sheets or tarps or baffles or what-have-you-- inside the digester, because the methanogens like to become part of a biofilm. ("Biofilm" is a term which generally means an ecosystem on a surface, where, in the case of anaerobic digestion, the community of microbes would cooperate to digest the effluent. Because these biofilms develop on surfaces, increased surface area inside the digester will serve to anchor methanogens, better inoculate incoming effluent, and thereby help prevent wash-out.)<br><br>Other than that, several different kinds of digesters can be used, but be aware that there are often significant design differences between digesters that are built to use such dilute inputs and digesters that are built to use materials with far higher solids content. For example, the up-flow anaerobic sludge blanket (UASB)-type digesters are suited to this type of input. One reference you may be able to use to understand more about your situation is " A Biogas Trapping Facility for Handling Palm Oil Mill Effluent", found <a href="http://palmoilis.mpob.gov.my/publications/TOT/TT-491.pdf">here</a>.<br><br>Based on my brief review of your website, it is clear that your facility is either already or is trying to become a member of RSPO, the Roundtable on Sustainable Palm Oil. Your biogas effort should be integrated into the documentation you supply about this.<br><br><br><br>d.<o:p></o:p></p><div><p class=MsoNormal>-- <o:p></o:p></p><div><p class=MsoNormal><span style='font-size:13.0pt'>David William House</span><o:p></o:p></p><div><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:9.5pt'>"The Complete Biogas Handbook" </span><a href="www.completebiogas.com"><span style='font-size:10.0pt;font-family:"Courier New"'>www.completebiogas.com</span></a><span style='font-size:9.5pt'><br><em>Vahid Biogas</em>, an alternative energy consultancy </span><a href="www.vahidbiogas.com"><span style='font-size:10.0pt;font-family:"Courier New"'>www.vahidbiogas.com</span></a><span style='font-size:9.5pt'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>"Make no search for water. But find thirst,<br>And water from the very ground will burst." <o:p></o:p></span></p><div><p class=MsoNormal><span style='font-size:8.0pt;font-family:"Courier New"'>(Rumi, a Persian mystic poet, quoted in <em><span style='font-family:"Courier New"'>Delight of Hearts</span></em>, p. 77) <br><br></span><a href="http://bahai.us/"><span style='font-size:8.0pt;font-family:"Courier New"'>http://bahai.us/</span></a><span style='font-size:8.0pt;font-family:"Courier New"'><o:p></o:p></span></p></div></div></div></div></div></body></html>