<div>How quickly does biochar boost biogas output? This would give some clues as to whether biochar acts mainly as a biomass support. That is certainly a very plausible mechanism - but it's not the only possibility.</div>
<div><br></div>An alternative mechanism for a biochar boost is its huge capacity to absorb any inhibitors. This would probably give the process a rapid boost, increasing the biogas output within a few days - or even hours. On the other hand, microbial colonization of the extra surface would take many days - and would probably take weeks to effect a major increase in biogas output.<div>
<br></div><div>And, of course, biochar <i>could</i> improve a low C:N ratio, not by adding extra C but by removing excess N.<br><div><div><br></div><div>Another question is whether extra biomass-support material would <i>always</i> be of value. In a feedstock containing a lot of solids (eg manure or biomass crops), there is already a lot of surface available for colonization by biomass, so I suspect that one would need to add a high % of biochar to make much difference. And too a high % of biochar would make the mixture difficult to handle. </div>
<div><br></div><div>In contrast, biochar might have much more effect with a wholly soluble feedstock - partly because residence times are likely to be lower.</div><div><br></div><div>So, <b>does </b>anyone have rate data?</div>
<div><br></div><div>Duncan Martin</div><div>Ireland</div><div><br></div><div><br><br><div class="gmail_quote">On 6 October 2011 04:04, <span dir="ltr"><<a href="mailto:rongretlarson@comcast.net">rongretlarson@comcast.net</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div><div style="font-family:Arial;font-size:12pt;color:#000000"><div style="font-family:Arial;font-size:12pt;color:#000000">
AD (cc four lists):<br><br>
I have not previously seen the connection between Biochar and Biogas
that you described (below) today on the gasification list. In
particular, you say you "..<em> filled the digester</em><br style="font-style:italic">
<span style="font-style:italic">with charcoal, my system accepted three times the normal daily input</span><br style="font-style:italic">
<span style="font-style:italic">and produced three times as much gas.</span>" <br> I think
what you describe can be a very powerful push for both Biochar and
Biogas. Can you describe what you have learned a little more?<br>
<br>
I know too little of digesters, so this is not clear. I think I
know your kitchen-sized inverted "barrel" gas chamber and think I
understand the last part - of getting three times as much gas in the
next 24 hours or less (and 3X is a huge change!). Does the idea of
accepting three times more mean essentially the same thing? I would
think you could "jam" any amount in; what limits acceptance?<br>
<br>
Do you agree that this is very important new information? Do you
agree this information could help speed up both technologies? I believe
there is wide agreement that Biochar benefits from added biological
material (that would not be long-lived from a sequestration
perspective). Is there any reason to think that the traditional use of
digester effluent for ag improvements will be in any way harmed if it is
continued through the addition of carbon-negative Biochar? Should this
not promote sales of your charcoal-making stoves?<br>
<br>
If I haven't asked quite the right question - please answer the right
one. And congratulations on learning and reporting this.<br>
<br>
Ron<br><br><br><br><br><br>The remainder from AD Karve today on the gasification list:<br><br> There are a lot of very simple ideas that need to be tested. I am<br>currently working on increasing the efficiency of biogas digesters and<br>
feel that it might be possible to reduce the size and the capital<br>expense of a biogas system. For instance, when I filled the digester<br>with charcoal, my system accepted three times the normal daily input<br>and produced three times as much gas.<br>
< snip><br>Yours<br>A.D.Karve<br>*******************************************<br></div></div></div><br>_______________________________________________<br>
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<br></blockquote></div><br></div></div></div>