<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Arial; font-size: 12pt; color: #000000'>Tom and (now) 2 lists (adding biochar-policy):<br> <br> This may be the first time I have ever disagreed with you - so I look forward to further dialog, and apologize in advance should I be wrong here below.<br> <br> I think that there should be a lower limit cut-off - and 50% seems justifiable - based on the way we handle majority voting in a democracy. My main rationale is that, without such a limit, there could be a validity claim for a lot of material coming out of gasifiers that is <span style="text-decoration: underline; font-weight: bold;">mostly</span> ash. This refuse will be attempted to be sold as biochar in order to get the maximum price for a product that might otherwise need to pay a tipping fee to get rid of. From a sequestration promotion perspective, I would rather see the gasifiers move towards pyrolysis.<br><br> Your last point below on a sliding scale is (I think) going to be mandatory anyway. It will surely be (or at least should be) required to receive a carbon credit. If I am paying for carbon sequestration, I certainly don't want to pay for ash and dirt. In all likelihood that payment will even be low-balled to ensure that the labile component also does not get much/any reward.<br><br> I can't think of any biomass input besides rice husks apt to have a problem satisfying a 50% minimum rule. To achieve 50% carbon should be pretty easy - even for rice husks - by merging different chars (if needed). I believe Paul Olivier has already reported that he had a superior flame when mixing rice and coffee husks as the input. <br><br>Ron<br><hr id="zwchr"><b>From: </b>"Tom Miles" <tmiles@trmiles.com><br><b>To: </b>"Discussion of biomass cooking stoves" <stoves@lists.bioenergylists.org>, crispinpigott@gmail.com<br><b>Sent: </b>Wednesday, October 26, 2011 8:43:11 PM<br><b>Subject: </b>Re: [Stoves] [biochar-production] Re: Stoves Digest, Vol 14, Issue 17<br><br>Where is the evidence that a Minimum should be established at 50% ash?<br><br>IBI guidelines for specification need to recognize that there are different<br>qualities of biochar for different purposes. The draft guidelines do specify<br>a method for analyzing carbon, determining H:C ration, and determining C in<br>carbonates. I do not agree that a threshold should be established for<br>calling a residue a biochar. When does wood ash become biochar? According to<br>the draft guidelines it would not become IBI certified "biochar" until it<br>had less than 50% ash regardless of the amount of stable carbon it would be<br>contributing to the soil for sequestration purposes at more than 50% ash. <br><br>I don’t think we need to draw a line to call it biochar. A sloped line might<br>be drawn for the carbon sequestration benefit that you would get for<br>decreasing amounts of stable carbon. <br><br>Tom <br><br>-----Original Message-----<br>From: stoves-bounces@lists.bioenergylists.org<br>[mailto:stoves-bounces@lists.bioenergylists.org] On Behalf Of Frank Shields<br>Sent: Wednesday, October 26, 2011 3:55 PM<br>To: crispinpigott@gmail.com; 'Discussion of biomass cooking stoves'<br>Subject: Re: [Stoves] [biochar-production] Re: Stoves Digest, Vol 14, Issue<br>17<br><br>Dear Crispin, Tom,<br><br>I think we need to define a minimum *carbon* content for a material to be<br>called *biochar*. We can't call something a biochar if it has less than 1%<br>carbon for example. So where do we draw the line? We need to include all<br>natural biomass made into biochar like rice hulls. The material needs to<br>have enough carbon to be useful. So I say 50% carbon a minimum to be<br>'excellent' biochar knowing that most all natural, clean biomass will<br>produce a biochar with greater than 70% carbon. But open to other values to<br>make a scale. This makes it a product with enough value for a grower to<br>purchase and spread. <br><br>I think the product should have the carbon content defined for quality (not<br>DAF). We should not include the oxygen and hydrogen and ash. We should<br>calculate the percent carbon content on the biochar sample dry weight (200<br>deg C). If we base quality on percent fixed matter (C-H-O) after subtracting<br>the ash I think there is a mistake. Because we 'make' more ash when we<br>change the cations into carbonates (increasing weight) during the process.<br>More cations from vegetative matter the more the problem. And this quantity<br>of ash is not what we are spreading on the field. Also the carbon trapped in<br>the ash (as CO3) is not included in the fixed carbon fraction - it should be<br>because it comes from the organic carbon in the raw sample. These are just<br>details and perhaps not that important. To do what I think is needed we must<br>determine the carbon using a Leco CHN analyzer. More work with expensive<br>equipment. But if we want to get carbon credits in the future we need to<br>start off accurately measuring the potential CO2 we are fixing. When money<br>is involved these details need to be addressed. Now is the time or we will<br>be back here again at a later time. <br><br>Just because the carbon content is 0.1% and the ash is 99.9% doesn't mean<br>the product is not beneficial for an ag field. But I don't think we should<br>call it biochar even if someone did add a spoonful into a soil mix. This<br>rating has nothing to do with benefit to a field. That is site specific. It<br>has something to do with label on the bag (or may in the future). <br><br><br>Regards<br>Frank<br><br><br><br><br><br><br><br><br>Vegatative plant material is 10 to 20 percent. We test a lot for nutrients.<br>It is very hard to get the customer to bring us a clean sample as it takes<br>so very little dust and dirt to bring the ash concentration up. I think<br>harvesting biomass for biofuel and one will not be careful to harvest clean<br>samples. <br><br>If you have 15% ash in a dry organic material. Loose 60% of the organic<br>fraction during pyrolysis you have something like 20+ percent ash. And, as<br>you point out, there can be biomass with much greater than 20% ash. <br><br>I suggested the 50% thinking this would be high enough to include most all<br>biomass that is made into biochar. Thinking we need some limit that if there<br>is less than 50% carbon <br><br> <br><br><br><br><br>Frank Shields<br>Control Laboratories, Inc.<br>42 Hangar Way<br>Watsonville, CA 95076<br>(831) 724-5422 tel<br>(831) 724-3188 fax<br>frank@compostlab.com<br>www.compostlab.com<br> <br> <br><br>-----Original Message-----<br>From: stoves-bounces@lists.bioenergylists.org<br>[mailto:stoves-bounces@lists.bioenergylists.org] On Behalf Of Crispin<br>Pemberton-Pigott<br>Sent: Wednesday, October 26, 2011 12:42 PM<br>To: Discussion of biomass cooking stoves<br>Subject: Re: [Stoves] [biochar-production] Re: Stoves Digest, Vol 14,Issue<br>17<br><br>Dear Frank<br><br>Apart from the special case of rice hull, how could you get a 50% ash level<br>in char? Trees are about 0.5% ash. There is not much left of the fuel if<br>the char is 1% of the initial mass. <br><br>Regards<br>Crispin<br><br>Frank,<br> <br>I see the ash/carbon content as a sliding scale with relative changing<br>benefits rather than a threshold level. If biochar has less carbon than ash<br>is there still an agronomic benefit?<br> <br>It is not clear how the IBI guidelines will be used. The guidelines should<br>list those components that should be measured. The recommended levels of<br>those components for different purposes could be separate recommendations<br>from IBI to a certification agency.<br> <br>If the purpose is stability and carbon sequestration why limit counting<br>recalcitrant carbon even if it is 0.1% carbon or, 99.9% ash?<br> <br>Tom<br>_______________________________________________<br>Stoves mailing list<br><br>to Send a Message to the list, use the email address<br>stoves@lists.bioenergylists.org<br><br>to UNSUBSCRIBE or Change your List Settings use the web page<br>http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists<br>.org<br><br>for more Biomass Cooking Stoves, News and Information see our web site:<br>http://www.bioenergylists.org/<br><br><br><br>_______________________________________________<br>Stoves mailing list<br><br>to Send a Message to the list, use the email address<br>stoves@lists.bioenergylists.org<br><br>to UNSUBSCRIBE or Change your List Settings use the web page<br>http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists<br>.org<br><br>for more Biomass Cooking Stoves, News and Information see our web site:<br>http://www.bioenergylists.org/<br><br><br><br>_______________________________________________<br>Stoves mailing list<br><br>to Send a Message to the list, use the email address<br>stoves@lists.bioenergylists.org<br><br>to UNSUBSCRIBE or Change your List Settings use the web page<br>http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org<br><br>for more Biomass Cooking Stoves, News and Information see our web site:<br>http://www.bioenergylists.org/<br><br></div></body></html>