We've been toying around with a thermogravimetric analysis (TGA) method based on <a href="http://www.ncbi.nlm.nih.gov/pubmed/22242866">Harvey et al (2012)</a> that indexes chars to graphite, as a kind of idealized end-member of "complete charring."<div>
<br></div><div>The ASTM determination of "volatile matter" for coals really is not a good fit for biochar. It's not really clear what you're measuring when applying that method to biochar, as the prescribed heating (devised originally for coal) alters the char. Some biochar researchers have realized that and altered the method to try to make it more appropriate for char, but then it's non-standard and you can't compare different researchers' datasets.</div>
<div><br></div><div>As Frank mentioned, the H:C, and I would also add O:C, ratios are sometimes used as a proxy for recalcitrance. We measure those too, so if anyone is interested I can let you know how they compare to results from the TGA method.</div>
<div><br></div><div>We have not systematically measured S content in our chars (normally just do C, N, H, ash, and O by difference) - I would assume it's quite low but I'd like to hear from others. We could start collecting S content data if folks think there's likely to be substantial S content. Thoughts?</div>
<div><br></div><div>Josh</div><div><br><br><div class="gmail_quote">On Tue, Feb 5, 2013 at 7:48 PM, Frank Shields <span dir="ltr"><<a href="mailto:frank@compostlab.com" target="_blank">frank@compostlab.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div bgcolor="white" lang="EN-US" link="blue" vlink="purple"><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Alex,<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">It’s the H/C ratio that has been considered. <u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I like the term Fixed Carbon’ when we actually measure the carbon content in the left overs. <u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Regards<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Frank<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Frank Shields<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Control Laboratories, Inc.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">42 Hangar Way<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Watsonville, CA 95076<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><a href="tel:%28831%29%20724-5422" value="+18317245422" target="_blank">(831) 724-5422</a> tel<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><a href="tel:%28831%29%20724-3188" value="+18317243188" target="_blank">(831) 724-3188</a> fax<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><a href="http://www.biocharlab" target="_blank"><span style="color:blue">www.biocharlab</span></a>.com<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></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"> Alex English [mailto:<a href="mailto:english@kingston.net" target="_blank">english@kingston.net</a>] <br>
<b>Sent:</b> Tuesday, February 05, 2013 3:36 PM<br><b>To:</b> Discussion of biomass cooking stoves<br><b>Cc:</b> Frank Shields; 'Crispin Pemberton-Pigott'; <a href="mailto:biochar@yahoogroups.com" target="_blank">biochar@yahoogroups.com</a>; 'Hugh McLaughlin'; 'Ron Larson'; 'Thomas Reed'</span></p>
<div><div class="h5"><br><b>Subject:</b> Re: [Stoves] Characteristics of biochar was Re: [biochar] grassifier & cedar chip char<u></u><u></u></div></div><p></p></div></div><div><div class="h5"><p class="MsoNormal"><u></u> <u></u></p>
<div><p class="MsoNormal"><br>Perhaps it should be called fixed-up carbon, its whats left after getting rid of the rif-raf that can['t tough it out in the kitchen when thing get hot.<br><br>What other tests are there that would give a better representation of the biological recalcitrance of char?<br>
<br>Alex<br><br>On 05/02/2013 5:33 PM, Frank Shields wrote:<u></u><u></u></p></div><blockquote style="margin-top:5.0pt;margin-bottom:5.0pt"><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Paul,</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">My biggest problem with the term ‘fixed carbon’ is that it is not a measurement of the carbon at all. Just the stuff left over after heating that can contain Oxygen and hydrogen. </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Frank </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></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"> Stoves [<a href="mailto:stoves-bounces@lists.bioenergylists.org" target="_blank">mailto:stoves-bounces@lists.bioenergylists.org</a>] <b>On Behalf Of </b>Paul Anderson<br>
<b>Sent:</b> Tuesday, February 05, 2013 1:17 PM<br><b>To:</b> Crispin Pemberton-Pigott; Discussion of biomass cooking stoves; <a href="mailto:biochar@yahoogroups.com" target="_blank">biochar@yahoogroups.com</a>; Hugh McLaughlin; Ron Larson; Thomas Reed<br>
<b>Subject:</b> Re: [Stoves] Characteristics of biochar was Re: [biochar] grassifier & cedar chip char</span><u></u><u></u></p></div></div><p class="MsoNormal"> <u></u><u></u></p><div><p class="MsoNormal">Crispin, <br>
<br>The influence of the coal industry on the testing is not a perfect match for what biomass gasification is all about and the testing of biomass and biochar.<br><br>Biomass can be 50% carbon, but with decay it will all go to CO2. Fixed carbon must be created in the carbonization process.<br>
<br>In Atlanta airport about to fly to Uganda for 3 weeks. I hope that others will comment, and not rely on me to reply.<br><br>Paul<br><br><br><br><u></u><u></u></p><pre>Paul S. Anderson, PhD aka "Dr TLUD"<u></u><u></u></pre>
<pre>Email: <a href="mailto:psanders@ilstu.edu" target="_blank">psanders@ilstu.edu</a> Skype: paultlud Phone: <a href="tel:%2B1-309-452-7072" value="+13094527072" target="_blank">+1-309-452-7072</a><u></u><u></u></pre>
<pre>Website: <a href="http://www.drtlud.com" target="_blank">www.drtlud.com</a><u></u><u></u></pre><p class="MsoNormal">On 2/5/2013 10:09 AM, Crispin Pemberton-Pigott wrote:<u></u><u></u></p></div><blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Dear Paul</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p>
<div><p><u></u><span>1.<span style="font:7.0pt "Times New Roman""> </span></span><u></u>As far as I know, there is no "fixed carbon" in the biomass. It is fixed during the process of carbonization/pyrolysis.<br>
<br><br><br><u></u><u></u></p><p><span style="color:#1f497d">That is the problem – it you give a sample of wood to a lab and they perform a ‘coal analysis test’ on it you will get a report on the amount of ‘fixed carbon’. The point I was making is that it is a metric of convenience arising from the test procedure, not a reference to a material property.</span><u></u><u></u></p>
<p> <u></u><u></u></p><p><br>2. Some biomass such as seeds have "oils" that vaporize or are volatile. They are generally not pyrolyzed. However, the lignin and other "stuff" in biomass is what is pyrolyzed and gives off pyrolytic gases that are volatile. At low temperatures, the future volatiles are not yet in a form that can be called volatile. But they will volatize when subjected to higher temperatures.<br>
<br>I will accept what the chemist eventually clarify for us.<u></u><u></u></p><p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p>
<p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">The % Volatiles are defined as that fraction that will boil (literally) at a given temperature. Choose you temperature. So when using a defined method, the result changes with the temperature your use.</span><u></u><u></u></p>
<p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">See for example <a href="http://www.sigmatest.org/Coal-Testing-India.html" target="_blank">http://www.sigmatest.org/Coal-Testing-India.html</a></span><u></u><u></u></p>
<p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal" style="line-height:13.5pt;background:white"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">“</span><b><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:#565656">Proximate analysis - Moisture, Volatile matter, Ash and Fixed Carbon: </span></b><u></u><u></u></p>
<p class="MsoNormal" style="line-height:13.5pt;background:white"><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:#565656">“Proximate analysis indicates the percentage by weight of the Fixed Carbon, Volatiles, Ash, and Moisture Content in coal. The amounts of fixed carbon and volatile combustible matter directly contribute to the heating value of coal. Fixed carbon acts as a main heat generator during burning. High volatile matter content indicates easy ignition of fuel. The ash content is important in the design of the furnace grate, combustion volume, pollution control equipment and ash handling systems of a furnace.”</span><u></u><u></u></p>
<p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">This week we tried to get some tests of fuel content and were offered ‘coal analysis’ tests. It all sounds good but if you look into the procedure, you are not getting what you think – i.e. it is not an analysis of the elements that we are used to talking about in the biomass fuel biz.</span><u></u><u></u></p>
<p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Getting a lab test result of this type using an instrument designed to do ANSI/ASTM D3172 tests <a href="http://www.marsap.com/anamedinstru.com/coal.shtml" target="_blank">http://www.marsap.com/anamedinstru.com/coal.shtml</a> and turning it into a ‘standard’ analysis is quite messy and I have a spreadsheet for doing that if you need it. It was necessary for the Asian Dev Bank (which built the SEET Lab) to do this because all that is available is standard coal analyses, but the HTP test method is more scientific in the sense that it uses the chemical composition of the fuel, not an approximation of it. It is also necessary to get the ‘as received, ash-free’ heat content. Coal analysis methods gives AR (as received moisture), AD (after drying but not ‘actually dry’) and FC (fixed carbon, but not ‘actual carbon’ content). It also view some of the moisture as ‘inherent’.</span><u></u><u></u></p>
<p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">There are two things which come back ‘wrong’: the moisture content and the carbon content. Finding out what the carbon content of the volatiles was is nearly impossible. The right approach is XRD and XRF.</span><u></u><u></u></p>
<p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">To give you an idea of how far wrong the method is for determining Carbon, here is a standard test result of some coals and sawdust briquette. It is well known that the sawdust contains about 50% Carbon. It was rated as having 16% ‘fixed carbon’. In other words it is basically a useless measurement when it comes to biochar (or anything else).</span><u></u><u></u></p>
<p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p style="margin-left:0in"><img border="0" width="527" height="353" src="cid:image001.png@01CE03C0.0AFE1170"><u></u><u></u></p>
<p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Regards</span><u></u><u></u></p>
<p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Crispin</span><u></u><u></u></p><p style="margin-left:0in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p>
<p class="MsoNormal" style="line-height:13.5pt;background:white"><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:#565656"> </span><u></u><u></u></p></div><p class="MsoNormal"> <u></u><u></u></p>
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