<html><head></head><body style="background-color: rgb(255, 255, 255); line-height: initial;"> <div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);">Dear Frank</div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><br></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);">The helium is detected as a carrier gas as far as I know how it works. More on that in May. </div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><br></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);">There is a problem in principle with the method you outline below requiring one rather large change to make it work. </div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><br></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; text-align: initial; line-height: initial;">The SeTAR's chemical mass balance test method (currently advertised with a heterogeneous test cycle as the standard burn cycle) is not a <i>carbon mass balance</i><span> method for a very good reason. Carbon in combustion gases, measured and referenced to a known carbon content of the fuel, making the carbon proxy for fuel gas, doesn't work for biomass combustion in cooking stoves. </span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; text-align: initial; line-height: initial;"><span><br></span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; text-align: initial; line-height: initial;"><span>Hood-based or stack-based emissions measurements that rely on a carbon mass balance method will <i>only</i><span> work if the fuel is fed into the fire continuously and the production of carbonaceous ash is produced continuously in a steady state device. That is definitely <i>not</i><span> a wood-fired cooking stove's mode of operation. </span></span></span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; text-align: initial; line-height: initial;"><span><span><span><br></span></span></span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; text-align: initial; line-height: initial;"><span><span><span>What I mean is that the fire might burn very well at high power but not be burning much carbon at all. That is the issue. Later it might burn at a lower power but mostly combusting charcoal. In effect the fuel composition (composition of what is burning) changes continuously and the calculation of a carbon-based mass balance method assumes that it be constant. It is not obvious at first when looking at the formulas but it is an underlying assumption. The method assigns to the fuel gases an attribute it may not possess (a constant carbon fraction) something known as a 'category error'. </span></span></span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; text-align: initial; line-height: initial;"><span><span><span><br></span></span></span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; text-align: initial; line-height: initial;"><span><span><span>Under certain conditions, particularly when igniting wet coal with hot wood, or damp wood, the stove will manufacture oxygen and hydrogen from water from an endothermic water gas shift reaction to such an extent that the oxygen level in the stack exceeds the level in ambient air. In this condition all formulas for combustion performance break down and the answers become ridiculous. In fact they are giving wrong answers long before breakdown is reached but it is not obvious. </span></span></span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; text-align: initial; line-height: initial;"><span><span><span><br></span></span></span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; text-align: initial; line-height: initial;"><span><span><span>Thus I adopted some years ago a different approach using a total chemical mass balance instead of a carbon mass balance and the calculations not only come right the answers are correct (imagine!)</span></span></span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; text-align: initial; line-height: initial;"><span><span><span><br></span></span></span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; text-align: initial; line-height: initial;"><span><span><span>A few people have studied this approach in depth, including Yixiang Zhang, Tafedzwe Makonese, David Beritault, Odnoo in Ulaanbaatar and Harold Annegarn. </span></span></span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;"><br></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;">The promise it holds is that the chemical mass balance approach can be applied accurately to the combustion of a fuel that is continuously changing it total chemistry. If you use carbon as a proxy for fuel and the fuel is wood, and the stove is making charcoal, you can calculate a number, no problem, but the number doesn't represent what just happened. </span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;"><br></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;">Hood-and-velocity systems and mass balance systems both have significant challenges but 'on balance' mass seems to offer some important advantages, mostly to do with the measurement of condensed volatile particles and the issue of wood (well, damp wood) making O2 and H2. </span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;"><br></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;">Paul and Julien and I are considering holding a brief Test Camp at which this would be covered in a minor class on calculating performance outputs. I am in South Africa at the moment discussing changes to the SeTAR method with Harold that will make the approach 'universal', I guess is the right word. </span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;"><br></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;">Biomass burned in an inhomogeneous manner presents special problems for the tester that haven't been addressed by methods designed for burning solid fuels in a steady state or liquid fuels at a variable rate. </span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;"><br></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;">The EPA carbon balance methods, for example, give results that are out in excess of 100% of value when applied to some wood stoves, and that is <i>overall</i><span> with larger errors during the burn. Some overall corrections can be applied after the test but that doesn't address the problem of real time readings which are the basis of gas mass and PM mass totals. </span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;"><span><br></span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;"><span>The chemical mass balance approach seems to offer a way forward. </span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;"><span><br></span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;"><span>Regards </span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;"><span>Crispin in wonderful windy Muizenberg</span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;"><span><br></span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;"><span>+++++++++</span></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-size: initial; line-height: initial; text-align: initial;"><br></span></div><div id="_originalContent" style=""><meta http-equiv="Content-Type" content="text/html charset=utf-8"><div class=""><a href="http://www.hovacinc.com/images/VQM_Comparison_of_Ion_Trap_Quadrupole_Mass_Spectrometers.pdf" class="">PDF Granville-Phillips Gas Analysis Products</a></div><div class=""><br class=""></div><div class="">Try the above. Scroll down to a few pages to see what the mass spec will read </div><div class=""><br class=""></div><div class="">Thanks</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><br class=""><div apple-content-edited="true" class="">
Frank Shields<br class=""><a href="mailto:franke@cruzio.com" class="">franke@cruzio.com</a><br class=""><br class="">
</div>
<br class=""><div><blockquote type="cite" class=""><div class="">On Apr 4, 2015, at 7:28 PM, Inversiones Falcon <<a href="mailto:invfalcones53@yahoo.com" class="">invfalcones53@yahoo.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class=""><div style="background-color: rgb(255, 255, 255); font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 16px;" class=""><div dir="ltr" class=""><span class="">Hi Frank I did not get any file, will you pleas send it to me.</span></div><div dir="ltr" class=""><span class=""><br class=""></span></div><div dir="ltr" class=""><span class="">Best reagard</span></div><div dir="ltr" class=""><span class=""><br class=""></span></div><div dir="ltr" class=""><span class="">Gustavo</span></div><br class=""> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" id="yui_3_16_0_1_1428200262009_3719" class=""> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" id="yui_3_16_0_1_1428200262009_3718" class=""> <div dir="ltr" id="yui_3_16_0_1_1428200262009_3717" class=""> <hr size="1" class=""> <font size="2" face="Arial" id="yui_3_16_0_1_1428200262009_3716" class=""> <b class=""><span style="font-weight:bold;" class="">From:</span></b> Frank Shields <<a href="mailto:franke@cruzio.com" class="">franke@cruzio.com</a>><br class=""> <b class=""><span style="font-weight: bold;" class="">To:</span></b> Discussion of biomass cooking stoves <<a href="mailto:stoves@lists.bioenergylists.org" class="">stoves@lists.bioenergylists.org</a>>; "<a href="mailto:franke@cruzio.com" class="">franke@cruzio.com</a> com" <<a href="mailto:franke@cruzio.com" class="">franke@cruzio.com</a>> <br class=""> <b class=""><span style="font-weight: bold;" class="">Sent:</span></b> Saturday, April 4, 2015 5:12 AM<br class=""> <b class=""><span style="font-weight: bold;" class="">Subject:</span></b> [Stoves] Testing gases from stoves<br class=""> </font> </div> <div class="y_msg_container" id="yui_3_16_0_1_1428200262009_3720"><br class=""><div id="yiv0589633299" class=""><div class="qtdSeparateBR"><br class=""><br class=""></div><div class="yiv0589633299yqt7552492537" id="yiv0589633299yqtfd23492"><div class="">
<div class="yiv0589633299MsoNormal"></div></div></div></div><br class=""><div id="yiv0589633299" class=""><div id="yui_3_16_0_1_1428200262009_3722" class=""><div class="yiv0589633299MsoNormal"></div><div class="yiv0589633299MsoNormal"><br clear="none" class="yiv0589633299"></div><div class="yiv0589633299MsoNormal">Dear Crispin and Stovers,</div>
<div class="yiv0589633299MsoNormal"> </div>
<div class="yiv0589633299MsoNormal" id="yui_3_16_0_1_1428200262009_3721">I found this to be an interesting report (attached) . I have
been looking for a system that would test the combustion gases of interest –
and helium. And I found it! It think this system (ion trap mass
spectrometer or quadrupole mass spectrometer) may be what’s in Crispin’s hand
held tester(?). I think it may teat for
helium but, perhaps, is just not set up to do it because ‘Who would want to test
helium along with combustion gases?’ – We Would! </div>
<div class="yiv0589633299MsoNormal" id="yui_3_16_0_1_1428200262009_3723">This could make testing gases much more accurate and easier.
How I suggest it working is as follows:</div>
<div class="yiv0589633299MsoNormal" id="yui_3_16_0_1_1428200262009_3724">We pipe in helium at ~ 0.5L/minute into the stove at fuel level
in a known and steady rate during the combustion experiment. So we know the total carbon in the stove from
the added fuel and the constant rate helium is leaving the stack. We monitor the CO, CO2, H, O2 produced during
the experiment and determine their concentrations. The volatile carbon not determined will be tars and other unburned
carbon.</div>
<div class="yiv0589633299MsoNormal" id="yui_3_16_0_1_1428200262009_3725">The calculations are: (combustion components) per (helium
detected). </div>
<div class="yiv0589633299MsoNormal" id="yui_3_16_0_1_1428200262009_3726">This makes it such we do not care about dilution of primary
or secondary air. We can make adjustments to them during the experiment and it
will not make a difference. We only need
to make sure we have complete mixing where we pull out the gas sample for testing. The helium is called a Surrogate Standard and
knowing that every minute there is 0.5 liters leaving the stack no matter how
diluted or how fast it leaves makes that a solid unit of measure we can ratio the
components of interest off. We only need to have the makers of combustion
measuring device add helium to the other components of interest and we add
helium to the front end of the experiment at a steady known rate. </div><div class="yiv0589633299yqt7552492537" id="yiv0589633299yqtfd40178"></div><div class="yiv0589633299yqt7552492537" id="yiv0589633299yqtfd75484">
<div class="yiv0589633299MsoNormal"> </div>
</div><div class="yiv0589633299MsoNormal"></div><div class="yiv0589633299yqt7552492537" id="yiv0589633299yqtfd96821">Regards</div>
<div class="yiv0589633299MsoNormal"> </div>
<div class="yiv0589633299MsoNormal">Frank</div>
<div class="yiv0589633299MsoNormal"> </div>
Frank Shields<br clear="none" class="yiv0589633299"><div class="yiv0589633299"><a rel="nofollow" shape="rect" class="yiv0589633299" ymailto="mailto:franke@cruzio.com" target="_blank" href="mailto:franke@cruzio.com">franke@cruzio.com</a><div class="yiv0589633299yqt7552492537" id="yiv0589633299yqtfd60543"><br clear="none" class="yiv0589633299"><br clear="none" class="yiv0589633299">
</div></div><div class="yiv0589633299yqt7552492537" id="yiv0589633299yqtfd42147">
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