<html><body><div style="font-family: times new roman, new york, times, serif; font-size: 12pt; color: #000000"><DIV><SPAN style="FONT-SIZE: small">Dear Friends,</SPAN><BR></DIV>
<DIV><SPAN style="FONT-SIZE: small">I would like to share with you and all in Stove List, two videos and their respective photo albums on the Cooking Performance of the Whirly Pinay TLUD Stove which I am developing; and the Baking Performance of the Bingka Clay Oven heated by a Whirly Pinay TLUD stove. But before discussing these 2 videos and photo albums, I would like to thank Crispin and Andrew for sharing their views on the amount of CO that is generated in burning residual char in a stove (such as my Eco-Kalan and Whirly Pinay TLUD Clay Stove).</SPAN></DIV>
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<DIV>From Crispin:</DIV>
<DIV><SPAN style="COLOR: #1f497d; mso-fareast-language: EN-CA; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'">I have taken many measurement of CO/CO2 at various stages and what I see is that in the late burning stage the CO/CO2 ratio is not as bad as many assume – even in a poorly sheltered fire. The combustion of char tends to stabilise at 12-16% CO/CO2 with 14% being common in a ‘cold fire’. It is not true at all that the carbon mostly emerges as CO.</SPAN><SPAN style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman','serif'; mso-fareast-language: EN-CA; mso-fareast-font-family: 'Times New Roman'"></SPAN></DIV>
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<P style="MARGIN: 0px; LINE-HEIGHT: normal"><SPAN style="COLOR: #1f497d; mso-fareast-language: EN-CA; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'">To get high CO one has to ‘force’ the production of it such as in a hot, choked, air-inadequate fire. Then one can see the CO/CO2 reach 30% or more. It is not uncommon to see 25% in poorly constructed stoves, but not at the end. Little well-aerated char fires stabilise in that 12-16% range.</SPAN><SPAN style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman','serif'; COLOR: black; mso-fareast-language: EN-CA; mso-fareast-font-family: 'Times New Roman'"></SPAN></P>
<P style="MARGIN: 0px; LINE-HEIGHT: normal"><SPAN style="COLOR: #1f497d; mso-fareast-language: EN-CA; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'"></SPAN> </P>
<P style="MARGIN: 0px; LINE-HEIGHT: normal"><SPAN style="COLOR: #1f497d; mso-fareast-language: EN-CA; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'">It is often said that “the CO is really high”. That is relative true compared with a really good fire, but CO is highest in hot, bad fires where there is enough energy to create a high burn rate and poor mixing or poor combustion.</SPAN><SPAN style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman','serif'; COLOR: black; mso-fareast-language: EN-CA; mso-fareast-font-family: 'Times New Roman'"></SPAN></P>
<P style="MARGIN: 0px; LINE-HEIGHT: normal"><SPAN style="COLOR: #1f497d; mso-fareast-language: EN-CA; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'"></SPAN> </P>
<P style="MARGIN: 0px; LINE-HEIGHT: normal"><SPAN style="COLOR: #1f497d; mso-fareast-language: EN-CA; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'">From Andrew:</SPAN></P>
<P style="MARGIN: 0px; LINE-HEIGHT: normal"><SPAN style="COLOR: #1f497d; mso-fareast-language: EN-CA; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'"><SPAN style="FONT-SIZE: 12pt; FONT-FAMILY: 'Calibri','sans-serif'; LINE-HEIGHT: 115%; mso-fareast-language: EN-US; mso-fareast-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-CA; mso-bidi-language: AR-SA; mso-bidi-font-size: 10.0pt">Your palangay way looks like it is a good candidate for retained heat<BR>cooking.<BR></SPAN></SPAN></P>
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<P style="MARGIN: 0px; LINE-HEIGHT: normal"><SPAN style="COLOR: #1f497d; mso-fareast-language: EN-CA; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'"><SPAN style="FONT-SIZE: 12pt; FONT-FAMILY: 'Calibri','sans-serif'; LINE-HEIGHT: 115%; mso-fareast-language: EN-US; mso-fareast-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-CA; mso-bidi-language: AR-SA; mso-bidi-font-size: 10.0pt">Even so the method you mention of allowing char embers to burn out and<BR>produce the remaining necessary heat need not necessarily produce a<BR>lot of CO. This is because the conditions for a full CO generator<BR>require the char to be hot and deep so that oxygen first encountering<BR>a hot piece of char will dissociate on the char surface and form CO2,<BR>this CO2 then would only be reduced to CO if it encountered another<BR>bit of hot char in the absence of any other oxygen, this reduction to<BR>CO is also endothermic, so it lowers temperature. Hence if the char<BR>bed is shallow and heat is being radiated from it little CO need form<BR>but some always will.<BR></SPAN></SPAN></P>
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<P style="MARGIN: 0px; LINE-HEIGHT: normal"><SPAN style="COLOR: #1f497d; mso-fareast-language: EN-CA; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'"><SPAN style="FONT-SIZE: 12pt; FONT-FAMILY: 'Calibri','sans-serif'; LINE-HEIGHT: 115%; mso-fareast-language: EN-US; mso-fareast-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-CA; mso-bidi-language: AR-SA; mso-bidi-font-size: 10.0pt"></SPAN></SPAN><SPAN style="FONT-SIZE: small; COLOR: #1f497d; mso-fareast-language: EN-CA; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'"><SPAN style="FONT-FAMILY: 'Calibri','sans-serif'; LINE-HEIGHT: 115%; mso-fareast-language: EN-US; mso-fareast-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-CA; mso-bidi-language: AR-SA; mso-bidi-font-size: 10.0pt"><SPAN style="COLOR: #000000">CRISPIN & ANDREW, THANK YOU! - I take comfort from what you have shared. It encourages me to go on practising the Philippine cultural tradition of cooking rice or corn last the "palangay" way. </SPAN></SPAN></SPAN></P>
<P style="MARGIN: 0px; LINE-HEIGHT: normal"><SPAN style="FONT-SIZE: small; COLOR: #1f497d; mso-fareast-language: EN-CA; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'"><SPAN style="FONT-FAMILY: 'Calibri','sans-serif'; LINE-HEIGHT: 115%; mso-fareast-language: EN-US; mso-fareast-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-CA; mso-bidi-language: AR-SA; mso-bidi-font-size: 10.0pt"><SPAN style="COLOR: #000000">I have one last question on the CO. How quickly (or slowly) does the CO change to CO2 once it is released to the open air through a chimney or by diffusion from a stove?</SPAN></SPAN></SPAN></P>
<P><SPAN style="FONT-SIZE: small; COLOR: #1f497d; mso-fareast-language: EN-CA; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'"><SPAN style="FONT-FAMILY: 'Calibri','sans-serif'; LINE-HEIGHT: 115%; mso-fareast-language: EN-US; mso-fareast-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-CA; mso-bidi-language: AR-SA; mso-bidi-font-size: 10.0pt"><SPAN style="COLOR: #000000">Now back to the Whirly Pinay TLUD clay stove videos and photos.</SPAN></SPAN></SPAN></P>
<P style="MARGIN: 0px; LINE-HEIGHT: normal">Cooking Bam-i & Rice with Whirly Pinay TLUD Stove, Eco-Kalan Project, June 11, 2015</P>
<P style="MARGIN: 0px; LINE-HEIGHT: normal"><A href="https://youtu.be/HZhHzQUfrGk" target=_blank>https://youtu.be/HZhHzQUfrGk</A></P>
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<P style="MARGIN: 0px; LINE-HEIGHT: normal"> June 11, 2015 Cooking Bam-i and Rice with Whirly Pinay TLUD Clay Stove, Eco-Kalan Project</P>
<P style="MARGIN: 0px"><A href="https://plus.google.com/photos/113101643783889350444/albums/6159008359940818145" target=_blank>https://plus.google.com/photos/113101643783889350444/albums/6159008359940818145</A></P>
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<P style="MARGIN: 0px">My Comments:</P>
<P style="MARGIN: 0px" data-mce-style="margin: 0px;">1. Cooking with the Whirly Pinay can be fun when you start with a "dead" and dry firewood and a strong fire. We don't have a moisture measuring device at Felipa Beach so we put our pre-cut wood in the sun for at least 3 days and store the dry fuel in a covered container. Dry firewood makes starting a strong fire easy. We use kerosene to start a fire and make sure there is sufficient primary air to produce a strong flame before containing the wood gas in a combustion chamber with inlets for the secondary air. I prefer to close the supply of primary air during pyrolysis and to open it to burn the char when cooking rice or soup with leafy vegetables or fish and other seafood at the end. </P>
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<P style="MARGIN: 0px" data-mce-style="margin: 0px;">2. As a cook using firewood for fuel, I make my decisions on what to do with the char on the basis of its best use. A burning char is best for keeping the food hot without burning the food at the bottom of the pot until it is time to serve. It is best for foods that cook readily and do not require high heat like omelettes, shrimps, and sauces.</P>
<P style="MARGIN: 0px" data-mce-style="margin: 0px;"> </P>
<P style="MARGIN: 0px" data-mce-style="margin: 0px;">3. As a baker using a Bingka Clay Oven heated by a Whirly Pinay Stove fuelled with wood, I make my decision on what to do with the char on the basis of its best use also. In the baking I have done so far, the oven temperature has to be around 500 degrees Fahrenheit. Burning the char cannot produce sufficient heat to maintain that high a temperature so it does not make sense to burn it. Instead, I save it and mix it with sand and organic matter of which I have plenty of at Felipa Beach. Have a look at the video and photos below.</P>
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<P style="MARGIN: 0px"><SPAN style="FONT-SIZE: 14pt; LINE-HEIGHT: 115%"></SPAN> Baking Hopia with Bingka Oven & Whirly Pinay TLUD Stove, Eco-Kalan Project, July 30, 2015</P>
<P style="MARGIN: 0px; LINE-HEIGHT: normal"> <A href="https://youtu.be/vHfSjZINxUA" target=_blank>https://youtu.be/vHfSjZINxUA</A></P>
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<P style="MARGIN: 0px; LINE-HEIGHT: normal">July 30, 2015 Baking Hopia with Bingka Oven and Whirly Pinay TLUD Clay Stove, Eco-Kalan Project</P>
<P style="MARGIN: 0px; LINE-HEIGHT: normal"><SPAN style="FONT-SIZE: medium; COLOR: #1f497d; mso-fareast-language: EN-CA; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'"><SPAN style="FONT-FAMILY: 'Calibri','sans-serif'; LINE-HEIGHT: 115%; mso-fareast-language: EN-US; mso-fareast-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-CA; mso-bidi-language: AR-SA; mso-bidi-font-size: 10.0pt"><SPAN style="COLOR: #000000"></SPAN></SPAN></SPAN> <A href="https://plus.google.com/photos/113101643783889350444/albums/6178681391871082273" target=_blank>https://plus.google.com/photos/113101643783889350444/albums/6178681391871082273</A></P>
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<P style="MARGIN: 0px; LINE-HEIGHT: normal">Warm regards,</P>
<P style="MARGIN: 0px; LINE-HEIGHT: normal">Rebecca Vermeer</P>
<P style="MARGIN: 0px; LINE-HEIGHT: normal">Eco-Kalan Project in the Philippines</P>
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<P style="MARGIN: 0px; LINE-HEIGHT: normal"><SPAN style="COLOR: #1f497d; mso-fareast-language: EN-CA; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: 'Calibri','sans-serif'; LINE-HEIGHT: 115%; mso-fareast-language: EN-US; mso-fareast-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-CA; mso-bidi-language: AR-SA; mso-bidi-font-size: 10.0pt"><SPAN style="COLOR: #000000"> </SPAN></SPAN></SPAN><SPAN style="COLOR: #1f497d; mso-fareast-language: EN-CA; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Calibri','sans-serif'; LINE-HEIGHT: 115%; mso-fareast-language: EN-US; mso-fareast-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-CA; mso-bidi-language: AR-SA"><BR></SPAN></SPAN></P></DIV>
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<DIV style="FONT-SIZE: 12pt; TEXT-DECORATION: none; FONT-FAMILY: Helvetica,Arial,sans-serif; FONT-WEIGHT: normal; COLOR: #000; FONT-STYLE: normal"><B>From: </B>"Ronal W. Larson" <rongretlarson@comcast.net><BR><B>To: </B>"Discussion of biomass" <stoves@lists.bioenergylists.org><BR><B>Cc: </B>"Rebecca A. Vermeer" <ravermeer@telus.net>, "Roberto Poehlmann" <Roberto.Poehlmann@grupogtd.com>, "Paul Anderson" <psanders@ilstu.edu>, "Crispin Pemberton-Pigott" <crispinpigott@outlook.com><BR><B>Sent: </B>Tuesday, August 4, 2015 4:38:22 PM<BR><B>Subject: </B>Re: [Stoves] Charcoal burning, secondary flame vs no flame<BR>
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<DIV>List and ccs</DIV>
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<DIV><SPAN class=Apple-tab-span style="WHITE-SPACE: pre"></SPAN>1. I think we should first try to answer the original question from Mr. Poehlmann - which I take to be whether it is better to burn char in the TLUD or in another device. I think the exchanges below say clearly that the answer is the latter.</DIV>
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<DIV><SPAN class=Apple-tab-span style="WHITE-SPACE: pre"></SPAN>But I would urge also taking a look at doing neither - but rather placing the produced char into soil. You have a char product that is clearly worth something in any/every market. If you care about climate change, placing this char in the ground (then can be called biochar) will be worth more than dollars.</DIV>
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<DIV><SPAN class=Apple-tab-span style="WHITE-SPACE: pre"></SPAN>2. I suggest that we follow the available stove testing literature - with the best I know of being that from a webinar given by EPA’s Jim Jetter.</DIV>
<DIV><A href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=307494" target=_blank>http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=307494</A></DIV>
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<DIV><SPAN class=Apple-tab-span style="WHITE-SPACE: pre"></SPAN>Slide 22 shows total CO output by weight of less than 1% in an apparently well done test</DIV>
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<DIV><SPAN class=Apple-tab-span style="WHITE-SPACE: pre"></SPAN>3. I am not up to date on CO mortality figures, but would personally be very scared of the 9% value offered as an average by Crispin. The values at one or two sigma away must have lethal potential many places and we certainly hear of CO-caused deaths. Anyone following this closely?</DIV>
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<DIV>Ron</DIV>
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<DIV>On Aug 4, 2015, at 9:40 AM, Crispin Pemberton-Pigott <<A href="mailto:crispinpigott@outlook.com" target=_blank>crispinpigott@outlook.com</A>> wrote:</DIV><BR class=Apple-interchange-newline>
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<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">Dear Rebecca and Paul</SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)"> </SPAN></DIV>
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<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="COLOR: rgb(31,73,125)">RAV>…</SPAN><SPAN>I have always been worried about the CO level that is produced in wood burning stoves (3-stones, traditional and improved) that become charcoal burning at the end stage of cooking. I am specifically referring to the traditional way rice is cooked in the Philippines to prevent it from burning at the bottom of the pot. First, the water is brought to boil at high power; then rice is added and stirred until most of the water is absorbed; and then any remaining unburned wood is removed and the rice, in the covered pot above the stove, continues to cook to perfection the "palangay" way -- i.e., with the heat from the glowing embers of the charcoal remains. Alternatively, rice and water are brought to boil together and then cooked the "palangay" way.</SPAN></DIV></DIV>
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<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN> </SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">Understood.</SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)"> </SPAN></DIV></DIV>
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<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN>Have you or anyone else taken CO/CO2 measurements under the above described cooking conditions, both indoor and outdoor?</SPAN></DIV></DIV>
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<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="COLOR: rgb(31,73,125)"> </SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">I have taken many measurement of CO/CO2 at various stages and what I see is that in the late burning stage the CO/CO2 ratio is not as bad as many assume – even in a poorly sheltered fire. The combustion of char tends to stabilise at 12-16% CO/CO2 with 14% being common in a ‘cold fire’. It is not true at all that the carbon mostly emerges as CO.</SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)"> </SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">To get high CO one has to ‘force’ the production of it such as in a hot, choked, air-inadequate fire. Then one can see the CO/CO2 reach 30% or more. It is not uncommon to see 25% in poorly constructed stoves, but not at the end. Little well-aerated char fires stabilise in that 12-16% range.</SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)"> </SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">It is often said that “the CO is really high”. That is relative true compared with a really good fire, but CO is highest in hot, bad fires where there is enough energy to create a high burn rate and poor mixing or poor combustion.</SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)"> </SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">Let’s use the example of 14.28% CO/CO2. I choose that because the CO as a fraction of C is 1/8<SUP>th</SUP>. The ratio of CO to CO2 is then 1:7 which is 14.28%. So we are burning char with 1/8<SUP>th</SUP><SPAN class=Apple-converted-space> </SPAN>of the carbon emerging as CO and 7/8 as CO2, OK?</SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)"> </SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">If the char is 85% carbon (realistically, this is a reasonable guess) then the heat available is about 29.5 MJ/kg. We lose about 75% of heat for all CO produced instead of CO2. Therefore we get as a loss:</SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)"> </SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">0.75 x 1/8 x 29.5 = 2.765 MJ</SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)"> </SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">So instead of getting 29.5 we get 26.73 MJ/kg, which is a loss of 9.375% or 9-3/8<SUP>ths</SUP><SPAN class=Apple-converted-space> </SPAN>per cent at 14,28% CO/CO2.</SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)"> </SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">So in round numbers it is reasonable to assume you are losing 10% of the heat energy in the form of uncombusted carbon.</SPAN></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SUB><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)"> </SPAN></SUB></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 0pt"><SPAN> </SPAN></DIV></DIV>
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<P class=MsoNormal style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 12pt"><SPAN style="FONT-FAMILY: Helvetica, sans-serif"><BR></SPAN><SPAN style="FONT-FAMILY: Helvetica, sans-serif; COLOR: rgb(31,73,125)">PSA></SPAN><SPAN style="FONT-FAMILY: Helvetica, sans-serif">Concerning the issue of what is the heat lost (not liberated) if CO from charcoal escapes instead of being burned, you have illuminated my (our) understanding.</SPAN><SPAN style="FONT-FAMILY: Helvetica, sans-serif; COLOR: rgb(31,73,125)"></SPAN></P>
<P class=MsoNormal style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 12pt"><SPAN style="FONT-FAMILY: Helvetica, sans-serif; COLOR: rgb(31,73,125)">></SPAN><SPAN style="FONT-FAMILY: Helvetica, sans-serif">In a "typical" charcoal stove that is generating dangerous amounts of CO, what percentage of the consumed carbon is "well burned" (and becomes CO2) versus the carbon that is only transformed into CO? </SPAN><SPAN style="FONT-FAMILY: Helvetica, sans-serif; COLOR: rgb(31,73,125)"></SPAN></P>
<P class=MsoNormal style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 12pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">It is highly dependent on the kitchen conditions. In a well-ventilated kitchen CO is not an issue, first because low level CO is not all that dangerous, and second because one doesn’t have to breathe the CO or the smoke, just because it comes out of the stove. In a real kitchen the smoke rises strongly to the top and most leaves by way of ventilation holes or gaps. In other words a ‘single box model’ of kitchen emissions being spread evenly around the room at all times is unreasonable. Kitchens don’t work like that. There is some advanced mathematical modelling done by KK Prasad at Eindhoven University in the 80’s on this matter. CO and PM are strongly concentrated above the stove, and are not spread around the room. Thus the exposure is affected much more by the kitchen than the actual emitted mass.</SPAN></P>
<P class=MsoNormal style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 12pt"><SPAN style="FONT-FAMILY: Helvetica, sans-serif; COLOR: rgb(31,73,125)">></SPAN><SPAN style="FONT-FAMILY: Helvetica, sans-serif">The reply might need to give some range of values or qualify the responses relating to a "high heat" charcoal fire versus a "low heat" charcoal fire, probably with the latter being proportionately much more of the carbon ending up as CO, with a corresponding 75% loss of the heat value for that amount of charcoal.</SPAN><SPAN style="FONT-FAMILY: Helvetica, sans-serif; COLOR: rgb(31,73,125)"></SPAN></P>
<P class=MsoNormal style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 12pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">The CO emitted by a charcoal stove on high power is usually more than the same stove at low power even if the combustion conditions at the end are poor. However, modern charcoal stoves are far better at combusting the fuel than the old and new ‘Jikos’. I am hoping to be able to point to a new charcoal stove product soon that has been waiting in the wings for launch. It has greatly reduced CO production throughout the burn. We need some examples like this to stimulate the industry. We have been setting targets too low.</SPAN></P>
<P class=MsoNormal style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 12pt"><SPAN style="FONT-FAMILY: Helvetica, sans-serif; COLOR: rgb(31,73,125)">></SPAN><SPAN style="FONT-FAMILY: Helvetica, sans-serif">There is a big difference between (hypothetical numbers follow) 50% of carbon going to CO instead of CO2 (with the loss of 75% of the heat value of half of the carbon [75% of 50% = 38% lost heat) versus only 5% of carbon going to CO (75% of 5 % = 4% lost heat). Of course, it is the CO that can kill you that is more important than some amount of lost heat.</SPAN><SPAN style="FONT-FAMILY: Helvetica, sans-serif; COLOR: rgb(31,73,125)"></SPAN></P>
<P class=MsoNormal style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 12pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">CO as a hazard is always going to be a hazard. On the other hand don’t over-sell a danger. If the 2-hr exposure limit is met, that’s OK. Remember that we have emission targets, it is not a contest/race (though we love those too). Having no CO at all is great – better efficiency, no health risk. In practice however, people produce CO all the time and we don’t die from exhaling our own air. People have a CO/CO2 ratio of about 1.6%.</SPAN></P>
<P class=MsoNormal style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 12pt"><SPAN style="FONT-FAMILY: Helvetica, sans-serif">Comment: We are discussing "char-gasification", the oxidation of solid carbon (but as charcoal it is not necessarily pure) into either CO or CO2. The O2 that enters as primary air can result in either CO or CO2. The role of secondary air is a very different story for char-gasification than it is for the combustion of pyrolytic gases as in the context of TLUD micro-gasifiers.</SPAN><SPAN style="FONT-FAMILY: Helvetica, sans-serif; COLOR: rgb(31,73,125)"></SPAN></P>
<P class=MsoNormal style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 12pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">I don’t have much add to that. It is important to recognise that CO2 produces at the pyrolysis front is often converted to CO endothermically in the char bed above it. CO<SUB>2</SUB><SPAN class=Apple-converted-space> </SPAN>happily goes back and forth several times to CO in a fire, or even to C<SUP>++</SUP>. It is not simple and direct. Similarly water in the fuel can be split into H<SUB>2</SUB><SPAN class=Apple-converted-space> </SPAN>and O. When measuring the content of unburned gases from a gasifier, you can find all sorts of strange totals of C and O<SUB>2</SUB><SPAN class=Apple-converted-space> </SPAN>and water vapour and H<SUB>2</SUB>. Wouldn’t you be surprised to find that the total of the O in the gas is CO, CO<SUB>2</SUB>, H<SUB>2</SUB>O, NO, NO<SUB>2</SUB>, SO, SO<SUB>2</SUB>, and O<SUB>2</SUB><SPAN class=Apple-converted-space> </SPAN>is higher than the concentration in air?</SPAN></P>
<P class=MsoNormal style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 12pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">Regards</SPAN></P>
<P class=MsoNormal style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', serif; MARGIN: 0cm 0cm 12pt"><SPAN style="FONT-SIZE: 11pt; FONT-FAMILY: Calibri, sans-serif; COLOR: rgb(31,73,125)">Crispin</SPAN></P></DIV></DIV></DIV>_______________________________________________<BR>Stoves mailing list<BR>
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