<html><head></head><body data-blackberry-caret-color="#00a8df" 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);"><span style="font-family: Calibri, 'Slate Pro', sans-serif; font-size: initial; text-align: initial; line-height: initial;">Dear AD</span></div><div id="_originalContent" style=""><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);"><div style="text-align: initial; width: 330px; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif;"><br></div><div style="text-align: initial; width: 330px; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif;">Very interesting. Are you using the drums 'as is' without the encompassing shell and cover? Does the TLUD process yield less char?</div><div style="text-align: initial; width: 330px; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif;"><br></div><div style="text-align: initial; width: 330px; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif;">I would appreciate seeing a description of the new system. </div><div style="text-align: initial; width: 330px; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif;"><br></div><div style="text-align: initial; width: 330px; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif;">Thanks</div><div style="text-align: initial; width: 330px; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif;">Crispin in Monsoon Yogya</div><span style="color: rgb(0, 0, 0); font-family: sans-serif;"><br></span><br style="color: rgb(0, 0, 0); font-family: sans-serif;"><div style="color: rgb(0, 0, 0); font-family: sans-serif;"><div>Dear Crispin,<br>we no longer use the oven and retort process for charring agricultural<br>waste but use the TLUD principle, because the old oven and retort<br>process required more hardware, resulting into higher capital cost.<br>Yours<br>A.D.Karve<br>***<br>Dr. A.D. Karve<br><br>Chairman, Samuchit Enviro Tech Pvt Ltd (<a href="http://www.samuchit.com/">www.samuchit.com</a>)<br><br>Trustee & Founder President, Appropriate Rural Technology Institute (ARTI)<br><br><br>On Fri, Feb 13, 2015 at 5:52 AM, Crispin Pemberton-Pigott<br><<a>crispinpigott@outlook.com</a>> wrote:<br>> Dear Jock and Paul and All<br>><br>> This is conceptually very similar to what Dr AD Karve has been doing with<br>> the sugar cane leaves except for two things. He is using 7 barrels at a time<br>> in the fire and the gas exits the bottom of the containers (barrels) so as<br>> to use the heat for cooking the char instead of cooking the pot.<br>><br>> The Karve Koncept uses the least total fuel to make the char (the primary<br>> product). The capping of the top to keep air out and heat in allows for<br>> simultaneous cooking but requires more fuel (to make the char) but has a<br>> second task to accomplish so it doesn't matter.<br>><br>> In both cases the systems are able to make char from material that is hard<br>> to work with. In the second case an 'easier to burn fuel' is used to char a<br>> 'hard to burn fuel'.<br>><br>> When sawdust is used for cooking it is often burned using the 'central<br>> hole' drum approach with a stick forming the hole while it is packed around<br>> with sawdust. A second stick makes the side air entrance.<br>><br>> Cecil reports that a standard way of having that approach not have to burn<br>> at high power all the time and to reduce the smoke bursts is to put a single<br>> stick of fuel into the side hole where it provides a continuous ignition<br>> source for the gases inside. This burns slowly and is pushed in now and<br>> then. Viewed systemically it is also a co-firing burner that uses a<br>> different fuel to maintain the production and burning of the gases.<br>><br>> Most practical cooking stoves have some measure of power control. As this<br>> approach is micro-tized please consider how it might be controlled up and<br>> down. For space heating it is not much of a requirement so a MPFront would<br>> suit the power requirment well.<br>><br>> Regards<br>> Crispin in the Monsoon<br>><br>> Paul,<br>><br>> I will try to answer your questions from the perspective of a teaching tool,<br>> not a production unit.<br>><br>> Cheers,<br>><br>> Jock<br>><br>> Jock Gill<br>> P.O. Box 3<br>> Peacham, VT 05862<br>><br>> <a href="invoke://1,default:0,eyJ1cmkiOiJ0ZWw6KzEtKDgwMiktNTAzLTEyNTgiLCJkYXRhIjoiS3pFZ0tEZ3dNaWtnTlRBekxURXlOVGdBIn0=">+1 (802) 503-1258</a><br>><br>> Stewardship: not dominion, extraction or exploitation<br>><br>><br>> On Feb 12, 2015, at 11:53 AM, Paul Anderson <<a href="invoke://1,default:0,eyJ1cmkiOiJtYWlsdG86cHNhbmRlcnNAaWxzdHUuZWR1IiwiZGF0YSI6ImNITmhibVJsY25OQWFXeHpkSFV1WldSMUFBPT0ifQ==">psanders@ilstu.edu</a>> wrote:<br>><br>> To all, both Stovers and Biochar makers.<br>><br>> I thank Marc and Jock and Kirk (and probably some others, including Peter<br>> Hirst with his barrel-size unit, on video) for their efforts with a retort<br>> can inside of a TLUD gasifier. (see some messages below). I mention the<br>> following topics for consideration.<br>><br>> 1. Where inside the TLUD is the retort can to be placed? The retort needs<br>> heat to it, but the TLUD heat INSIDE THE FUEL BED is only at the top and<br>> then progressing slowly downward with the MPF (Migratory Pyrolytic Front),<br>> meaning that the bottom of the can does NOT get heated until the MPF is<br>> getting close.<br>><br>><br>> My approach is to simply place the retort can on the bottom of the empty<br>> TLUD - centered. I have the primary air come in from the sides, not the<br>> bottom, to avoid cooling of the lower portion of the retort. The top of the<br>> retort can is at about at the level of the secondary air supply, perhaps a<br>> bit below.<br>><br>> Then I fill the space between the retort can and the TLUD with fuel -- I use<br>> wood pellets for demos.<br>><br>> Start the TLUD in the usual fashion.<br>><br>> When the TLUD has pyrolized the last of the pellets, the retort is left<br>> sitting in a very hot bed of charcoal that reaches part way up its sides. I<br>> allow the charcoal to continue to burn, with primary air, until the retort<br>> is finished -- no more combustible gases coming out. While the charcoal is<br>> burning, the upper part of the retort is bathed in very hot exhaust gases.<br>> Thus it is important (?) that the top of the retort can be below the cooling<br>> secondary air.<br>><br>> At the end, since both the TLUD and the Retort are small, it is not<br>> difficult to extract the retort can and then dump the charcoal remaining in<br>> the TLUD into quenching water. I sometimes empty the retort into a mason<br>> jar and seal it in the usual way. This gives me bone dry biochar.<br>> Quenching hot biochar in water gives me instantly fully saturated [hydrated]<br>> biochar - or so says Hugh. It is also safe to handle and will not<br>> spontaneously re-ignite.<br>><br>> Keeping the retort in the the TLUD, below the secondary air, and away from<br>> the primary air, both of which would tend to cool the retort, seems to work<br>> well.<br>><br>> Note: Wood pellets work well in my system. Larger grass tablets seems to<br>> be have a more difficult time transferring heat inside the retort. Perhaps<br>> part because they expand when they get hot?<br>><br>> In my educational units, the TLUD is a large coffee can from Costco - very<br>> nice steel. The resort is a 1 quart paint can - not such nice steel. BTW,<br>> you only need two or three holes in the lid of the 1 quart can to allow the<br>> gases out. I suspect this also helps to keep heat in the retort. The<br>> escaping gases will take heat away as they exit the retort - yes?<br>><br>> I hope this helps.<br>><br>> Cheers,<br>><br>> Jock<br>><br>><br>> Therefore, should the retort can be above the fuel level but below the entry<br>> of secondary air? Maybe not, because the can and its contents could chill<br>> the rising gases and hinder their combustion. But maybe this is not so<br>> crucial?<br>><br>> Maybe the retort can is only in the upper half(?) of the TLUD fuel?<br>><br>> Or maybe this does not make much difference?<br>><br>> 2. I like Jock's idea of the outlet holes being upward in the retort can.<br>> He reports seeing the small jets of flame. That means that the retort<br>> gases are entering into an environment with sufficient secondary air for<br>> combustion. This also is then an issue of the placement of the retort.<br>><br>> Please note that instead of outlet holes there could be an outlet Channel<br>> (pipe, tube, etc) that takes the retort gases to a different place.<br>> Remember that retort gases come out in a sequence of types that start with<br>> water vapor, then mixed gases, and finally the pyrolytic gases that are<br>> combustible. Retort processes do not occur the same way as TLUD processes.<br>><br>> 3. Placing the retort canister ABOVE the secondary air entry provides the<br>> maximum heat to the retort. Maybe it could be in the "riser" section, or<br>> up where the cooking pot would otherwise be placed. This has been done in<br>> barrel-size units by Doug Clayton and Hugh McLaughlin and is on video. The<br>> main problem encountered is the difficulty / danger of handling full barrels<br>> well above ground level, sometimes full of hot char.<br>><br>> 4. Of course, issues of char qualities need to be considered. About<br>> putting fines (very small) biomass into retorts, it is known that the<br>> transfer of heat from the edges to the center is HINDERED if the materials<br>> are too packed together.<br>><br>> Many of us are looking forward to further reports on this topic.<br>><br>> Paul<br>><br>> Doc / Dr TLUD / Prof. Paul S. Anderson, PhD<br>> Email: <a href="invoke://1,default:0,eyJ1cmkiOiJtYWlsdG86cHNhbmRlcnNAaWxzdHUuZWR1IiwiZGF0YSI6ImNITmhibVJsY25OQWFXeHpkSFV1WldSMUFBPT0ifQ==">psanders@ilstu.edu</a><br>> Skype: paultlud Phone: <a href="invoke://1,default:0,eyJ1cmkiOiJ0ZWw6KzEtMzA5LTQ1Mi03MDcyIiwiZGF0YSI6Ikt6RXRNekE1TFRRMU1pMDNNRGN5QUE9PSJ9">+1-309-452-7072</a><br>> Website: <a href="http://www.drtlud.com/">www.drtlud.com</a><br>><br>> On 2/12/2015 6:35 AM, Jock Gill wrote:<br>><br>> Marc,<br>><br>> I have also done this. I place feedstock in a smaller can that only has a<br>> few holes in its lid to allow the pyrolytic gases to escape and burn. I<br>> then place this, as you did, in a larger can used as a ND TLUD and surround<br>> the smaller can with fuel. This creates a retort within a TLUD. The TLUD<br>> will burn some of the charcoal it has made in order to finish the pyrolysis<br>> in the inner retort can.<br>><br>> I find, contrary to the given wisdom, that the inner "retort" can be placed<br>> with in the TLUD with the gas escape holes facing UP. This allows students<br>> to see the gas come out and ignite. If they can see the flames created by<br>> the gas coming out of the retort it much more powerful educational<br>> experience.<br>><br>> Well done,<br>><br>> Jock<br>><br>> Jock Gill<br>> P.O. Box 3<br>> Peacham, VT 05862<br>><br>> Cell: (617) 449-8111<br>><br>> <a href="invoke://1,default:0,eyJ1cmkiOiJodHRwOi8vZ29vZ2xlLmNvbS8rSm9ja0dpbGwiLCJkYXRhIjoiWjI5dloyeGxMbU52YlM4clNtOWphMGRwYkd3QSJ9">google.com/+JockGill</a><br>><br>> :> Extract CO2 from the atmosphere! <:<br>><br>> Via iPad<br>><br>> On Feb 12, 2015, at 5:07 AM, Marquitusus <<a href="invoke://1,default:0,eyJ1cmkiOiJtYWlsdG86bWFycXVpdHVzdXNAaG90bWFpbC5jb20iLCJkYXRhIjoiYldGeWNYVnBkSFZ6ZFhOQWFHOTBiV0ZwYkM1amIyMEEifQ==">marquitusus@hotmail.com</a>> wrote:<br>><br>> Hi, in the mids December I consulted the list about my problems with almond<br>> husks as TLUD's fuel.<br>> The problem is the smaller particles of this fuel obstruct the primary air<br>> flow and the pyrolisys stops.<br>><br>> Kirk suggested me using the "can method": just screening the fuel and use<br>> the smaller fraction for filling a can that will be put inside the reactor,<br>> surrounded by the large particles fraction. I recently tried this method,<br>> and it really worked! You can see pics here:<br>><a href="http://cuinessolars.jimdo.com/cuines/cuines-gasificadores/">http://cuinessolars.jimdo.com/cuines/cuines-gasificadores/</a><br>><br>> So, this opens the door for using any size of fuel in a ND-TLUD, from rice<br>> hulls to saw dust or any other little particles fuel ( I understand that in<br>> a FD-TLUD is not necessary, because of the forced air draft). Also, this<br>> method can allow to shorten the size of the chimneys or risers, because less<br>> draft is necessary.<br>><br>> The bad news are we need a can (that is exposed to high temps that will<br>> deteriorate it) and we need to previously screen the fuel, but I think these<br>> are minor handicaps compared to the benefits it brings<br>><br>> Marc<br>><br>> ____________________________<br></div></div></div><style><!-- .EmailQuote { margin-left: 1pt; padding-left: 4pt; border-left: #800000 2px solid; } --><br></style><br><!--end of _originalContent --></div></body></html>