Fr. J (adding list back in) see below
On Aug 22, 2013, at 2:03 AM, "[email protected]" <[email protected]> wrote: > Ron, > > You wrote: > #5 There are several other ways to make char while cooking besides the TLUD > approach. > > Q5a: Other than by pyrolysis+gasification? [RWL5a': I wold drop the word "gasification" - used in technical circles to consume char. All of the techniques for making any char can/should be called pyrolysis. Those involving cooking are a subset of the total. A good recent, comprehensive (free) overview of char-making techniques (only using the term "pyrolysis") is at https://fortress.wa.gov/ecy/publications/publications/1107017.pdf > Q5b: Such as? RWL5b': a. Visit www.worldstove.com. Nat Mulcahy has developed a technique in which hot oxygen free gases are caused by pressure differences created using Venturi principles to travel downward through the fuel body. After picking up some pyrolysis gases, they travel back to the burner after mixing with incoming "air" (can't call it either primary or secondary). Sometimes called "TLOD". Nat uses the name "Lucia". b. One can make (I believe, none around yet, that I know of) cookstoves that would be called BLDD (Bottom lit down draft). I'm working on. c. Look up the name Rok Oblak. He and list member Joshua Guinto have a nice design with a horizontal flow of air, called a Roket. Mostly using holey briquettes, but not restricted to that. d. If you handle a rocket stove cleverly, (or even any three-stone cook fire), you can pull char out, before the gasification process consumes it. e. There is a stove called an Anila, which is of a retort character - not controllable. A toroid shape with pyrolysis gases exiting the bottom, igniting and further heating the retort. f. There is an alternative pyrolysis approach called HTC - Hydrothermal Carbonization, where the "waste" product is water at about 230 C. Something like a pressure cooker. Hard to imagine being a cooker, but who knows. g. There are probably others, that I hope others will add. > > > You wrote: > #6 All these char producing stoves ... should not be called biochar-producers > (i.e. replace "biochar" with "char.) > > Q6: All biochar is char, but not all char is biochar. Is that correct? [RWL6': Yes. > > > You wrote: > #7 If that (stove-produced) char is itself combusted, that stove would in > most cases be able to be called carbon neutral. > > Q7: If the resulting char from a biomass stove is not allowed to combust > completely i.e., (not allowed to burn to ashes), what would that stove -- in > most cases -- be called? [RWL7' This is my option 5b'-d above. Cooks all over the world do this regularly. Quite a lot can be obtained if you watch what you are doing. > > carbon neutral? [RWL7a': Yes, possibly, if you did not place the char in the ground, or otherwise out of circulation. > > carbon positive? [RWL7b': Never (almost). Positive mostly means a fossil fuel. But if the fuel came from a region in serious biomass decline, this produced char might be carbon positive. It is happening in some countries, and getting worse. Avoiding this is a main reason for this list's existence. > carbon negative? [RWL7c' Only if the char is put away permanently (dumping in the ocean or a mine shaft qualifies). But is called biochar if the char is placed in the ground. > none of the above? [RWL7d': Two out of the three are normally possible: either carbon neutral or carbon negative: not b' (carbon positive) Do you have a new idea in mind? Lots of expertise on this list to help. Ron > > > > ---------- Forwarded Message ---------- > From: "[email protected]" <[email protected]> > To: [email protected] > Subject: Re: [Stoves] thank you, RWL > Date: Thu, 22 Aug 2013 01:09:47 GMT > > Most grateful! > > Am still digesting the material; almost as exciting as form criticism of > biblical texts! > >
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