[Gasification] [Stoves] Thickness of flame front

[Kevin Chisholm]

Dear Michael

Michael Antal wrote:
> Although I always admire Tom’s postings, they occasionally contain
> typographical errors.  We recover about 70% of the energy content of biomass
> in the energy content of charcoal.  This is well documented in a long series
> of papers.  Regards, Michael.
>   

If that char was slowly heated at atmospheric pressure, at what 
temperature would it start to give off volatiles?

Thanks.

Kevin
>  
>
> Michael J. Antal, Jr.
>
> Coral Industries Distinguished Professor of Renewable Energy Resources
>
> Hawaii Natural Energy Institute
>
> POST 109, 1680 East-West Rd.
>
> Honolulu, HI 96822
>
>  
>
> phone: 808/956-7267
>
> fax: 808/956-2336
>
> www.hnei.hawaii.edu
>
>   _____  
>
> From: Thomas Reed [mailto:tombreed at comcast.net] 
> Sent: Tuesday, January 22, 2008 6:55 AM
> To: Discussion of biomass cooking stoves; GASIFICATION; Michael Antal; Jim
> Fournier; agua Das
> Subject: Re: [Stoves] Thickness of flame front
>
>  
>
> Dear Andrew and All:
>
> I was involved with diamond synthesis at Union Carbide and have converted a
> few diamonds to graphite.  
>
> At 1000 C diamonds are pretty stable in a hard vacuum or argon at 1 atm.  
>
> At 1100C they begin to decompose slowly.
>
> At 1200 C they pop like popcorn....
>
> What a fascinating element.  And to think that the hydrogen people detest
> it.  
>
> Biocarbon or biocoal is carbon neutral and leaves the atmosphere as it is.
> It can be called "Green Carbon" or "Green Coal".  So after we have stopped
> our dependence on fossil fuels it will be the preferred energy form.  It is
> a better way to convert biomass to energy which can then be stored, shipped
> and burned carbon neutral.  
>
> Mike Antal has developed a process that recovers > 30% or 40% of the energy
> in biomass as biocoal with 12-13000 Btu/lb.  
>
> Hydrogen is NOT neutral - it removes O2 from the atmosphere without
> replacing it. 
>
> Your biomass curmudgeon, 
>
> TOM REED   
> BEF
> BEC
> WoodGas.com
>
>
>
>
>
> ÐÏࡱá
>
>
>
> AJH wrote: 
>
> On Fri, 18 Jan 2008 21:54:46 +0200, IPC wrote:
>  
>   
>
> "Some carbon-carbon bonds are so strong the carbon won't burn, diamond
> decomposes to graphite at 1200C but it doesn't burn."
>  
> Really?
>     
>
>  
> I think so, as I said the diamond first graphitises and then further
> heating will burn the graphite, I think this is how it was proved
> diamonds were carbon in the 18th century but a solar concentrator had
> to be used to get the temperature high enough.
>  
>  
>   
>
>  The only diamond I ever found was identified by a mineralogist.
> When I doubted his identification, he said "Watch!", lit a bunsen burner,
> put my stone on the end of a spatula and - Poof! 
>     
>
>  
> I heard a similar story about a researcher at a university that was
> "loaned" a diamond to do experiments on the vibrations of the bonds.
> To excite the diamond he placed it on a stainless steel ultrasonic
> transducer and proceeded to heat it up, being careful to keep below
> the transition temperature, it too disappeared and the physics
> department had to explain to De Beers how their diamond was now a
> small piece of cast iron (or more correctly cementite) in the middle
> of a stainless steel platter, search on cast iron eutectic mixture.
>  
>  
>   
>
> Don't leave your wife's jewels around in a fire.
>     
>
>  
> And this story featured in a novel about a girl casting her diamond
> engagement ring into the coal fire, regretting it but only finding a
> blob of gold in the ashes next morning, a young lecturer wanted to
> test this but De Beers wouldn't co operate!
>  
> IIRC diamond auto ignition point in pure oxygen is ~700C and someone I
> trust implicitly has told me he has preheated a diamond to ~400C and
> burned it by dropping it in liquid oxygen, he, like Tom Miles, has
> money to burn ;-).
>  
> AJH
>  
>  
>