[Terrapreta] Fw: "open-air dirt mound kiln"
joe ferguson
jferguson at nc.rr.com
Wed Oct 3 09:46:09 EDT 2007
Sean K. Barry wrote:
>
> ----- Original Message -----
> *From:* Sean K. Barry <mailto:sean.barry at juno.com>
> *To:* Robert Klein <mailto:arclein at yahoo.com>
> *Sent:* Tuesday, October 02, 2007 5:11 PM
> *Subject:* Re: [Terrapreta] "open-air dirt mound kiln"
>
> Hi Robert,
>
> You will have to study this more carefully, I think.
>
> As, I see it there are three possibilities with the operation of a
> "dirt mound kiln";
>
> 1) After and if pyrolysis commences, appropriately limiting the oxygen
> intake and "producer gas" with an H2, CO, CO2, N2, and CH4 content
> close to what I predicted will vent, unburned, from the kiln to the
> atmosphere (no flames). This may leave maybe 25% of the dry biomass
> weight in charcoal/ash (~40% by volume). The rest of the matter from
> the biomass WILL vent to the atmosphere as "producer gas". Unless it
> is capture and burned in a flame (a "flare"), then it will go
> unchanged into the atmosphere, and very fast! Free hydrogen gas at
> atmospheric pressure and temperature has a buoyancy such that it rises
> at 17,000 miles per hour from the surface. This is faster than escape
> velocity.
Where on earth did you get that number? URL, please?
> The emissions gases are "hot".
>
> 2) Enough oxygen will enter the dirt mound and most of the biomass
> carbohydrates will completely combust and vent to the atmosphere as
> CO2 and H2O, leaving little or no charcoal and the rest as white ash.
>
> 3) The oxygen intake is so limited that the "burn" quenches before
> pyrolysis begins, leaving some combusted biomass and some raw
> un-combusted biomass. Most of the exhaust will be CO2, H2O and carbon
> soot (smoke). The pyrolysis reaction can be quenched too, but this
> would mean that the flow of oxygen into the mound kiln would almost
> have to be completely blocked.
>
> You may not agree with any of this analysis. Hopefully, if you ever
> try this and want to have it adopted on a large scale by other people,
> then you will figure out a way to measure the emissions from this
> "dirt mound kiln".
>
> My stated opinion now, still, and before is that The efficiency of a
> "dirt mound charcoal kiln" (charcoal mass/feedstock mass) will be low
> and it will vent significant GHG in operation, if it can be made to
> work at all.
>
> Richard Haard and Larry Williams tried this (on the 'terrapreta'
> list). They did not know what I have been trying to tell you when
> they did it, either. They had some trouble making it work, although
> they finally were able to produce some charcoal. Clean (in the
> limited or no potent GHG sense), efficient pyrolysis of biomass IS NOT
> EASY. It is certainly not as easy as piling up corn stalks under root
> balls and lighting it on fire.
>
> Regards,
>
> SKB
>
> ----- Original Message -----
> *From:* Robert Klein <mailto:arclein at yahoo.com>
> *To:* Sean K. Barry <mailto:sean.barry at juno.com>
> *Sent:* Tuesday, October 02, 2007 4:08 PM
> *Subject:* Re: [Terrapreta] Biochar Packing Strategies
>
> Hi Sean
>
> I will add one quick comment at the moment. The
> earthen kiln that is constructed would be a closed
> shell including a topping of dirt. This will tend to
> naturally grab the heavies coming off the hot zone.
> And the operator would stand by to throw dirt on any
> breakthroughs.
>
> As you also pointed out, the shell is naturally leaky
> to gases, including oxygen. Thus it is reasonable to
> suppose that there is a steady but slow supply of
> oxygen which sustains the burn.
>
> I suggested that the burn is initiated through the
> expedient of emptying a bowl of red hot wood coals on
> the top of the stack, tipping the bowl on top of the
> burn and covering same with mud. This prevents the
> burning charge from been stifled as the charge
> migrates to the bottom of the stack.
>
> This hot spot will draw in oxygen through the stack
> and force production gas into the walls of the
> glowing chimney been created.
>
> Now I want to talk about the stoichiometry of the
> production gases. The gases will burn preferentially
> with the hydrogen and methane burning first,
> especially since they are been produced at a high
> temperature as you pointed out.
>
> This means that the methane and hydrogen end will be
> substantially reduced throughout the burn. The dirt
> shell helps a second time by slowing the exit of the
> gases.
>
> And yes there will still be leakage.
>
> Field trials can resolve the actual numbers relating
> to a well managed biochar burn. At this point,
> though, I suggest that light flammable gases will be
> much less than anyone imagined.
>
> By the way,has anyone determined the methane
> production of a smoldering forest floor that is the
> result of a forest fire or a slash and burn operation?
> It will clearly be at least equivalent to the
> carefully controlled earthen kiln as described. Such
> a global calculation will actually give us an upper
> limit to the amount of gases we want to permit
> globally since this method can replace and eventually
> displace slash and burn.
>
> regards
>
> Bob
>
>
> --- "Sean K. Barry" <sean.barry at juno.com
> <mailto:sean.barry at juno.com>> wrote:
>
> > Hi Robert,
> >
> > The pyrolysis reaction (otherwise known as
> > destructive distillation and/or partial combustion)
> > of biomass in air as the oxidant, generates
> > "producer gas". "Producer gas" is a mixture of
> > exhaust gases from complete combustion; Carbon
> > dioxide gas-CO2 and Water as a gas-H2O, un-reacted
> > inert gases; Nitrogen gas-N2, and some energy
> > containing fuel gases; Hydrogen gas-H2, Carbon
> > monoxide gas-CO, and Methane gas-CH4. There are
> > also some longer string hydrocarbons (e.g. Ethane
> > gas-C2H4, etc.) and some vaporized tars (these are
> > even longer string hydrocarbons and/or aromatic
> > hydrocarbons, consisting partly of 6-carbon benzene
> > rings and parts of benzene rings) in very small
> > amounts (15-2000 ppm). There can be un-reacted
> > Oxygen-O2, too, if the reaction has been quenched
> > (dropped below the ignition temperature of the
> > biomass feedstock and the other gases).
> >
> > The "producer gas" is not generated in any large
> > volume until most of the water is driven out of the
> > feedstock and the temperature of the biomass exceeds
> > about 250 degrees C, when the pyrolysis reaction
> > begins in earnest. The reaction requires an input
> > of external heat (or enough input of oxygen to keep
> > combustion occurring in the feedstock) until the
> > temperature exceeds about 400 degrees C, when the
> > reaction becomes exothermic and generates enough
> > heat on its own, to continue without external energy
> > being supplied. Reducing the supply of oxygen to
> > the reaction STOPS the combustion of fuel gases and
> > thus increases the output volume of the fuel content
> > of the "producer gas".
> >
> > In an "open-air" kiln, a dirt mound with biomass
> > inside of it, there must be a supply of oxidant (the
> > air) until the reaction becomes exothermic.
> > Otherwise the "burn" will smolder out. During this
> > part of the process, Water as gas-H2O, Carbon
> > dioxide gas-CO2, and soot (exploded off particles of
> > carbon) will be the bulk of the output volume of the
> > exhaust. The feedstock will be is in a state "full
> > combustion".
> >
> > The atomic weight of Hydrogen gas-H2 molecules is
> > 1+1 = 2, ~10-20% by volume of producer gas
> > The atomic weight of Carbon monoxide gas-CO
> > molecules is 12+16 = 28, ~10-20% by volume of
> > producer gas
> > The atomic weight of Carbon dioxide gas-CO2
> > molecules is 12+16+16 = 44, ~10-25% by volume of
> > producer gas
> > The atomic weight of Nitrogen gas-N2 molecules is
> > 14+14 = 28, ~40-50% by volume of producer gas
> > The atomic weight of Methane gas-CH4 molecules is
> > 12+1+1+1+1 = 16, ~2-4% by volume of producer gas
> >
> > Hydrogen-H2 is the lightest and Methane-CH4 is the
> > second lightest of these gaseous components. Only
> > if the oxygen is limited and there is not complete
> > combustion will there be any fuel gases left from
> > the reaction. There has to be flame to burn the
> > fuel gases. If there is no flame, then the fuel gas
> > components will rise out of the pyrolyzing biomass
> > and emit right into the open atmosphere.
> > This is a measurable fact, not a hypothesis.
> >
> > >At the time I made any such comment, this was a
> > very
> > >sleepy group and you had not weighed in. And you
> > are
> > >still the only person who has chosen to not agree
> > so
> > >far.
> >
> > This is not true, Robert. Adriana Downy at BEST,
> > Tom Miles, and Michael Bailes, have all voiced the
> > same opinion as me about Methane-CH4 from a
> > pyrolysis reaction. They said it in response to you
> > too. Do you need for me to produce those postings?
> > I know Stephen Joseph at BEST and Danny Day at
> > Eprida would agree with me on this too. Tom Reed
> > and Aqua Das at the Biomass Energy Foundation, Dr.
> > Michael ANtal, Jr. at the University of Hawaii have
> > all discussed this in their very close work with
> > biomass gasification and biomass-to-charcoal
> > reactions. I have read from ALL of these peoples
> > work. They and the others on this list who really
> > understand what a pyrolysis reaction in biomass is
> > know that what I am saying is true. Methane-CH4
> > emissions from a pyrolysis reaction at only 2-4%
> > levels are still potent GHG contributers.
> >
> > Just because some do not respond to you does not
> > constitute agreement with you. Just because you
> > miss or ignore the contradictory responses does not
> > constitute agreement with you. I am not a member of
> > the "sleepy" part of this group. I am not
> > disagreeing with you based on just being contrary.
> > I am arguing a valid point with you. I disagree
> > firmly and I can back up what I say about it. You
> > can't believe I think it is fair for you to go to
> > your blog and say I and everyone else here on the
> > 'terrapreta' list agrees with you.
> >
> > Robert, the troposphere is the lowest part of the
> > atmosphere. Methane-CH4 concentrations in the
> > atmosphere from the troposphere all the way up
> > through the stratosphere and ionosphere are rising
> > and have been rising for some time. Methane-CH4 is
> > decomposed in the atmosphere by reactions with
> > oxygen, just like combustion. The half-life of
> > Methane-CH4 in the atmosphere is ~ 7 years. That
> > means it takes ~7 years for only half of the
> > Methane-CH4 to decompose. It does not all decompose
> > within 7 years. Methane-CH4 has a much greater
> > ability to absorb and reflect infrared radiation
> > shooting up from the Earth's surface, than
> > Carbon-dioxide does.
> >
> > Natural gas is predominantly Methane gas-CH4, some
> > Carbon monoxide gas-CO, and some Hydrogen gas-H2.
> > When we burn it, those fuels are "fully combusted"
> > in flames (that is evidence of the exothermic nature
> > of combustion) and the fuel gases are gone,
> > converted into exhaust gases, CO2 and H2O. That is
> > also accepted chemistry and a measurable fact. I
> > have told you that Methane-CH4 emissions from a
> > pyrolysis reaction can be "flared". That means
> > burning them. No flames means emission of the
> > un-burned gases, including Methane-CH4. It is that
> > simple.
> >
> > I suggested to you that you could read
> >
> http://en.wikipedia.org/wiki/Methane<http://en.wikipedia.org/wiki/Methane
> <http://en.wikipedia.org/wiki/Methane%3Chttp://en.wikipedia.org/wiki/Methane>>
> > and
> >
> http://en.wikipedia.org/wiki/Green_house_gas<http://en.wikipedia.org/wiki/Green_house_gas
> <http://en.wikipedia.org/wiki/Green_house_gas%3Chttp://en.wikipedia.org/wiki/Green_house_gas>>
> > to get a better understanding of what I am reporting
> > to you. I do not believe that I am contradicting
> > anything that is said there. Those pages are
> > correct information, that is widely accepted and is
> > documented in several other reputable sources.
> >
> > Look here->
> >
> http://en.wikipedia.org/wiki/Global_warming_controversy<http://en.wikipedia.org/wiki/Global_warming_controversy
> <http://en.wikipedia.org/wiki/Global_warming_controversy%3Chttp://en.wikipedia.org/wiki/Global_warming_controversy>>
> > ...
> > Look here->
> >
> http://en.wikipedia.org/wiki/Climate_change_denial<http://en.wikipedia.org/wiki/Climate_change_denial
> <http://en.wikipedia.org/wiki/Climate_change_denial%3Chttp://en.wikipedia.org/wiki/Climate_change_denial>>
> > for even more information.
> >
> > This is an important issue to me, Robert. You can
> > dismiss it, if you want to. You sure seem to want
> > to. But, please DO NOT associate your views with
> > agreement from me anymore.
> >
> > Please note that I am not brow beating you in front
> > of the rest of this group. I want to, but I am not
> > doing it, because some of them get their panties in
> > a bunch over reading ti, thinking that I need to not
> > argue so vigorously with you anymore. You keep
> > coming back to me with claims that my views are
> > remarkable assertions and imply that they are just
> > opinions or unwarranted. I do present valid support
> > for what I say. Go ahead and read some of it. You
> > do not discuss this in scientific terms with me and
> > you do not rebut effectively anything I say.
> >
> > I appreciate any interest or traffic that you can
> > bring to the 'terrpreta' list. But, would you
> > please give me some level of respect by not saying
> > agreements with you were made with ALL of the
> > members on this list and then go post that to your
> > blog anymore?
> >
> >
> > Regards,
> >
> > SKB
> > ----- Original Message -----
> > From: Robert Klein<mailto:arclein at yahoo.com>
> > To: Sean K. Barry<mailto:sean.barry at juno.com>
> > Sent: Monday, October 01, 2007 5:47 PM
> > Subject: Re: [Terrapreta] Biochar Packing
> > Strategies
> >
> >
> >
> > Hi Sean
> >
> > Let us reply line by line to your concerns.
> >
> > --- "Sean K. Barry"
> > <sean.barry at juno.com<mailto:sean.barry at juno.com
> <mailto:sean.barry at juno.com%3Cmailto:sean.barry at juno.com>>>
> > wrote:
> >
> > > Robert,
> > >
> > > Everything you say is conjecture. For you to
> > say
> >
> === message truncated ===
>
>
>
>
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