B A HARPER on sun 19 oct 97
Hi everyone -
I am a potter and a student here at Northern Arizona University. I'm
beginning work on a paper about wood as a fuel from a potter's
perspective and am looking for opinions/concerns about this. What is
the future of wood fired kilns ? What is the responsibilty of the
wood firing potter in regards to the depletion of the source (using
"waste" wood, supplementing with gas, etc.) ? I have read Gil
Stengal's article, "Clean Air" in last month's CM, but didn't
understand what the "nonattainment" and "noncomplaince" zones were
and what they were based on. I am looking for information on
pollutants and hazards attributed specifically to wood kilns. Can
anyone suggest articles or books somehow relating to this ? Opinions
about regulations ? What are some of the alternatives that wood
fired potters have if regulations are tightened ?
I'd also be interested in hearing from other potters that wood fire
about how much wood they use, what type, how often, etc. Are there
any potters on Clayart that grow their own wood ?
Thanks in advance for any help.
Brian Harper
- from Flagstaff, AZ, where it snowed Oct. 11 !!!!
Sam Clarkson on mon 20 oct 97
Brian
It's my impression, and maybe some chemists out there will refute this,
that wood releases the same chemicals being burned as it does when it
decomposes in a forest or a landfill(obviously much more quickly when
burned.)
Most woodfirers that I know of use wood that is a waste product from
industry--molding makers, sawmills, etc, and is used as fuel by potters
instead of sent the dump to rot.
While this may to some seem environmentally destructive (smoky) to
some, when compared to coal burning and nuclear power plants which
create the electricity which we all consider so "clean"(just flip the
switch), those little puffs of smoke from the stacks of the woodkilns
across the country seem pretty insignificant to me.
If you are especially interested in potters who cultivate their own fuel,
check out pine mills pottery in east texas-they have a website.
although they use gas as well.
Akitajin \"Lee Love\" on tue 21 oct 97
Sam & Brian,
This is a pet subject of mine, I've talked about here off & on in
the past. There is a big ecological advantage in firing with non-waste
wood that is grown for the purpose of fuel. If a woodlot is kept to be
used as fuel, you end up with a net reduction of carbon in the air because
two thirds of the tree is left in the woods ( mostly underground) as roots
and scraps.
A friend of mine, who was an ecology adviser for Gov. Jerry Brown, was
working on a program with a partner, to make Minnesota energy
self-sufficient and part of the program included power plants that kept fast
growing trees (havested in 5 to 6 years) to serve as the fuel source for the
power plants. Switching to these renewable resources instead of using
gas, oil , coal or electricity that is also generated by nuclear power,
would go a long way in cleaning up our environment.
Buring waste wood is not as balanced, but if you don't drive your car
one day a week, you'll probably more than make up for it. Also, you can
plant trees that will help clean the air in the future.
/(o\' Lee In Saint Paul, Minnesota USA
\o)/' mailto:Ikiru@Kami.com
' Ikiru Pottery: http://www.millcomm.com/~leelove/ikiru.html
Gavin Stairs on tue 21 oct 97
Hi Brian and Sam,
It is a bit simplistic to say that the same stuff comes out whether the
wood is burnt or rotted in the forest. In burning, wood goes through a
process called pyrolysis, which means splitting by fire or heat. The wood
chemicals get broken down into smaller molecules, most of which become
gaseous in the flame, where they then burn. Some of these products do not
get burnt, which makes smoke. Smoke consists of partially pyrolysed
cellulose and lignin, some gases, carbon and ash. It also contains CO and
CO2, which are final combustion products, and traces of other final products.
Rotting in excess oxygen does not produce much free carbon, nor much of the
other partial pyrolysis products. It does produce CO2. The same amount of
CO2 is produced by either rotting or burning, neglecting the incomplete
combustion or humus production, and neglecting the amount of carbon that is
used directly by saprophytes (fungi, etc.), invertebrates and insects
directly at the rotting site.
Rotting in the absence of oxygen, on the other hand, produces other stuff,
like methane and free carbon, instead of CO2. This process eventually
results in beds of peat, lignin or coal, or natural gas and oil. Mineral
fuels.
Rotting is slow burning, but the slow fire does produce a much different
result, all told, than the fast fire. Mother nature has a better chance to
recycle the material of the wood in situ with rotting than with fire.
That said, the smoke from potters kilns IS pretty insignificant in the
grand picture. But don't forget that the first smogs of London and other
industrial cities in England (having the dubious distinction of being the
first such in the world) were from wood smoke, and that the killer smogs of
the late industrial revolution were from coal smoke only because all the
wood fuel had been burnt up. Potteries were great contributors to that.
We don't produce much pollution simply because we are insignificant
contributors to the gross product. We are nevertheless a small part of
that sad picture. It ill becomes us to become smug simply because we are
small. Our industrial counterparts are by no means small.
From time to time I see contributors to this list speaking of pottery as an
ecologically responsible, even beneficial, occupation. This is not
necessarily so, especially considering the relative inefficiency of studio
pottery firing. In firing pottery, we heat to temperatures almost
equivalent to those in blast furnaces. This means that we use energy at a
rate per unit mass similar to the glass and primary metal industries. By
contrast, plastics embody much less energy. To discriminate, one must
calculate the relative costs over the whole life cycle of the goods
produced, for all parts of the process. By this measure, a throw away
plastic or paper product might be costly, while a many times reused clay
pot might be cheap, but a recycled or long lived plastic piece might be
very much more cheap.
We are not necessarily the eco-darlings we may wish we were. I believe
that we should recognize the truth of what we do, whether good or bad.
This is not black and white. Pottery is to be valued for what it is; for
its beauty, durability, utility. Pottery is environmentally costly to
make. We should make some effort to make our pottery efficiently and well,
so that it has a good chance for a long, useful life bringing joy and
satisfaction to its possessors.
Gavin
At 08:58 AM 20/10/97 EDT, you wrote:
>----------------------------Original message----------------------------
>Brian
>It's my impression, and maybe some chemists out there will refute this,
>that wood releases the same chemicals being burned as it does when it
>decomposes in a forest or a landfill(obviously much more quickly when
>burned.)
....
stairs@echo-on.net
http://isis.physics.utoronto.ca/
416 530 0419 (home) 416 978 2735 (work)
Toronto, Ontario, Canada
David Hendley on tue 21 oct 97
Brian,
We have gone over all this on Clayart last summer.
Maybe you can access the archives (I don't know how to myself).
I, personally, feel GREAT about my wood firing.
My wood comes from a pallet mill.
If I don't retrieve it, it winds up either smoldering on a huge bonfire
or made into chips to be sent to a lumber (particle board) mill.
I live on 70 acres and have so many trees that I could fire my kiln forever
just by using dead trees.
But, it's not worth the effort.
Most winters I plant about 1000 pine trees on my property,
but they will never be used for kiln wood.
They are much more valuable as lumber, paper, or they
could end up at the pallet mill, where I could retrieve the
left over trimmings to burn in my kiln.
Contrast this with notoriously inefficient electricity used in
resistance heating applications, and notoriously under-insulated
electric kilns.
I think it is electric kiln users who should
be asked to justify, as you say, "the depletion of the source", which in
Texas is non-renewable natural gas.
This "pollution talk" is another example of government and
big companies taking freedom from indivduals.
The companies buy "pollution credits", and sell you
the products of their pollution.
Self-sufficient people cut them out of the (money) loop
and they don't like it.
Best wishes on your research and paper.
David Hendley
Maydelle, Texas
See David Hendley's Pottery Page at
http://www.sosis.com/hendley/david/
At 01:59 PM 10/19/97 EDT, you wrote:
>----------------------------Original message----------------------------
>Hi everyone -
>I am a potter and a student here at Northern Arizona University. I'm
>beginning work on a paper about wood as a fuel from a potter's
>perspective and am looking for opinions/concerns about this. What is
>the future of wood fired kilns ? What is the responsibilty of the
>wood firing potter in regards to the depletion of the source (using
>"waste" wood, supplementing with gas, etc.) ? I have read Gil
>Stengal's article, "Clean Air" in last month's CM, but didn't
>understand what the "nonattainment" and "noncomplaince" zones were
>and what they were based on. I am looking for information on
>pollutants and hazards attributed specifically to wood kilns. Can
>anyone suggest articles or books somehow relating to this ? Opinions
>about regulations ? What are some of the alternatives that wood
>fired potters have if regulations are tightened ?
>I'd also be interested in hearing from other potters that wood fire
>about how much wood they use, what type, how often, etc. Are there
>any potters on Clayart that grow their own wood ?
>Thanks in advance for any help.
>
>Brian Harper
> - from Flagstaff, AZ, where it snowed Oct. 11 !!!!
>
>
David Hendley
Maydelle, Texas
See David Hendley's Pottery Page at
http://www.sosis.com/hendley/david/
Joseph Bennion on wed 22 oct 97
Gavin's observations here are right on. As much as we would like to
believe other wise our activities as potters are environmentally
costly. I will always defend wood/salt as being no worse than the rest
and probably cleaner than electricity. My advice for hand craft
artists ( There are some loaded words.) is : If it doesn't come from
the heart don't put it in the kiln. We have enough commercial junk out
there with little more than a profit motive behind it. Lets do what we
do best: speak from heart to heart through the medium of clay whether
the pottery is useful or not.
Joe the Potter
===
Joseph Bennion "Never quit your day job."
PO Box 186 Jerry Garcia
Spring City, Utah 84662
801-462-2708
joe.the.potter@rocketmail.com
---Gavin Stairs wrote:
>
> ----------------------------Original
message----------------------------
> Hi Brian and Sam,
>
> It is a bit simplistic to say that the same stuff comes out whether
the
> wood is burnt or rotted in the forest. In burning, wood goes
through a
> process called pyrolysis, which means splitting by fire or heat.
The wood
> chemicals get broken down into smaller molecules, most of which become
> gaseous in the flame, where they then burn. Some of these products
do not
> get burnt, which makes smoke. Smoke consists of partially pyrolysed
> cellulose and lignin, some gases, carbon and ash. It also contains
CO and
> CO2, which are final combustion products, and traces of other final
products.
>
> Rotting in excess oxygen does not produce much free carbon, nor much
of the
> other partial pyrolysis products. It does produce CO2. The same
amount of
> CO2 is produced by either rotting or burning, neglecting the
incomplete
> combustion or humus production, and neglecting the amount of carbon
that is
> used directly by saprophytes (fungi, etc.), invertebrates and insects
> directly at the rotting site.
>
> Rotting in the absence of oxygen, on the other hand, produces other
stuff,
> like methane and free carbon, instead of CO2. This process eventually
> results in beds of peat, lignin or coal, or natural gas and oil.
Mineral
> fuels.
>
> Rotting is slow burning, but the slow fire does produce a much
different
> result, all told, than the fast fire. Mother nature has a better
chance to
> recycle the material of the wood in situ with rotting than with fire.
>
> That said, the smoke from potters kilns IS pretty insignificant in the
> grand picture. But don't forget that the first smogs of London and
other
> industrial cities in England (having the dubious distinction of
being the
> first such in the world) were from wood smoke, and that the killer
smogs of
> the late industrial revolution were from coal smoke only because all
the
> wood fuel had been burnt up. Potteries were great contributors to
that.
> We don't produce much pollution simply because we are insignificant
> contributors to the gross product. We are nevertheless a small part
of
> that sad picture. It ill becomes us to become smug simply because
we are
> small. Our industrial counterparts are by no means small.
>
> From time to time I see contributors to this list speaking of
pottery as an
> ecologically responsible, even beneficial, occupation. This is not
> necessarily so, especially considering the relative inefficiency of
studio
> pottery firing. In firing pottery, we heat to temperatures almost
> equivalent to those in blast furnaces. This means that we use
energy at a
> rate per unit mass similar to the glass and primary metal
industries. By
> contrast, plastics embody much less energy. To discriminate, one must
> calculate the relative costs over the whole life cycle of the goods
> produced, for all parts of the process. By this measure, a throw away
> plastic or paper product might be costly, while a many times reused
clay
> pot might be cheap, but a recycled or long lived plastic piece might
be
> very much more cheap.
>
> We are not necessarily the eco-darlings we may wish we were. I
believe
> that we should recognize the truth of what we do, whether good or bad.
> This is not black and white. Pottery is to be valued for what it
is; for
> its beauty, durability, utility. Pottery is environmentally costly to
> make. We should make some effort to make our pottery efficiently
and well,
> so that it has a good chance for a long, useful life bringing joy and
> satisfaction to its possessors.
>
> Gavin
>
> At 08:58 AM 20/10/97 EDT, you wrote:
> >----------------------------Original
message----------------------------
> >Brian
> >It's my impression, and maybe some chemists out there will refute
this,
> >that wood releases the same chemicals being burned as it does when it
> >decomposes in a forest or a landfill(obviously much more quickly
when
> >burned.)
> ...
> stairs@echo-on.net
> http://isis.physics.utoronto.ca/
> 416 530 0419 (home) 416 978 2735 (work)
> Toronto, Ontario, Canada
>
_____________________________________________________________________
Sent by RocketMail. Get your free e-mail at http://www.rocketmail.com
kinoko@junction.net on wed 22 oct 97
Thankyou,Gavin, Excellent post. It is well to remember that pollution is
additive and the reduction of any amount is valuable. As example: All
materials out-gas and this is greatly dependant upon temperature. Todays
new,plastic houses may be the worst polluters around,since they enclose
their inhabitants and we usually overheat rather than underheat,and thus
keep out-gassing to a minimum. I would suggest that,new
enclosures(houses,studios,even automobiles ) should be heated to a much
higher temperature than one reqires. Left closed for at least 4days.
Reducing the heat and thus reduce outgassing of materials. No doubt many of
the allergens now showing up are the direct result of over-heating.
D.Morrill>----------------------------Original
message----------------------------
>Hi Brian and Sam,
>
>It is a bit simplistic to say that the same stuff comes out whether the
>wood is burnt or rotted in the forest. In burning, wood goes through a
>process called pyrolysis, which means splitting by fire or heat. The wood
>chemicals get broken down into smaller molecules, most of which become
>gaseous in the flame, where they then burn. Some of these products do not
>get burnt, which makes smoke. Smoke consists of partially pyrolysed
>cellulose and lignin, some gases, carbon and ash. It also contains CO and
>CO2, which are final combustion products, and traces of other final products.
>
>Rotting in excess oxygen does not produce much free carbon, nor much of the
>other partial pyrolysis products. It does produce CO2. The same amount of
>CO2 is produced by either rotting or burning, neglecting the incomplete
>combustion or humus production, and neglecting the amount of carbon that is
>used directly by saprophytes (fungi, etc.), invertebrates and insects
>directly at the rotting site.
>
>Rotting in the absence of oxygen, on the other hand, produces other stuff,
>like methane and free carbon, instead of CO2. This process eventually
>results in beds of peat, lignin or coal, or natural gas and oil. Mineral
>fuels.
>
>Rotting is slow burning, but the slow fire does produce a much different
>result, all told, than the fast fire. Mother nature has a better chance to
>recycle the material of the wood in situ with rotting than with fire.
>
>That said, the smoke from potters kilns IS pretty insignificant in the
>grand picture. But don't forget that the first smogs of London and other
>industrial cities in England (having the dubious distinction of being the
>first such in the world) were from wood smoke, and that the killer smogs of
>the late industrial revolution were from coal smoke only because all the
>wood fuel had been burnt up. Potteries were great contributors to that.
>We don't produce much pollution simply because we are insignificant
>contributors to the gross product. We are nevertheless a small part of
>that sad picture. It ill becomes us to become smug simply because we are
>small. Our industrial counterparts are by no means small.
>
>>From time to time I see contributors to this list speaking of pottery as an
>ecologically responsible, even beneficial, occupation. This is not
>necessarily so, especially considering the relative inefficiency of studio
>pottery firing. In firing pottery, we heat to temperatures almost
>equivalent to those in blast furnaces. This means that we use energy at a
>rate per unit mass similar to the glass and primary metal industries. By
>contrast, plastics embody much less energy. To discriminate, one must
>calculate the relative costs over the whole life cycle of the goods
>produced, for all parts of the process. By this measure, a throw away
>plastic or paper product might be costly, while a many times reused clay
>pot might be cheap, but a recycled or long lived plastic piece might be
>very much more cheap.
>
>We are not necessarily the eco-darlings we may wish we were. I believe
>that we should recognize the truth of what we do, whether good or bad.
>This is not black and white. Pottery is to be valued for what it is; for
>its beauty, durability, utility. Pottery is environmentally costly to
>make. We should make some effort to make our pottery efficiently and well,
>so that it has a good chance for a long, useful life bringing joy and
>satisfaction to its possessors.
>
>Gavin
>
>At 08:58 AM 20/10/97 EDT, you wrote:
>>----------------------------Original message----------------------------
>>Brian
>>It's my impression, and maybe some chemists out there will refute this,
>>that wood releases the same chemicals being burned as it does when it
>>decomposes in a forest or a landfill(obviously much more quickly when
>>burned.)
>...
>stairs@echo-on.net
>http://isis.physics.utoronto.ca/
>416 530 0419 (home) 416 978 2735 (work)
>Toronto, Ontario, Canada
>
*****************************************
*****************************************
** Don and Isao Morrill **
** Falkland, B.C. **
** kinoko@junction.net **
*****************************************
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