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wood kiln emissions

updated tue 31 dec 96

 

John Baymore on mon 2 dec 96

Hi all. Back from Japan. It was a wonderful experience. (more on that later
when I catch up on my life).

Swore I wasn't going to get into this one .......... but..............
(this might be long.....sorry)

----------------------------Original message----------------------------
From: "Wesley R. Handrow"
Subject: Re: EPA new clean-air standards

The new standard that the rule refers to might just cover kilns firing
with wood. The small particle size is produced through the incomplete
burning of fuel(soot), this would take place during reduction. I've not
had a chance to go through the new standards with a fine toothed comb ....
-----------------------------------------------------------------

It suprises many potters to find out that the EPA does have jurisdiction (and
always did) over the emissions of any fuel-fired kiln. We are no different in
that regard than any manufacturer of clay products. Give their local offices a
call (they are in the phone book) and ask a few questions....... the answers
will suprise you. Installation permits and operation permits! Huh?
Monitoring? Few potters are aware of the EPA air quality regulations and even
less are in compliance. Local town governments are not aware that the EPA would
have any concerns or jurisdiction, so they almost never discuss it in their own
permitting process on a kiln installation.

Because we're looked on as "artists", few connect our activities with the world
of manufacturing. So we all just "get away with it". Except the unlucky
ones........ who have a neighbor complain. (Keep giving those neighbors nice
pots folks .)

Wesley's comment "....might just cover...." is an understatement. The new regs
certainly cover wood fired kilns, since wood fired kilns were covered before and
did not meet the OLD particulate emission standard! If this proposed standard
is enacted into law, they are even more non-compliant. (BTW......We are in a 60
day "public comment" period on this one. Get out your pens.) There are two
areas that wood kilns typically "fail" on even under the old standards......
opacity of emissions and airborne particulate volume.

While it was possible by the use of a simple afterburner system to deal with the
opacity issue (mostly unburned gases) on many types of wood kilns (anagamas NOT
typically being one of them), the particulate issue is one that only very
sophisticated treatment equipment will solve. That equipment would cost far
more than the kiln, is dependant on electric power, and has ongoing operating
and maintenence costs. Pretty impractical in most situations.

BTW....... the comment "......small particle size is produced through the
incomplete
burning of fuel(soot), ......" also points to the fact that if you fire any type
of kiln really dirty (which there is NO reason to do), you will be producing
particulate, which could put you in violation of the new (or old) particulate
regs. Raku smoke would fall into this category too.

Luckily for those who fire with wood (and drain oil, etc.) and do activities
like raku and pit firings, the EPA is not particularly aware of potters. (Yet!)
Besides that, we are really small guns in the "pollution business". If there
are direct complaints though, they will investigate potters. And they have been
known to shut down wood and salt kilns.

I just got back from Japan and saw many beautiful noborigama sitting there that
can no longer be fired due to air pollution laws. (Lots of gas and electric
kilns now.) This was happening to the potters, while a short distance away huge
volumes of rice straw and rice husk was being burned in smoking open piles,
people were burning their garbage each morning in little smoking piles, smoke
stacks from the major industrial plants appeared to be spewing TONS of junk into
the air (more than seen in the US), small businesses had little (unscrubbed)
incinerators in their back yards burning all their garbage, and so on, and so
on.

Interesting. The potters certainly were shut down........ but other polluting
activities apparently continue on pretty much unhindered. This in a culture
that holds pottery production in the highest esteem (And I discovered you can't
really understand how high without being there for at least a little while!).

So what is the future for the US? Like in the economic battles in the academic
world....... art and mucic seem to have little political clout. They are the
first to go.

Did you know that you can already "buy" permits from the US government that
ALLOW you to pollute with things like S02?....... all you need is money. SO2 is
sold by the TON. How many tons would you like to put into the air? It is sold
like commodities. What artist/potter puts the eqiv. of even a single a TON of
SO2 into the air in a year? With this new proposal, we could become visible
"scape goats" because of our lack of political power, while others "better
connected" in the world continue pretty much unaffected.

It is interesting to note that where I live people heat with wood regularly.
Many of my neighbors burn 6-9 cords of wood in their dampered-down wood stoves
each winter. These slow burning wood stoves put a lot of particulate and CO
into the air, along with a host of aldehydes (that wonderful wood fire smell we
all love) and other "good stuff". Just down the street less than a mile, my
town has a large brush pile at the "recycling center" that they burn about once
a week that probably is the equiv. of about 7-10 cords of wood. There is a
local manufacturer that burns some of the scrap particleboard (full of
chemicals) in their own incinerator....... every morning as it "comes up to
temp", thick rolling black smoke fills the air.

So we come to the old "mother's argument" ................ Just because other
do it, does it make it right? No. But we need to keep the pollution thing in
perspective. If there are people around, we will create some pollution of the
environment. What is an acceptable level? Is art important? How much
pollution is acceptable to produce art? None? As much as we want? Got me!

Having only experiental knowledge firing wood kilns and heating with wood for
over 20 years, no exact scientific data, I'd venture to say that a potter firing
an efficient 200 cu. foot wood kiln six times a year probably produces LESS air
pollution than a household heating completly with wood in a woodstove. Do we
shut them both down? One or the other? Which one? Why?

Now, on to those nice "clean" electric kilns, which on the surface seems to be
the obvious answer to this dilemma. (A little oversimplification here for the
sake of whatever might be left of "brevity" .)

Fuel fired kilns use fuel to produce heat directly. Electric kilns use fuel to
produce heat indirectly.

In a fuel kiln, most people might burn something like propane. The combustion
systems on gas kilns are pretty efficient........ they result in overall maybe
85-95% combustion efficiency even when firing "reduction". Once the kiln is at
color, unless adjusted for reduction or oxidation, they can easily run at 100%
combustion efficiency. Propane is also a very "clean" fuel...... it doesn't
contain much in the way of pollutants like Sulphur. There is no appreciable
particulate material given off, unless "free carbon" is produces through very
inefficient combustion.

So in a gas kiln, if you burn 1000 BTU's of fuel, you put just about all of that
heat directly into the chamber, where it is used to heat the wares and the kiln
chamber. You give off a certain amount of CO2, CO (if in reduction), unretained
heat, and small trace amounts of other materials.

Electric generation involves a couple of scenarios..... in one case coal is
burned and in the other radioactive material decay produces heat. Taking the
coal plant first:

Coal (containing lots of things like sulphur and particulate matter) is burned
to create heat that is used to make steam from water. This conversion is not
very efficient...... nowhere like using the heat directly. So we have burned
the same 1000 BTU's of fuel, but have gotten less than that amount of energy
equivalent back "stored" in the steam produced. We have added 1000 BTU's worth
of CO and CO2 to the air, some waste heat, and also some SO2 and particulates.

Then the hot steam is used to turn a turbine, with all it's attendant gears,
shafts, and so on that impart some friction losses....... again ineffieient
conversion of energy. The turbine drives a generator, which again is a bit
inefficient at making the mechanical energy into electruicity. Then the
elecricity is fed into the transmission wires to get it to the kiln..........
and the transmission losses are pretty large.

So if you burn that 1000 BTU's of unrenewable fossil fuel at the coal fired
electric generating plant, you then SUBTRACT all the effiency losses in order to
get the "real" useful heat at the kiln chamber. The total losses are quite
large. So only a fraction from that original 1000 BTU's burned are actually
released in the electric kiln chamber to heat the kiln and pots. So if you
needed that 1000 BTU's of heat in the kiln, you needed to burn MORE than 1000
BTU's at the coal plant to get the equiv. of 1000 BTU's at the kiln.

So, in an electric kiln (hooked by a wire to a coal fired electric plant) you
have burned more non-renewable fossil fuel than you would have had to if you
burned it directly at the kiln site, and (even with all the scrubbers the law
demands) have put a lot of things like fly ash and particularly SO2 into the
air. (And I can buy the right to not scrub the effluent real well if I have the
money.)

We forget that the "firebox" of an electric kiln really exists..... it is just
located a LONG, LONG way from the chamber . So from my point of view, the
electric kiln just hides the real impacts of firing pottery....... and when you
look at the issues of efficient consumption of non-renewable fuels and air
pollution put together, I think direct fuel burning is probably the more
ecologicaly sound.

Heck....... if I had burned the coal directly in the kiln, even without the
scrubbers it might have been an environmental "wash", since I would have used
far less coal. An interesting thesis paper topic here!



Now on to the nuclear powered electric kiln :

When someone tells me how we are going to safely get rid of the radioactive
waste we are creating at nuclear power plants (at an alarming rate), then I'll
agree that nuclear is "non-polluting". Hiding it in cans (or cracks) in the
ground is NOT acceptable. Until then, I think it is the WORST polluter of our
environment. It is just that we are hiding the real impact of the generation of
power. Chernobyl was just a "warning shot" across our bow on one of the danges.
So a nuclear powered kiln , from my point of view is a real polluter.

Sorry, but I think my wood kiln is clean by comparison. At least I see right in
front of me when it is smoking more than I want it to, and can adjust the
stoking. And I am intimately aware of the "price" of my pottery making.



In addition, generally American electric kilns (the Japanese make some very well
insulated ones) are woefully underinsulated; 2.5"-3" IFB compared to the typical
7-9" in a fuel fired kiln. So heat energy is being wasted big time when firing
most electric kilns. Wasted heat is fuel burned that does not have to be
burned....... thermal pollution, CO2 created, and fossil fuel depleted. (Or
worse, more radioactive waste created than needs to be.)

So those who promote electric kilns as a "clean" alternative are not really
accurate. They just are not seeing the real environmental impacts as clearly in
their backyard (a true case of NIMBY anyone?). The acid rain being created by
the coal fired power plant in Ohio is one of the impacts of the electric kiln.
So is the INEFFICIENT consumption of non-renewable fuels. In most cases, so is
the generation of radioactive wastes that we don't know what to do with.

These concepts are, I think, important ones to get into the hands of local
governments that easily allow electric kiln installations with few questions but
balk solidly at any fuel fired kilns because they "pollute".

Then we get into the area of renewable vs. non-renewable energy sources. A wood
kiln certainly puts particulate matter into the air, but the fuel source is
completly renewable (and often is scrap wood). A natural gas kiln uses up a
non-renewable resource, but puts little particulate into the air. An electric
kiln uses up non-renewable resources and also puts SO2 and particulates in the
air. Which is better for the environment?

Or better yet..... is pottery making an "art form" that has outlived it's life
expectancy on this planet? Can we no longer afford the luxury of burning large
quantities of fuel (either renewable or non-renewable, directly or indirectly)
to make pots? WOW!....... scary thought.

Or is the real issue here that there are just too many people on this fragile
ball, not what we are doing while we are here?

This whole mess is a real toughie. I certainly don't have the answers. I do
think that we, as a group, have to be more concerned with this issue, since at
some point the government is going to tell us what we can do. They have the
right and the laws already....they just have not exercised that right through
enforcement yet. Can we as a group affect the laws? Do we have enough clout?
I don't know.

I am greatly interested in this issue and am throwing out these ideas to start a
discussion .......... please comment.



............................john

John Baymore
River Bend Potery

76506.3102@Compuserve.com

PS: There is another discussion thread going on mentioning getting rid of toxic
glaze wastes by firing it into a "blob" that is sort of related to this air
quality discussion. The EPA has complete, specific jurisdiction on this subject
too. Email Monona Rossol of A.C.T.S. at 75054.2542@Compuserve.com for a great
fact sheet about the hazardous waste regulations for small businesses (includes
potters). (It's available in the Crafts Forum library on Compuserve.)

PPS: BTW ........ I am working on a piece about this air quality issue for
print publication, so I must attach the following to this posting:

C1996 All rights reserved. May be freely posted to the CLAYART discussion
group list.

Don Sanami on tue 3 dec 96

John, it appears to me you are going all around the barn to get to the
undesirability of wood kiln emissions. Certainly thanking you for all of
the info but the fact remains that emissions are cumulative,travel for
vast distances,often,and are mixed with all the other crap floating
around. Rather than blame the criminals in industrial society,we must do
our small part to eliminate our role in polluting the planet. We gave up
wppd kilns several years ago for all the reasons you have advanced. New
times,require new methods and surely it is no sacrifice to work for the
common good. There is no question but what we must engage the most
drastic methods to extend our position to industry.
One additional point: True,we now fire electrically but I would point
out that our power is all generated hydro-electrically and that once the
dam and turbines are set-up and running and the kilns are built, the
system will last for many decades without breaking down.(One hopes!)
Art? Well,art exists in change not in stasis. New times.New methods.New
concepts of what constitutes Art. kinoko.

Paul Monaghan on wed 4 dec 96

Don Sanami wrote:
>
> ----------------------------Original message----------------------------
> John, it appears to me you are going all around the barn to get to the
> undesirability of wood kiln emissions. Certainly thanking you for all of
> the info but the fact remains that emissions are cumulative,travel for
> vast distances,often,and are mixed with all the other crap floating
> around. Rather than blame the criminals in industrial society,we must do
> our small part to eliminate our role in polluting the planet. We gave up
> wppd kilns several years ago for all the reasons you have advanced. New
> times,require new methods and surely it is no sacrifice to work for the
> common good. There is no question but what we must engage the most
> drastic methods to extend our position to industry.
> One additional point: True,we now fire electrically but I would point
> out that our power is all generated hydro-electrically and that once the
> dam and turbines are set-up and running and the kilns are built, the
> system will last for many decades without breaking down.(One hopes!)
> Art? Well,art exists in change not in stasis. New times.New methods.New
> concepts of what constitutes Art. kinoko.


John,

All good points. but where are you located and do you really get all
your power generated hydroelectrically. There are very few places on
earth that have hydro power exclusively. A great deal is from BURNING
fossil fuels and a small % from other sources such as nuclear.

Talk about potters small part in creating pollution so not to worry kind
of reminds me of the story of the starfish. This kid is walking along a
beach littered with thousands of stranded starfish and is throwing them
one by one back into thew ocean. An old man comes along and says, "hey
why waste your time? There are thousands of starfish on the beach and
you can't possibly make a difference". As the boy throws in another
fish he smiles and says, "it makes a difference to this one"!

Cheers,

Paul :-)
--
Paul J. Monaghan email: paul@web2u.com

WEB2U Productions --- http://www.web2u.com

The "COOLEST" Site on the WEB

FREE email to SANTA on www.web2u.com

Gavin Stairs on wed 4 dec 96

....
> One additional point: True,we now fire electrically but I would point
> out that our power is all generated hydro-electrically and that once the
> dam and turbines are set-up and running and the kilns are built, the
> system will last for many decades without breaking down.(One hopes!)
....

Hydro electric power is not completely impact free. Recent studies from a
test site on the Manitoba/Ontario border area (a test site being shut down
for "economic" reasons, btw) has shown, for example, that an improperly
inundated storage lake can produce large amounts of greenhouse gases for a
long time. This comes from the vegetable matter which is drowned. I would
extend that thought to recognize that this vegetable matter must in any case
be harvested and either burned (--> CO2,CO, etc) or otherwise used (highly
unlikely to be 100% used as, eg lumber). This must result in an equivalent
environmental impact. Plus, there's all that landscaping of former animal
(human) habitat. And the mining of limestone, iron ore, copper ore,
petroleum products, etc, for the concrete of the dam, the generators and
transmission lines, not to mention the poisons used to keep the power lines
clear. Am I being clear enough? There is no currently widespread method of
generating electricity for power nets that may be considered environmentally
friendly.

Perhaps the best systems for generating electricity, which are not
particularly widespread yet, are high efficiency gas turbines. These are
considered by some to be relatively good because: they are small and locally
sited, meaning that the power is not transported long distances; they are
relatively pollution free, since their fuel gasses are more or less fully
combusted at low temperatures; they can use virtually any available fuel
gasses which might otherwise be vented as a waste, or be derived from local
low grade sources (eg., conversion from soft coal, waste digestor methane,
blow-off oil well gas, etc.) This last is the key: it is equally possible
to use an inherently dirty fuel.

One might also add the traditional low impact sources: wind and solar.
However, it would be wise to check carefully the life costs of all the
elements of such systems before making claims.

It seems to me that the fundamental problem here is sheer numbers: there
are too many of us using energy. Whatever we do, we are bound to have an
impact. From this, it would seem that the environmantally correct approach
for any kiln operator would be to work toward high efficiency in whatever
firing system is employed. Sufficient, but not excessive, insulation;
sufficient, but not excessive, ventilation; efficient firing cycles;
efficient batch sizes; efficient oven design (low internal heated mass);
efficiency in learning and testing, so as not to have to discard fired ware;
and finally efficient power supply. This last is the one where you can
consider the overall environmental cost of your heating system, be it
electric, petrofuel, or biofuel.

Mind you, all or the above is not much more than a band-aid. We are
probably overloading the world's carrying capacity for all of this stuff by
factors of tens, whereas these measures, taken together, can't have more
than a factor of two or a few effect. The real answer is not to consume
power, produce pollutants in the first place, and not just in respect of
ceramic work. This is not a real possibility, I suppose.

Clearly, this is not a simple question, nor is a potter likely to be well
versed in all the contributory technologies. Nor is the owner of a kiln
likely to be able to replace it on these grounds alone, should a more
eco-friendly device become available. Nor are government regulations
neccessarily going to indicate the best alternative, though they may require
one approach over another. I suppose the best that can be asked is that we
all become more aware of the consequences of what we do, and gradually work
toward bettering our own situations.

Bye, Gavin Stairs