Wood burning said to be worse than anyone thought.

[NNadir]

Here's an interview in which the "expert," being interviewed by a solar oven sales promotion group, says bad things about wood burning:

http://solarcooking.org/ghouse.htm

Wood burning - biomass burning - is thought to result in about 4 million air pollution deaths per year, mostly in the third world, although one would expect that such types of deaths also occur in places like Maine.

This of course, is not a serious link, inasmuch as it is an "off the cuff" interview and not a peer reviewed paper.

Still, this is the internet, and we can say anything we want.

[pretzel4gore]

1. foxnews says 'bush is god, worship him, or die!'

and they don't use the net to do it (public airwaves)...

[cali]

2. What crap.

I heat with wood, small, well insulated house, and I use only 2 cords a year. Yes, wood burning does contribute to air pollution, but it's not nearly the contribution of other sources. VT has a large number of people who heat with wood, but out air quality is pretty good.

[phantom power]

6. Wood burning pollution in the 3rd world occurs inside the house.

Wood is burned in a shack or hut, with no chimney, or an inefficient one. Smoke stays inside.

[Wilber_Stool]

3. I believe what they are talking about

are people that build a fire in a hut with no chimney. It wouldn't take long for that to kill any one.

[Canuckistanian]

5. Some of our local people are involved in Guatemala Stove Project

http://www.guatemalastoveproject.org/

There's dealing with just this issue.

[Trevelyan]

4. When people objected to my smoking, I would mention the smoke from wood

fires in the now luxurious fireplaces that only a few people have but they wouldn't argue about it only say disgustedly that it wasn't the same thing. hmmm, now I have sources to give them.

[DELUSIONAL]

7. There is solid research in peer reviewed journals

I was doing research on wood smoke -- because I have developed an extreme sensitivity to wood smoke -- specifically smoke from evergreen trees.

At the moment I don't have access to the dozens of journal articles that I photocopied -- but if a search is done on Medline or other medical research database I suspect that many of the articles would be listed.

Some of the research was done in Washington State -- because of the huge number of people who heat their homes with wood. The medical community was seeing huge increases in asthma and other lung disease in areas with high levels of wood smoke.

Hum I guess the US is really a third world country???

[NNadir]

8. I suspect you are right. Here is an article about benzene produced by

burning wood in a peer reviewed journal:

Large amounts of wood, wood waste, manufactured wood products are burned on grates to produce process heat and electricity in industrial boilers. Industrial combustion chambers generate high temperatures for relatively long residence times; however, emissions of volatile organic substances are of concern if the residence time, temperature, and turbulence are inadequate. The typical industrial plant does not measure volatile organic emissions, but does measure oxygen and carbon monoxide concentrations. With sufficient excess O2 and low enough CO, the organic emissions are thought to be acceptably low. For example, the Wisconsin Department of Natural Resources (DNR) specifies good combustion practice as maintaining CO less than 600 ppmv corrected to 7% oxygen plus furnace exit temperatures greater than 675 °C for 1.0 s.1 The purpose of this project was to determine the adequacy of this criterion with respect to volatile organic emissions for selected wood and manufactured wood products in a laboratory combustor of known flow and temperature characteristics. Manufactured wood products contain wood, wood...

...For lean combustion of plywood the benzene emission factor was less than 7 ( 5 íg/g of wood and the toluene emission factor was less than 3 ( 5 microgram/g of wood for furnace exit temperatures of 650-950 °C and a residence time of 0.5-1.5 s. For exit temperatures below 650 °C the benzene and toluene emissions increased rapidly with decreasing temperatures. When the residence time was 2-3 s, the critical temperature for rapid increase in benzene and toluene emissions was 450 °C. Emissions of formaldehyde were less than 20 ( 10 microgram/g of wood for lean combustion of plywood with exit temperatures above 500 °C and residence time of 1 s. For exit temperatures below 500 °C and for shorter residence times the formaldehyde emissions increased rapidly and emission factors of over 1000 íg/g of wood were obtained. There was little difference in formaldehyde emission between pure pine and plywood for lean combustion. Benzene, toluene, and formaldehyde emissions correlated with CO concentration, and for plywood emission remained low provided the CO was below 4000 ppmv. For pure pine, formaldehyde emission remained low when the CO was below 2000 ppmv.

http://pubs.acs.org/cgi-bin/abstract.cgi/enfuem/1996/10/i02/abs/ef950194h.html

Energy Fuels, 10 (2), 299 -304, 1996. ef950194h

This article implys that the hotter you burn wood, the safer it is, however I note that many fires are not monitored continuously for temperature, and undoubtedly there are health concerns created by some wood burning fires.

But you knew that.

Still, as in all cases, the burning of wood needs to be compared with alternatives. Wood burning is safer than burning coal.

Some remarks from the ExternE reports:

A range of about 0.7 - 0.8 c€/kWhth has been calculated for wood boilers, where the upstream chain contributes 20% - 30% to total damages. Particles and nitrogen oxides emissions contribute most, i.e. nearly 60% and about 30%, respectively, to total damages. The modern fireplace gives more than 1.5 c€/kWhth, mostly due to the high particle release. GHG contribute 7% or less to total external costs for modern wood systems, because the CO2 from wood combustion is compensated by tree sequestration...

http://www.externe.info/expoltec.pdf

The external cost of coal is three times larger. Since wood approaches (but does not completely obtain) greenhouse gas neutrality, it is to be preferred in the current crisis.

[dcfirefighter]

9. Life doesn't achieve greenhouse gas neutrality

being close is as good as we're going to get.

I'd like to know at what density of modern woodburning stoves does the air quality become significantly impacted - and a similar comparison for traffic.

IMO, a relatively dense neighborhood of electrically heated homes with 'decorative'/emergency wood burning modern stoves wouldn't have a significantly worse air quality than a similar, stove free neighborhood. New stoves, with secondary combustion chambers, are a far improvement over straight chimneys.

[NNadir]

10. I don't have the answer to that question.

Qualitatively, I know wood fires can be choking simply by leaving my home on a cold night.

My wife has basically banned wood fires in my house - although I love them - on the grounds that my kids have had lots of respiratory symptoms (colds, flu, strep) this winter.

I love the fires - and I rationalize them by noting that the use of my recirculating fireplace prevents the use of fossil fuels and that the wood is downed anyway - but I know the fires aren't perfectly good for our family.

[eppur_se_muova]

12. Really important details...ADDITIVES to wood products.

"Manufactured wood products contain wood, wood fiber, and non-wood additives such as adhesives, wood preservatives, and fire retarding chemicals. Secondary manufacturing processes can add plastic overlays, paints, varnishes, lacquers, fillers, strength additives, and dyes. Residue is in the form of edge trimmings, sawdust, sander dust, shavings, and fiber sludge which could be used to replace fossil fuels for steam generation at the industrial site. Eventually the manufactured products are discarded, and rather than going to a landfill, the wood products may be burned in a boiler.

Previous studies that looked at the pyrolysis products of sweet gum hardwood and lignin by Nunn2,3 show that the pyrolysis products can contain up to 2 wt % formaldehyde. The particleboard we selected was made from sawdust and contained 6% phenol formaldehyde resin solids. The plywood contained 2.5% urea formaldehyde resin. Because of the formaldehyde resin, there is concern that the formaldehyde emissions may be higher than in pure wood. Formaldehyde is considered a hazardous
air pollutant by the 1990 Clean Air Act. Under proper operating conditions a wood-fired, spreader-stoker boiler has low benzene and formaldehyde emissions; however, when the temperature and/or excess oxygen are too low, these emissions can be high.4"

The urea-formaldehyde and phenol-formaldehyde resins should be expected to produce formaldehyde on heating! Also, I would expect pine and other evergreens to be worst for benzene and toluene -- this is where tuprentine comes from, after all. Hardwood should be much better, I'll have to look up refs 2 & 3.

[jpak]

11. Modern pellet stoves are so combustion efficient

that they are exempt from EPA emission standards.

http://www.epa.gov/woodstoves/basic.html

Most new wood stoves sold in the US meet EPA emission standards.

While some stoves/heaters have catalytic converters, most have firebox designs that eliminate the need for them.

It's mo-rans that use fireplaces in suburban neighborhoods that contribute the most to wood smoke pollution...

:rofl:

[eppur_se_muova]

13. Thanks for the data link. nt

[dcfirefighter]

14. What is the density at which a suburb becomes a rural area?

And wood burning stoves would then be OK?

What is the trade-off balance for an urban-dweller's reduced use of oil (transport) but desire for a home-ey fire?

I would imagine that developed nation's homeowner 'ambiance' woodburning's effect on world pollution is negligible. While I can occasionally catch a whiff of woodsmoke in my suburban neighborhood, it's not until I get out in the sticks do I notice the ABSENCE of exhaust odors.

[jpak]

15. Pellet stoves are the only good way to burn wood in the 'burb's

http://www.hometips.com/cs-protected/guides/pellet.html

They emit very little particulate material (<1 gram per hour compared to 5 grams for EPA certified wood stoves) and don't require conventional chimneys.

People in the 'burb's would probably better off installing Energy Star windows and doors and stuffing more insulation in their attics though....

[Name removed]

17. Deleted message

Message removed by moderator. Click here to review the message board rules.

[dcfirefighter]

18. We're all counting on something 'new' to fix our problems

be it a fleet of new pellet stoves, or a fleet of new PWR's. We TRY to keep our proposed solutions within the realm of existing technology, pellet stoves are well within that realm. While the suburbs might not be killing us with woodsmoke - they are killing us with oil combustion - I doubt there is a living arrangement that regularly uses more fossil fuel than the process of getting goods & services into and out of suburbs.

As for woodstoves, there are many 'stove' projects out there trying to come up very very cheap home-made stoves for people in developing nations. (There are similar solar stove projects as well). While I personally support the need for nuclear power development in the industrial and post industrial world, I think that, in the developing world, greater strides towards sustainability could be made with changes in economic systems and reliance on intermittent renewables.

Water can be stored & pumped easily with intermittent power,
Water can be treated & purified relatively easily with biological & physical means, relatively easily.
Common chemicals can be purchased cheaply on the world market from countries with 'high powered' industrial infrastructure.
Food & Fiber can be grown sustainably, without chemicals, and using only hand tools and manual labor.
Locally Grown food requires no energy intense transportation network, nor does it require a high energy density fuel network
Most food can be stored by drying, curing, or canning. Locally produced food has fewer storage requirements.
It is possible to refrigerate food & medicine using only intermittent renewable resources. Thermal mass is cheap.
It is possible to heat a home in almost any climate using only passive methods.
It is possible to perform some cooling in almost any climate using only passive, or relatively passive, methods.

This sort of standard of living would be an improvement for much of the world, however, they would be regressive for most of the developed world. While the world doesn't need the developed world to maintian 4000 s.f HVAC'd houses or a 5000 lb SUV car culture, the world DOES need a relatively energy intense technology sector. The world, or more precisely, humanity, needs innovators building airplanes and rocketships. In the longest of views, humanity is doomed if it does not colonize beyond earth's bounds. In the more immediate terms, humanity is doomed if it's best and brightest are too busy growing their own food to work on eradicating disease, poverty, and warfare.

[NNadir]

19. I have no objections to what you say, really.

You have made excellent points, and you're right, I do advocate some "new" stuff. :-)

I stand corrected. I think the stuff I advocate is most cost effective, but I freely confess that I have backed myself into a corner because of some personal contempt.

Thanks for the correction on that score.

I do not believe, however, that it is really in the realm of reality to hope to escape the earth. The earth is what we have, what we will always have, and we should take care of it, because there really are no lifeboats, not at least for humanity at large.

Space travel is a very expensive (energetically) enterprise.

[dcfirefighter]

22. yes, there are more pressing issues.

And I never expect a 'lifeboat' situation, just multiple human populations in multiple ecologies on multiple planetoids. But, that's 99.97% scifi for now, and we both know our problems are 100% in the present.

I would certainly agree that 1) nuclear power is the only current technology that provides high quality, reliable, carbon-free energy, and 2) the 'externalities' of nuclear power are covered better than any form of fossil fuel.

I would also state that cities & towns are 'greener' than dispersed rural living and a whole lot greener than suburbs (though that is where I live). IMO, a collection of self-sufficent homesteads is an example of regressive civilization. As such, providing energy for cities & towns is generally easier done by specialists in a centralized location, rather than generalists (Harry Homeowner?) in dispersed locations.

I'm not entirely sure of the economies of scale regarding nuclear generation, but I believe that these costs are driven largely by licensing and NIMBYism - and as such, they favor HUGE multi-reactor sites: i.e. once the NIMBYism is overcome, communities are more than eager to get another reactor. Absent the NIMBYism, I think smaller reactors could be economic for smaller cites, especially if the design & licensing were amortized across many copies. IOW, a town of 50,000 in a rural area might have it's own 100 MW reactor, 'green' building codes, oil-free internal transport system, and railway connections. Such a town might be surrounded by 'off the grid' day farms.

[NNadir]

27. Again, I agree with most of what you say.

I think large reactor complexes can offer quite a bit however from a fuel cycling standpoint.

A large reactor complex having a few examples of various types of reactors, including some high temperature reactors to produce fluid fuels can offer certain economies of scale, including infrastructure overlap.

The large "nuclear park" strategy used in Japan is exactly this kind of strategy, although Japan, benefits from high population density, and of course, right now, Japan relies almost solely on thermal natural water moderated reactors.

In the case where humanity survives global climate change this mix would include, in my view, reactors with high neutron economy, including CANDUs, and high temperature reactors, high efficiency reactors, of which the molten salt reactor is a superior example.

I think it may be wise to have smaller reactors near smaller cities just as you suggest. I expect as the wolf nears the door that NIMBY attitudes will give way to more realistic approaches.

NIMBY has its greatest appeal in times of wealth and ease, but clearly those times are coming to an end.

I emphatically agree with you that cities and towns offer the lowest environmental cost. I, of course, am a suburban myself, but I do feel somewhat hypocritical because of that. I hope I can convince my wife to relocate to Brooklyn or Manhattan in our old age.

[jpak]

20. Yet another pathetic attempt to demean renewable energy technologies.

And all those poor people allegedly dying from wood smoke inhalation can afford multi-billion dollar nucular fuel cycles, reactors and modern electrical grids????

:rofl:

Pellet stoves have been around for years and so have EPA certified wood stoves.

They work, work well and heat homes for much less than the cost of nucular electricity.

[NNadir]

23. I am not trying to "demean" renewable technologies.

I simply note, by using something called "data" that they don't have very much meaning, when the unit is something called "exajoules."

As for "EPA certified," I note that the exhaust system on my automobile is also "EPA certified." That doesn't mean that my automobile is "good for the environment."

The external cost of wood burning, with respect to emissions has been calculated and can be found in a graphic representation on page 36 of this report:

http://www.externe.info/expoltec.pdf

If one is familiar with how to read bar graphs, one can easily assess the environmental effects of various forms of energy. The graph is available on page 36 of the 49 page report. Nuclear energy, in case people are incapable of seeing well, is the two tiny bars on the extreme right of the graph entitled "External costs of heating systems, associated with emissions from the operation of boiler/cogeneration unit and with the rest of energy chain."

The bar for wood burning is relatively easy to find. Just look for that really, really big bar at 6kW log burning systems. It's the second biggest one on the graph. The other wood burning external costs are right nearby. Their in that cluster that is about 3X bigger than "natural gas," and twice as big as "diesel."

Enough said.

[jpak]

25. That analysis doesn't apply to large modern wood-fired power plants

Maine has 415 MW of wood-fired power plant capacity that generates ~25% of the state's electricity.

They don't "burn logs"

They don't emit visible smoke (there is a 30 MW plant in my hometown - the neighbors don't complain).

http://www.epa.gov/globalwarming/greenhouse/greenhouse5/text/wood.text.html

and they emit less NOx and SOx than fossil fuel plants....

http://www.mainepoweroptions.org/GreenPower.htm

Enough said.

[NNadir]

28. Unquestionably there are some wood plants that are better than others.

Maine however is an energy province, and a single modern plant in Maine clearly doesn't represent the "wood burning" world as a whole.

The measured results in the link I have provided do not represent a model plant in the sparsely inhabited State of Maine. I also note that the link does not represent the global climate change costs - but only the pollutant costs - probably represented mostly by particulates. As I understand it, most of the cancer deaths worldwide associated with burning wood, numbering in the millions, have to do with particulates.

Personally, I think that wood burning is not as bad as fossil fuel use. I am generally supportive of anything that is close to carbon neutral, at least for the duration of the global climate crisis. If one doesn't need to truck wood very far, or spend too much energy grinding it into cute little pellets, I think it can be close to carbon neutral, especially when new trees are planted to replace burned trees, and where the soil is not overly depleted by hauling the nutrients in ash off the land. Certainly there are some locations, especially those with low population density, where wood burning is sustainable. In other places, notably those subject to deforestation, it isn't so good. Maine has an advantage that it is only #38 in population density. http://en.wikipedia.org/wiki/List_of_U.S._states_by_population_density I'm sure they can clear cut up there without clearing the entire state.

You are correct when you note that wood does not contribute very much to acidic pollution as represented by nitrogen and sulfur chemistry. This is an advantage, and a big one too.

Once and if fossil fuels are replaced, as they must be if humanity is to survive, I will be perfectly happy to debate the alternatives that have replaced them. Some clearly are better than others - and the suitability of various alternatives vary very much with location. I am very pleased that quantitative work is being done to evaluate energy forms. This is important policy information and the EU should be proud of their efforts in pioneering this approach, even if the results are not always what one would or wood expect.

Location is indeed an important parameter. Iceland and Costa Rica, for instance, both have excellent opportunities for geothermal energy, while Florida does not. Maine can live by wood burning; New Jersey (#1 in population density) can't. Florida, as I noted elsewhere, has an excellent opportunity for renewable energy from hydroelectric power if only it can capture the energy of the incoming water as the state submerges. One hopes they have plans for the shoreline dams to capture this huge surge of energy. This opportunity will not be available to states where most of the land is 20 meters above sea level.

[dcfirefighter]

24. Cost Comparison 20 MBTU / yr

Pellet Stove = $2,500 up front cost
Pellets 20 MBTU / ton
Efficiency 85%
Tons required 1.18
Cost per ton = $150
Cost per year = $177

Ground Source Heat Pump = $2,500 up front cost
COP = 4
Electricity Required = 1465 kWh
Cost per kWh (nuclear, retail price) = $0.08
Cost per year = $117

Pellet stove heat is more than 50% more expensive than nuclear-electric heat. This gap could be increased through use of district heating plans.

The externalities of nuclear power are largely captured (see NNadir's favorite Externe report).
The externalities of timber & forest products are largely subsidized, as are the transportation costs of moving tons of pellets from the Pacific Northwest to east coast population centers. The out of pocket costs for pellet stove use could be lowered by using dried corn, but the subsidized externalitites would be greater.

[jpak]

26. Sorry in New England the economics are a little different

http://www.lasvegassun.com/sunbin/stories/tech/2006/feb/03/020308495.html

<snip>

Put another way, the cost per million Btu for fuel oil is $23.47; for electricity, $39.73; for wood pellets $17.86 and for grass pellets provided by a producers' co-op to farmers who grow the grass, at $10.20.

<snip>

The average NE household that heats with electricity spends twice as much per year (~$4000) as households that heat with oil, gas or wood. (~$2000)...which is why virtually no one heats with electricity...and heat pumps aren't used because they would be covered with snow for much of the heating season (most winters anyway)...

[dcfirefighter]

29. Nuclear via GSHP is even better, using your numbers.

How much do trucks pay for highway use?
How much damage do they do?
How much diesel fuel is used to transport tons of pellets?
How much of an agricultural subsidy is available to new england grass growers - especially since real estate in new england typically requires a major subsidy or severe use restrictions in order for farms to be profitable.

I'm not sure of your mathematical experience or skill, but according to your price for wood pellets (@$17.86/MBTU) wood pellets are more expensive - $357 vs $177 than I calculated for 20 MBTU.

Electricity is more expensive up there - as high as $0.12 / kWh. Using your values and 12 cents / kwh, the comparison is now $357 (wood pellet) to $176 (nuke via gshp). If you want to leverage your agricultural subsidies (subsidies are NEVER sustainable), you could burn grass pellets for $204 per 20 MBTU, better than wood pellets, not as good as nuke via gshp. I concede that most New England homes would require more than 20MBTU, but the percentage differences would be the same:
subsidized grass pellets: 16% more expensive
wood pellets (probably from subsidized / public land timber): 103% more expensive (using your numbers).

Also, the GSHP can be used to heat water (wood stoves generally can't, not while remaining EPA compliant - too much cooling of the combustion chamber), and nicely, they can be used to air condition your house. A solar hot water system could be used in conjunction with a pellet stove, but that would be an additional expense - especially considering size required to heat cold winter water with weak winter sun, assuming someone was willing to sweep the snow off off the collectors.

GSHP (Ground Source Heat Pumps) would work fine in winter - their heat sink is the earth itself (ground source), which, even in New England, remains above 50 deg. F year round. Here is a link to a case study in Maine, of a 4300 s.f. house using 164 MBTU/yr. A normal sized house would use less, obviously. Because a GSHP can be used to heat water, off peak rates (less than $0.12/kWh) can be used to store heat energy in relatively inexpenseive thermal mass (concrete floors or water barrels). If all heating is done at off peak rates of $0.05 / kWh, pellet heat is 389% more expensive than nuclear via gshp.

[jpak]

31. According to that link the heating cost of the GSHP was $800 per year

which is significantly higher than $177 per year for your wood pellet cost estimate.

Not putting down GSHP, but pellet stoves offer more cost advantages over the long or short run - not to mention the taxes we pay to subsidize nucular each year...

[poopfuel]

32. and does anyone consider this as well about nuclear?

Coal and uranium mines can deduct up to 50 percent of their taxable income. In both instances, total deductions can frequently exceed the original investment costs of buying and preparing the land for resource extraction

[dcfirefighter]

35. That's a horrible rule

if you are talking about deducting the reduction in value due to the extracted wealth. Same with oil wells, I believe.

I just tax system would actually tax those people MORE for extracting natural value from teh Common-Wealth.

[dcfirefighter]

33. $800 for 8x the energy

$800 for 164 MBTU vs. $356 for 20 MBTU with pellets.
Or $4.88/MBTU(nuke via gshp) vs. $17.8/MBTU (wood via pellet stove)

No doubt we subsidize nuclear, as well as every other energy source. Such subsidies hide teh full price of energy - allowing people to consume more of it than they would if they had to pay 'full' price.

In the absense of subsidies, people would consume less, own fewer cars, etc: renewables would make up a larger fraction of energy production.

If you count allowing unchecked dumping of wastes as a subsidy, and full cost charging for emissions as removing subsidies, nuclear would be the cheapest constant source.

[jpak]

30. Ground source heat pump for $2500?? Try $20,000 LOL

http://peswiki.com/index.php/Directory:Home_Generation:Ground_Source_Heat_Pump

http://www.est.org.uk/myhome/generating/types/groundsource/

Conventional heat pumps "don't work that well" in subfreezing weather - that's why you don't see them in northern NE.

Pellet stoves rule...

:)

[dcfirefighter]

34. Unit Cost ~ $2,500

Installation cost, a bit more ;)
So, even at $20,000 (a very high value), at 100 MBTU a year, it would pay for itself vs. a pellet stove within 15 years, PLUS it:

Heats water
Has zone control (A $20,000 install would have multiple, hydronic zones)
Heats the whole house vs. one radiant point.
Provides airconditioning.
Doesn't require an annual delivery of fuel
Doesn't have to be cleaned out regularly
No risk of CO poisoning.

Cut out the A/C, zone control, etc. and you could get an install of $5000 for a small unit that would heat the sort of home that could be heated by a single pellet stove.

[depakid]

16. Anyone who's ever lived in a valley under an inversion layer

can pretty much tell you that wood fires are nasty enough on the ground level. It shouldn't surprise anyone that inefficient cooking fires would be even worse sources of unwanted emmissions.

[GumboYaYa]

21. We have heated our home this winter primarily with

solar thermal air heaters and wood fires. We are almost done with our second cord of wood and may get a third. As a result, we have used approximately 700 cubic feet of gas less than we used last year over the same period; some of that reduction is attributable to a warmer winter. While I know that burning wood creates some air pollution, I always assumed we were choosing a less pollutive way of heating our home. Was I wrong based on those numbers?