Which is more polluting... A car or a wood stove?

Pagey said:

Six billion people exhaling CO2 every day. Sounds far, far more polluting to me. Better hope the world governments don't do the math on that one, or we might be facing some sort of population control. Oh, wait...

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You breathe out about a kg of CO2 a day. A car produces 8.8 kg of CO2 per gallon burned.

Source: Emissions in Grams/hour or day
Cigarette .4 grams/hour (0.8 grams/pack)
Gas or Propane Furnace .001 grams/hour ( 0.024 grams/day)
Oil furnace .02 grams/hour (0.48 grams/day)
Pellet Stove 2.4 grams/hour ( 56.6 grams/day)
Single Simulated Log 8 grams/hour
Certified Wood Stove 8.2 grams/hour (196.8 grams/day)
Non-certified wood stove 15.6 grams/hour
Fireplace-hardwood: 30 grams/hour
(36 lbs. or 16 kg burned over 3 hours.)
Fireplace-softwood: 59 grams/hour.
(31 lbs.or 14kg burned over 3 hours.)
Auto-with Catalytic Converter .66 grams/hour
Auto-without Catalytic Converter 3.5 grams/hour
Auto-smoking 6 grams/hour
Diesel 14 ton Truck or Bus >1994 36 grams/hour
Diesel Truck or Bus < 1993 70 grams/hour

seems the way to go is to use condensed wood gas as a fuel for our cars....need to find something without fuel injection prolly for a retro fit.

and just because something is natural doesn't mean its not a pollutant. anything, well, most things, in excess can be dangerous.....even water.. hydro-toxicity.

BeGreen said:

Very interesting graph. That would be fine particulate emissions, not CO2. Still it's an interesting comparison illustrating where we need to work first on air cleanup, fireplaces included. If they put ocean going boats on this chart, like some that call locally on the ports of Seattle and Tacoma, the particle emissions from bunker fuel would be way off of this chart.

PS: certified wood stove is listed at the top of the range. 2-4gms/hr is more typical.

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There are a few things that the graph does not take into account. For instance; extraction and transportation pollution, which you would think would be quite a bit more for some of the fuels listed.

If we're talking about CO2, wood-burning appliances are carbon neutral, tree growing absorbing CO2, yadda yadda yadda. Stove wins. Particulates a different story depending on stove, fuel, methods, more yaddas. Car wins (probably). Extra helping? Chili, hands down.

But if we really want to get into it, you need to look at production and transport of the firewood. I make all my own stove wood, and between the saws, splitter, and tractor, I'm at the gas station once a week. And that fuel is not carbon-neutral.

2-man saw and a maul, now we're talking!

EDIT: B-BAR beat me to the 'extraction and transportation' part

FyreBug said:

Back from the break... First of all there were some mention as to CO2 is a pollutant or not. It depends on how you define a 'pollutant'. Just about anything can become toxic in high enough a concentration. Let us just say to assuage some sensibilities the terminology should have been "higher rate of CO2 emmission" although it's a mouthful. And please do not take this too seriously, this is just a fun exercise. There's too many variables but at least it provides a bit of a picture. All numbers are metric it's easier to calculate. So here we go...

1L of gas gives off 2.88kg CO2 after combustion.
Or volumetric mass of gasoline = 0.75
Where 750g of gas = 2.88kg of CO2

in addition 1g of gas generate 13.35 Wh

Therfore 1lbl gas generate 6008W
But a 1lbl of wood generate 8500BTU = 2428W

It means that if it takes 15 Litres (4 US Gallons) of gas to travel 300 Kms (185 miles) it would take you 28.12kg (62 lbs) of wood to develop the same energy.

15L of gasoline will emit : 43,2kg of CO2
28.12kg of wood : 4.22kg of CO2

Which means a car emits about 10 times more CO2! Yah baby, my Ferrari does 150 miles per face cord!

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Good stuff. This doesn't even account for CO2 emissions from the production and distribution of gas does it?

FyreBug said:

And now for some slightly useless information.

15L of gasoline will emit : 43,2kg of CO2
28.12kg of wood : 4.22kg of CO2

Which means a car emits about 10 times more CO2! Yah baby, my Ferrari does 150 miles per face cord!

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I know this is all in good fun. Moreover, like most forum members, I do not consider burning harvested deadwood (or livewood replaced by new seedlings) as adding net CO2 to the atmosphere. Therefore, my only comment about FyreBug's calculations is that complete combustion of wood (at 20% moisture content) is going to produce roughly 10 times the amount of CO2 stated. Probably just a decimal point.....but who cares??

However, particulate matter emissions are threatening to become a much, much bigger issue. At the rate PM regulations are expanding worldwide (spurred by secondhand tobacco smoke and urban traffic PM health effect findings) most of us may well see a time that our children or grandchildren will no longer be able to sit around a campfire at school, scout or other youth camps because the organizers don't want to be liable.... Sorry, just realized I am going off topic.

To stay on topic: the proposed new EPA regulations still appear to allow approx. 10 times higher particulate matter emissions from stoves burning wood than from car engines running on a comparable amount (energy-wise) on diesel fuel. Although this may not sound too bad, one has to take into consideration that, in contrast with tobacco smoke and traffic-dominated urban PM, there are few if any reliable studies directly tying population-wide health effects to wood smoke (not talking about people with allergies or other uncommon predisposing conditions here).

I have researched pyrolysis/combustion processes as well as pollutant/health issues intensively for more than three decades and strongly favor a pro-active government role in protecting community health. However, what is urgently needed here are some relatively simple studies that can show whether it makes any sense to lump wood smoke in with the tobacco smoke and/or urban traffic PM threats. Oops, going OT again.......

Will try to bring some of this up in a separate thread, at some point.

Henk

Does anyone else have a problem the figures? Who did the testing on what machines? Based on what it says, most of the data doesn't meet EPA standards, especially the stoves, right???

I am voting for a coal fired car without scrubbers.

like i said .. electric cars ie: the volt , and the new nissan leaf, are pretty much coal fired i mean if you burn the coal to make the electricty isnt that like having a coal fired car? just playing devils advocate.

who cares

littlesmokey said:

Does anyone else have a problem the figures? Who did the testing on what machines? Based on what it says, most of the data doesn't meet EPA standards, especially the stoves, right???

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If you are referring to roughly estimating the CO2 yields per unit weight of wood, one does not need much testing since the chemistry is fairly straightforward as long as we are talking complete combustion: e.g. using a catalytic or thermal afterburner stove.

The literature says that wood contains approximately 50% carbon, on average. So, FyreBug's 28.12 kg of wood contains approximately 14 kg of carbon.

When carbon (atomic weight 12) reacts with two atoms of oxygen (atomic weight 16 each) the resulting CO2 molecule has a molecular weight of 44.
In other words, 1 kg of carbon produces 44/12 (3.667) kg of CO2 and 14 kg of carbon produces 14 x 3.666 = 51.333 kg of CO2.

Because there are always small carbon losses to other combustion products (creosote, soot, VOCs, CO), it seemed that FyreBug's CO2 weight (4.22 kg) could perhaps be off by a factor 10.

Henk

It matters not to me which is more polluting. I occasionally have to drive the car and I heat with wood and will continue to do so, albeit in a very efficient stove.

GIVE US THE DAMN RECIPE, so we call all polute equally. :coolgrin:

Off topic but here are figures for various home heating fuels from The Forestry commission in GB.

Kg CO2 per KWH
Wood logs,chips pellets 0.025 (modern EPA stove or not!)
Coal 0.291
Natural gas 0.194
Oil 0.265
Thanks,
Tom

jensent said:

Off topic but here are figures for various home heating fuels from The Forestry commission in GB.

Kg CO2 per KWH
Wood logs,chips pellets 0.025 (modern EPA stove or not!)
Coal 0.291
Natural gas 0.194
Oil 0.265
Thanks,
Tom

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O(K, so my British English is a little weak, and i speak American English, But the graph means Greek to me.

littlesmokey said:

jensent said:

Off topic but here are figures for various home heating fuels from The Forestry commission in GB.

Kg CO2 per KWH
Wood logs,chips pellets 0.025 (modern EPA stove or not!)
Coal 0.291
Natural gas 0.194
Oil 0.265
Thanks,
Tom

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O(K, so my British English is a little weak, and i speak American English, But the graph means Greek to me.

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What the figures say is that coal,oil,and natural gas heat produce ten times the CO2 per given unit of heat as burning logs, chips or pellets.

jensent said:

Off topic but here are figures for various home heating fuels from The Forestry commission in GB.

Kg CO2 per KWH
Wood logs,chips pellets 0.025 (modern EPA stove or not!)
Coal 0.291
Natural gas 0.194
Oil 0.265
Thanks,
Tom

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These British values for CO2 production from wood are meant to report carbon footprint data and already incorporate a more than 90% offset for renewable carbon fuels. The reason they don't totally offset wood as "carbon neutral" is that wood decomposition is a slow process, so that burning dead wood may lead to a temprary acceleration of CO2 released to the atmosphere. Moreover, some of the live wood might not have been replaced by new seedlings.

When using one of the straight CO2 calculators on the web, you will find approx. 1.7 kg of CO2 produced per kg of wood and 2.5 kg or more CO2 per kg of coal.

Henk

Not a lot of people are processing wood without the aid of fossil fuels in saws, trucks, etc

Hi! Do you have a link for this graph you posted? Just curious what the source is.

Is trailnotes your website? Great idea.

BrowningBAR said:

Source: Emissions in Grams/hour or day
Cigarette .4 grams/hour (0.8 grams/pack)
Gas or Propane Furnace .001 grams/hour ( 0.024 grams/day)
Oil furnace .02 grams/hour (0.48 grams/day)
Pellet Stove 2.4 grams/hour ( 56.6 grams/day)
Single Simulated Log 8 grams/hour
Certified Wood Stove 8.2 grams/hour (196.8 grams/day)
Non-certified wood stove 15.6 grams/hour
Fireplace-hardwood: 30 grams/hour
(36 lbs. or 16 kg burned over 3 hours.)
Fireplace-softwood: 59 grams/hour.
(31 lbs.or 14kg burned over 3 hours.)
Auto-with Catalytic Converter .66 grams/hour
Auto-without Catalytic Converter 3.5 grams/hour
Auto-smoking 6 grams/hour
Diesel 14 ton Truck or Bus >1994 36 grams/hour
Diesel Truck or Bus < 1993 70 grams/hour

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Texas Fireframe said:

Hi! Do you have a link for this graph you posted? Just curious what the source is.

Is trailnotes your website? Great idea.

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I do have a source for that info... somewhere. I'll try to find it again. And yes, TrailNote is my (and my business partner) website. I'm glad you like. Just trying to keep people safe.