neutral (adjective) def. a position of disengagement; a state of no activity or development
What is "carbon-neutral" fuel? There is only one usable (non-polluting) carbon-neutral fuel: hydrogen.
There is no such thing as a carbon-based carbon-neutral fuel. This is a nonsensical oxymoron.
Neutral means not used. Thus a fuel cannot be both carbon-based, and carbon-neutral.
The whole idea of "carbon-neutrality" has nothing to do with combustive fuels anyway. Instead, the CN
concept has to do with the means of creating usable energy without having to burn something. For
example: wind, solar, hydroelectric, nuclear, and geothermal sources are actually carbon-neutral, since
they do not require a chemical oxidation/reduction reaction to create energy. No flame, no air pollution.
People who burn wood have effectively hi-jacked this term "carbon-neutral," when they should label it
"carbon-offset." They should not call wood-burning "carbon-neutral." It simply cannot be so, by definition.
It is claimed that since trees grow, it is acceptable to burn wood, since it is replaced by new trees, in
new wood, which is formed naturally from CO2 re-sequestered from the atmosphere, (unlike mined
'fossil' fuels, which do not) But even this carbon-offsetting idea remains an unproven theory.
In order to better understand the macro scale of this, we will create a small model: a simplified one-tree
model. One tree, chopped down, has acquired and stored several years worth of solar energy. Combustion
of that tree, in hours, releases that energy, as well as a large amount of CO2 into the atmosphere.
Without tree replacement, we have increased greenhouse gases, the same as if we had burned coal, oil,
or gas. With replacement of one tree sapling, we have not done much at all to compensate for this emission,
that is, reduce present atmospheric CO2 concentration. But with the replacement planting of hundreds of
saplings, we may possibly come close to achieving an actual offsetting. But who does this? Are the
woodburners actually going out and planting these new trees?
True carbon-offsetting requires quite a dedicated, conscientious effort on the part of the woodburner:
The burner must faithfully re-plant hundreds of saplings per year, in order to maintain a true carbon offset.
A newly-planted sapling cannot possibly sequester a similar amount of CO2 as a felled 20-30 year old
mature tree. But acres of saplings might. But is anyone planting these trees?
I have done some calculations of the thermodynamic process of carbon offset wood burning. In order to
claim a true carbon offset, the woodburner must continually replace trees on a plot of land of at least 29
acres. And that effort will heat only a small 860 sq. foot bungalow style house.
(The calculations are published below.)
But there are obstacles to this controversial offsetting:
• A lot of people do not live in such small houses, they prefer the larger 2,500 sq foot monsters, which
would require 62 acres of usable, available trees.
• Not many people actually live on, nor own, sixty acres of land. (Many woodburners have 1-10 acre lots.)
• An actual effort must be made to replant trees on one's own land, hire someone to plant trees on their
land, or on public lands. Better, they should get a job in forestry, planting thousands of trees (better yet,
volunteer to plant those trees) Those thousands of trees can be, at least in part, the solution to global
warming. (as would be not cutting them down at all)
The Energy Advocate wrote:"Connecticut has lots of trees that could be burned. But how fast does the forest renew itself?
You can continuously get about 1/2 cord per acre per year of hardwood from Connecticut's
forests. Note: 1/2 cord represents a certain amount of energy: 15.5 billion joules. 1 year is a
certain amount of time: 31.6 million seconds and 1 acre is a certain area: 43,560 sq. feet =
4047 sq. meters. The acre produces about 500 watts (not electric!); the average power density
is about 0.12 watts per square meter." Copyright © The Energy Advocate
My calculations were close to the Energy Advocate's for the acreage power density. I have used their
500W/acre figure. (Thank you E.A.) (I will publish my own acreage/ energy calculations in another post.)
(note: power = energy/time) that is: 1 watt = 1 joule per second
References:
http://www.energyadvocate.com/firewood.htm
http://en.wikipedia.org/wiki/Carbon_offset
Using Carbon Offsets to Neutralize Your Emissions
http://www.davidsuzuki.org/Climate_Chan ... eutral.asp
Biofuels not necessarily all that green
http://www.davidsuzuki.org/about_us/Dr_ ... 140701.asp
Physics, Serway-Faughn, Saunders pub. "Laws of Thermodynamics"
With every family requiring 60-acre plots (just for fuel) and another 20 (for food,) such a plan as carbon offsetting, which
may have worked for Colonial America, but does not seem to work well for the overcrowded, overpolluted 21st century.
