I have finished a paper looking at the CO2 output of 3 kilns and if they are carbon neutral. If you would like to download a Word document of the paper you can click here. It is about 29 pages long and almost 9,500 words. No brevity here. I don’t want to post parts of the paper since there are many footnotes that need to be read to understand the context. If you want to really understand how the figures were arrived at you should download the entire document. I will answer any questions about the figures if I can. After writing 29 pages I am not sure there is much I can add though. Below please find the summary and my opinion from the paper.
Summary.
Wood puts out more CO2 per unit of fuel used than other fuels. That is accepted in all analysis of fuel density that I looked at. Depending on the size of the kiln and the fuel used to generate electricity wood will sometimes throw out less CO2 per set energy amount if the kiln is fired with electricity. The smaller the kiln the more likely wood will put out less CO2 than if fired by electricity if the electricity is generated by coal. It should be noted that the trend is toward cleaner generation of electricity in the U.S.
Wood comes in a far second place compared to electricity generated by everything other than coal. On a lifecycle weighted basis wood comes in last with even coal far cleaner.
If a wood firer was only concerned with putting out the least amount of CO2 this paper shows wood isn’t the best fuel.
In order to be considered carbon neutral an individual wood firer would have to keep an amount of trees in reserve for a set amount of years. There are of course other offset mechanisms available but this paper didn’t look at them. The other offsets would probably be more appropriate for most wood firers. I only looked at using trees as an offset mechanism.
The acreage needed to be kept in reserve to keep carbon neutral ranged from 1.3 acres for the natural gas fired kiln profiled to 18 acres for my kiln.
There are some countries that have increased their forest coverage. The world taken as a whole is seeing 73,000 square kilometers being deforested each year. This trend is slowing.
My opinion.
Is it possible to be carbon neutral as a wood firer? It is absolutely possible. It is also absolutely possible to be carbon neutral firing with gas or electric. If you are using trees as an offset tool it is far more realistic to offset the CO2 for a gas fired kiln than it is for wood.
Having done this research will I switch fuels? No. I never considered myself carbon neutral and still don’t. I am not looking to motivate wood firers to change fuels. I would like to move the debate along. If a wood firer takes a theoretical position that since wood is renewable it is carbon neutral and therefore a desirable fuel the position is just that, theoretical. The playing field is very crowded and the competition is fierce for available offset resources. I think as the kiln moves up in size and firing frequency it becomes more difficult to show how one is carbon neutral. That isn’t to say everyone who fires with wood isn’t carbon neutral but as a sector of the ceramics industry my view is wood firers aren’t carbon neutral.
I decided to write this paper as a response to the papers titled “WOOD: THE MOST ECOLOGICALLY SOUND FUEL?” and “A Change in the Air”
I agree with some of the points laid out in the papers. I disagree with others.
The 3 kilns outlined below are fired by full time potters.
I don’t personally believe in “off shoring” or externalizing solutions. That is in respect to paying a tropical country to preserve rainforest so I can continue my lifestyle. I believe in the assumptions of offset solutions and I am aware some of the assumptions for externalized offsets are economically based. I don’t think the effects of externalized offsets are well known or can be known for a long time. The thinking that the “lungs of the world” theory works in some cases but I am allowed to look at the forests in my country in a different light in other cases has an inherent tension and is contradictory. I do think preserving forests and rainforests is a great idea. I also think keeping ones own house or country in order is a great idea. There is tremendous resistance from tropical based countries to seeing their sovereign lands used to offset other countries CO2 outputs.
I am not trying to get wood firers to change fuel with this paper. I will continue to fire with wood. I don’t and won’t call my self carbon neutral. When I can meet the offsets requirement I laid out in the part of the paper dealing with individual kiln offsets I might call myself carbon neutral.
The data I have is for 2 kilns that are roughly the same size and one, mine, that is closer to the size of the kiln fired by the author of the ““WOOD: THE MOST ECOLOGICALLY SOUND FUEL?” paper. , . I am not interested in incomplete burning and the effects on the environment that will have or comparisons in efficiencies between these 3 types of kilns. I am principally concerned with the CO2 output of the kilns.
I was genuinely surprised to see the reaction to my blog posts on carbon output of wood firers. I would call my self CO2 neutral if I decide to get enough land and keep it in trees for 40-50 years as I have laid out in part 3, How much land would you need to plant to offset the emissions for one kiln load?. In Japan that would be very expensive.
If one is only concerned with CO2 outputs wood isn’t the way to go.
The following is from a new report.
The problem with all this biomass, critics argue, is that wood can actually churn out more greenhouse gases than coal. New trees might well cancel that out, but they do not grow overnight. That means the low-carbon attributes of biomass are often realized too slowly to be particularly useful for combating climate change.
The net effect of harvesting wood for bioenergy is complicated
and requires more analysis. Each ton of wood
consumed in a boiler instead of coal does not significantly
alter combustion emissions. However, some of the wood
in standing timber is typically not utilized and is left to
decay in the forest or nearby, causing additional emissions.
Much of the carbon in roots will also decompose.
Replanting may accelerate release of carbon from forest
soils.
Sustainability isn’t guaranteed because one is using wood. The report above and most papers looking at forest permanence cite factors that are highly variable such as individual management practices in CO2 targets not being met.
I would like to thank Bill Geisinger for his patient proofing and data and Hank Murrow for his data and answers to numerous questions. I would also like to thank my sister for her proofreading as I sent her revised copy after revised copy.
The next part of this paper is in a question and answer format. This is the format I used to research.
Tags: carbon, carbon output, wood firing
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