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bodger
Joined: 23 May 2006
Posts: 6704
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 Posted: Thu Oct 01, 09 6:37 am Post subject: Bio Mass ? |
 
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Just how green is Bio Mass ? I really don't know that much about it, other than it burns renewable wood rather than fossil fuels. What else has this system got to recommend it ? Are the trees better being left and put to use helping to trap carbon emissions? If they end up being burnt, isn't any carbon that they've taken from the atmosphere simply re released ?
http://news.bbc.co.uk/1/hi/wales/wales_politics/8283923.stm
Is this just another way of polluting the planet or is it a genuine step in the right direction ? |
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Jamanda
Downsizer Moderator
Joined: 22 Oct 2006
Posts: 18637
Location: North Devon
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| Posted: Thu Oct 01, 09 6:41 am Post subject: |
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The point is they use fast growing plants which take in CO2 and then release it, (carbon neutral) as a pose to just releasing it which is the case with fossil fuels. |
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bodger
Joined: 23 May 2006
Posts: 6704
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| Posted: Thu Oct 01, 09 6:46 am Post subject: |
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You'll have to explain that a bit more to me I'm afraid.  Couldn't you argue that coal is carbon neutral but simply millions of years old ?
Last edited by bodger on Thu Oct 01, 09 6:47 am; edited 1 time in total |
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Jamanda
Downsizer Moderator
Joined: 22 Oct 2006
Posts: 18637
Location: North Devon
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| Posted: Thu Oct 01, 09 6:47 am Post subject: |
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Later - have to go to work. |
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Treacodactyl
Downsizer Moderator
Joined: 28 Oct 2004
Posts: 19541
Location: In the pond with the frogs
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| Posted: Thu Oct 01, 09 6:52 am Post subject: |
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Coal will take carbon that's locked away and release it and there's nothing in place to lock it away again. (IIRC coal is plant matter that fell into swamps and we don't really have many similar places around the world, even if we did the process take millions of years so we would release huge amounts of CO2 and hardly any will be locked away for thousands of years).
With bio-mass such as short rotation coppice (SRC) the plant takes out CO2 as it grows and re-releases it when burn so there's no net increase in CO2. Actually there will be more CO2 taken out of the air as the roots stay behind but I expect that would balance with the CO2 used to mechanically harvest and process the wood. |
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bodger
Joined: 23 May 2006
Posts: 6704
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| Posted: Thu Oct 01, 09 7:30 am Post subject: |
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Thanks for that.
So fossil fuels have already worked their magic and in an ideal world we'd leave them where they are along with the carbon that they've taken from the environment. Our aim with bio mass therefore, is not to reduce the carbon in the environment but to keep the levels that we have now, fairly static by juggling it between growing trees and using them to produce energy.
I realise that this is a rather simplistic assessment but is this more or less what bio mass is about ? |
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Treacodactyl
Downsizer Moderator
Joined: 28 Oct 2004
Posts: 19541
Location: In the pond with the frogs
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| Posted: Thu Oct 01, 09 7:34 am Post subject: |
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That sounds about right, I also seem to recall it being much hotter with higher CO2 concentrations when coal was formed so if we burn it all it seems logical we'd go back to similar conditions (tropical, higher sea levels, less land mass extinctions etc.) |
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RichardW
Joined: 24 Aug 2006
Posts: 5693
Location: Llyn Peninsular North Wales
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| Posted: Thu Oct 01, 09 8:04 am Post subject: |
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Burning them simply releases the Co2 that will be released when the tree dies & rots down any way. |
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cab
Joined: 01 Nov 2004
Posts: 30063
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| Posted: Thu Oct 01, 09 8:20 am Post subject: |
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You've also got to ask how much fuel is used in planting, tending, harvesting, processing and transporting the biomass. Its not always clear cut that you're making a big carbon saving by burning biomass. Ultimately the energy density of biomass that hasn't been compressed and processed my millions of years of geology may be a lot lower than that which has (fossil fuels), so burning fossil fuels to make and move biomass may not always be quite as good an idea as you'd hope. |
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Jamanda
Downsizer Moderator
Joined: 22 Oct 2006
Posts: 18637
Location: North Devon
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| Posted: Thu Oct 01, 09 5:36 pm Post subject: |
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But you also have to factor in the fossil fuel you would use to extract and move the fossils fuel. I believe the coal burnt at Drax now comes from China, where as when they trailed co-burning with willow it came from Eggborough (about five miles away) |
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Erikht
Joined: 08 Feb 2005
Posts: 3060
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| Posted: Mon Nov 02, 09 8:03 am Post subject: |
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| bodger wrote: |
Thanks for that.
So fossil fuels have already worked their magic and in an ideal world we'd leave them where they are along with the carbon that they've taken from the environment. Our aim with bio mass therefore, is not to reduce the carbon in the environment but to keep the levels that we have now, fairly static by juggling it between growing trees and using them to produce energy.
I realise that this is a rather simplistic assessment but is this more or less what bio mass is about ? |
The carbon is supposed to return to the system, but preferably at the same time rate as it got there in the first place, slowly. |
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Rob R
Joined: 28 Oct 2004
Posts: 16638
Location: York
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| Posted: Mon Nov 02, 09 9:11 am Post subject: |
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| Jamanda wrote: |
| But you also have to factor in the fossil fuel you would use to extract and move the fossils fuel. I believe the coal burnt at Drax now comes from China, where as when they trailed co-burning with willow it came from Eggborough (about five miles away) |
That's right, it's crazy that we can't even produce our own pollution cheaper than shipping it half way around the world. 
The collapse of the original biomass scheme has left many acres of willow in East Yorkshire that are now way past cutting for biomass. Like most things we do it is a question of scale- we tend to always think 'big is better', rather than the truth which is 'big is cheaper'. |
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vegplot
Joined: 19 Apr 2007
Posts: 11014
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| Posted: Mon Nov 02, 09 3:12 pm Post subject: |
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| bodger wrote: |
Thanks for that.
So fossil fuels have already worked their magic and in an ideal world we'd leave them where they are along with the carbon that they've taken from the environment. Our aim with bio mass therefore, is not to reduce the carbon in the environment but to keep the levels that we have now, fairly static by juggling it between growing trees and using them to produce energy.
I realise that this is a rather simplistic assessment but is this more or less what bio mass is about ? |
in a nutshell yes.
coal, oil, peat etc is natures way of locking up carbon until the day the sun burns up the earth by which time it won't matter, that is until we came along. |
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dpack
Joined: 02 Jul 2005
Posts: 13779
Location: w yorks /earth
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| Posted: Mon Nov 02, 09 3:17 pm Post subject: |
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umm
i have some cheap greenwash for sale |
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Nat S
Joined: 15 Aug 2008
Posts: 3552
Location: York
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| Posted: Mon Nov 02, 09 3:46 pm Post subject: |
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Fossil fuel gets used up wayyyyy faster than it's remade. So even if biomass is less efficient, it will still be there when coal runs out. (unless by the time we've burnt all the coal, oil and gas the earth won't be able to sustain life  ) |
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