Is biomass really green?

[nickchapman]

Hi everyone,

I've ended up in an intense debate with a friend about if biomass really is 'clean'.

Their argument is that as you are burning the fuel, it is putting carbon into the atmosphere but I understood that biomass was better as it stops the fuel from rotting into the ground which releases carbon and methane?

But having had a quick look online, I see that biomass gets quite the bashing.

I suppose it's obvious but I guess it depends on if the fuel source you are comparing it to. i.e. is biomass better than fossil fuels? Of course.
is biomass better than solar or wind power? I don't know.

What do you think?

[nickchapman]

I've been thinking about this...

Take Christmas Trees, for example. (The thing that kicked the debate off in the first place).

Is using them for biomass a green option when an alternative is chipping them and using them as mulch or being composted? I honestly don't know. The methane element raises questions over the decomposing in my mind.

But then consider that the biomass fuel is potentially replacing the need for a fossil fuel, so does it get extra points for that?

Man, this is hurting my head. Someone jump in before the confusion hurts me lol

[dguzzi]

I think in the end, if you burn it, its bad.
I had a similar thought about methane, is it better released raw, or burned?

[Solar Mike]

Anything you do with biomass is carbon neutral; eg take a tree growing in a forest, over its lifetime it sequests carbon in its growing mass, absorbs C02 and releases oxygen.

If the tree falls over and rots all that stored carbon is eventually released into the atmosphere by the micro-organisms that eat it; it you chop it down and burn it same thing happens; if you build a house with it and 150 years later the house is demolished and burnt or treated timber sent to landfill, same thing happens.

Planting a forest is at a bigger scale, but forests dont last forever, at some point perhaps 500 years hence that forest will get burnt or turned into houses, the return to atmosphere part is just delayed. Any money spent on "Carbon Credits" has amounted to nothing. ie wasted.

Cheers
Mike

[dguzzi]

Well, the delay could/would be a positive.

[Solar Mike]

Very true, plant enough forest to mitigate present CO2, maybe will give us time to come up with a proper solution.

[nickchapman]

Excellent points, thanks guys.

The question is though, will burning a biofuel produce anything nasty compared to decomposition?

Interesting point about the delay... the company I work for uses carbon credits, I didn't think about that aspect.

In that sense then, the trees simply serve to trap carbon until they die?

But then that is assuming that the forests as a whole won't stick around...

A healthy forest could grow and produce more trees, meaning, as whole, it's taking more carbon out of the atmosphere than it used to, even with the carbon neutral relationship of the individual trees.

Also, a point I made before is questioning if using biofuel (or an equivalent tbh) gets any extra points for replacing something that's a net contributor of carbon, eg fossil fuels.

I'm no expert, of course, but shouldn't an accurate measure of its efficacy / green credentials consider the carbon saving of the fuel source it replaces, or at least the most commonly available source.

So biofuel might be carbon neutral in nominal terms, when looking at the whole picture, it could be considered as green as its use has reduced carbon output compared to fossil fuels?

Seems that being 'green' is more than just its carbon output?

So for example, most eco friendly products will probably not be carbon neutral, but the thing theyre replacing is way worse so we can still call it 'green'.

Am I making sense here? lol

[Zwerius]

What I didnt read so far, is that in every "burning-process" nitrogen and oxygen from the air react to different Nitrous Oxides (NOx), which cause acidic rain and thus belong to the poluters of our atmosphere.
This happens when you burn coal, oil, gas or wood in the same way.
You can only limit it, if you can keep teh flame temperature below 800°C, which is not so easy. There are Low NOx burners, that supply the combustion air in stages, so that the combustion temperature is lowered. This reduces the amount of NOx, but doesn't bring it back to zero. In natural decomposition of wood, there is no NOx formation.
So, don't just look to CO2 that's released and taken up again.

[nickchapman]

YESSS!
Thank you.

So in a nut shell, this boils down to chemistry...

Im wondering if methane or nitrogen oxides are worse?

[Zwerius]

Originally Posted by nickchapman

YESSS!
Thank you.

So in a nut shell, this boils down to chemistry...

Im wondering if methane or nitrogen oxides are worse?

It's hard to say which is worse.
Methane is a greenhouse gas, like CO2. However, methane is about 25 times more potent than CO2.
NOx gasses are no greenhouse gasses, but they cause acid rain and take care of acidification of our environment (including the sea where corals are destroyed by these acids)