Capturing Carbon With Garbage Heaps

davide marney writes "In a Washington Post opinion piece, Hugh Price argues that using a decidedly low-tech solution to sequestering excess carbon — making piles of agricultural waste — is better than many 'green' solutions already in practice. Sometimes the easy answer is the right answer. After all, it's how coal forms, and we know that works pretty well."

Comments

Actually

[iONiUM]

I read TFA and his answer is two fold: 1. stop burning waste or plowing it from forests/farms and instead pile it (as the summary says), and 2. plant more trees and plants.

It's a pretty interesting idea, but it seems like it would be really hard to get traction because people won't believe it work. To be fair, while the theory seems pretty sound to me, it still seems like it wouldn't work. Why this is, I cannot say. Perhaps because it seems too easy.

Re:Actually

[andre.david]

Yep, but you usually output about 100-200 gr of feces (that's the figure I remember from my Physiology class, can't find a citation; The best I found on-line is here). Since we usually eat a lot more than that, the mass should be leaving the body by other means. We don't lose much heavy molecules through the urine and perspiration. The latter contains mostly water and salts, while the former also contains some waste molecules, but not in a meaningful amount (weight-wise). That leaves only one other venue - CO2 in our respiration.

Bingo: water.
Not just feces and urine should account for a lot of what comes out, most folks forget that most things we eat also have a lot of water.

Also your conclusion is wrong, since breathing puts out a lot of water (as does keeping our skin nice-looking; "hydrating" creams acts by sucking water from the lower skins layers to the top).

I think the amount of carbon we emit in the form of CO2 has got to be puny. But let's see:

Normal breathing uses 6 l/min of air and when it comes out it goes from 0.04% CO2 to (4 to) 5% CO2.

Now, 6 l/min = 8640 l/day or (340 to) 430 liter of CO2 exhaled per day. That's (630 to) 790 gram of CO2 output per day. That is actually in line with an estimation of 1 kg.

But the O2 was not actually coming from us; it is taken from the air and given back with the C attached to it. The carbon atom is 27.3% of the CO2 atomic mass, so we are actually putting out (172 to) 216 gram of carbon per day.

So let's peg that as 200 gram/day of matter output through CO2 rejection. Now, to put this into perspective, we need to somehow estimate how much mass a person inputs per day. The problem is that this varies wildly. I think we can agree on 2 kg/day of water from drinking fluids. On top of this we have food; I just looked up a couple of snacks (150 g) and instant meals (350 g) and I think that a 3 meal day with a couple of snacks could easily get to 1.4 kg/day of food.

That's a total of around 3.4 kg/day of mass coming in and 0.2 kg/day of mass going out through CO2 in breathing. That's around 6% of our mass loss.

So, please tell your nephew - supposing he has a good diet with plenty of fluids - that >90% of what he ingests goes out as urine, perspiration, water loss in respiration and feces.

ps - I have not counted nails, hair and skin cells, which are always growing (the former) and being renewed (the latter).
pps - I found a study that puts feces at 300 g/day and a post that puts water loss at 2.8 kg/day. Add to that the 200 g/day of carbon out through CO2 and you get a good match to the supposed 3.4 kg/day total input.

Methane

[Anonymous Coward]

One word methane. It results from anarobic decomposition and is a far more potent greenhouse gas than CO2.

Re:Methane

[stazeii]

doh... methane is about 10x (not 20x) more potent a greenhouse gas than CO2... stupid typo.

Re:Yeah

[antifoidulus]

Actually the federal government already gives away tons of money to farmers to farm stuff then keep it inside a giant silo instead of selling it.

Re:I had this "idea" singe many years

[bdleonard]

Somebody from De Beers will be calling you shortly to correct your last statement.

Re:Make charcoal

[TapeCutter]

You can plow the charcoal into the ground, it's a great "fertliser".

Convert methane to methanol

[voss]

You can convert methane to methanol.

Methanol is FAR cheaper than ethanol.

http://en.wikipedia.org/wiki/Methanol_fuel
http://en.wikipedia.org/wiki/Methanol_economy

Re:No fertilizer allowed

[Scott Wood]

You're assuming that those 100 men would vanish in the absence of employment -- rather than consume resources funded by unemployment, or perhaps another job that was viable only because the glut of available labor pushed wages low enough, or because the work week was shortened to spread the work among everyone.

People don't just go away because their job did.

Landfill contamination isn't so simple

[bperkins]

Aside from some of the obvious mistakes this opinion piece makes.

> There is no need to worry about toxins leaching into the water supply. No elaborate liner or monitoring is required

This is wrong. There are some situations where organic rich runoff can cause problems.

The following link:
http://toxics.usgs.gov/topics/rem_act/saco.html

describes:
" dissolved organic carbon in the leachate plume is dissolving arsenic from arsenic-containing iron oxides in the aquifer and bedrock"

Re:Yeah

[Jarik C-Bol]

you missed the part of the article where it mentions that oxygen is required for decomposition, in properly constructed heaps, oxygen content is so low that decomposition fails to occur, thus sequestering the carbon. They are not trying to make coal/oil (however if the stacks are undisturbed long enough that would happen, just not in our lifetimes) They are just trying to keep the carbon out of the cycle. Granted, the idea does have its flaws, but its not so blatantly stupid as you would like it to be.