New CO2 Harvester Could Help Scrub the Air 368
sciencehabit sends this excerpt from ScienceNOW: "Researchers in California have produced a cheap plastic capable of removing large amounts of carbon dioxide (CO2) from the air. Down the road, the new material could enable the development of large-scale batteries and even form the basis of 'artificial trees' that lower atmospheric concentrations of CO2 in an effort to stave off catastrophic climate change."
Massive farms of artificial trees... (Score:5, Insightful)
From TFA:
The polymer could be useful for building massive farms of artificial trees that would aim to reduce atmospheric concentrations of CO2 and prevent the worst ravages of climate change. But that's only if countries around the globe are willing to spend untold billions of dollars to rein in atmospheric CO2.
It also says:
So you have to expend a fairly large amount of energy heating the media to 85C/185F to get it to give up the CO2, (then more energy to store the CO2).
How long it takes to saturate the polymer is not mentioned, but unless its months between regeneration, the CO2 generated while collecting the polymer media, transporting it to a facility, HEATING it, capturing the recovered CO2, could exceed the amount it could capture. And then you are still left with the CO2 you captured. What to do with that?
So the original purpose of this polymer, to keep C02 out of batteries seems to be a far better use for the polymer than environmental CO2 sequestration.
While far from perfect, farming real trees seems a less energy intensive method [wikipedia.org] especially when treated as a crop, harvested at the optimal time, with the wood used for long duration storage.
Re:Massive farms of artificial trees... (Score:5, Insightful)
*CO2 floats away*
To where? Still what hasn't been accounted for is the amount of energy required to produce the polymer. It's probably a petroleum based polymer which requires oil extraction, shipping, processing in a refinery and/or chemical plant, and manufacture. I want to see mass and energy balances. The softer approach of planting trees is probably still the best approach when compared to energy intense Engineering approaches. Trees also have the advantage of binding up water vapour, which is a green house gas much more powerful than CO2.
Re:Massive farms of artificial trees... (Score:4, Insightful)
We as a species should just decide on whether we want to live in the tropics or the arctic. This constant back and forth is getting tiring.
Re:Massive farms of artificial trees... (Score:5, Insightful)
Sorry mate, entropy. Having gained energy by combining Carbon with air, you must put in energy to get your carbon back. All you end up with is a huge/complicated/inefficient battery. AS there are already large amounts of carbon lying around natrually (coal) , it probably isn't worth it.
Re:And once we have a few gigatonnes of CO2 (Score:3, Insightful)
Or make diamonds from it :)
Re:Frayed Knot (Score:0, Insightful)
Meh. They can't even figure out if the sun is a factor in climate yet.
We produce 29 billion tons per year of CO2 (Score:5, Insightful)
And we're going to catch a significant fraction of it in plastic that we have to manufacture? Seriously?
How about we use something self-replicating instead, which does the same thing and produces useful by-products, like, say, trees?
--PM
Dunno what you'd call me (Score:5, Insightful)
I don't think of myself as an environmentalist or anything like that. I'm all for better energy efficiency and cleaner forms of energy, but something like this strikes me as rather dumb. You have to spend energy making these things, and then energy running them, not to mention time and money all to remove a bit of CO2 out of the air. Wouldn't it make more sense to plant more trees instead, and spend the rest of your time and money on cleaner and more efficient methods of powering well everything?
I don't deny that climate change is happening, it's always been happening and I believe that we have some impact on the way it changes, so being as responsible as we can with what we do with 'waste' like CO2 or other byproducts is always important, but things like this in the modern "green" movement just make me shake my head in disbelief.
Re:Massive farms of artificial trees... (Score:5, Insightful)
I often wonder where people who deny pollution is having any effect on the earth think they are going to live if they are wrong.
Well, some of them aren't real good with the concept of "I could be wrong."
Re:Dunno what you'd call me (Score:4, Insightful)
But how do you patent a tree and retire a millionaire after the IPO?
Re:Massive farms of artificial trees... (Score:2, Insightful)
It means the CO2 can be extracted from the absorber (PEI) by heating the material (after saturate it with CO2) up to 85c. This is not that much energy to extract the CO2 out as compared to other CO2 absorbers.
But I still agree that trees would be the best way to deal with CO2. The article said that his original idea of trapping CO2 is to combine it with Hydrogen to produce methanol fuel (as below quoted).
"he (Olah) suggests that society could harvest atmospheric CO2 and combine it with hydrogen stripped from water to generate a methanol fuel for myriad uses."
The problem with this is that how much does it cost to "strip" hydrogen from water and "generate" the methanol fuel with the capture CO2? Also, what other "wastes" produced by the process? No detail on it... This is just something for those who like to get fames for a short period of time...
Re:Massive farms of artificial trees... (Score:5, Insightful)
The softer approach of planting trees is probably still the best approach....
You're overlooking one irreducibly important fact: planting trees won't make this polymer's producer any money. They don't have a patent on trees, dammit!
Re:Massive farms of artificial trees... (Score:5, Insightful)
That said, reducing current emissions is the first step. Harvesting existing CO2 is probably step 10 or 11 down that path.
Re:Massive farms of artificial trees... (Score:4, Insightful)
"he (Olah) suggests that society could harvest atmospheric CO2 and combine it with hydrogen stripped from water to generate a methanol fuel for myriad uses."
Here's my suggestion: operate a brewery, use the CO2 resulted from fermentation to generate methanol for a myriad of uses... and sell the beer as a by-product.
Re:Massive farms of artificial trees... (Score:5, Insightful)
blah blah blah.
Planting trees doesn't remove the CO2, it jsut hold it temperarly.
Half of the CO2 gathered during the day is released at night, the other half id given up when it rots.
They said the same thing about storing Carbon in Coal. Its just temporary.
Forests do not all give up half the CO2 gathered at night. In fact Trees sequester about 70+ pounds per tree per year. They make it into wood.
The tree eventually dies. 50 to 200 years later.
The wood rots 5 to 30 years later.
But the forest keeps growing.
New trees feed off of the old rotting trees.
The carbon is sequestered for as long as the Forest stands.
You can't look at one tree and shrug it off as a zero sum game.
The living trees, the dead trees, the leaf litter on the ground, the humus of the soil hold ton upon tons of CO2.
Weigh the forest, living dead, and 10 feet of humus. Put it all on the scale. The whole damn thing.
Divide by 3. That's roughly the weight of the carbon sequestered by the forest. Forever, as long as you let it grow.
Re:Massive farms of artificial trees... (Score:5, Insightful)
Ways to sequester captured CO2 as lumber:
* Build houses and furniture out of it
* Use pyrolysis (partial burning without enough oxygen) to create char products (essentially make charcoal). Add it to soil. It improves the nutrient holding capacity of soil and takes a long time to decay itself when buried (~200 years). The reason it holds nutrients is charred wood has lots of tiny holes in it from the plant cells. Nutrients don't get washed away as easily. Holding more nutrients allows the next generation of trees to grow faster, or feed more people, depending what you use the land for. Pyrolysis also generates a bit of energy as a side effect.
* Store the wood in a dry or cold location where it won't rot. There are plenty of deserts and ice caps for that. If you put it on ice, wood is a good insulator, and can reduce melting of glaciers by keeping the sun off them in the summers. That won't make a difference in the middle of Antarctica, but it can help around the margins of ice caps where melting is happening.