Pilot Test Of Storing Carbon Dioxide In Rocks Shows Impressive Outcome (theaustralian.com.au)

For years we have been trying to find different ways to limit carbon dioxide produced from fossil fuels. Some researchers believe that things would be very convenient if we could just deposit carbon dioxide in rocks. A pilot project around this idea has shown an impressive result. John Ross, reporting for the Australian: Scientists say they have demonstrated a foolproof way of sequestering atmospheric carbon dioxide -- turning it into rock. An international team of researchers says it has demonstrated for the first time that CO2 can be permanently locked away from the atmosphere by injecting it into volcanic bedrock. The study, reported this morning in the journal Science, could overcome the leakage problems that have plagued attempts to bury CO2 gas underground. Lead author Juerg Matter said between 95 per cent and 98 per cent of the injected CO2 had been mineralised in less than two years, "which is amazingly fast.""Until now it was thought this process would take hundreds to thousands of years," University of Southampton, which led the new study, said in a statement. "The current study has demonstrated that it can take as little as two years."

Comments

Re:If it was that easy and worked that well

[Rei]

No, it means that it was a pilot project and it's the first time they've tried this.

It's great news. I've been following as they've been working on this project. Most people wouldn't think we'd have much carbon dioxide here since virtually all of our power is either hydroelectric or geothermal, but we're actually abnormally high emitters per capita. Now, most of that's not easy to capture - we can pretty much rule out the fishing fleet, and two of the three aluminum smelters aren't that close to a geothermal plant (although I don't know if their technique needs to be directly coordinated with a geothermal plant or not). However, geothermal wells also can have surprising levels of CO2 emissions. They're quite varied, and generally far less than burning fossil fuels for power, but some of the worst wells can actually get up to a good fraction of the emissions of of an equivalent amount of fossil fuel power. So this experiment was conducted at Hellisheiði, which is the biggest geothermal plant in Iceland (and one of the biggest in the world), with the goal of making it eventually fully close-cycle. Maybe they'll also reduce their H2S emissions at the same time.

Concerning one thing in the article:

But Dr Matter said there was a risk of mobilising trace metals, potentially polluting downstream waterways. And any injection of water or CO2 into deep subsurface reservoirs carried the danger of “micro” earthquakes.

They're already making regular earthquakes on the production end, so what's the big difference? More to the point, who would even notice? Wow, gee, earthquakes in Iceland, we've never gotten those before ;)

I also don't have much concerns about trace metals flowing into waters. Those are geothermal layers. Any waters there are geothermal waters. Which means that they're pretty "contaminated" to begin with. You don't drink geothermal waters, or anything that they flow into. I have a lot more concerns about 1) agricultural / livestock / septic system contamination, and 2) suspended particulate (aka surface water contamination). See Mývatn for the effects of both, Lagarfljót particularly for the latter. Our main areas of concern with bodies of water have generally been with either clouding them or causing algal blooms.

Then again, though, why should we even bother helping reduce CO2 levels? Make Iceland Covered With Redwoods Again! ;)

One of many feedback mechanisms

[dlenmn]

Believe it or not, you're not the first person to think of feedback loops at work in climate change. There are many known feedback mechanisms (relevant wikipedia article), both negative and _positive_. Let's not pretend that the "Net Primary Productivity" feedback mechanism (what you're talking about) will save us. In fact, it seems to be a pretty weak feedback loop compared to feedback loops that are at work. After all, we're burning up a _lot_ of dead plants (many of them from the days when the earth was covered with jungles). We'd need a lot of new plants to make up for it, and they'd have to show up pretty fast to overpower the other feedback mechanisms. It's easy to see that this feedback loop isn't too strong: just look at the amount of biomass around us and compare it to how much was there 50 years ago. The amount of biomass hasn't changed much even though the CO2 concentration in the atmosphere has gone up an appreciable amount.

These feedback loops are included in climate models. No one pretends that we fully understand them or model them exactly, but people have put a lot of thought into them and have a decent grasp of their workings.

Re:An alternative?

[hawkfish]

Stop clear-cutting all the trees for lumber and to put up crappy strip malls and subdivisions!

That is backwards. A mature forest does not remove net CO2. You need to cut it down, sequester the wood in housing or whatever, and then let the forest regrow. If forests are going to be used to remove carbon, we need to cut down more of them.

Well, but old growth forests actually remove more carbon than their younger replacements, so it isn't that simple:

"Rather than slowing down or ceasing growth and carbon uptake, as we previously assumed, most of the oldest trees in forests around the world actually grow faster, taking up more carbon," said Richard Condit, staff scientist at the Smithsonian Tropical Research Institute. "A large tree may put on weight equivalent to an entire small tree in a year."

So by leaving an old growth forest in place, we sequester the carbon (in the forest) and improve the uptake.

Re:How to collect "atmospheric" CO2?

[Solandri]

CO2 can be extracted from the atmosphere for about $160/ton.

Gasoline emits 8.887 kg of CO2 per gallon of gasoline, so that's 112.5 gallons of gasoline for one ton of CO2. At current prices, that's about $225 worth of gasoline, so this process is "worth it" in terms of recapturing CO2 produced by burning gasoline (basically stick a $1.42/gal tax on gasoline to pay for it).

Electricity generation results in 0.703 kg of CO2 per kWh (same EPA source), so that's 1422 kWh per ton of CO2. At a U.S. average of $0.115/kWh, that's $163.50 worth of electricity. So it would basically double the average price of electricity in the U.S. Still doable, although the similarity of the price means this is getting close to the break-even point where the energy cost to recapture the CO2 approaches the energy gained by producing it (by burning fuel) in the first place.

Cost of sequestration would have to be added on top of this though.