SoylentNews is people
SoylentNews
In November, the Paris Climate Agreement goes into effect to reduce global carbon emissions. To achieve the set targets, experts say capturing and storing carbon must be part of the solution. Several projects throughout the world are trying to make that happen. Now, a study on one of those endeavors, reported in the ACS journal Environmental Science & Technology Letters, has found that within two years, carbon dioxide (CO2) injected into basalt transformed into solid rock.
Lab studies on basalt have shown that the rock, which formed from lava millions of years ago and is found throughout the world, can rapidly convert CO2 into stable carbonate minerals. This evidence suggests that if CO2 could be locked into this solid form, it would be stowed away for good, unable to escape into the atmosphere. But what happens in the lab doesn't always reflect what happens in the field. One field project in Iceland injected CO2 pre-dissolved in water into a basalt formation, where it was successfully stored. And starting in 2009, researchers with Pacific Northwest National Laboratory and the Montana-based Big Sky Carbon Sequestration Partnership undertook a pilot project in eastern Washington to inject 1,000 tons of pressurized liquid CO2 into a basalt formation.
After drilling a well in the Columbia River Basalt formation and testing its properties, the team injected CO2 into it in 2013. Core samples were extracted from the well two years later, and Pete McGrail and colleagues confirmed that the CO2 had indeed converted into the carbonate mineral ankerite, as the lab experiments had predicted. And because basalts are widely found in North America and throughout the world, the researchers suggest that the formations could help permanently sequester carbon on a large scale.
Similar results were found in Iceland.
Does injecting CO2 into rock really make more sense than not putting it into the atmosphere in the first place?
(Score: 2) by bradley13 on Sunday November 20 2016, @02:08PM
Let's assume that injecting CO2 into rock formations is a desireable goal. An honest question that I haven't seen answered anywhere: What is the energy requirement to extract CO2 from the atmosphere, liquify it, and inject it? Does this energy exceed the energy once gained by burning carbon to produce the CO2 in the first place?
I really don't know, but my intuition is that this is likely to have a negative energy balance, and much of that energy will come from carbon-based fuels...
Everyone is somebody else's weirdo.
(Score: 1) by khallow on Sunday November 20 2016, @03:07PM
Let's assume that injecting CO2 into rock formations is a desireable goal.
What has that rock formation ever done for us? It's just holding us back! Well, it and 6*10^24 kg just like it.
What is the energy requirement to extract CO2 from the atmosphere, liquify it, and inject it?
Rather low, if you just take it directly from the exhaust of a coal burning plant. And even if we extract CO2 directly from atmosphere, it's worth noting at low concentrations, a doubling of CO2 results in almost halving the energy cost of extracting that CO2 from atmosphere (assuming you're aiming for a moderately pure final concentration of the gas). So as the CO2 problem gets worse, the effort to remove it from atmosphere would get better.
(Score: 2) by linkdude64 on Sunday November 20 2016, @03:53PM
I imagine we would see increasing returns on conversion/extraction technology if it were opened to the free market and used by companies to offset pollution in response to tighter environmental regulations.
Rather than re-design your whole plant or throw away your perfectly good old machinery that just isn't efficient enough, bolt on a CO2 extractor and call it a day.
(Score: 0) by Anonymous Coward on Sunday November 20 2016, @05:21PM
It might be possible to do at an energy profit. The trick is to burn plants, which get their carbon from the atmosphere, in a biomass power plant, and run the concentrated CO2 from that plant through this process. The reason this works is that the reaction that locks the CO2 in the rock is slightly energetically favorable, it's just a question of bringing concentrated CO2, water, and rocks into the same place for long enough. The reason it doesn't happen fast enough for our needs in nature is probably a question of low concentration, and possibly the reaction results shielding the reactants from each other.
And to another questioner's question about getting the carbon back should we need it: that's actually really simple. Just heat up the rocks enough, and they'll release the bound CO2. It's the same process we use to turn limestone into concrete.
(Score: 1) by nethead on Sunday November 20 2016, @07:07PM
Does this energy exceed the energy once gained by burning carbon to produce the CO2 in the first place?
Since this was done on the Hanford Reservation I'm guessing the energy was nuclear.
How did my SN UID end up over 3 times my /. UID?