Stories
Slash Boxes
Comments

SoylentNews is people

posted by on Sunday November 20 2016, @09:45AM   Printer-friendly
from the rock-of-ages dept.

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?


Original Submission

 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 2) by TheLink on Sunday November 20 2016, @05:10PM

    by TheLink (332) on Sunday November 20 2016, @05:10PM (#429947) Journal

    We're not interested in energy equivalent. We're instead interested in carbon content.

    More relevant is CO2 absorption per day of trees.

    You can burn an entire 2 ton tree in a day but it doesn't grow to even half that size in one day. So the enormous number of trees required is likely magnitudes more than you imply with your calculations.

    Remember those numbers are barrels per _day_ not per year or decade. Not all of those barrels of oil are burnt per day, but a substantial percentage does get burnt every day.

    So I'm wondering if this CO2 injection method can scale. Can it take the CO2 output of a typical power plant without consuming too much energy?

    Starting Score:    1  point
    Karma-Bonus Modifier   +1  

    Total Score:   2  
  • (Score: 1) by khallow on Sunday November 20 2016, @07:07PM

    by khallow (3766) Subscriber Badge on Sunday November 20 2016, @07:07PM (#430011) Journal

    You can burn an entire 2 ton tree in a day but it doesn't grow to even half that size in one day. So the enormous number of trees required is likely magnitudes more than you imply with your calculations.

    Not sure where you're going with that since one can grow lots of trees (example was 4 metric ton tree which is 50% carbon BTW) at a time and they'll steadily consume carbon over the course of a tree's lifespan. The real problem as you said is not the length of time it takes to grow trees, but rather the enormous quantity of carbon dioxide that one needs to sink.

    • (Score: 2) by TheLink on Monday November 21 2016, @09:48AM

      by TheLink (332) on Monday November 21 2016, @09:48AM (#430416) Journal

      You said:

      We're not interested in energy equivalent. We're instead interested in carbon content.

      That's roughly 7 metric tons of CO2 when fully burned. That's 16-17 times as much CO2 instead of merely twice. It's still an enormous number of trees, but an order of magnitude less than you claimed.

      But that's incorrect and missing the forest for the trees. Neither the carbon content nor the effective CO2 locked up is relevant. As I said: More relevant is CO2 absorption _per_day_ of trees. You could have a 4 ton hardwood tree but if it absorbs CO2 at a low rate and takes 200 years to reach that size it barely counts.

      Not sure where you're going with that since one can grow lots of trees

      Never said we couldn't grow lots of trees. My point is can we grow enough to absorb the CO2 from the millions of barrels of oil burnt per _day_?

      Those oil consumption figures are not per year, they are per day. The time scales for trees are typically "year" or even years than "day".

      These sites say a tree can absorb 48 pounds of CO2 per _year_:
      https://projects.ncsu.edu/project/treesofstrength/treefact.htm [ncsu.edu]
      http://www.arborenvironmentalalliance.com/carbon-tree-facts.asp [arborenvironmentalalliance.com]

      So one barrel of oil per day = 0.43 metric tons CO2 per day= 947.9877 pounds per day.
      One tree at 48 pounds/per year = 0.131506849 pounds per day

      So you need about 7200 trees to counter each barrel of oil burnt. Let's assume 40 million barrels of oil burnt per day worldwide (US and China combined use 30 million barrels of oil per day). So you need an _additional_ 288 billion trees.

      Apparently there are 3 trillion trees in the world. A 10% increase is probably doable, but how long will it take to plant 300+ billion trees (not all will survive), and where will you plant them?

      If it would take a very long time then keep in mind that within that time we are very likely to run out of cheap oil and stop burning so much of it.

      • (Score: 1) by khallow on Monday November 21 2016, @06:02PM

        by khallow (3766) Subscriber Badge on Monday November 21 2016, @06:02PM (#430708) Journal

        A 10% increase is probably doable, but how long will it take to plant 300+ billion trees (not all will survive), and where will you plant them?

        Which is a fine point. But we need to keep in mind that IF we have space for them, it's just not that hard to plant that many trees with a reasonable factor of excess to cover the ones that don't survive. I think you could get all those trees planted inside of five years.

        • (Score: 2) by TheLink on Tuesday November 22 2016, @09:07AM

          by TheLink (332) on Tuesday November 22 2016, @09:07AM (#431137) Journal

          Assuming 600 trees per acre - https://www.state.sc.us/forest/nurspa.htm [state.sc.us] you'd need 2 million square km. That's a bit more than the entire land area of Mexico. Just getting/preparing that amount of land could take a while and a lot of money. I'm sure we have that much spare space in the whole world but it might take longer than 5 years to just to get that land and projects started. You wouldn't need all of it at once but you'd still need to acquire and prepare it at a high rate if you actually want to do it within 5 years. You'd need about 80000 additional tree planters assuming each person can do about 15000 seedlings per week.

          FWIW the Gobi Desert is "only" 1.3 million square km. Imagine all the environmentalists protesting if China somehow managed to destroy the entire desert with trees: https://en.wikipedia.org/wiki/Green_Wall_of_China#Measuring_success [wikipedia.org]
          http://www.bbc.com/news/science-environment-35496350 [bbc.com]

          Note that that is a closer to a 70 year project than a 5 year one. So if it's going to be a 300 year project we'd probably have burned up most of the cheaper oil and would be locked in to the consequences for decades by then.