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Carbon capture and storage: Difference between revisions
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Carbon capture and storage (CCS, or sometimes CCUS{{x|carbon capture, utilization and storage}}) is an industrial process where CO<sub>2</sub> emissions are captured and stored deep in the Earth. This is a somewhat questionable approach to reducing [[climate change]]. | Carbon capture and storage (CCS, or sometimes CCUS{{x|carbon capture, utilization and storage}}) is an industrial process where CO<sub>2</sub> emissions are captured and stored deep in the Earth. This is a somewhat questionable approach to reducing [[climate change]]. | ||
==Capture== | {{considerations}} __NOTOC__ | ||
==Capture - types== | |||
===Direct air capture (DAC)=== | ===Direct air capture (DAC)=== | ||
Trying to take CO<sub>2</sub> out of the air uses almost as much [[energy]] as you got when you burned the equivalent amount of [[fossil fuels]] in the first place. In other words, it's basically useless. | {{sum|Not viable}} | ||
Trying to take CO<sub>2</sub> out of the air uses almost as much [[energy]] as you got when you burned the equivalent amount of [[fossil fuels]] in the first place. {{light|(In other words, it's basically useless.)}} Any amount of green energy used in DAC, could have been used in any other industry (in place of fossil fuels) and done more to stop climate change. | |||
<!-- TODO: compare to forests: Trees capture (sequester) carbon more efficiently using the sun's energy (photosynthesis). The limiting factor is land, ... --> | <!-- TODO: compare to forests: Trees capture (sequester) carbon more efficiently using the sun's energy (photosynthesis). The limiting factor is land, ... --> | ||
===Point source capture=== | ===Point source capture=== | ||
Capturing the emissions at the source | {{sum|Viability: Unknown {{rn}} }} | ||
==Storage== | Capturing the emissions at the source: | ||
CO<sub>2</sub> is pumped into rocks deep in the ground.{{en}} | * Suited for coal power plants, natural gas power plants, and some factories. | ||
* Not suited for smaller sources like cars & trucks. | |||
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==Storage - considerations== | |||
CO<sub>2</sub> is pumped into rocks deep in the ground. It reacts with minerals to become ''mineral carbonates'', which are chemically stable. {{en}} | |||
===Earthquakes=== | |||
{{sum|Possible problem}} | |||
<q>Sequestering of carbon deep underground, through multiple impermeable boundaries, can increase earthquakes, just as with waste water storage from [[fracking]].</q> | |||
External links: | |||
* [https://www.sciencenews.org/article/pumping-carbon-dioxide-deep-underground-may-trigger-earthquakes?mode=magazine&context=189624 Pumping carbon dioxide deep underground may trigger earthquakes], Science News, Jan 9, 2015 | |||
===Sinkholes=== | |||
{{sum|Possible problem}} | |||
<q>Once carbon dioxide is pumped underground in large quantities (in this case, billions of tons), it displaces natural groundwater pools, causing groundwater to seep elsewhere underground, which greatly increases the risk of sink-holes and water seepage on the surface above.</q> | |||
===Rejection=== | |||
<q>Carbon dioxide is naturally buoyant, and will thus spread around its initial injection point, and seep back out of the earth unless it is injected through one or more impermeable boundaries.</q> | |||
===Storage capacity=== | |||
{{sum|Possible problem}} | |||
This section needs info on ''how much'' carbon could really be stored in the ground - both globally and in terms of some local regions. {{rn}} | |||
===CO<sub>2</sub> transport=== | |||
{{sum|Unknown}} | |||
CO<sub>2</sub> sources are not necessarily near geographic regions suitable for CO<sub>2</sub> storage. Pipelines would need to be built. <sup>[RESEARCH needed - viability]</sup> | |||
===Utilization=== | |||
{{sum|Not helpful in the big picture}} | |||
The "utilization" part of CCUS: The CO<sub>2</sub> is sometimes "used" before being stored. In practice, the only usage is for mining more oil & gas.{{en}} | |||
== | ==External links== | ||
This page contains some content copied from RationalWiki's [https://rationalwiki.org/wiki/Clean_coal page on "clean coal"], which has some good info debunking carbon capture. | |||