Wiki Education Foundation-supported course assignment edit

  This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): JoseZZ.

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Article introduction needlessly understates the potential edit

It currently says 'This technique can give 1.43 W/m-2 of globally-averaged negative forcing, which is almost sufficient to reverse the warming effect of current levels of anthropogenic CO2 emissions. It is notable, however, that CO2 levels will have risen by the time this could be achieved.'

What the cited paper actually says (section 3.23):

'chemical air capture with storage, using e.g. sodium hydroxide and lime, could potentially generate whatever size of carbon sink societies were willing to pay for, as it is unlikely to be limited by available substrates or land surface area (Keith et al., 2006). Ultimately the amount of CO2 sequestered may be limited by the size of available geologic reservoirs, but their storage capacity is estimated to exceed available fossil fuel resources (IPCC, 2005; 10 House et al., 2006). In the long term, air capture and storage activity appears to have the potential to sequester >1000 PgC and cancel the total emissions from a strong mitigation scenario, i.e. RFfinal ≈ −1.43W/m−2, and more.'

So there's no need to say "air capture can produce amount X of negative forcing, which is almost enough to solve the problem, but by the time we could do this, we'd need to do more". Amount X (1.43 W/m-2) is just a number that Lenton and Vaughan (authors of the paper) came up with to set a specific criterion of strong mitigation. All they are saying is that air capture can meet this criterion they invented - indeed they clearly say it can exceed it, to the point that it should in principle be able to offset the burning of all known fossil fuels; the potential geological reservoirs for storage are that big. Mporter (talk) 04:29, 15 August 2009 (UTC)Reply

Fixed, but can probably be better. - 2/0 (cont.) 16:01, 29 October 2009 (UTC)Reply

Crystal Balling edit

There's a lot of crystal ball bullshit in this article. I think it's fair to say that it doesn't meet quality standards. 136.159.117.2 (talk) 20:45, 28 October 2009 (UTC)Reply


Another method to separate carbon dioxide edit

To sequester carbon (CO2) from the atmosphere it needs to be separated. A few years ago workers at Los Alamos by accident found that they could separate gases with sound waves. They thought it was a new idea and they now have a US patent 6733569 for their method, which is said to consume too much energy to be useful for such things as removing co2 from the atmosphere.

However, in 1935 a Mr. C. W. Banton at the Daniel Guggenheim Airship Institute tested a LOW ENERGY acoustic method of gas separation, and it worked. If perfected it could likely be able to separate atmospheric CO2 at an economical cost. I will gladly send the scanned info (12 pages) to anyone who is interested. contact jesseblenn@gmail.com A good understanding of physics in needed, but it is a simple system.

If it can be made to work a perfect system would be to use wind power in high wind areas like the Tierra del Fuego to do it. The CO2 could be sequestered underground nearby if feasible or if not liquified and sent on gas ships to suitable locations, where it could first be passed through turbines where it would expand for energy generation (cooling the area, how about using to cool buildings in Arabia?) before being sequestered underground.

Here are some excerpts from the report: Daniel Guggenheim Airship Institute, C.W. Banton, 1935

Since the only work required to separate a mixture of non-reactive gases is very small and is only the work against entropy, it would be very desirable if some process could be devised by means of which gases could be separated by supplying only approximately this small amount of energy….The acoustic method of separation described below is an attempt to realice such a process.

When a good adjustment has been reached, the separation may be carried out continuously with dependable results, but the composition of the mixture, temperature, and pressure must remain constant.

A sample of producer gas (from wood chips) was handled with very good results in apparutus of the form described above. —Preceding unsigned comment added by 201.237.156.34 (talk) 09:33, 22 November 2009 (UTC)Reply

Biochar as a CDR methodology? edit

This Wiki entry on carbon dioxide removal (CDR) nowhere mentions the word "biochar" - although Biochar is regularly (at least for the last year or so) listed as a CDR methodology.

I'd be glad to write something, but only if the editors agree it appropriate (or might be).

67.190.182.221 (talk) 01:56, 18 April 2010 (UTC) Ronal Larson rongretlarson@comcast.net 303/526-9629; Golden ColoradoReply

Added this and other technologies mentioned in the Royal Society report in my last edit. Nepomuk 3 (talk) 04:47, 10 September 2011 (UTC)Reply

Scrubbing towers edit

The discovery channel reported that the scrubbing tower uses fan blades similar to that of room ventilators. I think that this could be improved by using fan blades similar to those found in wind tunnels --> ie 8 foot/16 foot high speed wind tunnel/16 foot transonic wind tunnel. This would decrease power consumption even more. 91.182.16.165 (talk) 12:06, 2 August 2010 (UTC)Reply

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updating introduction for links, clarity edit

I've been going through the references. A number were broken. Haven't finished yet, but in several cases I was able to find the article that was referenced at a different URL.

After viewing the articles referenced in the introduction, I've also edited the first two paragraphs slightly to better fit with what the articles referenced. The second paragraph, starting "CDR is supported by" was too vague; what was "supported by" supposed to mean in this context? I tried to keep the changes purely editorial -- not substantive. There are substantive changes that I think should be made as well, but I won't do anything about those until I've described them here in talk and given others a chance to weigh in. Agnostic Engineer (talk) 09:19, 27 March 2013 (UTC)Reply

Crushing olivine edit

Crushing olivine hasn't been mentioned. Perhaps it's not that effective, but worthy of mentioning nonetheless. See

KVDP (talk) 14:58, 1 January 2014 (UTC)Reply

Merge to carbon sequestration? edit

Since there is a merger proposal but no discussion i create one. The main difference of carbon sequestration and carbon dioxide removal is that CS includes natural processes. Thus CDR should be merged into CS prokaryotes (talk) 11:50, 16 April 2014 (UTC)Reply

Merge into CS - there's not enough content to require two articles and CS is the more general topic. Jojalozzo 12:16, 1 May 2014 (UTC)Reply

I agree with Prokaryotes, the two articles should be merged, as having the two closely related (nearly the same) topics in separate locations seems redundant.2602:306:320A:AF0:A9A9:317E:D61E:713B (talk) 05:12, 15 May 2015 (UTC)Reply

Any reason this hasn't been done yet? 61.68.207.107 (talk) 03:55, 2 April 2018 (UTC)Reply

I suggest that it is important to keep the "Carbon Dioxide Removal" page. The term "carbon dioxide removal" refers to capturing CO2 and is what people will use when looking for information on that topic. "Carbon Sequestration" is what can be done with CO2 once it has been captured. Just make sure there are links between the two topics. If these two topics are merged then why not merge others such as "CO2 scrubbers" or "Carbon Sink" or "Carbon capture and utilization"? Merging all of these related topics under a term such as "CO2 Issues" might make sense with regard to gathering all of the related topics into one page but it might then be vast and somewhat unwieldy. By leaving the topics separate but linked it might make searching easier for many people. Note that "Direct air capture", the technical term for CO2 removal, would be the better term and a page already exists for it. One might merge the material from those two pages under the "Direct air capture" heading, but then I would suggest the "Carbon Dioxide Removal" page should be kept with nothing more than a direct link to "Direct air capture". In that way people searching for CO2 removal would be redirected to "Direct air capture". — Preceding unsigned comment added by Ian Marcil (talkcontribs) 21:11, 9 July 2019 (UTC)Reply

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NaOH-based Direct Air Capture Processes (UC Berkeley - CBE 195 CCS - Extra Credit) edit

I'm planning to explain how DCA would actually work using NaOH as the solvent in a thin-film absorption process with solvent regeneration. I will include a PFD and simple standard ChemE analyses.

Sources:

  1. Zeman, Frank. Energy and Material Balance of CO2 Capture form Ambient Air. Environ. Sci. Technol. 2007, 41, 7558-7563.
  2. Smit, B.; Reimer, J. A.; Oldenburg, C. M.; Bourg, I. C. Introduction to Carbon Capture and Sequestration; 2014; Vol. 1.

JoseZZ (talk) 23:22, 26 April 2017 (UTC)Reply

I've added a "Direct Air Capture (DCA) Process Example using NaOH" section to this article. JoseZZ (talk) 01:30, 27 April 2017 (UTC)Reply

Merger proposal edit

I propose that Negative_carbon_dioxide_emission be merged into Carbon_dioxide_removal. Jesse L Reynolds (talk) 08:52, 18 May 2017 (UTC)Reply

Looks like that was done some time ago. Klbrain (talk) 20:30, 16 June 2019 (UTC)Reply

    Y Merger complete.

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Fast-growing plants? Bamboo? Real trees? edit

Why is there nothing in this article about using fast-growing plants like bamboo? 61.68.207.107 (talk) 03:04, 2 April 2018 (UTC)Reply

We would need reliable sources discussing it as a method of CO2 removal. (Realistically, plants take CO2 out of the air until they die and decay. You'd need to permanently entomb the resulting plants to make a difference.) - SummerPhDv2.0 05:40, 27 December 2018 (UTC)Reply

Biochar edit

Does this make sense?

Article says;

The offset of GHG emission, if biochar were to be implemented, would be ... [equating] to about 106 metric tons of CO2 equivalents.

@Chaumvo: 106 tons? By one company? In the UK? Per year? Or is that Gigatonnes (by the whole world)?

Where does the biochar go? Surely you can only add a few tonnes per hectare; and only once? Not year after year?

MBG02 (talk) 22:21, 26 December 2018 (UTC)Reply

deleted Chidgk1 (talk) 17:10, 13 May 2021 (UTC)Reply

concrete edit

Concrete can be carbon negative - bind more than its production causes emissions. This could be a huge thing considering how much concrete gets produced annually and that the carbon stays captured in concrete. https://www.greenbiz.com/article/concrete-change-making-cement-carbon-negative https://www.cement.org/for-concrete-books-learning/concrete-technology/concrete-design-production/concrete-as-a-carbon-sink This might be added to the article. — Preceding unsigned comment added by Lastdingo (talkcontribs) 12:18, 21 June 2019 (UTC)Reply

Greenhouse gas removal edit

What is the difference between this article and Greenhouse gas removal? Looks redundant to me. 80.71.142.166 (talk) 19:07, 29 October 2019 (UTC)Reply

There are more greenhouse gases than CO2. Greenhouse gas removal article also talks about methane. – K4rolB (talk) 11:58, 31 October 2019 (UTC)Reply

Requested move 21 November 2019 edit

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.

The result of the move request was: No consensus to move — Martin (MSGJ · talk) 22:42, 29 November 2019 (UTC) — Martin (MSGJ · talk) 22:42, 29 November 2019 (UTC)Reply


Carbon dioxide removalArtificial carbon dioxide removal – This article is not correctly named. It does not discuss carbon dioxide removal in general, but specifically artificial carbon dioxide removal. It uses quotes and sources from people who are discussing carbon dioxide removal in general (which includes natural methods and is discussed at carbon sequestration. Therefore I propose this article be removed to artificial carbon dioxide removal while the content that revers to carbon dioxide removal in general be moved to carbon sequestration. Alec Gargett (talk) 11:41, 21 November 2019 (UTC) Alec Gargett (talk) 11:41, 21 November 2019 (UTC)Reply

  • Oppose "Removal" already implies artificial removal. Otherwise it would be "carbon dioxide absorption" or something along those lines.ZXCVBNM (TALK) 07:46, 23 November 2019 (UTC)Reply
    • ""Removal" already implies artificial removal". Not really. Carbon sequestration using afforestation for example, which is not discussed in this article, is not "artificial", but it is still carbon dioxide removal. Alec Gargett (talk) 06:58, 25 November 2019 (UTC)Reply

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

Merger proposal edit

I propose to merge Greenhouse gas removal into Carbon dioxide removal. As discussed on Talk:Greenhouse gas removal, technologies for deliberately removing greenhouse gases other than carbon dioxide are speculative. When people talk about greenhouse gas removal, they are talking about carbon dioxide. Clayoquot (talk | contribs) 20:44, 21 December 2019 (UTC)Reply

I redirected Greenhouse gas removal into Carbon dioxide removal. I did not merge any content as I didn't find anything in Greenhouse gas removal that I felt was worth copying over. Clayoquot (talk | contribs) 22:27, 9 January 2020 (UTC)Reply

Extended content on direct air capture cut from article edit

I removed the sections below as they are too much detail for this article. They might be suitable for the Direct air capture article. Clayoquot (talk | contribs) 04:56, 24 February 2020 (UTC)Reply

Example CO2 scrubbing chemistry edit

Calcium oxide edit

Calcium oxide (quicklime) will absorb CO2 from atmospheric air mixed with steam at 400 °C (forming calcium carbonate) and release it at 1,000 °C. This process, proposed by A. Steinfeld, can be performed using renewable energy from thermal concentrated solar power.[1] Quicklime is made by heating limestone to release the CO2 within it. Quicklime is mixed with sand for brick building as mortar, where it hardens by absorption of CO2.

Sodium hydroxide edit

Zeman and Lackner outlined a specific method of air capture using sodium hydroxide.[2] Carbon Engineering, a Calgary, Alberta firm founded in 2009 and partially funded by Bill Gates, is developing a process to capture carbon dioxide using a solution of potassium hydroxide mixed with some water at their pilot plant. They hope to create and sell synthetic fuels at a cost of $100 a ton.[3] They have partnered with Greyrock.[4]

References

  1. ^ "Can technology clear the air?". New Scientist. 2009-01-12. Retrieved 2009-10-29.
  2. ^ Zeman, F.S.; Lackner, K.S. (2004). "Capturing carbon dioxide directly from the atmosphere". World Resour. Rev. 16: 157–72.
  3. ^ Anne Eisenberg (January 5, 2013). "Pulling Carbon Dioxide Out of Thin Air". The New York Times. Retrieved January 8, 2013.
  4. ^ Vidal, John (February 4, 2018). "How Bill Gates aims to clean up the planet" – via www.theguardian.com.

Direct air capture (DAC) process example using NaOH edit

 
Main steps in a DAC process that uses NaOH (caustic soda) as the absorber.[1]

Among the technologies studied for direct air capture (DAC), the use of aqueous hydroxide sorbents is one of the most promising approaches.[2] In this process, CO2 from the air is chemically dissolved into NaOH(aq) solution as Na2CO3; the Na2CO3 is then reacted with solid Ca(OH)2, which regenerates the solvent and produces CaCO3 crystals; lastly, heat is applied to the CaCO3 crystals to produce pure CO2 gas.[1]

Air is pumped through the CO2 absorber as the first step of this process.[1][3] CO2 absorber for DAC are designed either as a counter-current spray tower or as a counter-current thin-falling-film contractor to maximize the contact area between the air and the solvent and thus maximize the absorption driving force.[1][3] The solvent is regenerated in the causticization unit by reacting the Na2CO3 with Ca(OH)2, which also transfers the captured CO2 to the form of CaCO3 solid crystals.[1] A mechanical filter is then used to separate the CaCO3 crystals from the water.[1] Since the crystals come out wet from the filter, they are dried in a steam dryer.[1] Then the dry crystals are heated in a furnace to produce CaO and pure CO2 gas.[1] The CaO is then hydrated to regenerate the Ca(OH)2 used for the causticization reaction.[1] The pure CO2 stream is then compressed and ready to be transported for geologic sequestration, EOR, or other commercial applications.

1 M NaOH (aq) is a typical solvent concentration because this concentration is limited by the causticization reaction that regenerates the solvent and it is not too far from the practical maximum of 2 M NaOH.[1] The furnace/kiln can be powered renewably or by burning fuel on-site with pure oxygen produces in an on-site air separation unit.

NaOH is economically competitive with other absorbents--e.g., amines--used for DAC processes.[1] DAC processes are energy intensive.[1][3] Calcination (at the furnace) is the most energy intensive step of this process.[1][3]

References

  1. ^ a b c d e f g h i j k l m Zeman, Frank (2007-11-01). "Energy and Material Balance of CO2 Capture from Ambient Air". Environmental Science & Technology. 41 (21): 7558–63. doi:10.1021/es070874m. ISSN 0013-936X. PMID 18044541.
  2. ^ Sanz-Pérez, E.S.; Murdock, C.R.; Didas, S.A.; Jones, C.W. (2016). "Direct Capture of CO2 from Ambient Air". Chem. Rev. 116 (19): 11840–76. doi:10.1021/acs.chemrev.6b00173. PMID 27560307.
  3. ^ a b c d Berend Smit, Jeffrey A. Reimer, Curtis M. Oldenburg and Ian C. Bourg (2014). Introduction to Carbon Capture and Sequestration, Vol 1.{{cite book}}: CS1 maint: multiple names: authors list (link)

nanowire/bacteria hybrid that reduces CO2 to form acetate, add here &/or ... ? edit

X1\ (talk) 04:49, 1 April 2020 (UTC)Reply

CDR "slow to act" edit

I've removed the following: "CDR is slow to act, and requires a long-term political and engineering program to effect.<[1]" Any amount of CDR is helpful, and some CDR methods remove CO2 quickly. I think this statement might reflect confusion around what it means for climate change mitigation "to act". The CO2 that's already in the atmosphere will cause temperatures to continue to rise for years, even if we were to stop all human-caused emissions immediately (sorry I've ruined anyone's day). But any action that reduces overall emissions will slow the rate of that rise. Clayoquot (talk | contribs) 21:53, 3 October 2020 (UTC)Reply

References

  1. ^ Cao, L.; Caldeira, K. (2010). "Atmospheric carbon dioxide removal: Long-term consequences and commitment". Environmental Research Letters. 5 (2): 024011. doi:10.1088/1748-9326/5/2/024011.

Ocean acidification edit

I've removed the following for now:

CDR has been proposed as a means to reverse the ocean acidification that is threatening many marine species with extinction. However, a 2015 study concluded that this process would be extremely slow, and deep ocean waters would remain acidified for centuries even if atmospheric CO2 concentrations were to radically drop.[1]

I had already revised the paragraph from an earlier version.[1] The scenario that the source examines is a possible future scenario in which net global emissions are negative, i.e. humanity has overshot its 1.5 degree or 2 degree target and then decided to bring the CO2 concentration down in an attempt to reverse the warming that has already occurred. This is an important scenario and the article should discuss it, but until we can get that context in, the passage doesn't make sense. Clayoquot (talk | contribs) 17:10, 4 October 2020 (UTC)Reply

References

  1. ^ Mathesius, Sabine; Hofmann, Matthias; Caldeira, Ken; Schellnhuber, Hans Joachim (2015). "Long-term response of oceans to CO2 removal from the atmosphere". Nature Climate Change. 5 (12): 1107–13. doi:10.1038/nclimate2729.

Biochar: 106 metric tons, that's it?? edit

Something is wrong with the biochar section. You have '106 tons' in one sentence and several GIGAtons one sentence later, something is off. 162.207.203.26 (talk) 22:19, 30 January 2021 (UTC)Reply

I have removed the first sentence but there is also a problem with the second cite - over to you - you could edit the article yourself Chidgk1 (talk) 17:02, 13 May 2021 (UTC)Reply

Discount rate edit

-- further copy from Werner81 comment on chidgk1 talk page -- I also left the reference to the discount rate that you re-added... However, the sentence lacks context needed to make it clear. Any form of valuation, without exception, would be highly dependent on the discount rate and thus it does not tell me anything. Without more context, the sentence will only confuse readers, which is why I deleted it. I don't wish to offend you so I left it there, but I would suggest reviewing it to make the meaning clearer or if you are not comfortable doing so removing it yourself. --end copy--

I have to say I am confused about the economics of climate change generally - I asked for help from [the economics project] but no reply so far. I agree the discount rate needs context - but not sure I understand it well enough to explain properly.Chidgk1 (talk) 14:46, 10 December 2021 (UTC)Reply
Removed sentence which was: The value of BECCS and CDR generally in integrated assessment models in the long term is highly dependent on the discount rate.[1]

If anyone understands it properly it would be great if you could put it in the right place and add context Chidgk1 (talk) 16:00, 10 December 2021 (UTC)Reply

References

  1. ^ Köberle, Alexandre C. (2019-12-01). "The Value of BECCS in IAMs: a Review". Current Sustainable/Renewable Energy Reports. 6 (4): 107–115. doi:10.1007/s40518-019-00142-3. ISSN 2196-3010.

Relevance of EU Allowance? edit

(below moved from chidgk1 talk page in hope others will also read and clarify)

Hi Chidgk1,

I just wanted to provide some context on why I removed/edited the reference to the EU Allowance scheme for carbon credits. That scheme basically sets an allowance for companies to pollute x amount. If they pollute less, they can sell carbon credits based on the difference. If they pollute more, they need to buy the credits from other companies. These allowances are very different from carbon removal offsets where the offset represents carbon physically removed from the atmosphere by companies or processes that are net negative as described by the article in question. This means the companies literally removed carbon from the atmosphere rather than polluting less than they were "allowed to" within the context of the EU's program. I think it is important not to confuse carbon removal initiatives with the current EU Allowance system, which is overall a good initiative but which comes with all the baggage of a normal cap and trade system. I left your reference to the potential future development of the scheme to include carbon removal, which would be relevant.

... — Preceding unsigned comment added by Werner81 (talkcontribs) 14:31, 10 December 2021 (UTC)Reply

Werner81 Thanks for explaining. Re the EU are they not simply considering adding (properly certified and permanent) CDR to the EU Allowance system? At least that may be one option? Chidgk1 (talk) 14:46, 10 December 2021 (UTC)Reply

Hi Chidgk1, thank you for adding the reference to the community page! That would be a good development and I hope it happens. :) Currently, the EU Allowance system it is a cap and trade system based on allowances, which are defined in Article 3(a) of the EU ETS Directive as being "an allowance to emit one tonne of carbon dioxide equivalent during a specified period..." If a company pollutes less than they are allowed to under the system, they can sell their "allowances" as carbon credits, which represents a ton of carbon that has been avoided as opposed to removed. This is very different from an ecosystem based on removals where companies like biochar producers create net negative products. In other words, after compensating for the company's own carbon footprint, the product still absorbs more carbon from the atmosphere than it emits. — Preceding unsigned comment added by Werner81 (talkcontribs) 15:04, 10 December 2021 (UTC)Reply

But IF biochar can be properly verified presumably the EU could accept it for EUA? It seems the EUA price is quite close to biochar price now. Chidgk1 (talk) 16:04, 10 December 2021 (UTC)Reply