Researchers study activated carbon charged with hydroxides to capture atmospheric CO2
Researchers study activated carbon charged with hydroxides to capture atmospheric CO2
Genevieve OberholzerCNN article: https://www.cnn.com/2024/06/07/climate/carbon-capture-charcoal-sponge-intl/index.html
Nature publication:
https://doi.org/10.1038/s41586-024-07449-2
Carbon dioxide (CO2) is a greenhouse gas that is attributed to the leading cause of earth’s climate change. The gas is produced primarily by burning fossil fuels.1 When CO2 accumulates in the atmosphere, it absorbs and emits infrared radiation. Since the industrial revolution, the concentration of CO2 in the atmosphere has increased dramatically from about 280 ppm to 422 ppm.3 One major impact of this increase in CO2 is the rapid increase in earth’s temperature. Some of the consequences of the increased temperature of the earth are the melting of arctic ice caps, erratic and severe weather patterns, and increased flooding to name a few. In recent years, CO2 emissions have caught the attention of political leaders and scientists. As a result, legislation on climate change has been proposed on an international scale in an attempt to diminish the effects of CO2 emissions. Furthermore, technology designed to remove CO2 from the atmosphere is the subject of much research, especially in environmental chemistry.
A method to remove CO2 from the atmosphere was published in June 2024 by researchers at the University of Cambridge. Li et al reported their work on novel “charged-sorbents”.2 Charged sorbents are pieces of activated carbon fabric positively charged by applying a potential of +0.565 V (versus standard hydrogen electrode) with a 0.1 M KOH filling solution for 4 hours. The activated carbon fabric is then washed and dried to remove excess KOH and to prevent salt formation. This process results in an activated carbon cloth “doped” with reactive hydroxide ions. Researchers confirmed the incorporation of hydroxide ions in the pores of activated carbon samples via 1H solid-state nuclear magnetic resonance (NMR) measurements, as well as titrimetric analysis. Li et al performed several analyses to quantify the amount of CO2 absorbed. They also studied the mechanism behind CO2 capture, the stability of the activated carbon, and its retention of CO2 over time.
Once the activated carbon cloth had been functionalized with hydroxides, it was subjected to testing in a CO2 adsorption isotherm. CO2 adsorption isotherm measurements showed increased CO2 capture at low pressures compared to control samples. It was determined that samples synthesized with less-positive charging potentials and shorter charging times gave smaller CO2 uptake, as fewer hydroxide ions were incorporated into the fabric under these conditions.
Figure 1d, Low-pressure region of the CO2 adsorption isotherms 1e, CO2 uptake of PCS-OH and control samples at 0.4 mbar and 25 °C.2
The sorbents were heated to 150 °C under flowing dry air at atmospheric pressure for 12 h. Dry, pure CO2 adsorption isobars showed very similar capacities and uptake kinetics before and after air exposure, confirming the oxidative stability of the material. Li et al were able to show that the activated carbon could be reused via regeneration by joule heating. Direct air capture of CO2 was simulated with dry air containing 400 ppm CO2 at 30 °C, with desorption conducted under 100% N2 at 130 °C. These measurements showed a CO2 capacity of 0.2 mmol/g, which was similar to the data from the CO2 isotherms. Adsorption and desorption cycles were possible due to the activated carbon’s stability, and it only required heating temperatures from 90-100C. In terms of long-term stability, researchers found that 10% of its CO2 capacity was lost after 14 months. Humidity can affect the activated carbon, as the pores are filled with water, blocking access of CO2 to hydroxide sites.
This research was reported to the general public by Billy Stockwell, a journalist at CNN. Stockwell was able to simplify the research for a non-scientific audience. He was also able to present the aspects of the research that were most novel, such as the electrochemical use of hydroxide ions and the required regeneration temperature of 90-100C. However, I argue that it could have included more information about the research without sacrificing simplicity. He did not mention that the activated carbon needed to be “charged” under a specific electrode and potential. The amount of CO2 able to be absorbed is related to these parameters, as well as the time the electrochemical reaction occurred. He could have mentioned that the experimental conditions were optimized and required specific equipment. I felt that Stockwell wrote his article in such a way that made the reader think that they would be able to perform this experiment on their own. By simply obtaining a sheet of activated carbon at a hardware store, dipping it into some KOH, and hooking it up to a power source, the same results could be achieved in one’s kitchen. The click-baity title is clearly designed to attract viewers, but the sentiment seems a little too do-it-yourself for me. Stockwell also could have mentioned something about the stability of the activated carbon besides the effects of humidity.
Moreover, Stockwell’s article only focuses on Li et al’s work for about half of the article. Midway through he shifts the focus of his writing to the greater political context of CO2 emissions. He is able to establish a justification for the research – the United Nations predicts that CO2 capture may be necessary in tandem with reducing CO2 emissions. I think it was a good choice to discuss the UN’s goals and how the research aligns with it. Following this, there were a series of quotes from an interview with Alexander Forse, principal investigator and head of the chemistry department at the University of Cambridge. A first-person perspective from the principal investigator helps to validate the credibility of the research, but I felt that it made the article seem like a PR stunt for Cambridge. Forse spoke of the need for carbon capture industrially, then expressed his hopes to commercialize the technology. For me, it was almost like Stockwell was helping to promote the technology in an attempt to solicit an offer from a company looking to reduce its CO2 emissions.
Overall, Stockwell did not report anything that was inaccurate about the Nature publication, yet I felt a little bit more could have been said. For a reader who does not have a scientific background, this is a good introduction to the research that also contains some background information that motivates the research behind CO2 capture. Thus, I would rate this article 8/10.
References
(3) Mauna Loa data: https://gml.noaa.gov/ccgg/trends/
I think the CNN article has potentially leaned too heavily into "clickbait-y" language, particularly in the title. While I don't think Stockwell gave the impression that it was something anyone could do at home, I do think he may have given the impression that the process was a lot easier than it really is. I think the context at the end of the article isn't necessarily a bad addition because we don't hear as much about carbon dioxide removal in popular media as we do about lowering emissions. I agree that he could have spent some of his wordcount on the novel science the Nature article was proposing, though.
ReplyDeleteI agree that Stockwell made it seem like the process of carbon capture with charged sorbents was something easily done, especially when he wrote about the decreased temperature required for the absorption/desorption process. This process is also powered by only renewable materials, making it seem less energy intensive than the fossil fuel consumption to reach a temperature of 900C in an industrial process.
DeleteGreat job with the blog post and great pick for your articles. I was super interested to learn about the progress activated carbon is making towards capturing CO2. I read the journal article first and I had trouble understanding all the nuanced details of the experiment. When I went to read the CNN article I was pleasantly surprised that they pulled out the main points like you mentioned. In addition, the real world applications and connections to the water filters and sponges helped me to conceptualize and frame my understanding better. While the CNN article by no means captures the entirety of the journal article it does complement the journal article. It aided in my understanding of the topic. I also definitely agree that the title of the CNN article seemed click bait-ish. I would go even further and say I think the title of the article demeans and diminishes the work of Li et al. The work that Li et al did was very complex, controlled, and included multiple variables. The title of the CNN article does not convey any of that. Overall I agree with your comments and enjoyed learning about this topic.
ReplyDeleteThank you! I was really interested in finding an article that focused on a new chemical process that could be implemented against harmful gas emissions like CO2. I agree that the connection to water filters makes the audience have a better understanding of what the activated carbon is. I have to be honest, I never knew that activated charcoal sponges are widely used in kitchens and I never even heard of activated charcoal sponges before reading this article. I thought of activated charcoal as a powder or something in toothpaste.
DeleteThe CNN article is definitely an oversimplification of the work. In a way, I think Stockwell was trying to make it seem like anyone could have come up with this idea because the main material was something that many people use in their own homes. However, there is a sizable amount of literature precedent in attempting to use sorbents for CO2 capture. In the CNN article, it seems like science isn't guided by first principles, but ideas can be studied on a whim. Stockwell included this quote from Forse that I think supports this:
“This approach was a kind of crazy idea we came up with during the Covid-19 lockdowns, so it’s always exciting when these ideas actually work.”
Overall, the CNN article was a lot shorter than I expected. I appreciated how it talked about both the pros and cons of the Nature study providing both sides of the argument (to some extent). I agree with everyone else that the title and “hook” of the article is extremely misleading and an immense oversimplification of the methods section of the Nature paper. While some simplification is necessary to reach a broader audience, the way it was presented (like you guys have said) makes it seem too easy and very DIY. It could be possible that the author is trying to emphasize the simplicity and ease of this specific method of carbon capture compared to other methods, but this point can be made with actual evidence and data instead of framing the materials for this study as common kitchen or home items. This does make me question the purpose of the CNN article. However, I think the context provided in this article is very important as it emphasizes the importance of carbon capture and urgency of the situation but the flow of the article would have made more sense if that section was more directly connected to the Nature paper itself. Overall, I wish the CNN article could have presented the Nature paper in little more detail and maybe provide the context and background on the field and societal effects before going into the research itself.
ReplyDeleteAs a chemist, reading the preparation of the activated carbon sample in the Nature paper seems pretty straightforward, and I am also able to understand analytical techniques like solid state NMR, TGA, and CO2 isotherms. The method is not the majority of the Nature paper, but rather the quantification and mechanism of CO2 absorption and desorption. Stockwell mainly reports on the methodology because it is a lot easier to explain than some of the methods used by Li et al for testing the capabilities of the new charged sorbents. I think it's fair to say that the procedure of doping the activated carbon with hydroxides is important, but a lot of the work was in its optimization and application. Adding the hydroxides to the activated carbon is important, but if it wasn't actually able to capture more CO2 than other sorbents, Stockwell would have written a very different article. In the CNN article, Stockwell doesn't discuss how well the PCS-OH performed compared to control samples.
DeleteGreat job on the blog post! I think that this article is a perfect example of how scientific findings end up so diluted and misconstrued once they trickle down the chain of different medias. Although, I can appreciate how digestible Stockwell was able to make the Nature study, he may have simplified it too much in order to get his message funneled through to as many people as possible. I really like and agree with the way you called it "click-baity" and "DIY" as he excluded some key information about the methods and data in the Nature study that highlight some important limitations and findings. All in all, I agree with your analysis that although Stockwell did not misrepresent any information from the study, he over simplified it to a point where a read's biggest take away could have been that they carbon capture is not complex and should be the predominant form of mitigating CO2 in the atmosphere.
ReplyDeleteThank you! I am sure that journalists care very much about article viewership at CNN, and sometimes they use crafty tactics to convince someone to read an article that they otherwise would have no interest in. I think we live in a culture that is very polarized when it comes to environmental issues, so naming an article "How an unassuming ‘sponge’ in your home could suck planet-heating pollution from the atmosphere" might draw interest from both sides of the political spectrum. When I saw the title of the article for the first time, I was motivated to read the Nature publication because I wanted to understand what was really happening in the research.
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ReplyDeleteI agree with your analysis that the CNN article was a decent summary of Li et al.'s study. I particularly liked how most of the second half talked about the implications of carbon capture technologies v.s. lowering carbon emissions, along with giving credit to existing carbon capture technologies. Both of these elements drive home the point that this new material is not some magical new climate change remedy- we still need emissions regulations and other actions to slow down the climate crisis, even if our remediation tech is improving.
ReplyDeleteRegarding the level of detail, I think Stockwell gave an appropriate summary of the technology (with one exception). Especially for synthesis studies like this Nature paper, a lot of the content is fabrication methods and material characterization, which would not be understandable nor relevant to a non-scientific reader, who only needs to know the study's takeaway.
However, one part of the CNN article that bothered me was Stockwell's comparison of PCS-OH to an ordinary kitchen sponge. In reality, the only thing these two materials have in common is the fact that they're porous. While Stockwell later describes PCS-OH more accurately as a "sponge-like" "activated charcoal", his earlier terminology paints a really misleading (or straight up false) picture of what this new technology is, and even makes the article seem clickbait-y as you mentioned. I agree that it's important to describe scientific phenomena in a way that's understandable for the general public, but these descriptions must remain accurate to the original paper- especially in a time with a heightened amount of untrue/misleading info circulating.
I'm so glad you mentioned that Stockwell called the material a sponge! It bothered me too. It makes sense that he would use a sponge as an analogy for a porous material, but I don't think of a water filter as a sponge. I think of it as a filter. If there is activated carbon in the water filter in my kitchen, it is a lot smaller and thinner than an ordinary kitchen sponge and not at all the dimensions of the activated carbon used in the Nature publication. One easy way to make an audience understand something is to make it relatable, but I think the analogy is limited. It has the potential for confusion like you mentioned.
DeleteThis was a really interesting read, great article choice!
ReplyDeleteI agree that the article is somewhat "clickbait-ey," however, I am not necessarily upset by this choice. In the contemporary media climate, an average person's attention is being pulled in at least hundreds of directions. I'm sure we've all heard studies on shortening attention spans, or anecdotally, been personally victimized by the TikTok doom scroll. I think that the best case scenario for clickbait is that it ends up actually educating someone on a relevant issue.
I also agree that Stockwell may have given readers the impression that this technology/method is much more simple and easy to create or use than it actually is, I agree that this is somewhat misleading. However, it seems that the purpose of this article is not only to convey the ideas of the Nature publication, but also to contextualize the economic and political importance of carbon capture technologies more broadly speaking. For this reason, it seems acceptable to not be bogged down by the methodologies and specifics of this particular paper. This is why I think that Stockwell did not mention details like how the activated carbon needed to be "charged." I agree that this is a critical detail, but I can understand why it was omitted. I think these simplifications allow Stockwell to more clearly and concisely explain how this technology is a puzzle piece in the bigger picture to achieve the UN's goals.
You dissected this article really well! I agree with your analysis that despite being a little click-baity, the CNN article did a decent job of communicating Li et al's research. Stockwell broke down the development of activated carbon-felt carbon capture technology to a digestable topic that average readers can begin to understand; however, he may have simplified it too much to the point that it understated the complexity of the technology and hard work that Li et al put into developing this carbon capture technique.
ReplyDeleteI did appreciate the way that Stockwell tied this potential breakthrough in carbon capture to climate policy. As a person deeply concerned about the climate crisis (and all environmental issues), I believe that it is the job of science to inform public decisions for the good of the people. In their article, Stockwell not only explains the research findings but also takes the topic a step further by discussing how it can be applied to society's solutions to the climate crisis. While some aspects of the article felt silly, such as the click-bait title and lack of description of the research, I really respected the way they tied Li et al's carbon capture work to policy and real world applications.
Great choice for your article, it was a really interesting read. I agree that the title of the article oversimplifies the work presented in the research paper as clickbait, but I think that this is not necessarily a bad thing as long as the research is solidly explained in the article and the work is not too sensationalized. Additionally, I think the article simplifies the research from the Nature paper too much, resulting in an explanation that is actually more confusing than if the author had used more technical terms. The sentence, “But scientists discovered this changed when they mimicked the process of charging a battery — in which ions stick to a battery’s electrodes — using chemical compounds called hydroxides,” was confusing before I read the scientific paper because it sounded like the hydroxides were used to charge the battery when in reality a charge was applied to the activated carbon causing the hydroxide ions to accumulate in the pores of the charcoal material. This is somewhat clarified in the following paragraph, but I think the author should have mentioned something about the carbon cloth being positively charged by applying a potential to it causing the negatively charged hydroxide ions to gather in the carbon pores.
ReplyDeleteOverall I agree with your evaluation of the article, especially that it was a good decision to talk about carbon capture in a larger context and mention the Paris Agreement’s goals.
I agree with your statement that the CNN article did a great job of skipping the scientific term in the paper. I agree the synthesis details in the paper is not important for ordinary people. But It gave the readers the implication that those readers can also do their experiment on their own. However, the experiment performed on the paper was conducted under fine control, and there is no way to use a "sponge" in your home to absorb carbon dioxide. And the title is click-baiting. But overall, this article is good for ordinary reader.
ReplyDeleteI think you have done a great job summarizing both the article and the Nature paper and I wholeheartedly agree with your assessments. Overall, I think this CNN article has done a better job at reporting details, compared to some of the previous articles we have explored in class, but I think you bring up an excellent point about how the CNN article frames this "sponge" as an easy DIY project that the average person can do which could perhaps lead to false hope of a way to diminish CO2 in the homes of the general public. I really appreciated how the article also noted the importance of reducing CO2 production globally, rather than CO2 removal, because it does draw attention to fixing the problem at the source.
ReplyDeleteI think you did a great job examining the paper and the CNN article! The CNN article was surprisingly short and scientific. I might even argue slightly more scientific than a general audience may be interested in, but I think that makes sense coming from a source such as CNN. I think the article could use some sort of introductory statement about CO2 and general emissions to give the reader a bit more context which could make the second half of the article feel more connected to the discussion of the Li et al. paper other than just the quotes from the PI.
ReplyDeleteLike the other commenters, I really appreciate your explanation of the paper and the article, as well as your points about potential oversimplifications in the CNN article. While I agree that the article makes the process of CO2 capture by these activated carbons seem more simple than it needs to, I think it is relevant to remember that ultimately we, as college-educated scientists, are not the target audience. Most people reading this article do not know how this technology works, nor do they particularly care about learning. By keeping the explanation of Li et al.'s work relatively simple and drawing attention to broader climate concerns, Stockwell both keeps the audience's attention and gives them a reason to care. Given that the group also intends to commercialize their charged sorbent technology for CO2 capture, keeping the article accessible is in the best interest of both Stockwell and the group.
ReplyDeleteI really enjoyed both of these articles! The nature article was particularly interesting, especially the idea of using sorbents to capture CO2. I agree with your assessment (along with almost everyone else's) that the title is quite clickbait-y, though I wonder if that was intentional on Stockwell's part. I would imagine that most people have at least heard of activated charcoal, and some may even recognize it from their water filters. Often, science articles in popular media tend to focus less on the specifics of scientific methods and more on summarizing the new findings and their potential implications for future research, and I think Stockwell does a good job of this. For many readers, the details of an experiment can bog down the article and make it less accessible, but Stockwell didn’t make it seem like the experiment could be done at home. The Nature article is also directly linked fairly early in the CNN article for those who want to dive deeper into the research. While the science in Li et al.’s work is pretty neat, I suspect that the target audience might not feel the same way. For that reason, I think Stockwell did a decent job in making the key takeaways clear for the general public. The most important points are what carbon capture is and the fact that implementing charged activated charcoal (commonly found in water filters) could be a cheaper way to achieve it.
ReplyDeleteA very thorough and well-written review of both the CNN and Nature articles. I agree that there are some aspects of the scientific article which are left out of the CNN retelling but, on the whole, I think this is justified because the fine details (in my opinion) are not in the purview of the news sites or generally in the interest of the typical news site reader. All of these details, which would be of interest to some, are discoverable in the linked article, which I believe is enough. With regard to the use of the term "sponge", in defense of the author it was put in quotation marks in the title and when I first read it, I actually appreciated the analogy because I can easily imagine a sponge soaking up water and I can therefore more easily imagine that this material can "soak up" carbon dioxide.
ReplyDeleteI completely agree with your ranking of 8/10. I thought your use of the word "click-baity" was a very good description of the article. Something I notice that goes along with this idea is they link other CNN with the text "efficient tool to slow climate change." I find this misleading because they are presenting information from the study in the same sentence. On top of this, the actual article is not linked until the end of the fourth paragraph. I do not know if I am being a stickler, but it seems wrong to reference information from a study and then hide it link in the middle of the text. Many other articles and documents are linked throughout the piece. I believe this draws the focus away from the study itself and again gives that idea of clickbait.
ReplyDeleteI agree that this is most likely a PR stunt for Cambridge. Why else would they include a photo of the scientist that worked on the research. It does not add anything to the article and at first glance I thought it was an add.
I agree with a lot of what you said, good synopsis and good choice of articles! I think this is the first blog post we've had where the experimental procedures of the peer-reviewed article had some synthetic portions rather than purely computational/modeling work. I agree that the explanation of these synthetic methods was simplified. How do you think this level of simplification compared to other computational studies we've seen so far this semester? I feel like it is quite simplified but also gives more detail than was given in some of the articles that referenced publications using computational models. I'd be interested to hear your thoughts!
ReplyDeleteI was also curious about more of your opinions on the CNN article. I agree that it almost seems like Stockwell is trying to sell a product, and I'm not sure how to feel. Do you think that this takes away from the informative nature of the article and was this a part of the two points the article lost in your rating? If so, do you think there is way to write about a scientific product where the article can be promotional and educational without seeming disingenuous and/or self-serving?
Really good analysis of the article and paper! Like most others, I agree that the title of the article can be misleading in the sense that it could lead the reader to believe that this technology is easily achieved with at-home products. While I do appreciate the attempt at making real-world connections for a general audience, I agree that the wording could have been slightly more accurate, or could have been omitted completely to avoid confusion.
ReplyDeleteOne thing I really liked about the article was the discussion near the end about the broader impacts of carbon capture and its role in climate change efforts. Stockwell did a great job of highlighting the larger issue of reducing GHG emissions, but then pivoted into how carbon capture can potentially contribute to the IPCC's climate goals. Overall, I think that the article's main goal was to portray the results and explain their implications in a way that's very understandable to a wide audience. I feel that they definitely achieved this, with maybe a slight hiccup in phrasing in the beginning, so I would give this article a 9/10.
This was a great article choice! I was a bit surprised that CNN would chose to cover an article like this.
ReplyDeleteI agree that the CNN article oversimplifies the procedure Nature article but I don't know how they could incorporate details in a way that makes sense to a nonscientist. I expected the CNN article to provide a bit more context to the reader about direct air capture, maybe with a nod to SO2 scrubbers and coal. For a general audience, you need to give people a reason to care and actual hope that this process will actually work. There was also really cool "factoids" that could have been better emphasized from the Nature article, such as the porosity and relatively consistent CO2 uptake through the cycles. Also, the images they chose don't really add anything to the article, yet they take up so much real estate on the page. A cartoon version of 3b from the article or even just a picture of one of the emission sources mentioned would have made the article so much more memorable. The last sentence of the article referring to this as a "crazy lockdown idea" felt unprofessional to me and could have been left out in my opinion.
CNN did an okay job at explaining the Nature article, and I even like the corny title. But, it lacked context and had terrible images/figures explaining the main points.
I think you were a bit too gracious with your score.
I really liked both of these papers they were great reads! The CNN article does a great job at explaining science at a scientific level but at the same time allowing non-scientific readers to understand. I really like your own explanation and assessment of these two writings. I think I would appreciate if the article could lay down some more background but besides that I think the article was pretty spot on. The paper is well written also. My favorite part was when the author of the article started talking about the bigger picture and political aspect of CO2 emissions.
ReplyDeleteWhat an interesting article to pick! I like how you analyze the texts in your blog's second to last paragraph. I wonder if Stockwell contextualized the political climate of CO2 emissions as an exercise in questioning a scientific article. CNN readers might not be used to considering the politics of net zero emissions and might not know where CO2 is produced and regulated. If you are not a scientist reading the nature article it could be assumed that CO2 could be washed out of the atmosphere in scale shortly. It is necessary to point out that 'cleaning' the atmosphere of CO2 is a last resort option.
ReplyDeleteAfter reading the nature article, I am left wondering how much carbon dioxide is produced in the making of the sponge- and what long term carbon dioxide storage might look like.
I think it was an interesting article to read. I appreciate the excellent job done on the blog post, effectively summarizing the CNN article and the research paper. I agree with you that the article has a somewhat "click-baity" quality, it does provide valuable insights. The research offers valuable insights that could contribute to the development of practical and efficient CO2 capture technologies. But I also do think that the article might be missing a detailed look at the potential problems and challenges of applying the research findings in real-world situations, like issues such as scalability and how large scale production/use of activated carbon fabric can impact the environment. The oversimplification of the article could be misleading to the public.
ReplyDeleteI totally agree with your reading here, and I think that the CNN article does a good job of outlining the findings of the article. I agree with the whole "PR Stunt" angle you posit, I think that is definitely symptomatic of the gaps in the journalist's analysis here. I think the push for "commercialization" of the studies presented here definitely lead to a straying from a "public informing" motivation here, and definitely is a trend I have noticed in a lot of climate reporting, especially from these major outlets like CNN. Feels concerning!
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