Carbon Dioxide Removal (CDR)

[kassy]

Start-ups are adding antacids to the ocean to slow global warming. Will it work?


...

Chang, a chemical oceanographer leading the field work for Vesta, isn’t so sure just yet. Looking at the clear sediment tube, she is disappointed to discover a distinct layer of olivine crystals buried beneath about 10 centimetres of beach sand.

“The olivine is deeper than I was expecting,” she says. “I was hoping it would stay on top and mix in.”

That might signal trouble because it could slow down a series of reactions that could — along with many other factors — determine whether the beach lives up to its promise.

Vesta is one of many companies investigating unusual solutions for removing carbon from the atmosphere. Global temperatures are quickly approaching 1.5 °C above preindustrial levels and nations have yet to rein in emissions. Models suggest that the world would need to pull billions of tonnes of CO2 from the air each year by mid-century to keep temperatures from rising beyond 1.5–2 °C — a goal countries agreed on with the 2015 Paris climate agreement. Scientists, entrepreneurs and investors are increasingly looking to the oceans for solutions, which cover 70% of the planet and already soak up more than one-quarter of the greenhouse gases emitted each year.

...

Storms reshuffled everything during the winter, so one of Chang’s first tasks when this year’s fieldwork began last month was to find the olivine. Initial inspections suggested that it had spread farther than expected, and in some places the mineral got buried, which Chang says is less than ideal. The reactions will still take place with water in the sediments, she adds, “but the process is more efficient if the olivine is on the surface”.

...

https://www.nature.com/articles/d41586-023-02032-7

[Freegrass]

Start-ups are adding antacids to the ocean to slow global warming. Will it work?
https://www.nature.com/articles/d41586-023-02032-7

You only took out the negatives of the article Kassy, but it's actually a very good article. Thanks for posting!

I suggest people read the whole thing.

[kassy]

I would call them the most interesting field finds but yes always read the whole thing.

Knowing what works and what doesn´t helps refining the application and that is good.

[Freegrass]

I would call them the most interesting field finds but yes always read the whole thing.

Knowing what works and what doesn´t helps refining the application and that is good.

True. I think they need to figure out olivine grain size and beach composition now. I'm sure that'll have an effect on how deep the olivine gets buried. If the olive is too fine, it'll end up deeper in thicker grains of sand, I think. Like shaking a box of mixed nuts will always bring the biggest nuts to the top.

But I also think that if it gets mixed with the sand, the olivine will be grinded into smaller particles more easily. But then smaller particles will sink deeper...

Anyway... Good research. I'm happy they're finally getting on with it. I started off this thread with Vesta, so I hope they succeed. Although I do think now that glacial dust may be the cheaper solution. I guess it'll all come down to availability nearby the beaches...

[kassy]

Yes or the correct mix or amount. Anyway just a plan is never enough, you need to check if it works as expected and by learning new things we can also improve that.

Although I do think now that glacial dust may be the cheaper solution.

There is quite a lot we can use and we are going to need it all. The trick is probably to work out how we do it most efficiently in money and energy use. Of course this is all a drop in a bucket until we rein in our fossil fuel emissions.

[Freegrass]

Excellent video on carbon dioxide removal (CDR) with iron fertilization. I think he's covered all the pros and cons here.

[morganism]

Revolutionary Electrolyzer Efficiently Converts CO2 into Renewable Propane Fuel

A team of researchers at IIT has designed an electrolyzer device capable of efficiently converting carbon dioxide into propane using inexpensive and readily available materials. This breakthrough, detailed in a paper published in Nature Energy,  offers considerable promise in helping reduce greenhouse gas emissions and developing renewable chemical manufacturing.

“Making renewable chemical manufacturing is really important,” explains Mohammad Asadi, who spearheaded the study. “It’s the best way to close the carbon cycle without losing the chemicals we currently use daily.”

What makes this electrolyzer so innovative is its unique catalytic system. It leverages inexpensive metal and organic compounds to produce propane, a widely used fuel comprised of three carbon atoms. Until now, converting CO2 into complex multi-carbon molecules like propane has proven extremely challenging.

By employing a combination of experiments and computational modeling, the team gained a deep understanding of how their novel catalyst achieves high reaction activity and selectivity towards propane. These insights illuminated key factors influencing the catalyst’s performance and stability.

A major advantage of this technology is its implementation of a continuous-flow electrolyzer design. This enables the non-stop, scalable production of propane, overcoming limitations of conventional batch-style CO2 conversion systems. The engineering of this lab-scale prototype demonstrates IIT’s commitment to developing commercially viable sustainable energy solutions.
(more)

https://scienceswitch.com/2023/08/22/revolutionary-electrolyzer-efficiently-converts-co2-into-renewable-propane-fuel/


Imidazolium-functionalized Mo3P nanoparticles with an ionomer coating for electrocatalytic reduction of CO2 to propane

Abstract

Propane is a tri-carbon (C3) alkane widely used as a fuel. Despite recent advances in CO2 electrocatalysis, the production of C3+ molecules directly from CO2 is challenging due to high reaction barriers and competing reactions to C1, C2 and H2 products. Here we report a catalytic system composed of 1-ethyl-3-methylimidazolium-functionalized Mo3P nanoparticles coated with an anion-exchange ionomer that produces propane from CO2 with a current density of −395 mA cm−2 and a Faradaic efficiency of 91% at −0.8 V versus reversible hydrogen electrode over 100 h in an electrolyser. Our characterization and density functional theory calculations suggest that imidazolium functionalization improves the electrocatalytic properties of Mo atoms at the surface and favours the pathway towards propane by increasing the adsorption energies of carbon-based intermediates on the Mo sites. Our results indicate that the ionomer coating layer plays a crucial role in stabilizing the imidazolium-functionalized surface of Mo3P nanoparticles during long-term testing.

https://www.nature.com/articles/s41560-023-01314-8

[kassy]

Moved some posts to the more general chat thread:
https://forum.arctic-sea-ice.net/index.php/topic,3697.0.html

[morganism]

Integrating Synthetic CO2 Fixation in E. coli


Researchers at the Max-Planck-Institute for Terrestrial Microbiology have achieved a significant milestone in synthetic biology by developing a novel biochemical pathway that converts carbon dioxide (CO2) directly into acetyl-CoA, a key metabolic building block. This development marks a major advancement in synthetic CO2 fixing pathways within living cells, specifically in the bacterium E. coli.

The climate emergency has intensified the need for innovative solutions for CO2 capture and conversion. Synthetic biology offers new avenues for designing CO2-fixation pathways that are more efficient than those found in nature. However, implementing these new pathways in various in vitro and in vivo systems poses significant challenges. The group led by Tobias Erb has made a breakthrough in this field by designing and constructing a new synthetic CO2-fixation pathway, named the THETA cycle.

The THETA cycle is distinctive in its ability to convert two CO2 molecules into one molecule of acetyl-CoA in a single cycle. Acetyl-CoA is a central metabolite in nearly all forms of cellular metabolism and is crucial for the synthesis of various biomolecules, including biofuels, biomaterials, and pharmaceuticals. This makes it an exceptionally valuable compound in biotechnological applications.

The cycle was designed around two of the fastest known CO2-fixing enzymes: crotonyl-CoA carboxylase/reductase and phosphoenolpyruvate carboxylase. These powerful biocatalysts, found in bacteria, can capture CO2 more than ten times faster than the enzyme RubisCO, which is responsible for CO2 fixation in chloroplasts during natural photosynthesis.

In the laboratory, the functionality of the THETA cycle was confirmed in test tubes. Following this, the researchers embarked on a series of rational and machine learning-guided optimizations, which led to a hundredfold increase in the acetyl-CoA yield. The next critical step was to test its feasibility in vivo, for which the cycle was divided into three modules. Each module was successfully incorporated into E. coli, and their functionality was verified through growth-coupled selection and isotopic labelling.

Shanshan Luo, the lead author of the study, highlighted the uniqueness of the cycle, stating, "What is special about this cycle is that it contains several intermediates that serve as central metabolites in the bacterium's metabolism. This overlap offers the opportunity to develop a modular approach for its implementation." Luo noted the successful demonstration of the three individual modules in E. coli but also acknowledged that closing the entire cycle in vivo remains a significant challenge, given the need to synchronize the 17 reactions with the natural metabolism of E. coli, which involves hundreds to thousands of reactions
(more)

https://www.energy-daily.com/reports/Max_Planck_Institute_Breakthrough_Integrating_Synthetic_CO2_Fixation_in_E__coli_999.html


Construction and modular implementation of the THETA cycle for synthetic CO2 fixation

https://www.nature.com/articles/s41929-023-01079-z

[morganism]

Interest swelling in ocean carbon removal

Brad Ack gets why people might be leery about using fledgling technologies to sink billions of tonnes of carbon pollution in the ocean to tackle the climate crisis.

However, record levels of global warming have put the planet and ocean in such peril that aggressive large-scale measures are essential, said Ack, chief executive officer for Ocean Visions, a nonprofit coalition advancing ocean-climate solutions.

“The oceans have very significant potential to assist and be part of the giant carbon removal challenge we have,” Ack said. “The ocean is already the largest cycler of carbon on the planet.”

Even the near elimination of emissions from burning fossil fuels by 2050 won’t be enough to cool the planet’s system and superheated oceans or fully alleviate the rise of wildfire, droughts or floods, Ack said.

The United Nations Intergovernmental Panel on Climate Change (IPCC) has made clear a range of carbon dioxide removal (CDR) strategies is necessary to meet the international target to limit warming to 1.5 C.

Carbon removal, also known as negative emissions strategies, includes natural solutions like relying on forests, marshes or soil to trap and store carbon, or the deployment of emerging technology to pull carbon directly from the air or ocean, and then, storing it long term.

Estimates suggest between five and 16 billion tonnes of CO2, or 16 GtCO2 (gigatonnes), will need to be removed annually by 2050, depending on the rate of emissions reductions and whether we overshoot our climate targets.

It’s not a question of whether we do carbon removal, but rather where we do it, Ack stressed.

The ocean is already the planet’s greatest carbon sink, absorbing 30 per cent of human-caused emissions and 90 per cent of excess heat fuelled by greenhouse gases. Able to lock CO2 in the deep sea for hundreds and even thousands of years, oceans act as a reservoir for about 38 GtCO2 of this “blue carbon.”
(descriptn tech)
Professor Lisa Levin of Scripps Institution of Oceanography at UC San Diego, led a team study on how manipulating the ocean to curb the climate crisis might threaten deep-sea ecosystems or its vital carbon cycle services.

Decaying seaweed on the seabed could deplete oxygen and pumping excessive carbon dioxide into the deep sea could suffocate marine life.

Seeding the ocean with substances to boost alkalinity or plankton could reduce light, cause harmful levels of cadmium or nickel, destructive algal blooms, or increase ocean acidity.

“The technologies are pretty much unproven,” she said. There’s concern that if people do think about the ocean, they're thinking about it the wrong way — as a waste disposal system,” she said.

There’s a need for more research and integrated policy to make sure mCDR costs don’t outweigh the benefits, she said.

Ack agreed, noting Ocean Visions has created a blueprint to accelerate science and actions needed to prove or disprove the viability of novel ocean carbon removal methods by 2030.

“We’re a consortium of science organizations trying to ask and answer the most critical questions about whether or not this can scale and we can do it safely, effectively, and how it compares with all of the other alternatives,” Ack said.
(more)
https://www.nationalobserver.com/2024/01/08/news/interest-swelling-ocean-carbon-removal

[Freegrass]

Interest swelling in ocean carbon removal

https://www.nationalobserver.com/2024/01/08/news/interest-swelling-ocean-carbon-removal

Nice article Morganism. I like the last part of the article.


Ack agreed, noting Ocean Visions has created a blueprint to accelerate science and actions needed to prove or disprove the viability of novel ocean carbon removal methods by 2030.

“We’re a consortium of science organizations trying to ask and answer the most critical questions about whether or not this can scale and we can do it safely, effectively, and how it compares with all of the other alternatives,” Ack said.

To date, the focus of carbon clean-up has centred on land-based natural solutions, which simply cannot meet the significant carbon removal that’s necessary, Ack said.

Two billion tonnes of CO2, or two gigatonnes (GtCO2), are being removed annually — the vast majority using conventional land-based methods like protecting or restoring forests or soil management, recent research indicates.

A mere one per cent of that total comes from emerging technologies like direct air capture (DAC) and storage.

Yet natural terrestrial carbon removal, even scaled up to five GtCO2 by 2050, won’t be enough on its own to reach net zero.

It’s estimated novel methods including ocean-based options need to provide half of the 10 GtCO2 removal needed by mid-century. Those strategies must increase to an estimated 15 GtCO2 by the end of the century.

There will undoubtedly be trade-offs to large-scale interventions, but the climate crisis is now immune to tentative interventions, he said.

It’s analogous to using chemotherapy, which has unpleasant symptoms, to treat a lethal cancer, he added.

Global warming is on track to be increasingly life-threatening, he stressed.

“We know it and see it in our real lives,” Ack said.

‘Now the question is, how many different forms of medical intervention are we willing to try to keep ourselves alive?”

[morganism]

Capturing greenhouse gases with the help of light

(...)
 Light-controlled acid switch
Led by Maria Lukatskaya, Professor of Electrochemical Energy Systems, the scientists are exploiting the fact that in acidic aqueous liquids, CO2 is present as CO2, but in alkaline aqueous liquids, it reacts to form salts of carbonic acid, known as carbonates. This chemical reaction is reversible. A liquid's acidity determines whether it contains CO2 or a carbonate.

To influence the acidity of their liquid, the researchers added molecules, called photoacids, to it that react to light. If such liquid is then irradiated with light, the molecules make it acidic. In the dark, they return to the original state that makes the liquid more alkaline.

This is how the ETH researchers' method works in detail: The researchers separate CO2 from the air by passing the air through a liquid containing photoacids in the dark. Since this liquid is alkaline, the CO2 reacts and forms carbonates. As soon as the salts in the liquid have accumulated to a significant degree, the researchers irradiate the liquid with light. This makes it acidic, and the carbonates transform to CO2. The CO2 bubbles out of the liquid, just as it does in a bottle of cola, and can be collected in gas tanks. When there is hardly any CO2 left in the liquid, the researchers switch off the light and the cycle starts all over again, with the liquid ready to capture CO2.

It all depends on the mixture
In practice, however, there was a problem: the photoacids used are unstable in water. "In the course of our earliest experiments, we realised that the molecules would decompose after one day," says Anna de Vries, a doctoral student in Lukatskaya's group and lead author of the study.

So Lukatskaya, de Vries and their colleagues analysed the decay of the molecule. They solved the problem by running their reaction not in water but in a mixture of water and an organic solvent. The scientists were able to determine the optimum ratio of the two liquids by laboratory experiments and were able to explain their findings thanks to model calculations carried out by researchers from the Sorbonne University in Paris.

For one thing, this mixture enabled them to keep the photoacid molecules stable in the solution for nearly a month. For another, it ensured that light could be used to switch the solution back and forth as required between being acidic and being alkaline. If the researchers were to use the organic solvent without water, the reaction would be irreversible.

Doing without heating
Other carbon capture processes are cyclical as well. One established method works with filters that collect the CO2 molecules at ambient temperature. To subsequently remove the CO2 from the filters, these have to be heated to around 100 degrees Celsius. However, heating and cooling are energy-intensive: they account for the major share of the energy required by the filter method. "In contrast, our process doesn't need any heating or cooling, so it requires much less energy," Lukatskaya says. More than that, the ETH researchers' new method potentially works with sunlight alone.

"Another interesting aspect of our system is that we can go from alkaline to acidic within seconds and back to alkaline within minutes. That lets us switch between carbon capture and release much more quickly than in a temperature-driven system," de Vries explains.

With this study, the researchers have shown that photoacids can be used in the laboratory to capture CO2. Their next step on the way to market maturity will be to further increase the stability of the photoacid molecules. They also need to investigate the parameters of the entire process to optimise it further.

https://www.energy-daily.com/reports/Capturing_greenhouse_gases_with_the_help_of_light_999.html


Solvation-Tuned Photoacid as a Stable Light-Driven pH Switch for CO2 Capture and Release

https://pubs.acs.org/doi/10.1021/acs.chemmater.3c02435


Photoacids are organic molecules that release protons under illumination, providing spatiotemporal control of the pH. Such light-driven pH switches offer the ability to cyclically alter the pH of the medium and are highly attractive for a wide variety of applications, including CO2 capture. Although photoacids such as protonated merocyanine can enable fully reversible pH cycling in water, they have a limited chemical stability against hydrolysis (<24 h). Moreover, these photoacids have low solubility, which limits the pH-switching ability in a buffered solution such as dissolved CO2. In this work, we introduce a simple pathway to dramatically increase stability and solubility of photoacids by tuning their solvation environment in binary solvent mixtures. We show that a preferential solvation of merocyanine by aprotic solvent molecules results in a 60% increase in pH modulation magnitude when compared to the behavior in pure water and can withstand stable cycling for >350 h. Our results suggest that a very high stability of merocyanine photoacids can be achieved in the right solvent mixtures, offering a way to bypass complex structural modifications of photoacid molecules and serving as the key milestone toward their application in a photodriven CO2 capture process.

[morganism]

Study warns of overreliance on carbon dioxide removal in climate strategies

(...)
 The findings of the paper suggest a considerable overestimation by the Intergovernmental Panel on Climate Change (IPCC) regarding the extent to which CDR technologies, specifically bioenergy with carbon capture and storage (BECCS), and afforestation, can safely contribute to meeting climate targets. This overreliance on future carbon removal, as opposed to immediate emission reduction and fossil fuel phaseout, poses significant risks to food security, human rights, and natural ecosystems. The research underscores a misalignment with the sustainable thresholds for land-based CDR methods once the implications for biodiversity and human livelihoods are factored in.

Co-author Prof. Paul Leadley from the University of Paris-Saclay emphasizes the unrealistic expectations set by the IPCC's feasible cost assessments for CDR. He points out the inherent conflict between the extensive land requirements for CDR and the imperative to preserve biodiversity, freshwater resources, and food security. According to the study, the ambitious upper limits of CDR could entail converting land three times the size of the United States for bioenergy crops or tree planting, potentially displacing over 300 million people into food insecurity.
(more)

https://www.energy-daily.com/reports/Study_warns_of_overreliance_on_carbon_dioxide_removal_in_climate_strategies_999.html


Sustainability limits needed for CO2 removal
The true climate mitigation challenge is revealed by considering sustainability impacts

Many governments and industries are relying on future large-scale, land-based carbon dioxide (CO2) removal (CDR) to avoid making necessary steep greenhouse gas (GHG) emission cuts today (1, 2). Not only does this risk locking us into a high overshoot above 1.5°C (3), but it will also increase biodiversity loss, imperiling the Kunming-Montreal Global Biodiversity Framework (KMGBF) goals (4). Such CDR deployments also pose major economic, technological, and social feasibility challenges; threaten food security and human rights; and risk overstepping multiple planetary boundaries, with potentially irreversible consequences (1, 5, 6). We propose three ways to build on the Intergovernmental Panel on Climate Change (IPCC) analyses of CDR mitigation potential by assessing sustainability risks associated with land-use change and biodiversity loss: estimate the sustainable CDR budget based on socioecological thresholds; identify viable mitigation pathways that do not overstep these thresholds; and reframe governance around allocating limited CDR supply to the most legitimate uses.

https://www.science.org/doi/10.1126/science.adj6171

[SeanAU]

Some people have called me a doomer. Others call me a pessimist. Some people even call me a denier. While others call me a pain in the neck. Personally, I think I’m a realist.
If I look at the plans that most nations have made to limit their contribution to climate change, I think it just isn’t going to happen. The people making these plans are either ill-informed, delusional, or lying, or maybe all of the above. Now there’s a new publication just out of the University of Melbourne in Australia that, according to the press release, has revealed a “huge climate mitigation challenge” and claims that the IPCC has overestimated how much carbon dioxide removal can realistically accomplish. Yes. Let’s have a look.
Okay, I admit, I’m partly talking about this because I feel like some people have misunderstood my position on what we should do about climate change. They’re probably confused because I’ve said both that (a) we need to get serious about carbon dioxide removal and (b) carbon dioxide removal isn’t going to save the day. On top of that I have also said it's too late to do anything now. We're toast! So how do these these things fit together?
Well, it’s because I’m a doomer. Ooops no, sorry I mean, realist. I’m a realist. Carbon dioxide removal isn’t going to help much, but it’s going to help a little, and in contrast to the idea that we’ll “just stop oil,” I can not see it actually happening. Ever.
If you’re wondering why I have difficulties believing that we’ll stop using fossil fuels, let me tell you a little story from the local neighborhood. A couple of months ago they drilled a hole about 30 kilometers north of here. They found oil. The company reports happily that the oil is of very high quality, and now they’re building a well. Does this look like we’re going to stop using fossil fuels? Because it’s not what it looks like to me. Not here, not anywhere. So, carbon dioxide removal. Not great. But better than nothing. Let’s do it.
So much about me, but I wanted to talk about this new paper. First though, I need to sort out a terminology issue. Because I’ve noticed that a lot of people confuse Carbon Dioxide Removal, Carbon Capture and Storage, and Direct Air Capture. These are three different things.
Carbon Dioxide Removal is anything that reduces carbon dioxide levels in the atmosphere. Trees, for example, do carbon dioxide removal, but any technology which mimics this process also counts.
Carbon Capture and Storage, in contrast, is a way of partly preventing the emission of carbon dioxide, for example, on power plants. But it doesn’t entirely prevent the emission. So if you do it at a fossil fuel plant, that does not remove carbon dioxide from the atmosphere, it just reduces the emission. Therefore, Carbon Capture and Storage at fossil fuel plants is not a method of carbon dioxide removal.
However, if you do carbon capture and storage when burning biomass, then you actually do reduce the carbon dioxide in the atmosphere because the biomass, such as trees, are what took the carbon dioxide out of the air. This is called bioenergy with carbon capture and storage, BECCS for short. It is also a way of producing energy. Yes, you can actually make energy by removing carbon dioxide. Who knew? And since you can make energy and therefore money with it, this has been the most popular way of doing it. People love making money.
And finally, Direct Air Capture is a different method of carbon dioxide removal. It basically works by pumping air through huge filters and trapping the carbon dioxide. It’s highly inefficient because the density of carbon dioxide in the air is quite low and also it takes up energy. There are only a few experimental direct air capture installations to date.
There are some other methods of carbon dioxide removal - seawater extraction, biochar, enhanced weathering, but the currently most widely used one is BECCS. If someone tells you that carbon dioxide removal basically doesn’t exist, they’re probably confusing carbon dioxide removal with direct air capture.
It’s clear now that there’s no way we will limit warming to below 2 degrees without carbon dioxide removal. The International Energy Agency concluded in a report from 2022 that reaching net zero by 2050 is “virtually impossible” without carbon dioxide removal. The IPCC too writes very clearly that carbon dioxide removal “is part of all modeled scenarios that limit global warming to 2 degrees or lower by 2100.”
Okay, the thing is now that all plans to get to net zero by 2050 rely on extensive carbon dioxide removal in some way. Given that the currently biggest contributor is Bio Energy with Carbon Capture and Storage, a lot of people put their hopes on that.
And this then brings me to the new paper. The IPCC draws conclusions by working out what they call “mitigation pathways” that are basically possible courses of action. The authors of the new paper now say that as far as Carbon Dioxide Removal are concerned those pathways proposed in the IPCC report are not only unrealistic, they’re actually problematic.
They write that Carbon Dioxide Removal deployments, quote “pose major economic, technological, and social feasibility challenges; threaten food security and human rights; and risk overstepping multiple planetary boundaries, with potentially irreversible consequences” end quote.
As I said the major method of carbon dioxide removal is currently bioenergy with carbon capture and storage. And the problem is that to scale this up, you need all this bioenergy in the first place. That means in practical terms you need to grow stuff, and growing stuff needs land, land that other people might want to use for other things.
The authors of the new paper looked at the numbers which the IPCC assumes for this technology. The IPCC projects that BECCS could remove up to 10 or 11 billion tons of carbon dioxide per year. The authors then estimate that this would, quote: “require converting up to 29 million square kilometers of land—over three times the area of the United States—to bioenergy crops or trees, and potentially push over 300 million people into food insecurity” end quote.
They say that a realistic estimate would be more like 2 to 3 billion tons of carbon dioxide per year removed by this method, which is about a quarter of the IPCC estimate. Basically, this means that even the IPCC plans to limit warming to 2 degrees are unrealistic.
Though personally I think one doesn’t need a paper published in Science to see this. You just need to know that at the moment the amount of carbon dioxide that we actively remove mostly by BECCS is a little more than 2 million tons a year. Doesn’t look likely that we’re going to reach 2 billion anytime soon. While removing 11 billion tons of carbon dioxide per year is a fantasist delusion.

The paper is here:  Sustainability limits needed for CO2 removal
The true climate mitigation challenge is revealed by considering sustainability impacts
Alexandra Deprez et al Feb 1 2024
https://www.science.org/doi/10.1126/science.adj6171

[morganism]

Cutting-edge University of Auckland research converted waste carbon dioxide into a potential precursor for chemicals and carbon-free fuel.

Dr Ziyun Wang's researchers in the School of Chemical Sciences, in collaboration with researchers at Chinese institutions, have demonstrated a method for turning CO2 into formic acid, reported in the journal Nature.

In benchtop experiments, a catalyst made from waste lead-acid batteries enabled a transformation which hadn't been possible using previous catalysts.

 In tests, the new method efficiently converted CO2. for more than 5,000 hours, and the researchers' calculations suggest it can be cost-effectively scaled up for industry.

The experiments used a proton exchange membrane electrolyser. Carbon dioxide flowed into an electrochemical cell and was converted into formic acid, just like charging a battery.

     

Durable CO2 conversion in the proton-exchange membrane system

https://www.nature.com/articles/s41586-023-06917-5

Electrolysis that reduces carbon dioxide (CO2) to useful chemicals can, in principle, contribute to a more sustainable and carbon-neutral future1,2,3,4,5,6. However, it remains challenging to develop this into a robust process because efficient conversion typically requires alkaline conditions in which CO2 precipitates as carbonate, and this limits carbon utilization and the stability of the system7,8,9,10,11,12. Strategies such as physical washing, pulsed operation and the use of dipolar membranes can partially alleviate these problems but do not fully resolve them11,13,14,15. CO2 electrolysis in acid electrolyte, where carbonate does not form, has therefore been explored as an ultimately more workable solution16,17,18. Herein we develop a proton-exchange membrane system that reduces CO2 to formic acid at a catalyst that is derived from waste lead–acid batteries and in which a lattice carbon activation mechanism contributes. When coupling CO2 reduction with hydrogen oxidation, formic acid is produced with over 93% Faradaic efficiency. The system is compatible with start-up/shut-down processes, achieves nearly 91% single-pass conversion efficiency for CO2 at a current density of 600 mA cm−2 and cell voltage of 2.2 V and is shown to operate continuously for more than 5,200 h. We expect that this exceptional performance, enabled by the use of a robust and efficient catalyst, stable three-phase interface and durable membrane, will help advance the development of carbon-neutral technologies.

[morganism]

Carbon capture tech a 'complete falsehood', says Fortescue Metals chairman

PARIS, Feb 13 (Reuters) - Carbon capture is not a solution for the energy transition and political leaders need to provide real, non-greenwashed, commitments to encourage investment, Andrew Forrest, executive chairman of Fortescue Metals, said on Tuesday.
Speaking at the 50th anniversary meeting of the International Energy Agency, Australian billionaire Forrest said the investment community needs a level-playing field and honest answers from political leaders on phasing out fossil fuels in order to invest.
"There's a simple question from business leaders...when do we stop burning fossil fuels?" Forrest said at the Paris conference.
"If you want to drive capital...we must have clear and obvious disincentives for what is doing harm and clear incentives for what is doing good."
Countries including the U.S. have rolled out public subsidies for carbon capture and storage (CCS) projects as part of their incentives to push the green energy transition.
CCS technologies capture carbon dioxide emissions, often from a source like a factory smoke stack, to prevent them from being released into the atmosphere. The captured CO2 can then be stored permanently underground, or repurposed in industrial processes that use CO2.
Oil demand growth is not set to peak until the end of this decade at the earliest and Forrest said carbon capture was not a viable solution.
"We're going to keep burning fossil fuels and somehow magically get rid of the carbon down into the ground where there is no proof that it will stay there, but heaps of proof that it fails," Forrest told the conference.
"I say for policy makers everywhere do not be the next idiot waiting for the old lie to be trotted out and say I believe in carbon sequestration. It has only failed for 75 years...It's a complete falsehood."
Australia's Fortescue is a major iron ore producer, which is used in steel-making and it announced a new project last year to produce green steel on a commercial scale. Iron and steel-making account for a major share of global heavy industry emissions, and its trade has become source of contention between the United States and the EU, which have so far failed to negotiate a "green steel" trade deal.

https://www.reuters.com/business/energy/carbon-capture-tech-complete-falsehood-says-fortescue-metals-chairman-2024-02-13/

[morganism]

CCS Redux: “Best” Carbon Capture Facility In World Creates 25x More CO2 From Use Of Product

(...)
One of the articles looked at the 50-year history of mechanical carbon capture efforts, all entirely tied to the fossil fuel industry, most just used to pump more oil out of played out oil wells as enhanced oil recovery approaches. The assessment showed that virtually no CO2 by global standards has been captured by CCS and that a single year’s output of current wind and solar farms are avoiding 35 times the CO2 that has been ‘captured’ over 50 years of CCS history. Basically, all CCS is a rounding error on the actual solution, just stop emitting CO2.

But one of the global examples stood out, the Norwegian Equinor (nee Statoil) Sleipner facility in the North Sea.

It’s an amazing outlier in multiple ways. First off, it was put into operation in 1996, making it much older than most of the facilities. Second, it wasn’t being used for enhanced oil recovery, but was actually sequestering CO2 as far as can be told. Third, it has been in continual operation for now 28 years and sequestering about a million tons of CO2 a year, leading to it being the biggest actual sequestration facility in the world. (The US Shute Creek facility is just being used to pump more oil, and as a result is at very best achieve 20% of its claimed sequestration.) Finally, it was dirt cheap by CCS standards, with a recorded capital cost of less than $30 million, compared to billions on some failed US efforts.

Sadly, things don’t look as rosy under the covers as they do. This isn’t the magic bullet on how to successfully and cheaply sequester CO2 that it looks like.

Sleipner’s CO2 doesn’t magically appear before being sequestered. It’s part of the natural gas that they pump out of fields offshore from Norway in the North Sea. The gas contains 9% CO2, more than is allowed in the natural gas distribution network. They can’t sell it as is.

Carbon dioxide is stripped from natural gas with amine solvents and is deposited in a saline formation. The carbon dioxide is a waste product of the field’s natural gas production. Storing it underground avoids this problem and saves Statoil hundreds of millions of euros in carbon taxes. Sleipner stores about one million tons of CO2 a year, so has stored about 23 million tons. Given the price point, that looks close to a dollar per ton, which is an astounding figure when Australia’s history is about $4,300 AUD per ton, and the USA’s history is worse.

Basically they couldn’t sell the natural gas without getting rid of the CO2 and they had to do something with it. Norway had a carbon tax even in 1996, so it made economic sense for Equinor to sequester it instead of just venting it to the atmosphere. They had to build most of the capability regardless, so I’m pretty sure the represented cost is just the extra cost of injection on top of what they had to do anyway.

But this is the kicker. All the natural gas that they are shipping turns into a whole lot more CO2. The math is straightforward. For every 1000 kg of natural gas, they grab 90 kg of CO2 and sequester it. Assuming zero leaks, the 910 kg of natural gas is burned by customers, producing a bit over 2500 kg of CO2. Net CO2 emissions are approximately 2410 kg for every 1000 kg of natural gas they pump out of the ground.

What does that turn into in terms of real tons of CO2 sequestered vs emitted? Well, they are producing 36 million cubic meters of natural gas per day. They’ve been producing that daily since 1996, so that’s about 300 billion cubic meters of gas as of 2019. That turns into about 581 million tons of CO2 emitted by the natural gas, compared to the 23 million tons of CO2 that’s been sequestered.

That’s over 25 times more CO2 in the atmosphere than was sequestered. And Equinor is being paid for the natural gas and the sequestered CO2. Nice work if you can get it. Not so nice for the planet.

Every other carbon capture facility in the world is more expensive, sequesters less CO2, and has a much worse ratio than 25:1 for emitted vs captured. The fossil fuel industry and consumers of fossil fuels are producing vastly more CO2 emissions than the very best sequestration case study can manage.

https://cleantechnica.com/2024/02/15/ccs-redux-best-carbon-capture-facility-in-world-creates-25x-more-co2-from-use-of-product/

[Freegrass]

Interesting technology for storing CO2. Curious if it can be scaled up faster than their projections.

https://www.mineralcarbonation.com/

MCi Carbon can offer a carbon capture and use solution to emitting industries which transforms their CO2 into saleable materials. Our team has re-engineered the Earth's natural process of storing CO2 called mineral carbonation. 

This process of reacting CO2 with minerals usually occurs over millions of years geologically. We've accelerated this process for use in industrial settings.

Since 2016, MCi Carbon has been operating a semi-continuous global reference pilot plant, conducting intensive industrial programs to develop and refine the patented mineral carbonation process. We've successfully demonstrated CO2 abatement and generated low-carbon materials for product testing with prospective customers.