Direct Air Capture (of Carbon Dioxide)

[KiwiGriff]

 So I'll believe it when the first few dozen million giga tons.
CCS is an excuse to do nothing based on the creation of an as yet unknown technology in the future.
AKA.
Magical thinking.
The amount of air you would need to pump past any industrial type extraction method makes the idea absurd.
Even using natural methods like old growth forestry rely on mind boggling amounts for far too much time .
 

[sidd]

CCS (carbon capture and sequestration) only addresses exhaust from present fossil carbon burn. I am speaking of drawdown.  Besides, CCS has another thread.

Another point is that the interests of equity demand that the nations that burnt the most fossil carbon in the past ought to drawdown the most in future. Alas, that is probably not going to happen.

sidd

[KiwiGriff]

I Apologize  sidd .
I had the term wrong.
I meant the draw down of atmospheric CO2 being impossible with present technology at a palatable  economic cost.

[Sciguy]

I Apologize  sidd .
I had the term wrong.
I meant the draw down of atmospheric CO2 being impossible with present technology at a palatable  economic cost.

I think the term that is being used is "Negative Emissions Technology" abbrievated NET. The linked paper provides an overview of the current status of NET.

https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.2016.0447

Negativeemissions technologiesandcarbon captureandstoragetoachieve theParisAgreement commitments
R.StuartHaszeldine,StephanieFlude,Gareth JohnsonandVivianScott
SchoolofGeoSciences,UniversityofEdinburgh,Edinburgh,EH93FE, UK RSH,0000-0002-7015-8394

How will the global atmosphere and climate be protected? Achieving net-zero CO2 emissions will require carbon capture and storage (CCS) to reduce current GHG emission rates, and negative emissions technology (NET) to recapture previously emitted greenhouse gases. Delivering NET requires radical cost and regulatory innovation to impact on climate mitigation. Present NET exemplars are few, are at small-scale and not deployable within a decade, with the exception of rock weathering, or direct injection of CO2 into selected ocean water masses. To keep warming less than 2°C, bioenergy with CCS (BECCS) has been modelled but does not yet exist at industrial scale. CCS already exists in many forms and at low cost. However, CCS has no political drivers to enforce its deployment. We make a new analysis of all global CCS projects and model the build rate out to 2050, deducing this is 100 times too slow. Our projection to 2050 captures just 700 Mt CO2 yr−1, not the minimum 6000 Mt CO2 yr−1 required to meet the 2°C target. Hence new policies are needed to incentivize commercial CCS. A first urgent action for all countries is to commercially assess their CO2 storage. A second simple action is to assign a Certificate of CO2 Storage onto producers of fossil carbon, mandating a progressively increasing proportionofCO2 tobestored.NoCCSmeansno2°C.

I think that the conclusions are pessimistic given that renewables are rapidly replacing fossil fuels, so CCS won't be needed for existing fossil fuel infrastructure.  However, the best IPCC scenario, RCP 2.6, requires the deployment of NET to reduce carbon concentrations in the atmosphere.

One of the promising NETs available today is biomass burning with CCS.  Production of biochar with CCS is also a promising NET that could provide for soil restoration (helping improve that carbon sink) as well as biofuels for industrial feedstocks and aviation.  While those last two aren't negative emissions, they're at least carbon neutral and will allow us to completely transition off of fossil fuels.

[Sciguy]

Here's another study of Negative Emissions Technologies (NETs) that indicates more rapid deployment of renewable energy as well as reductions in methane emissions can reduce, but not eliminate, the amount of NETs that need to be deployed.

http://atoc.colorado.edu/~whan/ATOC4800_5000/Materials/CC_policy_renewable.pdf

Alternative pathways to the 1.5 °C target reduce the need for negative emission technologies

Detlef P. van Vuuren   1,2*, Elke Stehfest1, David E. H. J. Gernaat1,2, Maarten van den Berg1, David L. Bijl2, Harmen Sytze de Boer1,2, Vassilis Daioglou   1,2, Jonathan C. Doelman1, Oreane Y. Edelenbosch1,2, Mathijs Harmsen1,2, Andries F. Hof   1,2 and Mariësse A. E. van Sluisveld1,2

Mitigation scenarios that achieve the ambitious targets included in the Paris Agreement typically rely on greenhouse gas emission reductions combined with net carbon dioxide removal (CDR) from the atmosphere, mostly accomplished through large-scale application of bioenergy with carbon capture and storage, and afforestation. However, CDR strategies face several difficulties such as reliance on underground CO2 storage and competition for land with food production and biodiversity protection. The question arises whether alternative deep mitigation pathways exist. Here, using an integrated assessment model, we explore the impact of alternative pathways that include lifestyle change, additional reduction of non-CO2 greenhouse gases and more rapid electrification of energy demand based on renewable energy. Although these alternatives also face specific difficulties, they are found to significantly reduce the need for CDR, but not fully eliminate it. The alternatives offer a means to diversify transition pathways to meet the Paris Agreement targets, while simultaneously benefiting other sustainability goals.

[Tom_Mazanec]

Using Farmland to Address Climate Change
https://www.wibc.com/news/local-news/using-farmland-address-climate-change

The ag research group Indigo has launched what it calls the Terraton Initiative, a decadelong research project with a goal of sucking a trillion tons of carbon out of the atmosphere and into the soil. Indigo's Chris Malone explains harnessing photosynthesis could simultaneously address greenhouse gases and make soil more productive.

[sidd]

Re: Indigo

Called em up a while ago. They seem more interested in buying and selling my grain than soil carbon capture. The person(s) i spoke to promised to return my calls with more information about soil carbon capture, but so far, deafening silence.

They did claim in the press material that they were working with the Rodale institute. I know some people there, will have to drop by next time i'm by Kutztown.

sidd

[Tom_Mazanec]

Cutting climate pollution isn't enough — we also need carbon removal
https://thehill.com/opinion/energy-environment/462609-cutting-climate-pollution-isnt-enough-we-also-need-carbon-removal

Achieving a 100 percent clean economy will require a swift transition to renewables and other zero-carbon energy sources. But we also need to face the reality that meeting the Paris target will require taking carbon out of the atmosphere at massive scale. In part, that’s because eliminating emissions will be very challenging for some sectors, especially the transportation industry and agriculture. Removing carbon from the atmosphere would also bring concentrations down, helping to stabilize the climate at safer levels. So, the push for clean energy must be supplemented by a suite of technologies known as carbon dioxide removal (CDR).

It is not a question of what we’d prefer. It’s a question of insurmountable math.

[Sciguy]

Here's a recent study on Negative Emissions Technologies (NET) needed for the 1.5C and 2C goals.

https://link.springer.com/article/10.1007%2Fs10584-019-02516-4

Negative emissions and international climate goals—learning from and about mitigation scenarios

Abstract
For aiming to keep global warming well-below 2 °C and pursue efforts to limit it to 1.5 °C, as set out in the Paris Agreement, a full-fledged assessment of negative emission technologies (NETs) that remove carbon dioxide from the atmosphere is crucial to inform science-based policy making. With the Paris Agreement in mind, we re-analyse available scenario evidence to understand the roles of NETs in 1.5 °C and 2 °C scenarios and, for the first time, link this to a systematic review of findings in the underlying literature. In line with previous research, we find that keeping warming below 1.5 °C requires a rapid large-scale deployment of NETs, while for 2 °C, we can still limit NET deployment substantially by ratcheting up near-term mitigation ambition. Most recent evidence stresses the importance of future socio-economic conditions in determining the flexibility of NET deployment and suggests opportunities for hedging technology risks by adopting portfolios of NETs. Importantly, our thematic review highlights that there is a much richer set of findings on NETs than commonly reflected upon both in scientific assessments and available reviews. In particular, beyond the common findings on NETs underpinned by dozens of studies around early scale-up, the changing shape of net emission pathways or greater flexibility in the timing of climate policies, there is a suite of “niche and emerging findings”, e.g. around innovation needs and rapid technological change, termination of NETs at the end of the twenty-first century or the impacts of climate change on the effectiveness of NETs that have not been widely appreciated. Future research needs to explore the role of climate damages on NET uptake, better understand the geophysical constraints of NET deployment (e.g. water, geological storage, climate feedbacks), and provide a more systematic assessment of NET portfolios in the context of sustainable development goals.

The Fifth Assessment Report (AR5) by IPCC Working Group 3 (WG3) provided a good overview of the role of NETs for stringent climate stabilization targets. It highlighted that many 2 °C scenarios entail large-scale deployment of NETs after 2050 to compensate for residual CO2 emissions from sectors that are difficult to decarbonize, such as industry and aviation. It warned that these scenarios are mostly associated with a temporary overshoot of the climate goal and that delays in climate action and limitations in the availability of NETs can render the 2 °C goal infeasible. It also emphasized the challenges (e.g. societal concerns), risks (e.g. technological availability, biodiversity, water, food prices, inter-generational impacts) and uncertainties (e.g. geological storage, large bioenergy production) surrounding these technologies (see also Electronic Supplementary Material (ESM) for a complete review of NET statements in AR5).

Yet, the analysis of NETs in WG3 AR5 remained inaccessible because findings were scattered in various sections and sub-sections of the report (i.e. in Chaps. 2, 6, 7, 11, 13).

The recent IPCC Special Report on Global Warming of 1.5 °C (SR1.5) (IPCC 2018) filled this gap by drawing upon a set of recent reviews (Minx et al. 2018; Fuss et al. 2018; Nemet et al., 2018) that used formal methods of evidence synthesis. It further added a comprehensive analysis on the role of NETs in 1.5 °C scenarios based on newly emerging evidence. The report highlighted that all 1.5 °C scenarios with limited or no overshoot require NETs on the order of 100–1000 GtCO2 over the twenty-first century but that significant near-term emissions reductions (e.g. low energy demand, low material consumption, low GHG-intensive food consumption) can limit NET deployment to a few hundred GtCO2 without reliance on Bioenergy with Carbon Capture and Storage (BECCS). It also called attention to the lack of published pathways featuring NETs other than afforestation and reforestation (AR) and BECCS (see also Electronic Supplementary Material (ESM) for a complete review of NET statements in Fuss et al. 2018, IPCC 2018 and Rogelj et al. 2018b).

[Sciguy]

Improved agricultural techniques can help restore soil productivity and sequester great amounts of carbon.  Here's an overview of carbon sequestration in soil.

https://wedocs.unep.org/bitstream/handle/20.500.11822/28453/Foresight013.pdf?sequence=1&isAllowed=y

The potential of carbon sequestration in the soil

Abstract

Soil’s contribution to climate change, through the oxidation of soil carbon, is important. However, soils – and thus agriculture - can play a major role in mitigating climate change. Through multiple agricultural practices, we could help store vast amounts of atmospheric carbon in the soil, while at the same time regenerating soil fertility, plant health and whole ecosystems. This is a no regret option that offers multiple benefits and deserves high-level visibility.

Estimates for carbon sequestration through improved practices vary considerably (Figure 3) as the understanding of the interactions and especially the knowledge of the behavior of soils is still limited. Various studies indicate theoretical potentials of 0.8 to 8 GtC per year 35,40,44,51,53–57, partially including af-/ re-forestation practices, and reaching up to 10 GtC/ yr of additional carbon on agricultural land 41,55, while practically achievable carbon removal amounts are rather located in the lower range of 1.5 to 2.5 GtC/yr 30,53,58. With global carbon emissions in 2016 from fossil fuels and industry of 9.9 GtC plus 1.3 GtC due to land-use changes (such as deforestation)v 38, the potential for carbon sequestration through regenerative agricultural practices looks rather promising, although the implementation of such practices comes with different social, economic and expertise-related and other caveats. It requires funding and collaboration amongst scientists, policymakers, practitioners and multiple other stakeholders. Soil carbon sequestration has a large but not infinite sink capacity, and, importantly, is reversible through bad management. Global efforts to gradually change land use practices are difficult to implement, reducing thus the theoretical mitigation potential

[Sigmetnow]

Mark Z. Jacobson on Twitter: "People who support Carbon Capture+Direct Air Capture are condemning millions worldwide to die from pollution, which those techs increase or hold constant. They are also increasing CO2 compared w/spending same money on clean, renewables to replace fossils”
https://mobile.twitter.com/mzjacobson/status/1192913918374621185

The paper:

...Moreover, the CCU and SDACCU plants both increase air pollution and total social costs relative to no capture. Using wind to power the equipment reduces CO2e relative to using natural gas but still allows air pollution emissions to continue and increases the total social cost relative to no carbon capture. Conversely, using wind to displace coal without capturing carbon reduces CO2e, air pollution, and total social cost substantially. ...

https://web.stanford.edu/group/efmh/jacobson/Articles/Others/19-CCS-DAC.pdf

[Sciguy]

Enhanced rock weathering is another method to remove carbon dioxide from the air while improving the quality of agricultural soils.

https://www.nature.com/articles/s41586-020-2448-9

Beerling, D.J., Kantzas, E.P., Lomas, M.R. et al. Potential for large-scale CO2 removal via enhanced rock weathering with croplands. Nature 583, 242–248 (2020).

Abstract

Enhanced silicate rock weathering (ERW), deployable with croplands, has potential use for atmospheric carbon dioxide (CO2) removal (CDR), which is now necessary to mitigate anthropogenic climate change1. ERW also has possible co-benefits for improved food and soil security, and reduced ocean acidification2,3,4. Here we use an integrated performance modelling approach to make an initial techno-economic assessment for 2050, quantifying how CDR potential and costs vary among nations in relation to business-as-usual energy policies and policies consistent with limiting future warming to 2 degrees Celsius5. China, India, the USA and Brazil have great potential to help achieve average global CDR goals of 0.5 to 2 gigatonnes of carbon dioxide (CO2) per year with extraction costs of approximately US$80–180 per tonne of CO2. These goals and costs are robust, regardless of future energy policies. Deployment within existing croplands offers opportunities to align agriculture and climate policy. However, success will depend upon overcoming political and social inertia to develop regulatory and incentive frameworks. We discuss the challenges and opportunities of ERW deployment, including the potential for excess industrial silicate materials (basalt mine overburden, concrete, and iron and steel slag) to obviate the need for new mining, as well as uncertainties in soil weathering rates and land–ocean transfer of weathered products.

[Sciguy]

Offshore wind and direct air capture could work together to sequester a lot of CO2.

https://theconversation.com/amp/offshore-wind-farms-could-help-capture-carbon-from-air-and-store-it-long-term-saving-money-a-geophysicist-explains-how-173208

Offshore wind farms could help capture carbon from air and store it long-term, saving money – a geophysicist explains how

David Goldberg, Columbia University

January 25, 2022

Replacing fossil fuel-based energy with clean energy like wind power is essential to holding off the worsening effects of climate change. But that transition isn’t happening fast enough to stop global warming. Human activities have pumped so much carbon dioxide into the atmosphere that we will also have to remove carbon dioxide from the air and lock it away permanently.

Offshore wind farms are uniquely positioned to do both – and save money.

The world’s largest active direct air capture plant operating today does this by using waste heat and renewable energy. The plant, in Iceland, then pumps its captured carbon dioxide into the underlying basalt rock, where the CO2 reacts with the basalt and calcifies, turning to solid mineral.

A similar process could be created with offshore wind turbines.

If direct air capture systems were built alongside offshore wind turbines, they would have an immediate source of clean energy from excess wind power and could pipe captured carbon dioxide directly to storage beneath the sea floor below, reducing the need for extensive pipeline systems.

By nature, wind energy is intermittent. Demand for energy also varies. When the wind can produce more power than is needed, production is curtailed and electricity that could be used is lost.

That unused power could instead be used to remove carbon from the air and lock it away.

For example, New York State’s goal is to have 9 gigawatts of offshore wind power by 2035. Those 9 gigawatts would be expected to deliver 27.5 terawatt-hours of electricity per year.

Based on historical wind curtailment rates in the U.S., a surplus of 825 megawatt-hours of electrical energy per year may be expected as offshore wind farms expand to meet this goal. Assuming direct air capture’s efficiency continues to improve and reaches commercial targets, this surplus energy could be used to capture and store upwards of 0.5 million tons of CO2 per year.

That’s if the system only used surplus energy that would have gone to waste. If it used more wind power, its carbon capture and storage potential would increase.

Researchers have estimated that sub-seafloor geological formations adjacent to the offshore wind developments planned on the U.S. East Coast have the capacity to store more than 500 gigatons of CO2. Basalt rocks are likely to exist in a string of buried basins across this area too, adding even more storage capacity and enabling CO2 to react with the basalt and solidify over time, though geotechnical surveys have not yet tested these deposits.

[interstitial]

a little context 825 MWH is not very much. That is one MW for about 34 days. Using this energy would require installations at every windfarm as the primary reason for curtailment is insufficient capacity on power lines. Each wind farm would need to be able to use multiple MW of electricity. Each windfarm likely does not have many curtailments per year as if it did it would be worth it to upgrade the distribution line. As much as I hate to see waste It seems to me that the use of curtailed energy will not be economic.

[kassy]

Engineered bacteria produce chemicals with negative carbon emissions

Bacteria engineered to turn carbon dioxide into compounds used in paint remover and hand sanitiser could offer a carbon-negative way of manufacturing industrial chemicals.

Michael Köpke at LanzaTech in Illinois and his colleagues searched through strains of an ethanol-producing bacterium, Clostridium autoethanogenum, to identify enzymes that would allow the microbes to instead create acetone, which is used to make paint and nail polish remover. Then they combined the genes for these enzymes into one organism. They repeated the process for isopropanol, which is used as a disinfectant.

The engineered bacteria ferment carbon dioxide from the air to produce the chemicals. “You can imagine the process similar to brewing beer,” says Köpke. “But instead of using a yeast strain that eats sugar to make alcohol, we have a microbe that can eat carbon dioxide.”

After scaling up the initial experiments by a factor of 60, the team found that the process locks in roughly 1.78 kilograms of carbon per kilogram of acetone produced, and 1.17 kg per kg of isopropanol. These chemicals are normally made using fossil fuels, emitting 2.55 kg and 1.85 kg of carbon dioxide per kg of acetone and isopropanol respectively.

This equates to up to a 160 per cent decrease in greenhouse gas emissions, if this method were to be broadly adopted, say the researchers. The technique could also be made more sustainable by using waste gas from other industrial processes, such as steel manufacturing.

...

https://www.newscientist.com/article/2309078-engineered-bacteria-produce-chemicals-with-negative-carbon-emissions/

Neat trick. I wonder what more they can make eventually.

[oren]

Neat indeed, but I wonder what other inputs it requires, such as other chemicals and energy.

[SteveMDFP]

The engineered bacteria ferment carbon dioxide from the air to produce the chemicals. “You can imagine the process similar to brewing beer,” says Köpke. “But instead of using a yeast strain that eats sugar to make alcohol, we have a microbe that can eat carbon dioxide.”

After scaling up the initial experiments by a factor of 60, the team found that the process locks in roughly 1.78 kilograms of carbon per kilogram of acetone produced, and 1.17 kg per kg of isopropanol. These chemicals are normally made using fossil fuels, emitting 2.55 kg and 1.85 kg of carbon dioxide per kg of acetone and isopropanol respectively.

This equates to up to a 160 per cent decrease in greenhouse gas emissions, if this method were to be broadly adopted, say the researchers. The technique could also be made more sustainable by using waste gas from other industrial processes, such as steel manufacturing.

...

https://www.newscientist.com/article/2309078-engineered-bacteria-produce-chemicals-with-negative-carbon-emissions/

Neat trick. I wonder what more they can make eventually.

It is, indeed, a neat trick.  Of course, even the magic of biology can't escape the thermodynamic fact that converting CO2 to acetone requires a net input of a lot of energy.  I had to dig into details to find the energy source:  gaseous hydrogen.

So, this is another niche use for the green hydrogen economy.  If we as a species ever get serious about CO2 emissions, this could be scaled up.  It works best for concentrated sources, such as in cement production.  Without a neat trick like this, CO2 emissions from cement production is a very difficult problem to solve. 

[etienne]

I wonder what kind of efficiency you can have with such a path:
Electricity=>GH2=>acetone and isopropanol,
and we are in a "capture and release' concept.

It could be a greening scheme. I guess that the original CO2 emitter is clean because he captures his emissions, and the second one is clean because he works with captured carbon. Maybe I'm wrong, I don't know.

[SteveMDFP]

I wonder what kind of efficiency you can have with such a path:
Electricity=>GH2=>acetone and isopropanol,
and we are in a "capture and release' concept.

It could be a greening scheme. I guess that the original CO2 emitter is clean because he captures his emissions, and the second one is clean because he works with captured carbon. Maybe I'm wrong, I don't know.

Well, yes, if the acetone or alcohol is used as fuel, you still end up with carbon going into the atmosphere, although one gets 2 uses per carbon atom.  But these end products could end up as industrial feedstock for products of greater longevity.

[morganism]

How plasma could be key to harvesting resources for living on Mars

"“When bullet-like electrons collide with a carbon dioxide molecule, they can directly decompose it or transfer energy to make it vibrate,” says senior author Vasco Guerra, a professor at the University of Lisbon, in a statement. “This energy can be channeled, to a large extent, into carbon dioxide decomposition. Together with our colleagues in France and the Netherlands, we experimentally demonstrated the validity of these theories. Moreover, the heat generated in the plasma is also beneficial for the separation of oxygen.”

https://www.spacechatter.com/2022/08/18/plasma-key-to-living-on-mars/


Plasmas for in situ resource utilization on Mars: Fuels, life support, and agriculture

(...)
 By converting different molecules directly from the Martian atmosphere, plasmas can create the necessary feed-stock and base chemicals for processing fuels, breathing oxygen, building materials, and fertilizers. Different plasma sources operate according to different principles and are associated with distinct dominant physicochemical mechanisms. This diversity allows exploring different energy transfer pathways leading to CO2 dissociation, including direct electron-impact processes, plasma chemistry mediated by vibrationally and electronically excited states, and thermally driven dissociation. The coupling of plasmas with membranes is still a technology under development, but a synergistic effect between plasma decomposition and oxygen permeation across conducting membranes is anticipated. The emerging technology is versatile, scalable, and has the potential to deliver high rates of production of molecules per kilogram of instrumentation sent to space. Therefore, it will likely play a very relevant role in future ISRU strategies."

https://aip.scitation.org/doi/10.1063/5.0098011

[kassy]

The findings also have implications for combating global warming on Earth. “By dissociating carbon dioxide molecules to produce green fuels and recycle chemicals, the plasma technology may also aid in addressing climate change,” adds Guerra.

This is more a method to make synthetic fuels which is not carbon capture.

I doubt that the technique can be cheaper then green hydrogen solutions to this which are already being built to scale.

PS: Maybe also post it in The Mars thread?

[kassy]

Carbon capture and storage, known as CCS, is based on the idea that you can extract carbon dioxide from the smokestacks of coal plants or steel factories, compress it, transport it and then inject it back underground, where, in theory, it will remain forever. And that’s assuming you can find the right geologic conditions that are stable enough over millennia so that carbon doesn’t leak out and back into the atmosphere.

The problem is not only that the technology is enormously expensive, but that despite over 20 years of research, it is still unproven to work at the scale required to substantially reduce emissions. According to the Global Carbon Capture and Storage Institute, there are 27 operational CCS facilities globally, predominantly in the United States, jointly able to capture 36.6 million tonnes of carbon dioxide annually.

For context, the world emitted 39.4 billion tonnes of carbon dioxide in 2021 – that’s roughly 1000 times greater than what’s possible to capture with current CCS technology. Put another way, CCS plants can only offset around 0.1% of global carbon emissions each year. To reach net-zero emissions by 2050, scientists calculate that carbon dioxide needs to decline by approximately 1.4 billion tonnes each year.

The industry group estimates that between US$655 billion and US$1280 billion is required to make this a reality. Aside from the trillion-dollar price tag, it’s critical to realise that CCS projects take around ten years to progress through concept, feasibility, design and construction phases before becoming operational – time we simply don’t have.

from:
https://theconversation.com/friday-essay-i-feel-my-heart-breaking-today-a-climate-scientists-path-through-grief-towards-hope-188589

[interstitial]

Do not forget that 100% carbon capture is not currently possible and unlikely to ever be feasible. 80% has not been achieved over an extended period. The most successful US project captured under 60% over time.

[crandles]

https://www.science.org/doi/10.1126/sciadv.adg1956

Direct air capture (DAC) and sequestration of CO2: Dramatic effect of coordinated Cu(II) onto a chelating weak base ion exchanger

Direct air capture (DAC) is important for achieving net-zero greenhouse gas emissions by 2050. However, the ultradilute atmospheric CO2 concentration (~400 parts per million) poses a formidable hurdle for high CO2 capture capacities using sorption-desorption processes. Here, we present a Lewis acid-base interaction–derived hybrid sorbent with polyamine-Cu(II) complex enabling over 5.0 mol of CO2 capture/kg sorbent, nearly two to three times greater capacity than most of the DAC sorbents reported to date. The hybrid sorbent, such as other amine-based sorbents, is amenable to thermal desorption at less than 90°C. In addition, seawater was validated as a viable regenerant, and the desorbed CO2 is simultaneously sequestered as innocuous, chemically stable alkalinity (NaHCO3). The dual-mode regeneration offers unique flexibility and facilitates using oceans as decarbonizing sinks to widen DAC application opportunities.

https://www.bbc.co.uk/news/science-environment-64886116

Climate change: New idea for sucking up CO2 from air shows promise

The authors say that this novel approach captures CO2 from the atmosphere up to three times more efficiently than current methods.

The warming gas can be transformed into bicarbonate of soda and stored safely and cheaply in seawater.
...
Professor SenGupta shares that optimism, believing that this new approach can remove CO2 for less than $100 a tonne.

[Richard Rathbone]

$100/tonne isn't  what I'd call cheap. $10 maybe, $1 I would call cheap.

Also there's all the chlorine they are conveniently forgetting about. The overall chemistry for this sequestration is:

NaCl + H20 + CO2 +electricity => NaHCO3 (dumped in the ocean) + 0.5H2 (green H2!) + 0.5Cl2 (main use is PVC)

I'm not at all sure that generating 1 molecule of chlorine for every 2 molecules of carbon dioxide moved from air to ocean is a net environmental benefit.

[morganism]

Using bacteria to convert CO2 in the air into a polyester

(.)
 But the process can only be done in batches because of the need for electricity to start the process—toxic byproducts build up and kill the bacteria. This prevents the process from scaling. In this new effort, the research team in Korea overcame this problem.

The workaround involved adding a synthetic membrane at the start of the process that separates the bacteria from the toxic byproducts. This led to a two-sided process. On one side, chemical reactions prepared CO2 for fermentation, while the other side held other needed ingredients. The membrane then allowed the ingredients to flow slowly to the side with the bacteria, which used them to make bits of poly-3-hydroxybutyrate.

The research team ran the process, which involved periodically removing bacteria holding onto the PHB and adding fresh empty samples, for 18 days. They found it worked as planned and also made 11.5 mg of PHB per hour. The researchers note that the process does still require electricity but because it is so much more efficient than other methods, the cost of converting CO2 to a polyester was much cheaper. They also note that the process can be easily scaled up"

https://phys.org/news/2023-03-bacteria-co2-air-polyester.html

Biohybrid CO 2 electrolysis for the direct synthesis of polyesters from CO 2, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2221438120

[Sigmetnow]

Facing brutal climate math, US bets billions on direct air capture

April 18 (Reuters) - The world is failing to cut carbon emissions fast enough to avoid disastrous climate change, a dawning truth that is giving life to a technology that for years has been marginal – pulling carbon dioxide from the air.

Leading the charge, the U.S. government has offered $3.5 billion in grants to build the factories that will capture and permanently store the gas - the largest such effort globally to help halt climate change through Direct Air Capture (DAC) and expanded a tax credit to $180/tonne to bolster the burgeoning technology.
The sums involved dwarf funding available in other regions, such as Britain which has pledged up to 100 million pounds ($124 million) for DAC research and development. That compares with $12 billion in federal spending to drive demand for personal and commercial electric vehicles, Boston Consulting Group estimated.
…
Worsening climate change and inadequate efforts to cut emissions have thrust the issue known as carbon removal to the top of the agenda, and U.N. scientists now estimate billions of tonnes of carbon will need to be sucked out of the atmosphere annually to reach a goal of capping global warming at 1.5 degrees Celsius.
…
Yet the list of hurdles is long.
The biggest plant to-date is capturing only 4,000 tonnes a year and costs are high, the talent pool is fledgling and corporate buyers for the credits largely remain on the sidelines. The role of oil companies in the space has also raised eyebrows and developers must muster support for hubs from communities that have often been damaged by big energy projects.
Plus, the CO2 must be stored permanently.

The U.S. government has said it wants to back four hubs, and interviews with more than 20 state, federal, company and investor sources show at least nine applications have been filed in a first round, with two major Occidental Petroleum (OXY.N) projects also seen as strong contenders.
It is offering three levels of funding, ranging from $3 million for early stage feasibility studies to $12.5 million for engineering design studies to up to $500 million for projects ready to complete the procurement, construction and operation phases.

Among the most active firms so far has been Swiss start-up Climeworks, which has raised more than $800 million to date and is backed by Singaporean sovereign investor GIC.
In his first major interview since taking part in applications for three hubs - in Louisiana, California and North Dakota - Chief Executive Christoph Gebald said all had the potential to be scaled to the U.S. government's target of a million tonnes, known as a megatonne, a year.
…
Gebald said it would cost "easily in the billions" of dollars to create a megatonne facility and the firm could look to raise funds depending on the success of its three bids, although it would likely wait until 2024 to return to the market.
…
 
Another bidding for funding is start-up CarbonCapture Inc., in partnership with Frontier Carbon Solutions and a new company called Twelve, which will use captured carbon to make sustainable aviation fuel in Wyoming, Jonas Lee, chief commercial officer for CarbonCapture, told Reuters.
"This industry is fragile right now, but all the arrows are lined up in the right direction. Now, we have to do our job which is to put iron in the ground and start taking out meaningful amounts of CO2 from the atmosphere," Lee said.
"Hopefully that will help in a virtuous cycle that galvanizes even more support from corporations buying carbon credits, and maybe from state and local governments."

OIL INVOLVEMENT
The sites being bid for stretch across the breadth of the country, yet all have several things in common: they are near cheap, renewable energy and plenty of space to store the gas.
Unsurprisingly, perhaps, that has drawn the attention of some of the large, incumbent energy giants keen to position themselves for what could be a multi-trillion-dollar industry as demand for fossil fuels subsides.
Occidental Petroleum has said it is well positioned for federal grants for what could be the biggest Direct Air Capture plants in the world. It declined to say whether it had applied for support for two DAC projects it is developing in Texas.
 
Oil companies are also far ahead in getting permitted, sequestration wells, guaranteed to keep the CO2 in the ground.
“We have the pore space to begin with, from the reservoirs that are depleted or depleting, that we've operated that now can be repurposed into sequestration by the engineers who know how that reservoir reacts,” said Chris Gould, chief sustainability officer, at California Resources Corp (CRC.N), an oil company that aims for net zero emissions and is working with Climeworks on a California project.
But the oil companies are still looked at with scepticism by some in the carbon removal community.
"It's really essential for the success of direct air capture that this be about removing legacy emissions and not be about continued fossil fuel use," said Erin Burns, executive director of Carbon 180, a DAC consultancy. "We're hoping to see hubs that don't have ties to fossil fuel production."

COSTS
Most DAC processes use a liquid or solid that is engineered to naturally soak up carbon dioxide, then heated or treated to extract the carbon to be put underground.
But the energy to run the process, the factories, pipelines and storage is expensive. The jury is still out on whether it can be deployed at a scale big enough to affect the climate, at a cost the world can bear.
Across a range of technical processes, it can cost more than $1,000 to capture and lock away a ton of planet-warming carbon dioxide, yet the U.S. government has targeted a $100 a ton price tag.

Heirloom Carbon, a California company which with Climeworks is part of an application for a Louisiana hub, sees that as a realistic goal, while CarbonCapture told Reuters it expects to hit $250 a ton by 2030 and $150 a ton within a decade.
To get to a cost and scale that can affect the planet will mean designing an easily duplicated plant that does the same thing over and over again, like a franchised fast-food restaurant, said Dan Friedmann, chief executive of DAC firm Carbon Engineering, which is supplying technology to Occidental.
“It's a McDonald's kind of thing," he said.

https://www.reuters.com/world/us/facing-brutal-climate-math-us-bets-billions-direct-air-capture-2023-04-18/

[kassy]

We will need to remove a lot of carbon but everything we do not add could save us so much money.
Instead of throwing money at one part of the problem it would be so much better to aim for the root causes.

Plug leaky old wells , accelerate the transition, actually regulate the energy industry etc. There will not be a lack of atmospheric carbon to capture in the near future.

[Freegrass]

We will need to remove a lot of carbon but everything we do not add could save us so much money.
Instead of throwing money at one part of the problem it would be so much better to aim for the root causes.

Plug leaky old wells , accelerate the transition, actually regulate the energy industry etc. There will not be a lack of atmospheric carbon to capture in the near future.

Kassy, you keep repeating this. Don't you think we know that? Of course we need to stop emitting CO2 ASAP, but we're at 424 PPM now. We need to bring that back down to 350, and the only way to do this is by sequestering it.

It's not because some people are working one thing, that others can't work on the other. It'll be all of the above or fail.

[kassy]

Of course i know that but that was not the point.

Throwing money a some issue sounds like some sort of action but how much is going to be spent efficiently? A lot of it is probably just an industry giveaway. This has been done over and over. All the talk about net zero is useless without meaningful reductions. All the money we waste is stealing from the future too because we are not running on a surplus.

The actual reductions, or at least part of them are needed last year and more is needed this year and more next year and that goes on.

How well storing carbon in gas fields works is a guess. Why would you give lots of money to an industry that emits to do carbon capture when they do not report accurate numbers on leaks and don´t fix them even if it would make them more money?

With less money you can probably scale up some interesting alternatives that capture it in different ways which store better.

[FrostKing70]

Not sure where this should go, so posting in here:

https://apnews.com/article/carbon-removal-ocean-climate-change-global-warming

"California researchers attempt ocean climate solution"

"The process sends an electrical charge through seawater flowing through tanks on the barge. That then sets off a series of chemical reactions that trap the greenhouse gas into a solid mineral that includes calcium carbonate — the same thing seashells are made of. The seawater is then returned to the ocean and can pull more carbon dioxide out of the air. The calcium carbonate settles to the sea floor."

[sidd]

I dont immediately have it to hand, but the paper is open source. They use a rotating cylindrical grid with an electric current to generate OH- ions locally to precipitate calcium carbonate.

Sounds like it works, but i am not sure it will beat the current 100US$ a ton mark from playing with olivine.

sidd

[kassy]

Freegrass i moved this post to the capitalism thread because it is clearly going beyond the subject of this thread but i forgot to link that here.

Kassy,

Direct air capture and CCS are solutions that are way too expensive and completely insane. By the time the fossil fuel industry figures this out, other technologies will have surpassed them...

[FrostKing70]

Here is a new article about a start up to us geothermal energy to power direct carbon capture:

https://www.washingtonpost.com/climate-solutions/2023/02/23/geothermal-direct-air-capture-fervo/

"Now, however, a company is working to combine direct air capture with a relatively untapped source of energy: Heat from Earth’s crust. Fervo Energy, a geothermal company headquartered in Houston, announced on Thursday that it will design and engineer the first purpose-built geothermal and direct air capture plant. With the help of a grant from the Chan Zuckerberg Initiative, the company hopes to have a pilot facility online in 3 to 5 years."

"Even after generating electricity, most geothermal plants have a lot of waste heat — often clocking in around 212 degrees. And conveniently, that happens to be the exact temperature needed to pull carbon dioxide out of an air filter and bury it underground.

Hélène Pilorgé, a research associate at the University of Pennsylvania who studies carbon dioxide removal, says that one of the main ways to pull CO2 out of the air is known as the “solid sorbent” method. Big fans draw air into a box with an air filter; the air filter is then heated to around 212 degrees to remove the CO2 for burial. That high temperature “fits well with the energy that geothermal can provide,” Pilorgé said."

[vox_mundi]

A Reality Check On 'Direct Air Capture': Many Climate-Stabilization Plans May Be Based On Questionable Assumptions
https://phys.org/news/2024-11-reality-air-capture-climate-stabilization.html

The world must reduce the levels of greenhouse gases in the atmosphere, and strategies for achieving levels that will "stabilize the climate" have been both proposed and adopted. Many of those strategies combine dramatic cuts in carbon dioxide (CO2) emissions with the use of direct air capture (DAC), a technology that removes CO2 from the ambient air.

As a reality check, a team of researchers in the MIT Energy Initiative (MITEI) examined those strategies, and what they found was alarming: The strategies rely on overly optimistic—indeed, unrealistic—assumptions about how much CO2 could be removed by DAC.

Their investigation identified three unavoidable engineering challenges that together lead to a fourth challenge—high costs for removing a single ton of CO2 from the atmosphere. The details of their findings are reported in a paper published in the journal One Earth on Sept. 20.

... When it comes to removing CO2 from the air, nature presents "a major, non-negotiable challenge," notes the MITEI team: The concentration of CO2 in the air is extremely low—just 420 parts per million, or roughly 0.04%. In contrast, the CO2 concentration in flue gases emitted by power plants and industrial processes ranges from 3% to 20%.

Companies now use various carbon capture and sequestration (CCS) technologies to capture CO2 from their flue gases, but capturing CO2 from the air is much more difficult. To explain, the researchers offer the following analogy: "The difference is akin to needing to find 10 red marbles in a jar of 25,000 marbles, of which 24,990 are blue [the task representing DAC] versus needing to find about 10 red marbles in a jar of 100 marbles of which 90 are blue [the task for CCS]."

Given that low concentration, removing a single metric ton of CO2 from air requires processing about 1.8 million cubic meters of air, which is roughly equivalent to the volume of 720 Olympic-sized swimming pools. And all that air must be moved across a CO2-capturing sorbent—a feat requiring large equipment. For example, one recently proposed design for capturing 1 million metric tons of CO2 per year would require an "air contactor" equivalent in size to a structure about three stories high and three miles long.

Given the low concentration of CO2 in the air and the need to move large quantities of air to capture it, it's no surprise that even the best DAC processes proposed today would consume large amounts of energy—energy that's generally supplied by a combination of electricity and heat. Including the energy needed to compress the captured CO2 for transportation and storage, most proposed processes require an equivalent of at least 1.2 megawatt-hours of electricity for each metric ton of CO2 removed.

The source of that electricity is critical. For example, using coal-based electricity to drive an all-electric DAC process would generate 1.2 tons of CO2 for each metric ton of CO2 captured. The result would be a net increase in emissions, defeating the whole purpose of the DAC.

Many studies assume that a DAC unit could also get energy from "waste heat" generated by some industrial process or facility nearby. In the MITEI researchers' opinion, "that may be more wishful thinking than reality."

... Considering the first three challenges, the final challenge is clear: The cost per metric ton of CO2 removed is inevitably high. Recent modeling studies assume DAC costs as low as $100 to $200 per ton of CO2 removed. But the researchers found evidence suggesting far higher costs. ... Some estimates in the literature exceed $5,000 per metric ton captured per year.

Then there are the ongoing costs of energy. As noted under Challenge 2, removing 1 metric ton of CO2 requires the equivalent of 1.2 megawatt-hours of electricity. If that electricity costs $0.10 per kilowatt-hour, the cost of just the electricity needed to remove 1 metric ton of CO2 is $120.

Then there's the cost of storage, which is ignored in many DAC cost estimates.

... The largest DAC plant in operation today removes just 4,000 tons of CO2 per year, and the price to buy the company's carbon-removal credits on the market today is $1,500 per metric ton.

Howard Herzog et al, Getting real about capturing carbon from the air, One Earth (2024)
https://www.cell.com/one-earth/abstract/S2590-3322(24)00421-4?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2590332224004214%3Fshowall%3Dtrue

[Sigmetnow]

US Congress introduces a Carbon Dioxide Removal act.
 

Nan Ransohoff
This is a very big deal. @SenatorBennet & @lisamurkowski just introduced the Carbon Dioxide Removal Investment Act, which would provide a $250/ton tax credit for permanent CDR. Importantly, it's technology neutral. Any high-quality, permanent carbon removal would qualify.
11/21/24, 11:54 AM https://x.com/nanransohoff/status/1859641467402362889

Dana Jacobs
Today, a carbon removal tax credit is being introduced into the Senate by @SenatorBennet and @lisamurkowski. It helps rightsize the tax code so all types of carbon removal are supported and spells a hugely consequential boost for this industry.
11/21/24, 11:45 AM https://x.com/dana___jacobs/status/1859639204030153061

 
Creating a Carbon Removal Tax Credit — Carbon Removal Alliance
https://www.carbonremovalalliance.org/policy-work/creating-a-carbon-removal-tax-credit/
 
   —-
 
Cool!  This would help SpaceX as they develop ways to ramp the Sabatier process to an industrial level for Starship!
 
Another example of space science helping Earth.

Sabatier reaction
The Sabatier reaction or Sabatier process produces methane and water from a reaction of hydrogen with carbon dioxide at elevated temperatures (optimally 300–400 °C) and pressures (perhaps 3 MPa ) in the presence of a nickel catalyst. It was discovered by the French chemists Paul Sabatier and Jean-Baptiste Senderens in 1897. Optionally, ruthenium on alumina (aluminium oxide) makes a more efficient catalyst.
https://en.wikipedia.org/wiki/Sabatier_reaction

——-
EDIT:
Starship fuel created by the Sabatier reaction and burned during launch up to orbit can be considered part of a closed system — taken from the atmosphere, then returned to it — an improvement compared to fossil fuels which are brought up from under the Earth’s surface and added to the atmosphere.   However, additional carbon emissions will come from any non-renewable energy used to produce, handle and transport propellants before launch.

Starship emissions beyond Earth orbit (e.g., transport to the Moon, Mars or other planets) can generally be considered to be “removed,” because they dissipate into the vacuum of space rather than fall back to the atmosphere.