Seeding the oceans with nano-scale fertilizers could create a much-needed, substantial carbon sink. Credit: Stephanie King | Pacific Northwest National Laboratory
The urgent need to remove excess carbon dioxide from Earth’s environment could include enlisting some of our planet’s smallest inhabitants, according to an international research team led by Michael Hochella of the Department of Energy’s Pacific Northwest National Laboratory.
Hochella and his colleagues examined the scientific evidence for seeding the oceans with iron-rich engineered fertilizer particles near ocean plankton. The goal would be to feed phytoplankton, microscopic plants that are a key part of the ocean ecosystem, to encourage growth and carbon dioxide (CO2) uptake. The analysis article appears in the journal Nature Nanotechnology.
“The idea is to augment existing processes,” said Hochella, a Laboratory fellow at Pacific Northwest National Laboratory. “Humans have fertilized the land to grow crops for centuries. We can learn to fertilize the oceans responsibly.”
In nature, nutrients from the land reach oceans through rivers and blowing dust to fertilize plankton. The research team proposes moving this natural process one step further to help remove excess CO2 through the ocean. They studied evidence that suggests adding specific combinations of carefully engineered materials could effectively fertilize the oceans, encouraging phytoplankton to act as a carbon sink.
The organisms would take up carbon in large quantities. Then, as they die, they would sink deep into the ocean, taking the excess carbon with them. Scientists say this proposed fertilization would simply speed up a natural process that already safely sequesters carbon in a form that could remove it from the atmosphere for thousands of years.
“At this point, time is of the essence,” said Hochella. “To combat rising temperatures, we must decrease CO2 levels on a global scale. Examining all our options, including using the oceans as a CO2 sink, gives us the best chance of cooling the planet.”
Pulling insights from the literature
In their analysis, the researchers argue that engineered nanoparticles offer several attractive attributes. They could be highly controlled and specifically tuned for different ocean environments. Surface coatings could help the particles attach to plankton. Some particles also have light-absorbing properties, allowing plankton to consume and use more CO2.
The general approach could also be tuned to meet the needs of specific ocean environments. For example, one region might benefit most from iron-based particles, while silicon-based particles may be most effective elsewhere, they say.
The researchers’ analysis of 123 published studies showed that numerous non-toxic metal-oxygen materials could safely enhance plankton growth. The stability, Earth abundance, and ease of creation of these materials make them viable options as plankton fertilizers, they argue.
The team also analyzed the cost of creating and distributing different particles. While the process would be substantially more expensive than adding non-engineered materials, it would also be significantly more effective.
More information: Peyman Babakhani et al, Potential use of engineered nanoparticles in ocean fertilization for large-scale atmospheric carbon dioxide removal, Nature Nanotechnology (2022). DOI: 10.1038/s41565-022-01226-w
Smoke and steam billows from Belchatow Power Station, Europe’s largest coal-fired power plant near Belchatow, Poland on November 28, 2018. Inventors claim a new carbon capture “battery” could be retrofitted for industrial plants but also for mobile sources of CO2 emissions like cars and airplanes. Photo by REUTERS/Kacper Pempel
Renewable energy alone is not enough to turn the tide of the climate crisis. Despitethe rapid expansionof wind, solar and other clean energy technologies, human behavior and consumption are flooding our skies with too much carbon, and simply supplanting fossil fuels won’t stop global warming.
That’s why carbon capture technology is slowly being integrated into energy and industrial facilities across the globe. Typically set up to collect carbon from an exhaust stream, this technology sops up greenhouse gases before they spread into Earth’s airways.
But those industrial practices work because these factories produce gas pollutants like carbon dioxide and methane at high concentrations. Carbon capture can’t draw CO2 from regular open air, where the concentration of this prominent pollutant is too diffuse.
Moreover, the energy sector’s transition toward decarbonization is moving too slowly. It will take years —likely decades— before the world’s hundreds of CO2-emitting industrial plants adopt capture technology.
Humans have pumped about2,000 gigatonnes— billions of metric tons — of carbon dioxide into the air since industrialization, and there will be more.
But what if you could have a personal-sized carbon capture machine on your car, commercial airplane or solar-powered home?
Chemical engineers at the Massachusetts Institute of Technology have created a new device that can remove carbon dioxide from the air at any concentration.
Published in October in the journal Energy & Environmental Science, the project is the latest bid to directly capture CO2 emissions and keep them from accelerating and worsening future climate disasters.
Think of the invention as a quasi-battery, in terms of its shape, its construction and how it works to collect carbon dioxide. You pump electricity into the battery, and while the device stores this charge, a chemical reaction occurs that absorbs CO2 from the surrounding atmosphere — a process known as direct air capture. The CO2 can be extracted by discharging the battery, releasing the gas, so the CO2 then can be pumped into the ground. The researchers describe this back-and-forth as electroswing adsorption.
I realized there was a gap in the spectrum of solutions,” said Sahag Voskian, who co-led the project with fellow MIT chemical engineer T. Alan Hatton. “Many current systems, for instance, are very bulky and can only be used for large-scale power plants or industrial applications.”
Relative to current technology, this electroswing adsorber could be retrofitted onto smaller, mobile sources of emissions like autos and planes, the study states.
Voskian also pictures the battery being scaled to plug into power plants powered by renewables, such as wind farms and solar fields, which are known to create more energy than they can store. Rather than lose this power, these renewable plants could set up a side hustle where their excess energy is used to capture carbon.
“That’s one of the nice aspects of this technology — is that direct linkage with renewables,” said Jennifer Wilcox, a chemical engineer at Worcester Polytechnic Institute, who was not involved in the study.
The advantage of an electricity-based system for carbon capture is that it scales linearly. If you need 10 times more capacity, you simply build 10 times more of these “electroswing batteries” and stack them, Voskian said.
He estimates that if you cover a football field with these devices in stacks that are tens of feet high, they could remove about 200,000 to 400,000 metric tons of CO2 a year. Build another 100,000 of these fields, and they could bring carbon dioxide in the atmosphere back to preindustrial levels within 40 years.
One hundred thousand installations sounds like a lot, but keep in mind that these devices can be built to any size and run off the excess electricity created by renewables like wind and solar, which at the momentcannot be easily stored. Imagine turning the more than2 million U.S. homes with rooftop solarinto mini-carbon capture plants.
On paper, this invention sounds like a game changer. But it has a number of feasibility hurdles to surmount before it leaves the laboratory.
How electroswing battery works
The idea of using electricity to trigger a chemical reaction — electrochemistry — as a means for capturing carbon dioxide isn’t new. It has been around fornearly 25 years, in fact.
But Voskian and Hatton have now added two special materials into the equation: quinone and carbon nanotubes.
A carbon nanotube is a human-made atom-sized cylinder — a sheet of carbon molecules spread into a single layer and wrapped up like a tube. Aside from being more than100 times strongerthan stainless steel or titanium, carbon nanotubes are excellent conductors of electricity, making them sturdy building blocks for electrified equipment.
Much like a regular battery, Voskian and Hatton’s device has a positive electrode and a negative electrode — “plus” and “minus” sides. But the minus side — the negative electrode — is infused with quinone, a chemical that, after being electrically charged, reacts and sticks to CO2.
“You can think of it like the charge and discharge of a battery,” Voskian said. “When you charge the battery, you have carbon capture. When you discharge it, you release the carbon that you captured.”
Their approach is unique because all the energy required for their direct air capture comes from electricity. The three major startups in this emerging space —Climeworks,Global ThermostatandCarbon Engineering— rely on a mixture of electric and thermal (heat) energy, Wilcox said, with thermal energy being the dominant factor.
For power plants and industrial facilities, that excess heat — or waste heat, a byproduct of their everyday work, isn’t a perfect fit for carbon capture. Waste heat isn’t very consistent. Imagine standing next to a fire — its warmth changes as the flames flit about.
This heat can come from carbon-friendly options — such as a hydrothermal plant — but some current startups are preparing their capture systemsto run on thermal energy from fossil-fuel burning facilities. So they may capture 1.5 tons of CO2, but they also generate about a half ton in the process
In Voskian’s operation, “We don’t have any of that. We have full control over the energetics of our process,” he said.
Will it work?
Voskian and Hatton, who have launched a startup called Verdox, write in their study that operating electroswing carbon capture would cost between $50 to $100 per metric ton of CO2.
“If it’s true, that’s a great breakthrough,” said Richard Newell, president and CEO of Resources for the Future, a nonprofit research organizationthat develops energy and environmental policy on carbon capture. But, he cautioned, “the distance between showing something in the laboratory and then demonstrating it at a commercial scale is very big.”
In this diagram of the new system, air entering from top right passes to one of two chambers (the gray rectangular structures) containing battery electrodes that attract the carbon dioxide. Then the airflow is switched to the other chamber, while the accumulated carbon dioxide in the first chamber is flushed into a separate storage tank (at right). These alternating flows allow for continuous operation of the two-step process. Image courtesy of the researchers
The process could work on the gas at any concentrations, from power plant emissions to open air
A new way of removing carbon dioxide from a stream of air could provide a significant tool in the battle against climate change. The new system can work on the gas at virtually any concentration level, even down to the roughly 400 parts per million currently found in the atmosphere.
Most methods of removing carbon dioxide from a stream of gas require higher concentrations, such as those found in the flue emissions from fossil fuel-based power plants. A few variations have been developed that can work with the low concentrations found in air, but the new method is significantly less energy-intensive and expensive, the researchers say.
The technique, based on passing air through a stack of charged electrochemical plates, is described in a new paper in the journal Energy and Environmental Science, by MIT postdoc Sahag Voskian, who developed the work during his PhD, and T. Alan Hatton, the Ralph Landau Professor of Chemical Engineering.
The device is essentially a large, specialized battery that absorbs carbon dioxide from the air (or other gas stream) passing over its electrodes as it is being charged up, and then releases the gas as it is being discharged. In operation, the device would simply alternate between charging and discharging, with fresh air or feed gas being blown through the system during the charging cycle, and then the pure, concentrated carbon dioxide being blown out during the discharging.
As the battery charges, an electrochemical reaction takes place at the surface of each of a stack of electrodes. These are coated with a compound called poly-anthraquinone, which is composited with carbon nanotubes. The electrodes have a natural affinity for carbon dioxide and readily react with its molecules in the airstream or feed gas, even when it is present at very low concentrations. The reverse reaction takes place when the battery is discharged — during which the device can provide part of the power needed for the whole system — and in the process ejects a stream of pure carbon dioxide. The whole system operates at room temperature and normal air pressure.
“The greatest advantage of this technology over most other carbon capture or carbon absorbing technologies is the binary nature of the adsorbent’s affinity to carbon dioxide,” explains Voskian. In other words, the electrode material, by its nature, “has either a high affinity or no affinity whatsoever,” depending on the battery’s state of charging or discharging. Other reactions used for carbon capture require intermediate chemical processing steps or the input of significant energy such as heat, or pressure differences.
“This binary affinity allows capture of carbon dioxide from any concentration, including 400 parts per million, and allows its release into any carrier stream, including 100 percent CO2,” Voskian says. That is, as any gas flows through the stack of these flat electrochemical cells, during the release step the captured carbon dioxide will be carried along with it. For example, if the desired end-product is pure carbon dioxide to be used in the carbonation of beverages, then a stream of the pure gas can be blown through the plates. The captured gas is then released from the plates and joins the stream.
In some soft-drink bottling plants, fossil fuel is burned to generate the carbon dioxide needed to give the drinks their fizz. Similarly, some farmers burn natural gas to produce carbon dioxide to feed their plants in greenhouses. The new system could eliminate that need for fossil fuels in these applications, and in the process actually be taking the greenhouse gas right out of the air, Voskian says. Alternatively, the pure carbon dioxide stream could be compressed and injected underground for long-term disposal, or even made into fuel through a series of chemical and electrochemical processes.
The process this system uses for capturing and releasing carbon dioxide “is revolutionary” he says. “All of this is at ambient conditions — there’s no need for thermal, pressure, or chemical input. It’s just these very thin sheets, with both surfaces active, that can be stacked in a box and connected to a source of electricity.”
“In my laboratories, we have been striving to develop new technologies to tackle a range of environmental issues that avoid the need for thermal energy sources, changes in system pressure, or addition of chemicals to complete the separation and release cycles,” Hatton says. “This carbon dioxide capture technology is a clear demonstration of the power of electrochemical approaches that require only small swings in voltage to drive the separations.”
In a working plant — for example, in a power plant where exhaust gas is being produced continuously — two sets of such stacks of the electrochemical cells could be set up side by side to operate in parallel, with flue gas being directed first at one set for carbon capture, then diverted to the second set while the first set goes into its discharge cycle. By alternating back and forth, the system could always be both capturing and discharging the gas. In the lab, the team has proven the system can withstand at least 7,000 charging-discharging cycles, with a 30 percent loss in efficiency over that time. The researchers estimate that they can readily improve that to 20,000 to 50,000 cycles.
The electrodes themselves can be manufactured by standard chemical processing methods. While today this is done in a laboratory setting, it can be adapted so that ultimately they could be made in large quantities through a roll-to-roll manufacturing process similar to a newspaper printing press, Voskian says. “We have developed very cost-effective techniques,” he says, estimating that it could be produced for something like tens of dollars per square meter of electrode.
Compared to other existing carbon capture technologies, this system is quite energy efficient, using about one gigajoule of energy per ton of carbon dioxide captured, consistently. Other existing methods have energy consumption which vary between 1 to 10 gigajoules per ton, depending on the inlet carbon dioxide concentration, Voskian says.
The researchers have set up a company called Verdox to commercialize the process, and hope to develop a pilot-scale plant within the next few years, he says. And the system is very easy to scale up, he says: “If you want more capacity, you just need to make more electrodes.”
This work was supported by an MIT Energy Initiative Seed Fund grant and by Eni S.p.A.
Researchers develop process for carbon dioxide conversion.
University of Sydney researchers are drawing inspiration from leaves to reduce carbon emissions, using nanotechnology to develop a method for ‘carbon photosynthesis’ that they hope will one day be adopted on an industrial scale.
Professor Jun Huang from the University of Sydney Nano Institute and the School of Chemical and Biomolecular Engineering is developing a carbon capture method that aims to go one step beyond storage, instead converting and recycling carbon dioxide (CO2) into raw materials that can be used to create fuels and chemicals.
” Drawing inspiration from leaves and plants, we have developed an artificial photosynthesis method,” said Professor Huang.
To simulate photosynthesis, we have built microplates of carbon layered with carbon quantum dots with tiny pores that absorb CO2 and water.
“Once carbon dioxide and water are absorbed, a chemical process occurs that combines both compoundsand turns them into hydrocarbon, an organic compound that can be used for fuels, pharmaceuticals, agrichemicals, clothing, and construction.
“Following our most recent findings, the next phase of our research will focus on large-scale catalyst synthesis and the design of a reactor for large scale conversion,” he said.
While the research has been conducted on a nanoscale, Professor Huang hopes the technology will be used by power stations to capture emissions from burning fossil fuels.
“Our CO2 absorbent plates may be small, but our goal is to now create large panels, similar to solar panels, that would be used by industry to absorb and convert large volumes of CO2 ,” said Professor Huang.
CO emissions from the burning of fossil fuels and transport are the main cause of global warming, contributing up to 65 percent of the total global greenhouse gas emissions.
While plants ‘breathe’ in CO2 , a process called photosynthesis, deforestation and development has decreased their overall capacity to restore oxygen levels.
As nations attempt to curb emissions and divest from fossil fuels, Dr. Huang feels there should also be an increased focus on carbon capture and re-use to minimize the harmful impact of increased atmospheric CO2.
“The current global commitment to cut carbon emissions by 30 percent by 2030 is an enormous challenge, and one that will be difficult to achieve given that energy needs are accelerating,” said Professor Huang.
Carbon capture technologies have been around for over 10 years. However, they require carbon to being held in deep underground chambers.
“Carbon conversion could be a financially viable alternative as it would allow for the generation of industrial quantities of materials, such as methanol, which is a useful material for production of fuels and other chemicals,” he concluded.
DISCLOSURE
Professor Jun Huang’s research is supported by the Australian Research Council (DP180104010, the Sydney Research Accelerator Prizes (SOAR) and the University of Sydney Nano Institute Grand Challenge program.
The paper was authored by Dr Haitao Li, Dr Yadan Deng, Dr Youdi Liu, Dr Xin Zeng, Professor Dianne Wiley and Professor Jun Huang.
Every so often, fromCaliforniatoGermany, there’s news of “negative electricity prices,” a peculiar side effect of global efforts to generate clean energy.
Solar farms and wind turbines produce varying amounts of power based on the vagaries of the weather. So we build electrical grids to handle only the power levels we expect in a given location.
But in some cases, there’s more sun or wind than expected, and these renewable energy sources pump in more power than the grid can handle. The producers of that power then have to pay customers to use up the excess electricity; otherwise, the grid would be overloaded and fail.
As we build more and more renewable-power capacity in efforts to meet the emissions-reduction goals of the Paris climate agreement, these situations will become more common. Startups led by entrepreneurs who see this future on the horizon are now looking for ways to make money off the inevitable excess clean electricity.
On a mildly chilly day in April, with the smell of poo in the air, I met one of these startups at a sewage-water treatment plant in Copenhagen, Denmark.
Electrochaeatakes carbon dioxide produced during the process of cleaning wastewater, and converts it into natural gas. That alone would be impressive enough; if we want to stop global warming in its tracks, we need to do everything we can to keep CO2 from entering the atmosphere. But Electrochaea has also figured out a way to power the whole enterprise with the excess green energy produced during particularly sunny and windy days that otherwise would have gone to waste, because there would have been no way to store it.
In other words, when scaled up, Electrochaea’s process could be an answer to one of the biggest problems of the 21st century: energy storage, while also making a dent in cutting emissions.
The Electrochaea pilot plant in Copenhagen, with the Biofos water-treatment plant in the background.
This article is part of The Race to Zero Emissions series investigating carbon-capture technology. You can also read our feature laying out the case for using the technology to fight climate change.
The battery problem
The biggest problem with wind and solar energy is that they’re intermittent. There might be violent winds one day, and calm skies the next; broiling sunshine on Monday and 100% cloud cover on Tuesday. Some argue this problem is easily overcome by storing any excess energy in batteries until it’s needed at a later time. Further, battery advocates say, even though the bookcase-sized batteries required to store solar energy for a small home are expensive today, prices are fallingand will continue to fall for some time.
Except it’s not that easy. The batteries on the market for these applications are, essentially, large versions of the lithium-ion batteries found in mobile phones. They can only store energy for a certain amount of time—weeks, at most. As soon as the charging source is removed, they start to lose the charge.
That’s not a problem if the batteries are for ironing out the peaks and troughs of daily use. The trouble is that humanity’s energy demand is skewed based on local seasons, which requires sometimes drawing on every available source, and sometimes not using much energy at all.
Mumbai’s peak energy demand is during the hottest days of summer, when people run air conditioners to survive. London’s peak energy demand comes during the coldest days of winters, when people burn natural gas to heat their homes and offices.
Peak energy demand, whether for heating or cooling, can be as much as 20 times the energy consumed on an average day. Today, we shovel more coal or pump more natural gas into fossil-fuel power plants on those high-demand days. Some places, like Bridgeport in Connecticut, have old fossil-fuel plants, often coal, that they keep shut down most of the year and fire up onlyduring peak demand. Obviously, that won’t work in a future powered by renewable energy.
There are two solutions on the table for inter-seasonal energy storage, and they both involve massive investment in infrastructure: First, you could build so many solar panel fields or so many wind turbines that you could produce much more than 20 times the power of an average day. The upshot: you’d have much more excess energy on a low-demand day, but would at least be able to fill demand on peak-demand days. The second option is to get so many batteries that they can store up enough excess energy that, even as they lose their charge, there’s still enough power to get the grid through peak-demand days.
Even if both renewable generation and storage were affordable enough for these plans—and they’re not, yet—there’s still another economic wall that might be impossible to traverse: Most of the time, your new gigantic power plant and fleet of batteries would be useless, because peak demand happens only a few times each year. No government can waste the money needed to build something with so little utility.
Store it another way
Beyond batteries, there are other mechanical ways to store energy. One is to pump water into elevated lakes. Another is to compress air with excess energy. Yet another is to store energy in the form of a high-speed rotating disk. But, like batteries, none of these options can store energy between seasons.
There is one option for the inter-seasonal problem called underground thermal-energy storage. It works on a simple principle: no matter the temperature above ground, at a depth of about 15 meters, temperature in most places on Earth is about the same: 10°C (or 50°F). The planet’s soil provides natural insulation, and, in theory, we could use that insulation to store energy.
There have beensuccessful pilot projects around the world showing you can set up solar panels that, after filling the grid, use any excess electricity to heat gravel, heat-carrying chemicals, or water stored in tanks deep underground. With enough insulation, the heat could be stored for months, until it’s needed in homes nearby, and delivered to them via pipes and heat pumps. (This heat energy can also be converted to run air conditioners, where cooling is needed instead of heating.)
There are just two problems when it comes to scaling up:First, it’s expensive to build. Even if the cost of construction and management were to come down, if cities and towns haven’t already planned for underground reservoirs (and most haven’t), then it can be prohibitively exorbitant to find and secure the space. Second, the solution only works at a local scale, because transporting heat comes with natural losses. So the farther you need to move it from the storage site, the more loss you have to deal with.
Electrochaea provides another option, where renewable energy could be stored indefinitely and transported without losses.
The green goo
If you don’t mind the smell, wastewater treatment plants are fascinating. The Copenhagen plant takes in all the water sent down toilets, bathrooms, and kitchen sinks, and puts out H2O that’s nearly clean enough to drink—just one more step would be required, the plant operator told me. But since the city has no shortage of water, the treatment plant dumps its clean, but non-potable water into the North Sea.
Before that, the water goes through dozens of steps, including one where organic matter is allowed to settled to the bottom of large, open tanks. This sludge, rich in carbon-containing molecules, is transferred to a sealed bioreactor where microbes filtered from local soil are added. If this were done in the open tanks, the microbes would break the matter down slowly to produce carbon dioxide. But, in the bioreactor, in the absence of oxygen, a different set of microbes springs into action. They produce methane—the primary component of natural gas—instead.
The facility takes the methane (and any remaining sludge that can’t be broken down) and then burns it in a biomass power plant. “We produce more energy than we consume to clean up the water coming into our plant,” says Dines Thornberg, a manager at Biofos, the part-government-owned company that operates the treatment plant.
” … Batteries can’t solve the world’s biggest energy-storage problem. One startup has a solution.”
That may be true. But the process still does pollute, since some chemical degradation happens independent of microbes and creates carbon dioxide. To help Denmark hit its Paris agreement goals, Biofos wants to cut its own carbon footprint. That’s why the company gave Electrochaea valuable space at its plant to build the pilot-scale chemical plant that completes the job that Biofos’s microbes couldn’t do: convert the carbon dioxide released in the bioreactor into methane. To achieve this amazing transformation, Electrochaea gets help from microbial life called archaea.
Archaea are the oldest of the three branches of life, which include bacteria and eukaryotes (consisting of all other more advanced organisms including humans). Their ancient survival skills include one that us humans now can put to good use: an ability to naturally take in CO2 and turn it into methane.
Most scientists believe life on Earth was formed in hydrothermal vents, created by underwater volcanoes. The temperatures there can reach 400°C (750°F), far higher than that of boiling water. But the water in the vents doesn’t boil and the gases the vents release—including carbon dioxide and hydrogen—don’t explode thanks to the tremendous pressure applied by miles of seawater above. Some archaea that live in the vents have learned to use carbon dioxide as food, combining the carbon (C) from carbon dioxide (CO2) with hydrogen (H2) to form and release methane (CH4). Humans do the reverse, consuming carbon-rich food and combining it with oxygen—both readily available on land—to make and expel carbon dioxide.
Electrochaea’s pilot plant on Biofos’s premises takes up an area the size of a tennis court. As usual for a chemical factory, there’s a tangle of stainless steel pipes with sensors and control valves. The pipes all lead to a big cylindrical bioreactor, about 10 meters (30 ft) tall, kept at 60°C (140°F) and eight times the atmospheric pressure. Through a small glass window at the bottom of the bioreactor, I can see a bubbling mixture the color of an avocado milkshake. That’s Electrochaea’s proprietary species of archaea, cultured and bred to efficiently combine carbon dioxide and hydrogen to produce methane.
Electrochaea’s lab-scale bioreactor with archaea producing methane.
The gases injected into the bioreactor come from two sources. The wastewater-treatment plant sends a mixture of carbon dioxide and methane. Meanwhile, two shipping container-sized electrolyzers use renewable electricity to split water into hydrogen and oxygen. The oxygen is sent off into the atmosphere, and the hydrogen to the Electrochaea bioreactor.
The microbes are so effective that in the time the mixture of gases travels from the bottom of the bioreactor to its top, 99 out of every 100 molecules of carbon dioxide and hydrogen are converted into methane, water, and heat. The heat is useful: it helps keep the temperature inside the reactor steady. Meanwhile, as the archaea consume the CO2 and H2, they multiply. Because they are naturally occurring species, extra archaea can be simply dumped into sewers, flushed out by the water also created in the process.
The valuable product from the reaction is methane. In fact, the stuff created through this process is even more valuable than typical methane. It’s “renewable methane” or “biomethane,” because the gas was produced from non-fossil-fuel sources and without any fossil-fuel power. This methane can be used to run boilers in homes, power plants, and even cars or buses. It’s a cleaner fuel than coal and oil, producing the fewest emissions for each unit of energy released. Methane can also be very easily stored. In fact, across Europe, there are large underground stores, connected by pipes that can safely transport the gas.
When the system runs at full capacity, the archaea produce about 50 cubic meters of natural gas per hour. For every unit of energy of electricity fed into the system, it produces about 0.75 units of energy stored in the form of methane, according to Doris Hafenbradl, Electrochaea’s chief scientist. That’s not as good as lithium-ion batteries, which can reach near 100% efficiency. But unlike the energy stored in batteries, once methane is produced it can be stored indefinitely, because it doesn’t spontaneously degrade into other chemicals. If this process could be scaled up, it could solve renewable energy’s inter-seasonal storage problem.
Electrochaea’s plant does not need to be close to solar farms or wind turbines, because excess electricity can be extracted from anywhere on the grid. The limitations on location come based on access to CO2. Water treatment plants are fair game and so are ethanol producers (such as beer and liquor factories). Exhaust gasesfrom power plantscould be used, but they will need to be cleaned to remove sulfur and particulate emissions, which could harm archaea.
Solving problems at scale
The Copenhagen plant is one of three where Electrochaea has successfully installed its technology. The US National Renewable Energy Laboratory has one installation on its campus in Boulder, Colorado, and the last is part of a European Commission-funded project in Solothurn, Switzerland. Ultimately, Electrochaea’s core business model is to license the technology. The company is currently courting a Hungarian power company that wants to build a plant 10 times the size of the one in Copenhagen. It would be the startup’s biggest yet. And the carmaker Audi has shown interest in Electrochaea’s technology as a way to use biomethane in its natural-gas-powered cars.
Electrochaea is one of a growing number of players in the “power-to-gas” industry. ITM Power and Hydrogenics, for example, make electrolyzers that convert excess renewable energy into storable hydrogen. But hydrogen is not as widely used as natural gas. That’s why companies such as Electrochaea, MicrobEnergy, and ETOGas are betting that it’s worth the extra step of turning that hydrogen into methane. MicrobEnergy, as the name suggests, uses microbes for the conversion, just like Electrochaea. ETOGas, a Hitachi-supported startup, uses metal catalysts.
Doing it this way also gives these companies a potential second business model: Because these processes all involve injecting carbon dioxide into the system, it could turn out to be the case that they are hired to install their power-to-gas systems simply to reduce a facility’s CO2 emissions, whether it has an excess of renewable energy or not.
Electrochaea hasn’t secured a carbon-capture customer yet. And to be sure, its technology is carbon-capture and recycling—not storage or removal. The methane produced in the process will eventually be burned again, and that will put carbon dioxide into the atmosphere. In other words, it simply delays the production of greenhouse gases, instead of eliminating them.
That said, there is some value in delaying emissions. Every CO2 molecule not dumped in the atmosphere right now is a CO2 molecule that doesn’t absorb and retain sun’s heat. If nothing else, Electrochaea and companies like it may do their part in saving the planet simply by helping change the conversation around carbon dioxide, from treating it as a byproduct to considering it as a feedstock.
This is Part II of MIT’s 10 Technology Breakthroughs for 2019′ Re-Posted from MIT Technology Review, with Guest Curator Bill Gates. You can Read Part I Here
Part I Into from Bill Gates: How We’ll Invent the Future
I was honored when MIT Technology Review invited me to be the first guest curator of its 10 Breakthrough Technologies. Narrowing down the list was difficult. I wanted to choose things that not only will create headlines in 2019 but captured this moment in technological history—which got me thinking about how innovation has evolved over time.
Robot dexterity
NICOLAS ORTEGA
Why it matters If robots could learn to deal with the messiness of the real world, they could do many more tasks.
Key Players OpenAI
Carnegie Mellon University
University of Michigan
UC Berkeley
Availability 3-5 years
Robots are teaching themselves to handle the physical world.
For all the talk about machines taking jobs, industrial robots are still clumsy and inflexible. A robot can repeatedly pick up a component on an assembly line with amazing precision and without ever getting bored—but move the object half an inch, or replace it with something slightly different, and the machine will fumble ineptly or paw at thin air.
But while a robot can’t yet be programmed to figure out how to grasp any object just by looking at it, as people do, it can now learn to manipulate the object on its own through virtual trial and error.
One such project is Dactyl, a robot that taught itself to flip a toy building block in its fingers. Dactyl, which comes from the San Francisco nonprofit OpenAI, consists of an off-the-shelf robot hand surrounded by an array of lights and cameras. Using what’s known as reinforcement learning, neural-network software learns how to grasp and turn the block within a simulated environment before the hand tries it out for real. The software experiments, randomly at first, strengthening connections within the network over time as it gets closer to its goal.
It usually isn’t possible to transfer that type of virtual practice to the real world, because things like friction or the varied properties of different materials are so difficult to simulate. The OpenAI team got around this by adding randomness to the virtual training, giving the robot a proxy for the messiness of reality.
We’ll need further breakthroughs for robots to master the advanced dexterity needed in a real warehouse or factory. But if researchers can reliably employ this kind of learning, robots might eventually assemble our gadgets, load our dishwashers, and even help Grandma out of bed. —Will Knight
New-wave nuclear power
BOB MUMGAARD/PLASMA SCIENCE AND FUSION CENTER/MIT
Advanced fusion and fission reactors are edging closer to reality.
New nuclear designs that have gained momentum in the past year are promising to make this power source safer and cheaper. Among them are generation IV fission reactors, an evolution of traditional designs; small modular reactors; and fusion reactors, a technology that has seemed eternally just out of reach. Developers of generation IV fission designs, such as Canada’s Terrestrial Energy and Washington-based TerraPower, have entered into R&D partnerships with utilities, aiming for grid supply (somewhat optimistically, maybe) by the 2020s.
Small modular reactors typically produce in the tens of megawatts of power (for comparison, a traditional nuclear reactor produces around 1,000 MW). Companies like Oregon’s NuScale say the miniaturized reactors can save money and reduce environmental and financial risks.
From sodium-cooled fission to advanced fusion, a fresh generation of projects hopes to rekindle trust in nuclear energy.
There has even been progress on fusion. Though no one expects delivery before 2030, companies like General Fusion and Commonwealth Fusion Systems, an MIT spinout, are making some headway. Many consider fusion a pipe dream, but because the reactors can’t melt down and don’t create long-lived, high-level waste, it should face much less public resistance than conventional nuclear. (Bill Gates is an investor in TerraPower and Commonwealth Fusion Systems.) —Leigh Phillips
NENOV | GETTY
Predicting preemies
Why it matters 15 million babies are born prematurely every year; it’s the leading cause of death for children under age five
Key player Akna Dx
Availability A test could be offered in doctor’s offices within five years
A simple blood test can predict if a pregnant woman is at risk of giving birth prematurely.
Our genetic material lives mostly inside our cells. But small amounts of “cell-free” DNA and RNA also float in our blood, often released by dying cells. In pregnant women, that cell-free material is an alphabet soup of nucleic acids from the fetus, the placenta, and the mother.
Stephen Quake, a bioengineer at Stanford, has found a way to use that to tackle one of medicine’s most intractable problems: the roughly one in 10 babies born prematurely.
Free-floating DNA and RNA can yield information that previously required invasive ways of grabbing cells, such as taking a biopsy of a tumor or puncturing a pregnant woman’s belly to perform an amniocentesis. What’s changed is that it’s now easier to detect and sequence the small amounts of cell-free genetic material in the blood. In the last few years researchers have begun developing blood tests for cancer (by spotting the telltale DNA from tumor cells) and for prenatal screening of conditions like Down syndrome.
The tests for these conditions rely on looking for genetic mutations in the DNA. RNA, on the other hand, is the molecule that regulates gene expression—how much of a protein is produced from a gene. By sequencing the free-floating RNA in the mother’s blood, Quake can spot fluctuations in the expression of seven genes that he singles out as associated with preterm birth. That lets him identify women likely to deliver too early. Once alerted, doctors can take measures to stave off an early birth and give the child a better chance of survival.
Complications from preterm birth are the leading cause of death worldwide in children under five.
The technology behind the blood test, Quake says, is quick, easy, and less than $10 a measurement. He and his collaborators have launched a startup, Akna Dx, to commercialize it. —Bonnie Rochman
BRUCE PETERSON
Gut probe in a pill
Why it matters The device makes it easier to screen for and study gut diseases, including one that keeps millions of children in poor countries from growing properly
Key player Massachusetts General Hospital
Availability Now used in adults; testing in infants begins in 2019
A small, swallowable device captures detailed images of the gut without anesthesia, even in infants and children.
Environmental enteric dysfunction (EED) may be one of the costliest diseases you’ve never heard of. Marked by inflamed intestines that are leaky and absorb nutrients poorly, it’s widespread in poor countries and is one reason why many people there are malnourished, have developmental delays, and never reach a normal height. No one knows exactly what causes EED and how it could be prevented or treated.
Practical screening to detect it would help medical workers know when to intervene and how. Therapies are already available for infants, but diagnosing and studying illnesses in the guts of such young children often requires anesthetizing them and inserting a tube called an endoscope down the throat. It’s expensive, uncomfortable, and not practical in areas of the world where EED is prevalent.
So Guillermo Tearney, a pathologist and engineer at Massachusetts General Hospital (MGH) in Boston, is developing small devices that can be used to inspect the gut for signs of EED and even obtain tissue biopsies. Unlike endoscopes, they are simple to use at a primary care visit.
Tearney’s swallowable capsules contain miniature microscopes. They’re attached to a flexible string-like tether that provides power and light while sending images to a briefcase-like console with a monitor. This lets the health-care worker pause the capsule at points of interest and pull it out when finished, allowing it to be sterilized and reused. (Though it sounds gag-inducing, Tearney’s team has developed a technique that they say doesn’t cause discomfort.) It can also carry technologies that image the entire surface of the digestive tract at the resolution of a single cell or capture three-dimensional cross sections a couple of millimeters deep.
The technology has several applications; at MGH it’s being used to screen for Barrett’s esophagus, a precursor of esophageal cancer. For EED, Tearney’s team has developed an even smaller version for use in infants who can’t swallow a pill. It’s been tested on adolescents in Pakistan, where EED is prevalent, and infant testing is planned for 2019.
The little probe will help researchers answer questions about EED’s development—such as which cells it affects and whether bacteria are involved—and evaluate interventions and potential treatments. —Courtney Humphrie
PAPER BOAT CREATIVE | GETTY
Custom cancer vaccines
Why it matters Conventional chemotherapies take a heavy toll on healthy cells and aren’t always effective against tumors
Key players BioNTech
Genentech
Availability In human testing
The treatment incites the body’s natural defenses to destroy only cancer cells by identifying mutations unique to each tumor
Scientists are on the cusp of commercializing the first personalized cancer vaccine. If it works as hoped, the vaccine, which triggers a person’s immune system to identify a tumor by its unique mutations, could effectively shut down many types of cancers.
By using the body’s natural defenses to selectively destroy only tumor cells, the vaccine, unlike conventional chemotherapies, limits damage to healthy cells. The attacking immune cells could also be vigilant in spotting any stray cancer cells after the initial treatment.
The possibility of such vaccines began to take shape in 2008, five years after the Human Genome Project was completed, when geneticists published the first sequence of a cancerous tumor cell.
Soon after, investigators began to compare the DNA of tumor cells with that of healthy cells—and other tumor cells. These studies confirmed that all cancer cells contain hundreds if not thousands of specific mutations, most of which are unique to each tumor.
A few years later, a German startup called BioNTech provided compelling evidence that a vaccine containing copies of these mutations could catalyze the body’s immune system to produce T cells primed to seek out, attack, and destroy all cancer cells harboring them.
In December 2017, BioNTech began a large test of the vaccine in cancer patients, in collaboration with the biotech giant Genentech. The ongoing trial is targeting at least 10 solid cancers and aims to enroll upwards of 560 patients at sites around the globe.
The two companies are designing new manufacturing techniques to produce thousands of personally customized vaccines cheaply and quickly. That will be tricky because creating the vaccine involves performing a biopsy on the patient’s tumor, sequencing and analyzing its DNA, and rushing that information to the production site. Once produced, the vaccine needs to be promptly delivered to the hospital; delays could be deadly. —Adam Pior
BRUCE PETERSON/STYLING: MONICA MARIANO
The cow-free burger
Why it matters Livestock production causes catastrophic deforestation, water pollution, and greenhouse-gas emissions
Key players Beyond Meat
Impossible Foods
Availability Plant-based now; lab-grown around 2020
Both lab-grown and plant-based alternatives approximate the taste and nutritional value of real meat without the environmental devastation.
The UN expects the world to have 9.8 billion people by 2050. And those people are getting richer. Neither trend bodes well for climate change—especially because as people escape poverty, they tend to eat more meat.
By that date, according to the predictions, humans will consume 70% more meat than they did in 2005. And it turns out that raising animals for human consumption is among the worst things we do to the environment.
Depending on the animal, producing a pound of meat protein with Western industrialized methods requires 4 to 25 times more water, 6 to 17 times more land, and 6 to 20 times more fossil fuels than producing a pound of plant protein.
The problem is that people aren’t likely to stop eating meat anytime soon. Which means lab-grown and plant-based alternatives might be the best way to limit the destruction.
Making lab-grown meat involves extracting muscle tissue from animals and growing it in bioreactors. The end product looks much like what you’d get from an animal, although researchers are still working on the taste. Researchers at Maastricht University in the Netherlands, who are working to produce lab-grown meat at scale, believe they’ll have a lab-grown burger available by next year. One drawback of lab-grown meat is that the environmental benefits are still sketchy at best—a recent World Economic Forum report says the emissions from lab-grown meat would be only around 7% less than emissions from beef production.
Meat production spews tons of greenhouse gas and uses up too much land and water. Is there an alternative that won’t make us do without?
The better environmental case can be made for plant-based meats from companies like Beyond Meat and Impossible Foods (Bill Gates is an investor in both companies), which use pea proteins, soy, wheat, potatoes, and plant oils to mimic the texture and taste of animal meat.
Beyond Meat has a new 26,000-square-foot (2,400-square-meter) plant in California and has already sold upwards of 25 million burgers from 30,000 stores and restaurants. According to an analysis by the Center for Sustainable Systems at the University of Michigan, a Beyond Meat patty would probably generate 90% less in greenhouse-gas emissions than a conventional burger made from a cow. —Markkus Rovito
NICO ORTEGA
Carbon dioxide catcher
Why it matters Removing CO2 from the atmosphere might be one of the last viable ways to stop catastrophic climate change
Key players Carbon Engineering
Climeworks
Global Thermostat
Availability 5-10 years
Practical and affordable ways to capture carbon dioxide from the air can soak up excess greenhouse-gas emissions.
Even if we slow carbon dioxide emissions, the warming effect of the greenhouse gas can persist for thousands of years. To prevent a dangerous rise in temperatures, the UN’s climate panel now concludes, the world will need to remove as much as 1 trillion tons of carbon dioxide from the atmosphere this century.
In a surprise finding last summer, Harvard climate scientist David Keith calculated that machines could, in theory, pull this off for less than $100 a ton, through an approach known as direct air capture. That’s an order of magnitude cheaper than earlier estimates that led many scientists to dismiss the technology as far too expensive—though it will still take years for costs to fall to anywhere near that level.
But once you capture the carbon, you still need to figure out what to do with it.
Carbon Engineering, the Canadian startup Keith cofounded in 2009, plans to expand its pilot plant to ramp up production of its synthetic fuels, using the captured carbon dioxide as a key ingredient. (Bill Gates is an investor in Carbon Engineering.)
Zurich-based Climeworks’s direct air capture plant in Italy will produce methane from captured carbon dioxide and hydrogen, while a second plant in Switzerland will sell carbon dioxide to the soft-drinks industry. So will Global Thermostat of New York, which finished constructing its first commercial plant in Alabama last year.
Klaus Lackner’s once wacky idea increasingly looks like an essential part of solving climate change.
Still, if it’s used in synthetic fuels or sodas, the carbon dioxide will mostly end up back in the atmosphere. The ultimate goal is to lock greenhouse gases away forever. Some could be nested within products like carbon fiber, polymers, or concrete, but far more will simply need to be buried underground, a costly job that no business model seems likely to support.
In fact, pulling CO2 out of the air is, from an engineering perspective, one of the most difficult and expensive ways of dealing with climate change. But given how slowly we’re reducing emissions, there are no good options left. —James Temple
BRUCE PETERSON
An ECG on your wrist
Regulatory approval and technological advances are making it easier for people to continuously monitor their hearts with wearable devices.
Fitness trackers aren’t serious medical devices. An intense workout or loose band can mess with the sensors that read your pulse. But an electrocardiogram—the kind doctors use to diagnose abnormalities before they cause a stroke or heart attack— requires a visit to a clinic, and people often fail to take the test in time.
ECG-enabled smart watches, made possible by new regulations and innovations in hardware and software, offer the convenience of a wearable device with something closer to the precision of a medical one.
An Apple Watch–compatible band from Silicon Valley startup AliveCor that can detect atrial fibrillation, a frequent cause of blood clots and stroke, received clearance from the FDA in 2017. Last year, Apple released its own FDA-cleared ECG feature, embedded in the watch itself.
Making complex heart tests available at the push of a button has far-reaching consequences.
The health-device company Withings also announced plans for an ECG-equipped watch shortly after.
Current wearables still employ only a single sensor, whereas a real ECG has 12. And no wearable can yet detect a heart attack as it’s happening.
But this might change soon. Last fall, AliveCor presented preliminary results to the American Heart Association on an app and two-sensor system that can detect a certain type of heart attack. —Karen Hao
THEDMAN | GETTY
Sanitation without sewers
Why it matters 2.3 billion people lack safe sanitation, and many die as a result
Key players Duke University
University of South Florida
Biomass Controls
California Institute of Technology
Availability 1-2 years
Energy-efficient toilets can operate without a sewer system and treat waste on the spot.
About 2.3 billion people don’t have good sanitation. The lack of proper toilets encourages people to dump fecal matter into nearby ponds and streams, spreading bacteria, viruses, and parasites that can cause diarrhea and cholera. Diarrhea causes one in nine child deaths worldwide.
Now researchers are working to build a new kind of toilet that’s cheap enough for the developing world and can not only dispose of waste but treat it as well.
In 2011 Bill Gates created what was essentially the X Prize in this area—the Reinvent the Toilet Challenge. Since the contest’s launch, several teams have put prototypes in the field. All process the waste locally, so there’s no need for large amounts of water to carry it to a distant treatment plant.
Most of the prototypes are self-contained and don’t need sewers, but they look like traditional toilets housed in small buildings or storage containers. The NEWgenerator toilet, designed at the University of South Florida, filters out pollutants with an anaerobic membrane, which has pores smaller than bacteria and viruses. Another project, from Connecticut-based Biomass Controls, is a refinery the size of a shipping container; it heats the waste to produce a carbon-rich material that can, among other things, fertilize soil.
One drawback is that the toilets don’t work at every scale. The Biomass Controls product, for example, is designed primarily for tens of thousands of users per day, which makes it less well suited for smaller villages. Another system, developed at Duke University, is meant to be used only by a few nearby homes.
So the challenge now is to make these toilets cheaper and more adaptable to communities of different sizes. “It’s great to build one or two units,” says Daniel Yeh, an associate professor at the University of South Florida, who led the NEWgenerator team. “But to really have the technology impact the world, the only way to do that is mass-produce the units.” —Erin Winick
BRUCE PETERSON
Smooth-talking AI assistants
Why it matters AI assistants can now perform conversation-based tasks like booking a restaurant reservation or coordinating a package drop-off rather than just obey simple commands
Key players Google
Alibaba
Amazon
Availability 1-2 years
New techniques that capture semantic relationships between words are making machines better at understanding natural language.
We’re used to AI assistants—Alexa playing music in the living room, Siri setting alarms on your phone—but they haven’t really lived up to their alleged smarts. They were supposed to have simplified our lives, but they’ve barely made a dent. They recognize only a narrow range of directives and are easily tripped up by deviations.
But some recent advances are about to expand your digital assistant’s repertoire. In June 2018, researchers at OpenAI developed a technique that trains an AI on unlabeled text to avoid the expense and time of categorizing and tagging all the data manually. A few months later, a team at Google unveiled a system called BERT that learned how to predict missing words by studying millions of sentences. In a multiple-choice test, it did as well as humans at filling in gaps.
These improvements, coupled with better speech synthesis, are letting us move from giving AI assistants simple commands to having conversations with them. They’ll be able to deal with daily minutiae like taking meeting notes, finding information, or shopping online.
Some are already here. Google Duplex, the eerily human-like upgrade of Google Assistant, can pick up your calls to screen for spammers and telemarketers. It can also make calls for you to schedule restaurant reservations or salon appointments.
In China, consumers are getting used to Alibaba’s AliMe, which coordinates package deliveries over the phone and haggles about the price of goods over chat.
But while AI programs have gotten better at figuring out what you want, they still can’t understand a sentence. Lines are scripted or generated statistically, reflecting how hard it is to imbue machines with true language understanding. Once we cross that hurdle, we’ll see yet another evolution, perhaps from logistics coordinator to babysitter, teacher—or even friend? —Karen Hao
Australian scientists have unlocked a new and more “efficient” way to turn carbon dioxide back into solid coal, in a world-first breakthrough that could combat rising greenhouse gas levels.
Researchers at Melbourne’s RMIT University have used liquid metals to convert CO2 from a gas to a solid at room temperature.
The technique has potential to “safely and permanently” remove CO2 from the atmosphere, according to the new study published in the journal Nature Communications.
Carbon technologies have previously tended to focus on compressing CO2 into a liquid form, transporting it to a suitable site and injecting it underground.
The use of underground injections to capture and store carbon is not economically viable and sparks fears of an environmental catastrophe due to possible leaks from the storage site.
However, the new technique transforms CO2 into solid flakes of carbon, similar to coal, which can be stored more easily and securely.
Carbon dioxide is dissolved into a beaker containing an electrolyte liquid, then a small amount of the liquid metal catalyst is added, which is then charged with an electrical current.
The electrical current serves as a catalyst to slowly converts the CO2 into solid flakes of carbon.
Watch how researchers made their discovery
This is a “crucial first step” to developing a more sustainable approach to converting CO2 into a solid, RMIT researcher Dr Torben Daeneke said, noting that more research is required cement the process.
He described the process as “efficient and scalable”.
“While we can’t literally turn back time, turning carbon dioxide back into coal and burying it back in the ground is a bit like rewinding the emissions clock.
“To date, CO2 has only been converted into a solid at extremely high temperatures, making it industrially un-viable,” Dr Daeneke said.
The study’s lead author, Dr Dorna Esrafilzadeh, said the carbon produced could also be used as an electrode.
“A side benefit of the process is that the carbon can hold electrical charge, becoming a supercapacitor, so it could potentially be used as a component in future vehicles,” she said.
“The process also produces synthetic fuel as a by-product, which could also have industrial applications.”
The study was completed in collaboration with researchers from Germany (University of Munster), China (Nanjing University of Aeronautics and Astronautics), the US (North Carolina State University) and Australia (UNSW, University of Wollongong, Monash University, QUT).
Novel functionalized nanomaterials for CO2 capture. Credit: Copyright Royal Society of Chemistry (RSC). Polshettiwar et al. Chemical Science
Scientists at the University of Waterloo have created a powder that can capture CO2 from factories and power plants.
The powder, created in the lab of Zhongwei Chen, a chemical engineering professor at Waterloo, can filter and remove CO2 at facilities powered by fossil fuels before it is released into the atmosphere and is twice as efficient as conventional methods.
Chen said the new process to manipulate the size and concentration of pores could also be used to produce optimized carbon powders for applications including water filtration and energy storage, the other main strand of research in his lab.
“This will be more and more important in the future,” said Chen, “We have to find ways to deal with all the CO2 produced by burning fossil fuels.”
CO2 molecules stick to the surface of carbon when they come in contact with it, a process known as adsorption. Since it is abundant, inexpensive and environmentally friendly, that makes carbon an excellent material for CO2 capture. The researchers, who collaborated with colleagues at several universities in China, set out to improve adsorption performance by manipulating the size and concentration of pores in carbon materials.
The technique they developed uses heat and salt to extract a black carbon powder from plant matter. Carbon spheres that make up the powder have many, many pores and the vast majority of them are less than one-millionth of a metre in diameter.
“The porosity of this material is extremely high,” said Chen, who holds a Tier 1 Canada Research Chair in advanced materials for clean energy. “And because of their size, these pores can capture CO2 very efficiently. The performance is almost doubled.”
Once saturated with carbon dioxide at large point sources such as fossil fuel power plants, the powder would be transported to storage sites and buried in underground geological formations to prevent CO2 release into the atmosphere.
A paper on the CO2 capture work, In-situ ion-activated carbon nanospheres with tunable ultra-microporosity for superior CO2 capture, appears in the journal Carbon.
Professor Chen can be reached at zhwchen@uwaterloo.ca or 519-888-4567 ext. 38664.
Northeast Atlantic bathymetry, with Porcupine Bank and the Porcupine Seabight labelled.
A research expedition to a huge underwater canyon off the Irish coast has shed light on a hidden process that sucks the greenhouse gas carbon dioxide (CO2) out of the atmosphere.
Researchers led by a team from the University College Cork (UCC)took an underwater research droneby boat out to Porcupine Bank Canyon — a massive, cliff-walled underwater trench where Ireland’s continental shelf ends — to build a detailed map of its boundaries and interior. Along the way, the researchers reported in a statement, they noted a process at the edge of the canyon that pulls CO2 from the atmosphere and buries it deep under the sea.
All around the rim of the canyon live cold-water corals, which thrive on dead plankton raining down from the ocean surface. Those tiny, surface-dwelling plankton build their bodies out of carbon extracted from CO2 in the air. Then, when they die, the coral on the seafloor consume them and build their bodies out of the same carbon. Over time, as the coral die and the cliff faces shift and crumble, which sends the coral falling deep into the canyon. There, the carbon pretty much stays put for long periods. [ In Photos: ROV Explores Deep-Sea Marianas Trench
There’s evidence that a lot of carbon is moving this way; the researchers said they found “significant” dead coral buildup at the canyon bottom.
This process doesn’t move nearly enough carbon dioxide to prevent climate change, the researchers said. But it does shed light on yet another mechanism that keeps the planet’s CO2 levels regulated when human industry doesn’t interfere.
“Increasing CO2 concentrations in our atmosphere are causing our extreme weather,” Andy Wheeler, a UCC geoscientist and one of the researchers on the expedition, said in the statement. “Oceans absorb this CO2 and canyons are a rapid route for pumping it into the deep ocean where it is safely stored away.”
The mapping expedition covered an area about the size of Chicago and revealed places where the canyon has moved and shifted significantly in the past.
“We took cores with the ROV, and the sediments reveal that although the canyon is quiet now, periodically it is a violent place where the seabed gets ripped up and eroded,” Wheeler said.
The expedition will return to shore today (Aug. 10).
Net Power’s pilot natural gas plant with carbon capture, near Houston, Texas.
An Interview with Julio Friedmann
At current rates of greenhouse-gas emissions, the world could lock in 1.5 ˚C of warming as soon as 2021, an analysis by the website Carbon Brief has found. We’re on track to blow the carbon budget for 2 ˚C by 2036.
Amid this daunting climate math, many researchers argue that capturing carbon dioxide from power plants, factories, and the air will have to play a big part in any realistic efforts to limit the dangers of global warming.
If it can be done economically, carbon capture and storage (CCS) offers the world additional flexibility and time to make the leap to cleaner systems. It means we can retrofit, rather than replace, vast parts of the global energy infrastructure. And once we reach disastrous levels of warming, so-called direct air capture offers one of the only ways to dig our way out of trouble, since carbon dioxide otherwise stays in the atmosphere for thousands of years.
Julio Friedmann has emerged as one of the most ardent advocates of these technologies. He oversaw research and development efforts on clean coal and carbon capture at the US Department of Energy’s Office of Fossil Energy under the last administration. Among other roles, he’s now working with or advising the Global CCS Institute, the Energy Futures Initiative, and Climeworks, a Switzerland-based company already building pilot plants that pull carbon dioxide from the air.
In an interview with MIT Technology Review, Friedmann argues that the technology is approaching a tipping point: a growingnumber of projectsdemonstrate that it works in the real world, and that it is becoming more reliable and affordable. He adds that the boosted US tax credit for capturing and storing carbon, passed in the form of the Future Act as part of the federal budget earlier this year, will push forward many more projects and help create new markets for products derived from carbon dioxide (see “The carbon-capture era may finally be starting”).
But serious challenges remain. Even with the tax credit, companies will incur steep costs by adding carbon capture systems to existing power plants. And a widely cited 2011 study, coauthored by MIT researcher Howard Herzog, found that direct air capture will require vast amounts of energy and cost 10 times as much as scrubbing carbon from power plants.
(This interview has been edited for length and clarity.)
In late February, you wrote a Medium post saying that with the passage of the increased tax credit for carbon capture and storage, we’ve “launched the climate counter-strike.” Why is that a big deal?
It actually sets a price on carbon formally. It says you should get paid to not emit carbon dioxide, and you should get paid somewhere between $35 a ton and $50 a ton. So that is already a massive change. In addition to that, it says you can do one of three things: you can store CO2, you can use it for enhanced oil recovery, or you can turn it into stuff. Fundamentally, it says not emitting has value.
As I’ve said many times before, the lack of progress in deploying CCS up until this point is not a question of cost. It’s really been a question of finance.
The Future Act creates that financing.
I identified an additional provision which said not only can you consider a power plant a source or an industrial site a source, you can consider the air a source.
Even if we zeroed out all our emissions today, we still have a legacy of harm of two trillion tons of CO2 in the air, and we need to do something about that.
And this law says, yeah, we should. It says we can take carbon dioxide out of the air and turn it into stuff.
At the Petra Nova plant in Texas, my understanding is the carbon capture costs are something like $60 to $70 a ton, which is still going to outstrip the tax credit today. How are we going to close that gap?
There are many different ways to go about it. For example, the state of New Jersey today passed a 90 percent clean energy portfolio standard. Changing the policy from a renewable portfolio standard [which would exclude CCS technologies] to a clean energy standard [which would allow them] allowed higher ambition.
In that context, somebody who would build a CCS project and would get a contract to deliver that power, or deliver that emissions abatement, can actually again get staked, get financed, and get built. That can happen without any technology advancement.
The technology today is already cost competitive. CCS today, as a retrofit, is cheaper than a whole bunch of stuff. It’s cheaper than new-build nuclear, it’s cheaper than offshore wind. It’s cheaper than a whole bunch of things we like, and it’s cheaper than rooftop solar, almost everywhere. It’s cheaper than utility-scale concentrating solar pretty much everywhere, and it is cheaper than what solar and wind were 10 years ago.
What do you make of the critique that this is all just going to perpetuate the fossil-fuel industry?
The enemy is not fossil fuels; the enemy is emissions.
In a place like California that has terrific renewable resources and a good infrastructure for renewable energy, maybe you can get to zero [fossil fuels] someday.
If you’re in Saskatchewan, you really can’t do that. It is too cold for too much of the year, and they don’t have solar resources, and their wind resources are problematic because they’re so strong they tear up the turbines. Which is why they did the CCS project in Saskatchewan. For them it was the right solution.
Shifting gears to direct air capture, the basic math says that you’re moving 2,500 molecules to capture one of CO2. How good are we getting at this, and how cheaply can we do this at this point?
If you want to optimize the way that you would reduce carbon dioxide economy-wide, direct air capture is the last thing you would tackle. Turns out, though, that we don’t live in that society. We are not optimizing anything in any way.
So instead we realize we have this legacy of emissions in the atmosphere and we need tools to manage that. So there are companies like Climeworks, Carbon Engineering, and Global Thermostat. Those guys said we know we’re going to need this technology, so I’m going to work now. They’ve got decent financing, and the costs are coming down and improving (see “Can sucking CO2 out of the atmosphere really work?”).
Analysis of a newly approved tax credit shows it could make an immediate dent in industrial emissions and narrow the financial gap for power plants.
The cost for all of these things now today, all-in costs, is somewhere between $300 and $600 a ton. I’ve looked inside all those companies and I believe all of them are on a glide path to get to below $200 a ton by somewhere between 2022 and 2025. And I believe that they’re going to get down to $100 a ton by 2030. At that point, these are real options.
At $200 a ton, we know today unambiguously that pulling CO2 out of the air is cheaper than trying to make a zero-carbon airplane, by a lot. So it becomes an option that you use to go after carbon in the hard-to-scrub parts of the economy.
Is it ever going to work as a business, or is it always going to be kind of a public-supported enterprise to buy ourselves out of climate catastrophes?
Direct air capture is not competitive today broadly, but there are places where the value proposition is real. So let me give you a couple of examples.
In many parts of the world there are no sources of CO2. If you’re running a Pepsi or a Coca-Cola plant in Sri Lanka, you literally burn diesel fuel and capture the CO2 from it to put into your cola, at a bonkers price. It can cost $300 to $800 a ton to get that CO2. So there are already going to be places in some people’s supply chain where direct air capture could be cheaper.
We talk to companies like Goodyear, Firestone, or Michelin. They make tires, and right now the way that they get their carbon black [a material used in tire production that’s derived from fossil fuel] is basically you pyrolize bunker fuel in the Gulf Coast, which is a horrible, environmentally destructive process. And then you ship it by rail cars to wherever they’re making the tires.
If they can decouple from that market by gathering CO2 wherever they are and turn that into carbon black, they can actually avoid market shocks. So even if it costs a little more, the value to that company might be high enough to bring it into the market. That’s where I see direct air actually gaining real traction in the next few years.
It’s not going to be enough for climate. We know that we will have to do carbon storage, for sure, if we want to really manage the atmospheric emissions. But there’s a lot of ground to chase this, and we never know quite where technology goes.
In one of your earlier Medium posts you said that we’re ultimately going to have to pull 10 billion tons of CO2 out of the atmosphere every year. Climeworks is doing about 50 [at their pilot plant in Iceland]. So what does that scale-up look like?
You don’t have to get all 10 billion tons with direct air capture. So let’s say you just want one billion.
Right now, Royal Dutch Shell as a company moves 300 million tons of refined product every year. This means that you need three to four companies the size of Royal Dutch Shell to pull CO2 out of the atmosphere.
The good news is we don’t need that billion tons today. We have 10 or 20 or 30 years to get to a billion tons of direct air capture. But in fact we’ve seen that kind of scaling in other kinds of clean-tech markets. There’s nothing in the laws of physics or chemistry that stops that.
Electrochaea’s lab-scale bioreactor with archaea producing methane.
Novel functionalized nanomaterials for CO2 capture. Credit: Copyright Royal Society of Chemistry (RSC). Polshettiwar et al. Chemical Science
All around the rim of the canyon live cold-water corals, which thrive on dead plankton raining down from the ocean surface. Those tiny, surface-dwelling plankton build their bodies out of carbon extracted from CO2 in the air. Then, when they die, the coral on the seafloor consume them and build their bodies out of the same carbon. Over time, as the coral die and the cliff faces shift and crumble, which sends the coral falling deep into the canyon. There, the carbon pretty much stays put for long periods. [ 
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