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    Study shows making hydrogen with soda cans and seawater is scalable and sustainable

    Hydrogen has the potential to be a climate-friendly fuel since it doesn’t release carbon dioxide when used as an energy source. Currently, however, most methods for producing hydrogen involve fossil fuels, making hydrogen less of a “green” fuel over its entire life cycle.A new process developed by MIT engineers could significantly shrink the carbon footprint associated with making hydrogen.Last year, the team reported that they could produce hydrogen gas by combining seawater, recycled soda cans, and caffeine. The question then was whether the benchtop process could be applied at an industrial scale, and at what environmental cost.Now, the researchers have carried out a “cradle-to-grave” life cycle assessment, taking into account every step in the process at an industrial scale. For instance, the team calculated the carbon emissions associated with acquiring and processing aluminum, reacting it with seawater to produce hydrogen, and transporting the fuel to gas stations, where drivers could tap into hydrogen tanks to power engines or fuel cell cars. They found that, from end to end, the new process could generate a fraction of the carbon emissions that is associated with conventional hydrogen production.In a study appearing today in Cell Reports Sustainability, the team reports that for every kilogram of hydrogen produced, the process would generate 1.45 kilograms of carbon dioxide over its entire life cycle. In comparison, fossil-fuel-based processes emit 11 kilograms of carbon dioxide per kilogram of hydrogen generated.The low-carbon footprint is on par with other proposed “green hydrogen” technologies, such as those powered by solar and wind energy.“We’re in the ballpark of green hydrogen,” says lead author Aly Kombargi PhD ’25, who graduated this spring from MIT with a doctorate in mechanical engineering. “This work highlights aluminum’s potential as a clean energy source and offers a scalable pathway for low-emission hydrogen deployment in transportation and remote energy systems.”The study’s MIT co-authors are Brooke Bao, Enoch Ellis, and professor of mechanical engineering Douglas Hart.Gas bubbleDropping an aluminum can in water won’t normally cause much of a chemical reaction. That’s because when aluminum is exposed to oxygen, it instantly forms a shield-like layer. Without this layer, aluminum exists in its pure form and can readily react when mixed with water. The reaction that occurs involves aluminum atoms that efficiently break up molecules of water, producing aluminum oxide and pure hydrogen. And it doesn’t take much of the metal to bubble up a significant amount of the gas.“One of the main benefits of using aluminum is the energy density per unit volume,” Kombargi says. “With a very small amount of aluminum fuel, you can conceivably supply much of the power for a hydrogen-fueled vehicle.”Last year, he and Hart developed a recipe for aluminum-based hydrogen production. They found they could puncture aluminum’s natural shield by treating it with a small amount of gallium-indium, which is a rare-metal alloy that effectively scrubs aluminum into its pure form. The researchers then mixed pellets of pure aluminum with seawater and observed that the reaction produced pure hydrogen. What’s more, the salt in the water helped to precipitate gallium-indium, which the team could subsequently recover and reuse to generate more hydrogen, in a cost-saving, sustainable cycle.“We were explaining the science of this process in conferences, and the questions we would get were, ‘How much does this cost?’ and, ‘What’s its carbon footprint?’” Kombargi says. “So we wanted to look at the process in a comprehensive way.”A sustainable cycleFor their new study, Kombargi and his colleagues carried out a life cycle assessment to estimate the environmental impact of aluminum-based hydrogen production, at every step of the process, from sourcing the aluminum to transporting the hydrogen after production. They set out to calculate the amount of carbon associated with generating 1 kilogram of hydrogen — an amount that they chose as a practical, consumer-level illustration.“With a hydrogen fuel cell car using 1 kilogram of hydrogen, you can go between 60 to 100 kilometers, depending on the efficiency of the fuel cell,” Kombargi notes.They performed the analysis using Earthster — an online life cycle assessment tool that draws data from a large repository of products and processes and their associated carbon emissions. The team considered a number of scenarios to produce hydrogen using aluminum, from starting with “primary” aluminum mined from the Earth, versus “secondary” aluminum that is recycled from soda cans and other products, and using various methods to transport the aluminum and hydrogen.After running life cycle assessments for about a dozen scenarios, the team identified one scenario with the lowest carbon footprint. This scenario centers on recycled aluminum — a source that saves a significant amount of emissions compared with mining aluminum — and seawater — a natural resource that also saves money by recovering gallium-indium. They found that this scenario, from start to finish, would generate about 1.45 kilograms of carbon dioxide for every kilogram of hydrogen produced. The cost of the fuel produced, they calculated, would be about $9 per kilogram, which is comparable to the price of hydrogen that would be generated with other green technologies such as wind and solar energy.The researchers envision that if the low-carbon process were ramped up to a commercial scale, it would look something like this: The production chain would start with scrap aluminum sourced from a recycling center. The aluminum would be shredded into pellets and treated with gallium-indium. Then, drivers could transport the pretreated pellets as aluminum “fuel,” rather than directly transporting hydrogen, which is potentially volatile. The pellets would be transported to a fuel station that ideally would be situated near a source of seawater, which could then be mixed with the aluminum, on demand, to produce hydrogen. A consumer could then directly pump the gas into a car with either an internal combustion engine or a fuel cell.The entire process does produce an aluminum-based byproduct, boehmite, which is a mineral that is commonly used in fabricating semiconductors, electronic elements, and a number of industrial products. Kombargi says that if this byproduct were recovered after hydrogen production, it could be sold to manufacturers, further bringing down the cost of the process as a whole.“There are a lot of things to consider,” Kombargi says. “But the process works, which is the most exciting part. And we show that it can be environmentally sustainable.”The group is continuing to develop the process. They recently designed a small reactor, about the size of a water bottle, that takes in aluminum pellets and seawater to generate hydrogen, enough to power an electric bike for several hours. They previously demonstrated that the process can produce enough hydrogen to fuel a small car. The team is also exploring underwater applications, and are designing a hydrogen reactor that would take in surrounding seawater to power a small boat or underwater vehicle.This research was supported, in part, by the MIT Portugal Program. More

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    MIT D-Lab students design global energy solutions through collaboration

    This semester, MIT D-Lab students built prototype solutions to help farmers in Afghanistan, people living in informal settlements in Argentina, and rural poultry farmers in Cameroon. The projects span continents and collectively stand to improve thousands of lives — and they all trace back to two longstanding MIT D-Lab classes.For nearly two decades, 2.651 / EC.711 (Introduction to Energy in Global Development) and 2.652 / EC.712 (Applications of Energy in Global Development) have paired students with international organizations and communities to learn D-Lab’s participatory approach to design and study energy technologies in low-resource environments. Hundreds of students from across MIT have taken the courses, which feature visits from partners and trips to the communities after the semester. They often discover a passion for helping people in low-resource settings that lasts a lifetime.“Through the trips, students often gain an appreciation for what they have at home, and they can’t forget about what they see,” says D-Lab instructor Josh Maldonado ’23, who took both courses as a student. “For me, it changed my entire career. Students maintain relationships with the people they work with. They stay on the group chats with community members and meet up with them when they travel. They come back and want to mentor for the class. You can just see it has a lasting effect.”The introductory course takes place each spring and is followed by summer trips for students. The applications class, which is more focused on specific projects, is held in the fall and followed by student travel over winter break.“MIT has always advocated for going out and impacting the world,” Maldonado says. “The fact that we can use what we learn here in such a meaningful way while still a student is awesome. It gets back to MIT’s motto, ‘mens et manus’ (‘mind and hand’).”Curriculum for impactIntroduction to Energy in Global Development has been taught since around 2008, with past projects focusing on mitigating the effects of aquatic weeds for fisherman in Ghana, making charcoal for cookstoves in Uganda, and creating brick evaporative coolers to extend the shelf life of fruits and vegetables in Mali.The class follows MIT D-Lab’s participatory design philosophy in which students design solutions in close collaboration with local communities. Along the way, students learn about different energy technologies and how they might be implemented cheaply in rural communities that lack basic infrastructure.“In product design, the idea is to get out and meet your customer where they are,” Maldonado explains. “The problem is our partners are often in remote, low-resource regions of the world. We put a big emphasis on designing with the local communities and increasing their creative capacity building to show them they can build solutions themselves.”Students from across MIT, including graduates and undergraduates, along with students from Harvard University and Wellesley College, can enroll in both courses. MIT senior Kanokwan Tungkitkancharoen took the introductory class this spring.“There are students from chemistry, computer science, civil engineering, policy, and more,” says Tungkitkancharoen. “I think that convergence models how things get done in real life. The class also taught me how to communicate the same information in different ways to cater to different people. It helped me distill my approach to what is this person trying to learn and how can I convey that information.”Tungkitkancharoen’s team worked with a nonprofit called Weatherizers Without Borders to implement weatherization strategies that enhance housing conditions and environmental resilience for people in the southern Argentinian community of Bariloche.The team built model homes and used heat sensing cameras to show the impact of weatherization strategies to locals and policymakers in the region.“Our partners live in self-built homes, but the region is notorious for being very cold in the winter and very hot in the summer,” Tungkitkancharoen says. “We’re helping our partners retrofit homes so they can withstand the weather better. Before the semester, I was interested in working directly with people impacted by these technologies and the current climate situation. D-Lab helped me work with people on the ground, and I’ve been super grateful to our community partners.”The project to design micro-irrigation systems to support agricultural productivity and water conservation in Afghanistan is in partnership with the Ecology and Conservation Organization of Afghanistan and a team from a local university in Afghanistan.“I love the process of coming into class with a practical question you need to solve and working closely with community partners,” says MIT master’s student Khadija Ghanizada, who has served as a teacher’s assistant for both the introductory and applications courses. “All of these projects will have a huge impact, but being from Afghanistan, I know this will make a difference because it’s a land-locked country, it’s dealing with droughts, and 80 percent of our economy depends on agriculture. We also make sure students are thinking about scalability of their solutions, whether scaling worldwide or just nationally. Every project has its own impact story.”Meeting community partnersNow that the spring semester is over, many students from the introductory class will travel to the regions they studied with instructors and local guides over the summer.“The traveling and implementation are things students always look forward to,” Maldonado says. “Students do a lot of prep work, thinking about the tools they need, the local resources they need, and working with partners to acquire those resources.”Following travel, students write a report on how the trip went, which helps D-Lab refine the course for next semester.“Oftentimes instructors are also doing research in these regions while they teach the class,” Maldonado says. “To be taught by people who were just in the field two weeks before the class started, and to see pictures of what they’re doing, is really powerful.”Students who have taken the class have gone on to careers in international development, nonprofits, and to start companies that grow the impact of their class projects. But the most immediate impact can be seen in the communities that students work with.“These solutions should be able to be built locally, sourced locally, and potentially also lead to the creation of localized markets based around the technology,” Maldonado says. “Almost everything the D-Lab does is open-sourced, so when we go to these communities, we don’t just teach people how to use these solutions, we teach them how to make them. Technology, if implemented correctly by mindful engineers and scientists, can be highly adopted and can grow a community of makers and fabricators and local businesses.” More

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    Shaping the future through systems thinking

    Long before she stepped into a lab, Ananda Santos Figueiredo was stargazing in Brazil, captivated by the cosmos and feeding her curiosity of science through pop culture, books, and the internet. She was drawn to astrophysics for its blend of visual wonder and mathematics.Even as a child, Santos sensed her aspirations reaching beyond the boundaries of her hometown. “I’ve always been drawn to STEM,” she says. “I had this persistent feeling that I was meant to go somewhere else to learn more, explore, and do more.”Her parents saw their daughter’s ambitions as an opportunity to create a better future. The summer before her sophomore year of high school, her family moved from Brazil to Florida.  She recalls that moment as “a big leap of faith in something bigger and we had no idea how it would turn out.” She was certain of one thing: She wanted an education that was both technically rigorous and deeply expansive, one that would allow her to pursue all her passions.At MIT, she found exactly what she was seeking in a community and curriculum that matched her curiosity and ambition. “I’ve always associated MIT with something new and exciting that was grasping towards the very best we can achieve as humans,” Santos says, emphasizing the use of technology and science to significantly impact society. “It’s a place where people aren’t afraid to dream big and work hard to make it a reality.”As a first-generation college student, she carried the weight of financial stress and the uncertainty that comes with being the first in her family to navigate college in the U.S. But she found a sense of belonging in the MIT community. “Being a first-generation student helped me grow,” she says. “It inspired me to seek out opportunities and help support others too.”She channeled that energy into student government roles for the undergraduate residence halls. Through Dormitory Council (DormCon) and her dormitory, Simmons Hall, her voice could help shape life on campus. She began serving as reservations chair for her dormitory but ended up becoming president of the dormitory before being elected dining chair and vice president for DormCon. She’s worked to improve dining hall operations and has planned major community events like Simmons Hall’s 20th anniversary and DormCon’s inaugural Field Day.Now, a senior about to earn her bachelor’s degree, Santos says MIT’s motto, “mens et manus” — “mind and hand” — has deeply resonated with her from the start. “Learning here goes far beyond the classroom,” she says. “I’ve been surrounded by people who are passionate and purposeful. That energy is infectious. It’s changed how I see myself and what I believe is possible.”Charting her own courseInitially a physics major, Santos’ academic path took a turn after a transformative internship with the World Bank’s data science lab between her sophomore and junior years. There, she used her coding skills to study the impacts of heat waves in the Philippines. The experience opened her eyes to the role technology and data can play in improving lives and broadened her view of what a STEM career could look like.“I realized I didn’t want to just study the universe — I wanted to change it,” she says. “I wanted to join systems thinking with my interest in the humanities, to build a better world for people and communities.”When MIT launched a new major in climate system science and engineering (Course 1-12) in 2023, Santos was the first student to declare it. The interdisciplinary structure of the program, blending climate science, engineering, energy systems, and policy, gave her a framework to connect her technical skills to real-world sustainability challenges.She tailored her coursework to align with her passions and career goals, applying her physics background (now her minor) to understand problems in climate, energy, and sustainable systems. “One of the most powerful things about the major is the breadth,” she says. “Even classes that aren’t my primary focus have expanded how I think.”Hands-on fieldwork has been a cornerstone of her learning. During MIT’s Independent Activities Period (IAP), she studied climate impacts in Hawai’i in the IAP Course 1.091 (Traveling Research Environmental Experiences, or TREX). This year, she studied the design of sustainable polymer systems in Course 1.096/10.496 (Design of Sustainable Polymer Systems) under MISTI’s Global Classroom program. The IAP class brought her to the middle of the Amazon Rainforest to see what the future of plastic production could look like with products from the Amazon. “That experience was incredibly eye opening,” she explains. “It helped me build a bridge between my own background and the kind of problems that I want to solve in the future.”Santos also found enjoyment beyond labs and lectures. A member of the MIT Shakespeare Ensemble since her first year, she took to the stage in her final spring production of “Henry V,” performing as both the Chorus and Kate. “The ensemble’s collaborative spirit and the way it brings centuries-old texts to life has been transformative,” she adds.Her passion for the arts also intersected with her interest in the MIT Lecture Series Committee. She helped host a special screening of the film “Sing Sing,” in collaboration with MIT’s Educational Justice Institute (TEJI). That connection led her to enroll in a TEJI course, illustrating the surprising and meaningful ways that different parts of MIT’s ecosystem overlap. “It’s one of the beautiful things about MIT,” she says. “You stumble into experiences that deeply change you.”Throughout her time at MIT, the community of passionate, sustainability-focused individuals has been a major source of inspiration. She’s been actively involved with the MIT Office of Sustainability’s decarbonization initiatives and participated in the Climate and Sustainability Scholars Program.Santos acknowledges that working in sustainability can sometimes feel overwhelming. “Tackling the challenges of sustainability can be discouraging,” she says. “The urgency to create meaningful change in a short period of time can be intimidating. But being surrounded by people who are actively working on it is so much better than not working on it at all.”Looking ahead, she plans to pursue graduate studies in technology and policy, with aspirations to shape sustainable development, whether through academia, international organizations, or diplomacy.“The most fulfilling moments I’ve had at MIT are when I’m working on hard problems while also reflecting on who I want to be, what kind of future I want to help create, and how we can be better and kinder to each other,” she says. “That’s what excites me — solving real problems that matter.” More

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    New fuel cell could enable electric aviation

    Batteries are nearing their limits in terms of how much power they can store for a given weight. That’s a serious obstacle for energy innovation and the search for new ways to power airplanes, trains, and ships. Now, researchers at MIT and elsewhere have come up with a solution that could help electrify these transportation systems.Instead of a battery, the new concept is a kind of fuel cell — which is similar to a battery but can be quickly refueled rather than recharged. In this case, the fuel is liquid sodium metal, an inexpensive and widely available commodity. The other side of the cell is just ordinary air, which serves as a source of oxygen atoms. In between, a layer of solid ceramic material serves as the electrolyte, allowing sodium ions to pass freely through, and a porous air-facing electrode helps the sodium to chemically react with oxygen and produce electricity.In a series of experiments with a prototype device, the researchers demonstrated that this cell could carry more than three times as much energy per unit of weight as the lithium-ion batteries used in virtually all electric vehicles today. Their findings are being published today in the journal Joule, in a paper by MIT doctoral students Karen Sugano, Sunil Mair, and Saahir Ganti-Agrawal; professor of materials science and engineering Yet-Ming Chiang; and five others.“We expect people to think that this is a totally crazy idea,” says Chiang, who is the Kyocera Professor of Ceramics. “If they didn’t, I’d be a bit disappointed because if people don’t think something is totally crazy at first, it probably isn’t going to be that revolutionary.”And this technology does appear to have the potential to be quite revolutionary, he suggests. In particular, for aviation, where weight is especially crucial, such an improvement in energy density could be the breakthrough that finally makes electrically powered flight practical at significant scale.“The threshold that you really need for realistic electric aviation is about 1,000 watt-hours per kilogram,” Chiang says. Today’s electric vehicle lithium-ion batteries top out at about 300 watt-hours per kilogram — nowhere near what’s needed. Even at 1,000 watt-hours per kilogram, he says, that wouldn’t be enough to enable transcontinental or trans-Atlantic flights.That’s still beyond reach for any known battery chemistry, but Chiang says that getting to 1,000 watts per kilogram would be an enabling technology for regional electric aviation, which accounts for about 80 percent of domestic flights and 30 percent of the emissions from aviation.The technology could be an enabler for other sectors as well, including marine and rail transportation. “They all require very high energy density, and they all require low cost,” he says. “And that’s what attracted us to sodium metal.”A great deal of research has gone into developing lithium-air or sodium-air batteries over the last three decades, but it has been hard to make them fully rechargeable. “People have been aware of the energy density you could get with metal-air batteries for a very long time, and it’s been hugely attractive, but it’s just never been realized in practice,” Chiang says.By using the same basic electrochemical concept, only making it a fuel cell instead of a battery, the researchers were able to get the advantages of the high energy density in a practical form. Unlike a battery, whose materials are assembled once and sealed in a container, with a fuel cell the energy-carrying materials go in and out.The team produced two different versions of a lab-scale prototype of the system. In one, called an H cell, two vertical glass tubes are connected by a tube across the middle, which contains a solid ceramic electrolyte material and a porous air electrode. Liquid sodium metal fills the tube on one side, and air flows through the other, providing the oxygen for the electrochemical reaction at the center, which ends up gradually consuming the sodium fuel. The other prototype uses a horizontal design, with a tray of the electrolyte material holding the liquid sodium fuel. The porous air electrode, which facilitates the reaction, is affixed to the bottom of the tray. Tests using an air stream with a carefully controlled humidity level produced a level of more than 1,500 watt-hours per kilogram at the level of an individual “stack,” which would translate to over 1,000 watt-hours at the full system level, Chiang says.The researchers envision that to use this system in an aircraft, fuel packs containing stacks of cells, like racks of food trays in a cafeteria, would be inserted into the fuel cells; the sodium metal inside these packs gets chemically transformed as it provides the power. A stream of its chemical byproduct is given off, and in the case of aircraft this would be emitted out the back, not unlike the exhaust from a jet engine.But there’s a very big difference: There would be no carbon dioxide emissions. Instead the emissions, consisting of sodium oxide, would actually soak up carbon dioxide from the atmosphere. This compound would quickly combine with moisture in the air to make sodium hydroxide — a material commonly used as a drain cleaner — which readily combines with carbon dioxide to form a solid material, sodium carbonate, which in turn forms sodium bicarbonate, otherwise known as baking soda.“There’s this natural cascade of reactions that happens when you start with sodium metal,” Chiang says. “It’s all spontaneous. We don’t have to do anything to make it happen, we just have to fly the airplane.”As an added benefit, if the final product, the sodium bicarbonate, ends up in the ocean, it could help to de-acidify the water, countering another of the damaging effects of greenhouse gases.Using sodium hydroxide to capture carbon dioxide has been proposed as a way of mitigating carbon emissions, but on its own, it’s not an economic solution because the compound is too expensive. “But here, it’s a byproduct,” Chiang explains, so it’s essentially free, producing environmental benefits at no cost.Importantly, the new fuel cell is inherently safer than many other batteries, he says. Sodium metal is extremely reactive and must be well-protected. As with lithium batteries, sodium can spontaneously ignite if exposed to moisture. “Whenever you have a very high energy density battery, safety is always a concern, because if there’s a rupture of the membrane that separates the two reactants, you can have a runaway reaction,” Chiang says. But in this fuel cell, one side is just air, “which is dilute and limited. So you don’t have two concentrated reactants right next to each other. If you’re pushing for really, really high energy density, you’d rather have a fuel cell than a battery for safety reasons.”While the device so far exists only as a small, single-cell prototype, Chiang says the system should be quite straightforward to scale up to practical sizes for commercialization. Members of the research team have already formed a company, Propel Aero, to develop the technology. The company is currently housed in MIT’s startup incubator, The Engine.Producing enough sodium metal to enable widespread, full-scale global implementation of this technology should be practical, since the material has been produced at large scale before. When leaded gasoline was the norm, before it was phased out, sodium metal was used to make the tetraethyl lead used as an additive, and it was being produced in the U.S. at a capacity of 200,000 tons a year. “It reminds us that sodium metal was once produced at large scale and safely handled and distributed around the U.S.,” Chiang says.What’s more, sodium primarily originates from sodium chloride, or salt, so it is abundant, widely distributed around the world, and easily extracted, unlike lithium and other materials used in today’s EV batteries.The system they envisage would use a refillable cartridge, which would be filled with liquid sodium metal and sealed. When it’s depleted, it would be returned to a refilling station and loaded with fresh sodium. Sodium melts at 98 degrees Celsius, just below the boiling point of water, so it is easy to heat to the melting point to refuel the cartridges.Initially, the plan is to produce a brick-sized fuel cell that can deliver about 1,000 watt-hours of energy, enough to power a large drone, in order to prove the concept in a practical form that could be used for agriculture, for example. The team hopes to have such a demonstration ready within the next year.Sugano, who conducted much of the experimental work as part of her doctoral thesis and will now work at the startup, says that a key insight was the importance of moisture in the process. As she tested the device with pure oxygen, and then with air, she found that the amount of humidity in the air was crucial to making the electrochemical reaction efficient. The humid air resulted in the sodium producing its discharge products in liquid rather than solid form, making it much easier for these to be removed by the flow of air through the system. “The key was that we can form this liquid discharge product and remove it easily, as opposed to the solid discharge that would form in dry conditions,” she says.Ganti-Agrawal notes that the team drew from a variety of different engineering subfields. For example, there has been much research on high-temperature sodium, but none with a system with controlled humidity. “We’re pulling from fuel cell research in terms of designing our electrode, we’re pulling from older high-temperature battery research as well as some nascent sodium-air battery research, and kind of mushing it together,” which led to the “the big bump in performance” the team has achieved, he says.The research team also included Alden Friesen, an MIT summer intern who attends Desert Mountain High School in Scottsdale, Arizona; Kailash Raman and William Woodford of Form Energy in Somerville, Massachusetts; Shashank Sripad of And Battery Aero in California, and Venkatasubramanian Viswanathan of the University of Michigan. The work was supported by ARPA-E, Breakthrough Energy Ventures, and the National Science Foundation, and used facilities at MIT.nano. More

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    A new approach could fractionate crude oil using much less energy

    Separating crude oil into products such as gasoline, diesel, and heating oil is an energy-intensive process that accounts for about 6 percent of the world’s CO2 emissions. Most of that energy goes into the heat needed to separate the components by their boiling point.In an advance that could dramatically reduce the amount of energy needed for crude oil fractionation, MIT engineers have developed a membrane that filters the components of crude oil by their molecular size.“This is a whole new way of envisioning a separation process. Instead of boiling mixtures to purify them, why not separate components based on shape and size? The key innovation is that the filters we developed can separate very small molecules at an atomistic length scale,” says Zachary P. Smith, an associate professor of chemical engineering at MIT and the senior author of the new study.The new filtration membrane can efficiently separate heavy and light components from oil, and it is resistant to the swelling that tends to occur with other types of oil separation membranes. The membrane is a thin film that can be manufactured using a technique that is already widely used in industrial processes, potentially allowing it to be scaled up for widespread use.Taehoon Lee, a former MIT postdoc who is now an assistant professor at Sungkyunkwan University in South Korea, is the lead author of the paper, which appears today in Science.Oil fractionationConventional heat-driven processes for fractionating crude oil make up about 1 percent of global energy use, and it has been estimated that using membranes for crude oil separation could reduce the amount of energy needed by about 90 percent. For this to succeed, a separation membrane needs to allow hydrocarbons to pass through quickly, and to selectively filter compounds of different sizes.Until now, most efforts to develop a filtration membrane for hydrocarbons have focused on polymers of intrinsic microporosity (PIMs), including one known as PIM-1. Although this porous material allows the fast transport of hydrocarbons, it tends to excessively absorb some of the organic compounds as they pass through the membrane, leading the film to swell, which impairs its size-sieving ability.To come up with a better alternative, the MIT team decided to try modifying polymers that are used for reverse osmosis water desalination. Since their adoption in the 1970s, reverse osmosis membranes have reduced the energy consumption of desalination by about 90 percent — a remarkable industrial success story.The most commonly used membrane for water desalination is a polyamide that is manufactured using a method known as interfacial polymerization. During this process, a thin polymer film forms at the interface between water and an organic solvent such as hexane. Water and hexane do not normally mix, but at the interface between them, a small amount of the compounds dissolved in them can react with each other.In this case, a hydrophilic monomer called MPD, which is dissolved in water, reacts with a hydrophobic monomer called TMC, which is dissolved in hexane. The two monomers are joined together by a connection known as an amide bond, forming a polyamide thin film (named MPD-TMC) at the water-hexane interface.While highly effective for water desalination, MPD-TMC doesn’t have the right pore sizes and swelling resistance that would allow it to separate hydrocarbons.To adapt the material to separate the hydrocarbons found in crude oil, the researchers first modified the film by changing the bond that connects the monomers from an amide bond to an imine bond. This bond is more rigid and hydrophobic, which allows hydrocarbons to quickly move through the membrane without causing noticeable swelling of the film compared to the polyamide counterpart.“The polyimine material has porosity that forms at the interface, and because of the cross-linking chemistry that we have added in, you now have something that doesn’t swell,” Smith says. “You make it in the oil phase, react it at the water interface, and with the crosslinks, it’s now immobilized. And so those pores, even when they’re exposed to hydrocarbons, no longer swell like other materials.”The researchers also introduced a monomer called triptycene. This shape-persistent, molecularly selective molecule further helps the resultant polyimines to form pores that are the right size for hydrocarbons to fit through.This approach represents “an important step toward reducing industrial energy consumption,” says Andrew Livingston, a professor of chemical engineering at Queen Mary University of London, who was not involved in the study.“This work takes the workhorse technology of the membrane desalination industry, interfacial polymerization, and creates a new way to apply it to organic systems such as hydrocarbon feedstocks, which currently consume large chunks of global energy,” Livingston says. “The imaginative approach using an interfacial catalyst coupled to hydrophobic monomers leads to membranes with high permeance and excellent selectivity, and the work shows how these can be used in relevant separations.”Efficient separationWhen the researchers used the new membrane to filter a mixture of toluene and triisopropylbenzene (TIPB) as a benchmark for evaluating separation performance, it was able to achieve a concentration of toluene 20 times greater than its concentration in the original mixture. They also tested the membrane with an industrially relevant mixture consisting of naphtha, kerosene, and diesel, and found that it could efficiently separate the heavier and lighter compounds by their molecular size.If adapted for industrial use, a series of these filters could be used to generate a higher concentration of the desired products at each step, the researchers say.“You can imagine that with a membrane like this, you could have an initial stage that replaces a crude oil fractionation column. You could partition heavy and light molecules and then you could use different membranes in a cascade to purify complex mixtures to isolate the chemicals that you need,” Smith says.Interfacial polymerization is already widely used to create membranes for water desalination, and the researchers believe it should be possible to adapt those processes to mass produce the films they designed in this study.“The main advantage of interfacial polymerization is it’s already a well-established method to prepare membranes for water purification, so you can imagine just adopting these chemistries into existing scale of manufacturing lines,” Lee says.The research was funded, in part, by ExxonMobil through the MIT Energy Initiative.  More

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    How to solve a bottleneck for CO2 capture and conversion

    Removing carbon dioxide from the atmosphere efficiently is often seen as a crucial need for combatting climate change, but systems for removing carbon dioxide suffer from a tradeoff. Chemical compounds that efficiently remove CO₂ from the air do not easily release it once captured, and compounds that release CO₂ efficiently are not very efficient at capturing it. Optimizing one part of the cycle tends to make the other part worse.Now, using nanoscale filtering membranes, researchers at MIT have added a simple intermediate step that facilitates both parts of the cycle. The new approach could improve the efficiency of electrochemical carbon dioxide capture and release by six times and cut costs by at least 20 percent, they say.The new findings are reported today in the journal ACS Energy Letters, in a paper by MIT doctoral students Simon Rufer, Tal Joseph, and Zara Aamer, and professor of mechanical engineering Kripa Varanasi.“We need to think about scale from the get-go when it comes to carbon capture, as making a meaningful impact requires processing gigatons of CO₂,” says Varanasi. “Having this mindset helps us pinpoint critical bottlenecks and design innovative solutions with real potential for impact. That’s the driving force behind our work.”Many carbon-capture systems work using chemicals called hydroxides, which readily combine with carbon dioxide to form carbonate. That carbonate is fed into an electrochemical cell, where the carbonate reacts with an acid to form water and release carbon dioxide. The process can take ordinary air with only about 400 parts per million of carbon dioxide and generate a stream of 100 percent pure carbon dioxide, which can then be used to make fuels or other products.Both the capture and release steps operate in the same water-based solution, but the first step needs a solution with a high concentration of hydroxide ions, and the second step needs one high in carbonate ions. “You can see how these two steps are at odds,” says Varanasi. “These two systems are circulating the same sorbent back and forth. They’re operating on the exact same liquid. But because they need two different types of liquids to operate optimally, it’s impossible to operate both systems at their most efficient points.”The team’s solution was to decouple the two parts of the system and introduce a third part in between. Essentially, after the hydroxide in the first step has been mostly chemically converted to carbonate, special nanofiltration membranes then separate ions in the solution based on their charge. Carbonate ions have a charge of 2, while hydroxide ions have a charge of 1. “The nanofiltration is able to separate these two pretty well,” Rufer says.Once separated, the hydroxide ions are fed back to the absorption side of the system, while the carbonates are sent ahead to the electrochemical release stage. That way, both ends of the system can operate at their more efficient ranges. Varanasi explains that in the electrochemical release step, protons are being added to the carbonate to cause the conversion to carbon dioxide and water, but if hydroxide ions are also present, the protons will react with those ions instead, producing just water.“If you don’t separate these hydroxides and carbonates,” Rufer says, “the way the system fails is you’ll add protons to hydroxide instead of carbonate, and so you’ll just be making water rather than extracting carbon dioxide. That’s where the efficiency is lost. Using nanofiltration to prevent this was something that we aren’t aware of anyone proposing before.”Testing showed that the nanofiltration could separate the carbonate from the hydroxide solution with about 95 percent efficiency, validating the concept under realistic conditions, Rufer says. The next step was to assess how much of an effect this would have on the overall efficiency and economics of the process. They created a techno-economic model, incorporating electrochemical efficiency, voltage, absorption rate, capital costs, nanofiltration efficiency, and other factors.The analysis showed that present systems cost at least $600 per ton of carbon dioxide captured, while with the nanofiltration component added, that drops to about $450 a ton. What’s more, the new system is much more stable, continuing to operate at high efficiency even under variations in the ion concentrations in the solution. “In the old system without nanofiltration, you’re sort of operating on a knife’s edge,” Rufer says; if the concentration varies even slightly in one direction or the other, efficiency drops off drastically. “But with our nanofiltration system, it kind of acts as a buffer where it becomes a lot more forgiving. You have a much broader operational regime, and you can achieve significantly lower costs.”He adds that this approach could apply not only to the direct air capture systems they studied specifically, but also to point-source systems — which are attached directly to the emissions sources such as power plant emissions — or to the next stage of the process, converting captured carbon dioxide into useful products such as fuel or chemical feedstocks.  Those conversion processes, he says, “are also bottlenecked in this carbonate and hydroxide tradeoff.”In addition, this technology could lead to safer alternative chemistries for carbon capture, Varanasi says. “A lot of these absorbents can at times be toxic, or damaging to the environment. By using a system like ours, you can improve the reaction rate, so you can choose chemistries that might not have the best absorption rate initially but can be improved to enable safety.”Varanasi adds that “the really nice thing about this is we’ve been able to do this with what’s commercially available,” and with a system that can easily be retrofitted to existing carbon-capture installations. If the costs can be further brought down to about $200 a ton, it could be viable for widespread adoption. With ongoing work, he says, “we’re confident that we’ll have something that can become economically viable” and that will ultimately produce valuable, saleable products.Rufer notes that even today, “people are buying carbon credits at a cost of over $500 per ton. So, at this cost we’re projecting, it is already commercially viable in that there are some buyers who are willing to pay that price.” But by bringing the price down further, that should increase the number of buyers who would consider buying the credit, he says. “It’s just a question of how widespread we can make it.” Recognizing this growing market demand, Varanasi says, “Our goal is to provide industry scalable, cost-effective, and reliable technologies and systems that enable them to directly meet their decarbonization targets.”The research was supported by Shell International Exploration and Production Inc. through the MIT Energy Initiative, and the U.S. National Science Foundation, and made use of the facilities at MIT.nano. More

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    MIT students turn vision to reality

    Life is a little brighter in Kapiyo these days.For many in this rural Kenyan town, nightfall used to signal the end to schoolwork and other family activities. Now, however, the darkness is pierced by electric lights from newly solar-powered homes. Inside, children in this off-the-grid area can study while parents extend daily activities past dusk, thanks to a project conceived by an MIT mechanical engineering student and financed by the MIT African Students Association (ASA) Impact Fund.There are changes coming, too, in the farmlands of Kashusha in the Democratic Republic of Congo (DRC), where another ASA Impact Fund project is working with local growers to establish an energy-efficient mill for processing corn — adding value, creating jobs, and sparking new economic opportunities. Similarly, plans are underway to automate processing of locally-grown cashews in the Mtwara area of Tanzania — an Impact Fund project meant to increase the income of farmers who now send over 90 percent of their nuts abroad for processing.Inspired by a desire by MIT students to turn promising ideas into practical solutions for people in their home countries, the ASA Impact Fund is a student-run initiative that launched during the 2023-24 academic year. Backed by an alumni board, the fund empowers students to conceive, design, and lead projects with social and economic impact in communities across Africa.After financing three projects its first year, the ASA Impact Fund received eight project proposals earlier this year and plans to announce its second round of two to four grants sometime this spring, says Pamela Abede, last year’s fund president. Last year’s awards totaled approximately $15,000.The fund is an outgrowth of MIT’s African Learning Circle, a seminar open to the entire MIT community where biweekly discussions focus on ways to apply MIT’s educational resources, entrepreneurial spirit, and innovation to improve lives on the African continent.“The Impact Fund was created,” says MIT African Students Association president Victory Yinka-Banjo, “to take this to the next level … to go from talking to execution.”Aimed at bridging a gap between projects Learning Circle participants envision and resources available to fund them, the ASA Impact Fund “exists as an avenue to assist our members in undertaking social impact projects on the African continent,” the initiative’s website states, “thereby combining theoretical learning with practical application in alignment with MIT’s motto.”The fund’s value extends to the Cambridge campus as well, says ASA Impact Fund board member and 2021 MIT graduate Bolu Akinola.“You can do cool projects anywhere,” says Akinola, who is originally from Nigeria and currently pursuing a master’s degree in business administration at Harvard University. “Where this is particularly catalyzing is in incentivizing folks to go back home and impact life back on the continent of Africa.”MIT-Africa managing director Ari Jacobovits, who helped students get the fund off the ground last year, agrees.“I think it galvanized the community, bringing people together to bridge a programmatic gap that had long felt like a missed opportunity,” Jacobovits says. “I’m always impressed by the level of service-mindedness ASA members have towards their home communities. It’s something we should all be celebrating and thinking about incorporating into our home communities, wherever they may be.”Alumni Board president Selam Gano notes that a big part of the Impact Fund’s appeal is the close connections project applicants have with the communities they’re working with. MIT engineering major Shekina Pita, for example, is from Kapiyo, and recalls “what it was like growing up in a place with unreliable electricity,” which “would impact every aspect of my life and the lives of those that I lived around.” Pita’s personal experience and familiarity with the community informed her proposal to install solar panels on Kapiyo homes.So far, the ASA Impact Fund has financed installation of solar panels for five households where families had been relying on candles so their children could do homework after dark.“A candle is 15 Kenya shillings, and I don’t always have that amount to buy candles for my children to study. I am grateful for your help,” comments one beneficiary of the Kapiyo solar project.Pita anticipates expanding the project, 10 homes at a time, and involving some college-age residents of those homes in solar panel installation apprenticeships.“In general, we try to balance projects where we fund some things that are very concrete solutions to a particular community’s problems — like a water project or solar energy — and projects with a longer-term view that could become an organization or a business — like a novel cashew nut processing method,” says Gano, who conducted projects in his father’s homeland of Ethiopia while an MIT student. “I think striking that balance is something I am particularly proud of. We believe that people in the community know best what they need, and it’s great to empower students from those same communities.”  Vivian Chinoda, who received a grant from the ASA Impact Fund and was part of the African Students Association board that founded it, agrees.“We want to address problems that can seem trivial without the lived experience of them,” says Chinoda. “For my friend and I, getting funding to go to Tanzania and drive more than 10 hours to speak to remotely located small-scale cashew farmers … made a difference. We were able to conduct market research and cross-check our hypotheses on a project idea we brainstormed in our dorm room in ways we would not have otherwise been able to access remotely.”Similarly, Florida Mahano’s Impact Fund-financed project is benefiting from her experience growing up near farms in the DRC. Partnering with her brother, a mechanical engineer in her home community of Bukavu in eastern DRC, Mahano is on her way to developing a processing plant that will serve the needs of local farmers. Informed by market research involving about 500 farmers, consumers, and retailers that took place in January, the plant will likely be operational by summer 2026, says Mahano, who has also received funding from MIT’s Priscilla King Gray (PKG) Public Service Center.“The ASA Impact Fund was the starting point for us,” paving the way for additional support, she says. “I feel like the ASA Impact Fund was really amazing because it allowed me to bring my idea to life.”Importantly, Chinoda notes that the Impact Fund has already had early success in fostering ties between undergraduate students and MIT alumni.“When we sent out the application to set up the alumni board, we had a volume of respondents coming in quite quickly, and it was really encouraging to see how the alums were so willing to be present and use their skill sets and connections to build this from the ground up,” she says.Abede, who is originally from Ghana, would like to see that enthusiasm continue — increasing alumni awareness about the fund “to get more alums involved … more alums on the board and mentoring the students.”Mentoring is already an important aspect of the ASA Impact Fund, says Akinola. Grantees, she says, get paired with alumni to help them through the process of getting projects underway. “This fund could be a really good opportunity to strengthen the ties between the alumni community and current students,” Akinola says. “I think there are a lot of opportunities for funds like this to tap into the MIT alumni community. I think where there is real value is in the advisory nature — mentoring and coaching current students, helping the transfer of skills and resources.”As more projects are proposed and funded each year, awareness of the ASA Impact Fund among MIT alumni will increase, Gano predicts.“We’ve had just one year of grantees so far, and all of the projects they’ve conducted have been great,” he says. “I think even if we just continue functioning at this scale, if we’re able to sustain the fund, we can have a real lasting impact as students and alumni and build more and more partnerships on the continent.” More

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    Drug injection device wins MIT $100K Competition

    The winner of this year’s MIT $100K Entrepreneurship Competition is helping advanced therapies reach more patients faster with a new kind of drug-injection device.CoFlo Medical says its low-cost device can deliver biologic drugs more than 10 times faster than existing methods, accelerating the treatment of a range of conditions including cancers, autoimmune diseases, and infectious diseases.“For patients battling these diseases, every hour matters,” said Simon Rufer SM ’22 in the winning pitch. “Biologic drugs are capable of treating some of the most challenging diseases, but their administration is unacceptably time-consuming, infringing on the freedom of the patient and effectively leaving them tethered to their hospital beds. The requirement of a hospital setting also makes biologics all but impossible in remote and low-access areas.”Today, biologic drugs are mainly delivered through intravenous fusions, requiring patients to sit in hospital beds for hours during each delivery. That’s because many biologic drugs are too viscous to be pushed through a needle. CoFlo’s device enables quick injections of biologic drugs no matter how viscous. It works by surrounding the viscous drug with a second, lower-viscosity fluid.“Imagine trying to force a liquid as viscous as honey through a needle: It’s simply not possible,” said Rufer, who is currently a PhD candidate in the Department of Mechanical Engineering. “Over the course of six years of research and development at MIT, we’ve overcome a myriad of fluidic instabilities that have otherwise made this technology impossible. We’ve also patented the fundamental inner workings of this device.”Rufer made the winning pitch to a packed Kresge Auditorium that included a panel of judges on May 12. In a video, he showed someone injecting biologic drugs using CoFlo’s device using one hand.Rufer says the second fluid in the device could be the buffer of the drug solution itself, which wouldn’t alter the drug formulation and could potentially expedite the device’s approval in clinical trials. The device can also easily be made using existing mass manufacturing processes, which will keep the cost low.In laboratory experiments, CoFlo’s team has demonstrated injections that are up to 200 times faster.“CoFlo is the only technology that is capable of administering viscous drugs while simultaneously optimizing the patient experience, minimizing the clinical burden, and reducing device cost,” Rufer said.Celebrating entrepreneurshipThe MIT $100K Competition started more than 30 years ago, when students, along with the late MIT Professor Ed Roberts, raised $10,000 to turn MIT’s “mens et manus” (“mind and hand”) motto into a startup challenge. Over time, with sponsor support, the event grew into the renown, highly anticipated startup competition it is today, highlighting some of the most promising new companies founded by MIT community members each year.The Monday night event was the culmination of months of work and preparation by participating teams. The $100K program began with student pitches in December and was followed by mentorship, funding, and other support for select teams over the course of ensuing months.This year more than 50 teams applied for the $100K’s final event. A network of external judges whittled that down to the eight finalists that made their pitches.Other winnersIn addition to the grand prize, finalists were also awarded a $50,000 second-place prize, a $5,000 third-place prize, and a $5,000 audience choice award, which was voted on during the judge’s deliberations.The second-place prize went to Haven, an artificial intelligence-powered financial planning platform that helps families manage lifelong disability care. Haven’s pitch was delivered by Tej Mehta, a student in the MIT Sloan School of Management who explained the problem by sharing his own family’s experience managing his sister’s intellectual disability.“As my family plans for the future, a number of questions are keeping us up at night,” Mehta told the audience. “How much money do we need to save? What public benefits is she eligible for? How do we structure our private assets so she doesn’t lose those public benefits? Finally, how do we manage the funds and compliance over time?”Haven works by using family information and goals to build a personalized roadmap that can predict care needs and costs over more than 50 years.“We recommend to families the exact next steps they need to take, what to apply for, and when,” Mehta explained.The third-place prize went to Aorta Scope, which combines AI and ultrasound to provide augmented reality guidance during vascular surgery. Today, surgeons must rely on a 2-D X-ray image as they feed a large stent into patients’ body during a common surgery known as endovascular repair.Aorta Scope has developed a platform for real-time, 3-D implant alignment. The solution combines intravascular ultrasound technology with fiber optic shape sensing. Tom Dillon built the system that combines data from those sources as part of his ongoing PhD in MIT’s Department of Mechanical Engineering.Finally, the audience choice award went to Flood Dynamics, which provides real-time flood risk modeling to help cities, insurers, and developers adapt and protect urban communities from flooding.Although most urban flood damages are driven by rain today, flood models don’t account for rainfall, making cities less prepared for flooding risks.“Flooding, and especially rain-driven flooding, is the costliest natural hazard around the world today,” said Katerina Boukin SM ’20, PhD ’25, who developed the company’s technology at MIT. “The price of staying rain-blind is really steep. This is an issue that is costing the U.S. alone more than $30 billion a year.” More