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      in Environment

      Collaborative effort supports an MIT resilient to the impacts of extreme heat

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      Warmer weather can be a welcome change for many across the MIT community. But as climate impacts intensify, warm days are often becoming hot days with increased severity and frequency. Already this summer, heat waves in June and July brought daily highs of over 90 degrees Fahrenheit. According to the Resilient Cambridge report published in 2021, from the 1970s to 2000, data from the Boston Logan International Airport weather station reported an average of 10 days of 90-plus temperatures each year. Now, simulations are predicting that, in the current time frame of 2015-44, the number of days above 90 F could be triple the 1970-2000 average. While the increasing heat is all but certain, how institutions like MIT will be affected and how they respond continues to evolve. “We know what the science is showing, but how will this heat impact the ability of MIT to fulfill its mission and support its community?” asks Brian Goldberg, assistant director of the MIT Office of Sustainability. “What will be the real feel of these temperatures on campus?” These questions and more are guiding staff, researchers, faculty, and students working collaboratively to understand these impacts to MIT and inform decisions and action plans in response.This work is part of developing MIT’s forthcoming Climate Resiliency and Adaptation Roadmap, which is called for in MIT’s climate action plan, and is co-led by Goldberg; Laura Tenny, senior campus planner; and William Colehower, senior advisor to the vice president for campus services and stewardship. This effort is also supported by researchers in the departments of Urban Studies and Planning, Architecture, and Electrical Engineering and Computer Science (EECS), in the Urban Risk Lab and the Senseable City Lab, as well as by staff in MIT Emergency Management and Housing and Residential Services. The roadmap — which builds upon years of resiliency planning and research at MIT — will include an assessment of current and future conditions on campus as well as strategies and proposed interventions to support MIT’s community and campus in the face of increasing climate impacts.A key piece of the resiliency puzzleWhen the City of Cambridge released their Climate Change Vulnerability Assessment in 2015, the report identified flooding and heat as primary resiliency risks to the city. In response, Institute staff worked together with the city to create a full picture of potential flood risks to both Cambridge and the campus, with the latter becoming the MIT Climate Resiliency Dashboard. The dashboard, published in the MIT Sustainability DataPool, has played an important role in campus planning and resiliency efforts since its debut in 2021, but heat has been a missing piece of the tool. This is largely because for heat, unlike flooding, few data exist relative to building-level impacts. The original assessment from Cambridge showed a model of temperature averages that could be expected in portions of the city, but understanding the measured heat impacts down to the building level is essential because impacts of heat can vary so greatly. “Heat also doesn’t conform to topography like flooding, making it harder to map it with localized specificity,” notes Tenny. “Microclimates, humidity levels, shade or sun aspect, and other factors contribute to heat risk.”Collection efforts have been underway for the past three years to fill in this gap in baseline data. Members of the Climate and Resiliency Adaptation Roadmap team and partners have helped build and place heat sensors to record and analyze data. The current heat sensors, which are shoebox-shaped devices on tripods, can be found at multiple outdoor locations on campus during the summer, capturing and recording temperatures multiple times each hour. “Urban environmental phenomena are hyperlocal. While National Weather Service readouts at locations like Logan Airport are extremely valuable, this gives us a more high-resolution understanding of the urban microclimate on our campus,” notes Sanjana Paul, past technical associate with Senseable City and current graduate student in the Department of Urban Studies and Planning who helps oversee data collection and analysis.After collection, temperature data are analyzed and mapped. The data will soon be published in the updated Climate Resiliency Dashboard and will help inform actions through the Climate Resiliency and Adaptation Roadmap, but in the meantime, the information has already provided some important insights. “There were some parts of campus that were much hotter than I expected,” explains Paul. “Some of the temperature readings across campus were regularly going over 100 degrees during heat waves. It’s a bit surprising to see three digits on a temperature reading in Cambridge.” Some strategies are also already being put into action, including planting more trees to support the urban campus forest and launching cooling locations around campus to open during days of extreme heat.As data gathering enters its fourth summer, partners continue to expand. Senseable City first began capturing data in 2021 using sensors placed on MIT Recycling trucks, and the Urban Risk Lab has offered community-centered temperature data collection with the help of its director and associate professor of architecture, Miho Mazereeuw. More recently, students in course 6.900 (Engineering for Impact) worked to design heat sensors to aid in the data collection and grow the fleet of sensors on campus. Co-instructed by EECS senior lecturer Joe Steinmeyer and EECS professor Joel Voldman, students in the course were tasked with developing technology to solve challenges close at hand. “One of the goals of the class is to tackle real-world problems so students emerge with confidence as an engineer,” explains Voldman. “Having them work on a challenge that is outside their comfort zone and impacts them really helps to engage and inspire them.” Centering on peopleWhile the temperature data offer one piece of the resiliency planning puzzle, knowing how these temperatures will affect community members is another. “When we look at impacts to our campus from heat, people are the focus,” explains Goldberg. “While stress on campus infrastructure is one factor we are evaluating, our primary focus is the vulnerability of people to extreme heat.” Impacts to community members can range from disrupted nights of sleep to heat-related illnesses.As the team looked at the data and spoke with individuals across campus, it became clear that some community members might be more vulnerable than others to the impact of extreme heat days, including ground, janitorial, and maintenance crews who work outside; kitchen staff who work close to hot equipment; and student athletes exerting themselves on hot days. “We know that people on our campus are already experiencing these extreme heat days differently,” explains Susy Jones, senior sustainability project manager in the Office of Sustainability who focuses on environmental and climate justice. “We need to design strategies and augment existing interventions with equity in mind, ensuring everyone on campus can fulfill their role at MIT.”To support those strategy decisions, the resiliency team is seeking additional input from the MIT community. One hoped-for outcome of the roadmap and dashboard is for community members to review them and offer their own insight and experiences of heat conditions on campus. “These plans need to work at the campus level and the individual,” says Goldberg. “The data tells an important story, but individuals help us complete the picture.”A model for othersAs the dashboard update nears completion and the broader resiliency and adaptation roadmap of strategies launches, their purpose is twofold: help MIT develop and inform plans and procedures for mitigating and addressing heat on campus, and serve as a model for other universities and communities grappling with the same challenges. “This approach is the center of how we operate at MIT,” explains Director of Sustainability Julie Newman. “We seek to identify solutions for our own campus in a manner that others can learn from and potentially adapt for their own resiliency and climate planning purposes. We’re also looking to align with efforts at the city and state level.” By publishing the roadmap broadly, universities and municipalities can apply lessons and processes to their own spaces.When the updated Climate Resiliency Dashboard and Climate Resiliency and Adaptation Roadmap go live, it will mark the beginning of the next phase of work, rather than an end. “The dashboard is designed to present these impacts in a way everyone can understand so people across campus can respond and help us understand what is needed for them to continue to fulfill their role at MIT,” says Goldberg. Uncertainty plays a big role in resiliency planning, and the dashboard will reflect that. “This work is not something you ever say is done,” says Goldberg. “As information and data evolves, so does our work.”  More

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      in Energy

      AI method radically speeds predictions of materials’ thermal properties

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      It is estimated that about 70 percent of the energy generated worldwide ends up as waste heat.If scientists could better predict how heat moves through semiconductors and insulators, they could design more efficient power generation systems. However, the thermal properties of materials can be exceedingly difficult to model.The trouble comes from phonons, which are subatomic particles that carry heat. Some of a material’s thermal properties depend on a measurement called the phonon dispersion relation, which can be incredibly hard to obtain, let alone utilize in the design of a system.A team of researchers from MIT and elsewhere tackled this challenge by rethinking the problem from the ground up. The result of their work is a new machine-learning framework that can predict phonon dispersion relations up to 1,000 times faster than other AI-based techniques, with comparable or even better accuracy. Compared to more traditional, non-AI-based approaches, it could be 1 million times faster.This method could help engineers design energy generation systems that produce more power, more efficiently. It could also be used to develop more efficient microelectronics, since managing heat remains a major bottleneck to speeding up electronics.“Phonons are the culprit for the thermal loss, yet obtaining their properties is notoriously challenging, either computationally or experimentally,” says Mingda Li, associate professor of nuclear science and engineering and senior author of a paper on this technique.Li is joined on the paper by co-lead authors Ryotaro Okabe, a chemistry graduate student; and Abhijatmedhi Chotrattanapituk, an electrical engineering and computer science graduate student; Tommi Jaakkola, the Thomas Siebel Professor of Electrical Engineering and Computer Science at MIT; as well as others at MIT, Argonne National Laboratory, Harvard University, the University of South Carolina, Emory University, the University of California at Santa Barbara, and Oak Ridge National Laboratory. The research appears in Nature Computational Science.Predicting phononsHeat-carrying phonons are tricky to predict because they have an extremely wide frequency range, and the particles interact and travel at different speeds.A material’s phonon dispersion relation is the relationship between energy and momentum of phonons in its crystal structure. For years, researchers have tried to predict phonon dispersion relations using machine learning, but there are so many high-precision calculations involved that models get bogged down.“If you have 100 CPUs and a few weeks, you could probably calculate the phonon dispersion relation for one material. The whole community really wants a more efficient way to do this,” says Okabe.The machine-learning models scientists often use for these calculations are known as graph neural networks (GNN). A GNN converts a material’s atomic structure into a crystal graph comprising multiple nodes, which represent atoms, connected by edges, which represent the interatomic bonding between atoms.While GNNs work well for calculating many quantities, like magnetization or electrical polarization, they are not flexible enough to efficiently predict an extremely high-dimensional quantity like the phonon dispersion relation. Because phonons can travel around atoms on X, Y, and Z axes, their momentum space is hard to model with a fixed graph structure.To gain the flexibility they needed, Li and his collaborators devised virtual nodes.They create what they call a virtual node graph neural network (VGNN) by adding a series of flexible virtual nodes to the fixed crystal structure to represent phonons. The virtual nodes enable the output of the neural network to vary in size, so it is not restricted by the fixed crystal structure.Virtual nodes are connected to the graph in such a way that they can only receive messages from real nodes. While virtual nodes will be updated as the model updates real nodes during computation, they do not affect the accuracy of the model.“The way we do this is very efficient in coding. You just generate a few more nodes in your GNN. The physical location doesn’t matter, and the real nodes don’t even know the virtual nodes are there,” says Chotrattanapituk.Cutting out complexitySince it has virtual nodes to represent phonons, the VGNN can skip many complex calculations when estimating phonon dispersion relations, which makes the method more efficient than a standard GNN. The researchers proposed three different versions of VGNNs with increasing complexity. Each can be used to predict phonons directly from a material’s atomic coordinates.Because their approach has the flexibility to rapidly model high-dimensional properties, they can use it to estimate phonon dispersion relations in alloy systems. These complex combinations of metals and nonmetals are especially challenging for traditional approaches to model.The researchers also found that VGNNs offered slightly greater accuracy when predicting a material’s heat capacity. In some instances, prediction errors were two orders of magnitude lower with their technique.A VGNN could be used to calculate phonon dispersion relations for a few thousand materials in just a few seconds with a personal computer, Li says.This efficiency could enable scientists to search a larger space when seeking materials with certain thermal properties, such as superior thermal storage, energy conversion, or superconductivity.Moreover, the virtual node technique is not exclusive to phonons, and could also be used to predict challenging optical and magnetic properties.In the future, the researchers want to refine the technique so virtual nodes have greater sensitivity to capture small changes that can affect phonon structure.“Researchers got too comfortable using graph nodes to represent atoms, but we can rethink that. Graph nodes can be anything. And virtual nodes are a very generic approach you could use to predict a lot of high-dimensional quantities,” Li says.“The authors’ innovative approach significantly augments the graph neural network description of solids by incorporating key physics-informed elements through virtual nodes, for instance, informing wave-vector dependent band-structures and dynamical matrices,” says Olivier Delaire, associate professor in the Thomas Lord Department of Mechanical Engineering and Materials Science at Duke University, who was not involved with this work. “I find that the level of acceleration in predicting complex phonon properties is amazing, several orders of magnitude faster than a state-of-the-art universal machine-learning interatomic potential. Impressively, the advanced neural net captures fine features and obeys physical rules. There is great potential to expand the model to describe other important material properties: Electronic, optical, and magnetic spectra and band structures come to mind.”This work is supported by the U.S. Department of Energy, National Science Foundation, a Mathworks Fellowship, a Sow-Hsin Chen Fellowship, the Harvard Quantum Initiative, and the Oak Ridge National Laboratory. More

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      in Environment

      Study finds health risks in switching ships from diesel to ammonia fuel

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      As container ships the size of city blocks cross the oceans to deliver cargo, their huge diesel engines emit large quantities of air pollutants that drive climate change and have human health impacts. It has been estimated that maritime shipping accounts for almost 3 percent of global carbon dioxide emissions and the industry’s negative impacts on air quality cause about 100,000 premature deaths each year.Decarbonizing shipping to reduce these detrimental effects is a goal of the International Maritime Organization, a U.N. agency that regulates maritime transport. One potential solution is switching the global fleet from fossil fuels to sustainable fuels such as ammonia, which could be nearly carbon-free when considering its production and use.But in a new study, an interdisciplinary team of researchers from MIT and elsewhere caution that burning ammonia for maritime fuel could worsen air quality further and lead to devastating public health impacts, unless it is adopted alongside strengthened emissions regulations.Ammonia combustion generates nitrous oxide (N2O), a greenhouse gas that is about 300 times more potent than carbon dioxide. It also emits nitrogen in the form of nitrogen oxides (NO and NO2, referred to as NOx), and unburnt ammonia may slip out, which eventually forms fine particulate matter in the atmosphere. These tiny particles can be inhaled deep into the lungs, causing health problems like heart attacks, strokes, and asthma.The new study indicates that, under current legislation, switching the global fleet to ammonia fuel could cause up to about 600,000 additional premature deaths each year. However, with stronger regulations and cleaner engine technology, the switch could lead to about 66,000 fewer premature deaths than currently caused by maritime shipping emissions, with far less impact on global warming.“Not all climate solutions are created equal. There is almost always some price to pay. We have to take a more holistic approach and consider all the costs and benefits of different climate solutions, rather than just their potential to decarbonize,” says Anthony Wong, a postdoc in the MIT Center for Global Change Science and lead author of the study.His co-authors include Noelle Selin, an MIT professor in the Institute for Data, Systems, and Society and the Department of Earth, Atmospheric and Planetary Sciences (EAPS); Sebastian Eastham, a former principal research scientist who is now a senior lecturer at Imperial College London; Christine Mounaïm-Rouselle, a professor at the University of Orléans in France; Yiqi Zhang, a researcher at the Hong Kong University of Science and Technology; and Florian Allroggen, a research scientist in the MIT Department of Aeronautics and Astronautics. The research appears this week in Environmental Research Letters.Greener, cleaner ammoniaTraditionally, ammonia is made by stripping hydrogen from natural gas and then combining it with nitrogen at extremely high temperatures. This process is often associated with a large carbon footprint. The maritime shipping industry is betting on the development of “green ammonia,” which is produced by using renewable energy to make hydrogen via electrolysis and to generate heat.“In theory, if you are burning green ammonia in a ship engine, the carbon emissions are almost zero,” Wong says.But even the greenest ammonia generates nitrous oxide (N2O), nitrogen oxides (NOx) when combusted, and some of the ammonia may slip out, unburnt. This nitrous oxide would escape into the atmosphere, where the greenhouse gas would remain for more than 100 years. At the same time, the nitrogen emitted as NOx and ammonia would fall to Earth, damaging fragile ecosystems. As these emissions are digested by bacteria, additional N2O  is produced.NOx and ammonia also mix with gases in the air to form fine particulate matter. A primary contributor to air pollution, fine particulate matter kills an estimated 4 million people each year.“Saying that ammonia is a ‘clean’ fuel is a bit of an overstretch. Just because it is carbon-free doesn’t necessarily mean it is clean and good for public health,” Wong says.A multifaceted modelThe researchers wanted to paint the whole picture, capturing the environmental and public health impacts of switching the global fleet to ammonia fuel. To do so, they designed scenarios to measure how pollutant impacts change under certain technology and policy assumptions.From a technological point of view, they considered two ship engines. The first burns pure ammonia, which generates higher levels of unburnt ammonia but emits fewer nitrogen oxides. The second engine technology involves mixing ammonia with hydrogen to improve combustion and optimize the performance of a catalytic converter, which controls both nitrogen oxides and unburnt ammonia pollution.They also considered three policy scenarios: current regulations, which only limit NOx emissions in some parts of the world; a scenario that adds ammonia emission limits over North America and Western Europe; and a scenario that adds global limits on ammonia and NOx emissions.The researchers used a ship track model to calculate how pollutant emissions change under each scenario and then fed the results into an air quality model. The air quality model calculates the impact of ship emissions on particulate matter and ozone pollution. Finally, they estimated the effects on global public health.One of the biggest challenges came from a lack of real-world data, since no ammonia-powered ships are yet sailing the seas. Instead, the researchers relied on experimental ammonia combustion data from collaborators to build their model.“We had to come up with some clever ways to make that data useful and informative to both the technology and regulatory situations,” he says.A range of outcomesIn the end, they found that with no new regulations and ship engines that burn pure ammonia, switching the entire fleet would cause 681,000 additional premature deaths each year.“While a scenario with no new regulations is not very realistic, it serves as a good warning of how dangerous ammonia emissions could be. And unlike NOx, ammonia emissions from shipping are currently unregulated,” Wong says.However, even without new regulations, using cleaner engine technology would cut the number of premature deaths down to about 80,000, which is about 20,000 fewer than are currently attributed to maritime shipping emissions. With stronger global regulations and cleaner engine technology, the number of people killed by air pollution from shipping could be reduced by about 66,000.“The results of this study show the importance of developing policies alongside new technologies,” Selin says. “There is a potential for ammonia in shipping to be beneficial for both climate and air quality, but that requires that regulations be designed to address the entire range of potential impacts, including both climate and air quality.”Ammonia’s air quality impacts would not be felt uniformly across the globe, and addressing them fully would require coordinated strategies across very different contexts. Most premature deaths would occur in East Asia, since air quality regulations are less stringent in this region. Higher levels of existing air pollution cause the formation of more particulate matter from ammonia emissions. In addition, shipping volume over East Asia is far greater than elsewhere on Earth, compounding these negative effects.In the future, the researchers want to continue refining their analysis. They hope to use these findings as a starting point to urge the marine industry to share engine data they can use to better evaluate air quality and climate impacts. They also hope to inform policymakers about the importance and urgency of updating shipping emission regulations.This research was funded by the MIT Climate and Sustainability Consortium. More

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      in Environment

      How to increase the rate of plastics recycling

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      While recycling systems and bottle deposits have become increasingly widespread in the U.S., actual rates of recycling are “abysmal,” according to a team of MIT researchers who studied the rates for recycling of PET, the plastic commonly used in beverage bottles. However, their findings suggest some ways to change this.The present rate of recycling for PET, or polyethylene terephthalate, bottles nationwide is about 24 percent and has remained stagnant for a decade, the researchers say. But their study indicates that with a nationwide bottle deposit program, the rates could increase to 82 percent, with nearly two-thirds of all PET bottles being recycled into new bottles, at a net cost of just a penny a bottle when demand is robust. At the same time, they say, policies would be needed to ensure a sufficient demand for the recycled material.The findings are being published today in the Journal of Industrial Ecology, in a paper by MIT professor of materials science and engineering Elsa Olivetti, graduate students Basuhi Ravi and Karan Bhuwalka, and research scientist Richard Roth.The team looked at PET bottle collection and recycling rates in different states as well as other nations with and without bottle deposit policies, and with or without curbside recycling programs, as well as the inputs and outputs of various recycling companies and methods. The researchers say this study is the first to look in detail at the interplay between public policies and the end-to-end realities of the packaging production and recycling market.They found that bottle deposit programs are highly effective in the areas where they are in place, but at present there is not nearly enough collection of used bottles to meet the targets set by the packaging industry. Their analysis suggests that a uniform nationwide bottle deposit policy could achieve the levels of recycling that have been mandated by proposed legislation and corporate commitments.The recycling of PET is highly successful in terms of quality, with new products made from all-recycled material virtually matching the qualities of virgin material. And brands have shown that new bottles can be safely made with 100 percent postconsumer waste. But the team found that collection of the material is a crucial bottleneck that leaves processing plants unable to meet their needs. However, with the right policies in place, “one can be optimistic,” says Olivetti, who is the Jerry McAfee Professor in Engineering and the associate dean of the School of Engineering.“A message that we have found in a number of cases in the recycling space is that if you do the right work to support policies that think about both the demand but also the supply,” then significant improvements are possible, she says. “You have to think about the response and the behavior of multiple actors in the system holistically to be viable,” she says. “We are optimistic, but there are many ways to be pessimistic if we’re not thinking about that in a holistic way.”For example, the study found that it is important to consider the needs of existing municipal waste-recovery facilities. While expanded bottle deposit programs are essential to increase recycling rates and provide the feedstock to companies recycling PET into new products, the current facilities that process material from curbside recycling programs will lose revenue from PET bottles, which are a relatively high-value product compared to the other materials in the recycled waste stream. These companies would lose a source of their income if the bottles are collected through deposit programs, leaving them with only the lower-value mixed plastics.The researchers developed economic models based on rates of collection found in the states with deposit programs, recycled-content requirements, and other policies, and used these models to extrapolate to the nation as a whole. Overall, they found that the supply needs of packaging producers could be met through a nationwide bottle deposit system with a 10-cent deposit per bottle — at a net cost of about 1 cent per bottle produced when demand is strong. This need not be a federal program, but rather one where the implementation would be left up to the individual states, Olivetti says.Other countries have been much more successful in implementing deposit systems that result in very high participation rates. Several European countries manage to collect more than 90 percent of PET bottles for recycling, for example. But in the U.S., less than 29 percent are collected, and after losses in the recycling chain about 24 percent actually get recycled, the researchers found. Whereas 73 percent of Americans have access to curbside recycling, presently only 10 states have bottle deposit systems in place.Yet the demand is there so far. “There is a market for this material,” says Olivetti. While bottles collected through mixed-waste collection can still be recycled to some extent, those collected through deposit systems tend to be much cleaner and require less processing, and so are more economical to recycle into new bottles, or into textiles.To be effective, policies need to not just focus on increasing rates of recycling, but on the whole cycle of supply and demand and the different players involved, Olivetti says. Safeguards would need to be in place to protect existing recycling facilities from the lost revenues they would suffer as a result of bottle deposits, perhaps in the form of subsidies funded by fees on the bottle producers, to avoid putting these essential parts of the processing chain out of business. And other policies may be needed to ensure the continued market for the material that gets collected, including recycled content requirements and extended producer responsibility regulations, the team found.At this stage, it’s important to focus on the specific waste streams that can most effectively be recycled, and PET, along with many metals, clearly fit that category. “When we start to think about mixed plastic streams, that’s much more challenging from an environmental perspective,” she says. “Recycling systems need to be pursuing extended producers’ responsibility, or specifically thinking about materials designed more effectively toward recycled content,” she says.It’s also important to address “what the right metrics are to design for sustainably managed materials streams,” she says. “It could be energy use, could be circularity [for example, making old bottles into new bottles], could be around waste reduction, and making sure those are all aligned. That’s another kind of policy coordination that’s needed.” More

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      in Security

      Pioneering the future of materials extraction

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      The next time you cook pasta, imagine that you are cooking spaghetti, rigatoni, and seven other varieties all together, and they need to be separated onto 10 different plates before serving. A colander can remove the water — but you still have a mound of unsorted noodles. Now imagine that this had to be done for thousands of tons of pasta a day. That gives you an idea of the scale of the problem facing Brendan Smith PhD ’18, co-founder and CEO of SiTration, a startup formed out of MIT’s Department of Materials Science and Engineering (DMSE) in 2020. SiTration, which raised $11.8 million in seed capital led by venture capital firm 2150 earlier this month, is revolutionizing the extraction and refining of copper, cobalt, nickel, lithium, precious metals, and other materials critical to manufacturing clean-energy technologies such as electric motors, wind turbines, and batteries. Its initial target applications are recovering the materials from complex mining feed streams, spent lithium-ion batteries from electric vehicles, and various metals refining processes. The company’s breakthrough lies in a new silicon membrane technology that can be adjusted to efficiently recover disparate materials, providing a more sustainable and economically viable alternative to conventional, chemically intensive processes. Think of a colander with adjustable pores to strain different types of pasta. SiTration’s technology has garnered interest from industry players, including mining giant Rio Tinto. Some observers may question whether targeting such different industries could cause the company to lose focus. “But when you dig into these markets, you discover there is actually a significant overlap in how all of these materials are recovered, making it possible for a single solution to have impact across verticals,” Smith says.Powering up materials recoveryConventional methods of extracting critical materials in mining, refining, and recycling lithium-ion batteries involve heavy use of chemicals and heat, which harm the environment. Typically, raw ore from mines or spent batteries are ground into fine particles before being dissolved in acid or incinerated in a furnace. Afterward, they undergo intensive chemical processing to separate and purify the valuable materials. “It requires as much as 10 tons of chemical input to produce one ton of critical material recovered from the mining or battery recycling feedstock,” says Smith. Operators can then sell the recaptured materials back into the supply chain, but suffer from wide swings in profitability due to uncertain market prices. Lithium prices have been the most volatile, having surged more than 400 percent before tumbling back to near-original levels in the past two years. Despite their poor economics and negative environmental impact, these processes remain the state of the art today. By contrast, SiTration is electrifying the critical-materials recovery process, improving efficiency, producing less chemical waste, and reducing the use of chemicals and heat. What’s more, the company’s processing technology is built to be highly adaptable, so it can handle all kinds of materials. The core technology is based on work done at MIT to develop a novel type of membrane made from silicon, which is durable enough to withstand harsh chemicals and high temperatures while conducting electricity. It’s also highly tunable, meaning it can be modified or adjusted to suit different conditions or target specific materials. SiTration’s technology also incorporates electro-extraction, a technique that uses electrochemistry to further isolate and extract specific target materials. This powerful combination of methods in a single system makes it more efficient and effective at isolating and recovering valuable materials, Smith says. So depending on what needs to be separated or extracted, the filtration and electro-extraction processes are adjusted accordingly. “We can produce membranes with pore sizes from the molecular scale up to the size of a human hair in diameter, and everything in between. Combined with the ability to electrify the membrane and separate based on a material’s electrochemical properties, this tunability allows us to target a vast array of different operations and separation applications across industrial fields,” says Smith. Efficient access to materials like lithium, cobalt, and copper — and precious metals like platinum, gold, silver, palladium, and rare-earth elements — is key to unlocking innovation in business and sustainability as the world moves toward electrification and away from fossil fuels.“This is an era when new materials are critical,” says Professor Jeffrey Grossman, co-founder and chief scientist of SiTration and the Morton and Claire Goulder and Family Professor in Environmental Systems at DMSE. “For so many technologies, they’re both the bottleneck and the opportunity, offering tremendous potential for non-incremental advances. And the role they’re having in commercialization and in entrepreneurship cannot be overstated.”SiTration’s commercial frontierSmith became interested in separation technology in 2013 as a PhD student in Grossman’s DMSE research group, which has focused on the design of new membrane materials for a range of applications. The two shared a curiosity about separation of critical materials and a hunger to advance the technology. After years of study under Grossman’s mentorship, and with support from several MIT incubators and foundations including the Abdul Latif Jameel Water and Food Systems Lab’s Solutions Program, the Deshpande Center for Technological Innovation, the Kavanaugh Fellowship, MIT Sandbox, and Venture Mentoring Service, Smith was ready to officially form SiTration in 2020. Grossman has a seat on the board and plays an active role as a strategic and technical advisor. Grossman is involved in several MIT spinoffs and embraces the different imperatives of research versus commercialization. “At SiTration, we’re driving this technology to work at scale. There’s something super exciting about that goal,” he says. “The challenges that come with scaling are very different than the challenges that come in a university lab.” At the same time, although not every research breakthrough becomes a commercial product, open-ended, curiosity-driven knowledge pursuit holds its own crucial value, he adds.It has been rewarding for Grossman to see his technically gifted student and colleague develop a host of other skills the role of CEO demands. Getting out to the market and talking about the technology with potential partners, putting together a dynamic team, discovering the challenges facing industry, drumming up support, early on — those became the most pressing activities on Smith’s agenda. “What’s most fun to me about being a CEO of an early-stage startup is that there are 100 different factors, most people-oriented, that you have to navigate every day. Each stakeholder has different motivations and objectives. And you basically try to fit that all together, to create value for our partners and customers, the company, and for society,” says Smith. “You start with just an idea, and you have to keep leveraging that to form a more and more tangible product, to multiply and progress commercial relationships, and do it all at an ever-expanding scale.” MIT DNA runs deep in the nine-person company, with DMSE grad and former Grossman student Jatin Patil as director of product; Ahmed Helal, from MIT’s Department of Mechanical Engineering, as vice president of research and development; Daniel Bregante, from the Department of Chemistry, as VP of technology; and Sarah Melvin, from the departments of Physics and Political Science, as VP of strategy and operations. Melvin is the first hire devoted to business development. Smith plans to continue expanding the team following the closing of the company’s seed round.  Strategic alliancesBeing a good communicator was important when it came to securing funding, Smith says. SiTration received $2.35 million in pre-seed funding in 2022 led by Azolla Ventures, which reserves its $239 million in investment capital for startups that would not otherwise easily obtain funding. “We invest only in solution areas that can achieve gigaton-scale climate impact by 2050,” says Matthew Nordan, a general partner at Azolla and now SiTration board member. The MIT-affiliated E14 Fund also contributed to the pre-seed round; Azolla and E14 both participated in the recent seed funding round. “Brendan demonstrated an extraordinary ability to go from being a thoughtful scientist to a business leader and thinker who has punched way above his weight in engaging with customers and recruiting a well-balanced team and navigating tricky markets,” says Nordan. One of SiTration’s first partnerships is with Rio Tinto, one of the largest mining companies in the world. As SiTration evaluated various uses cases in its early days, identifying critical materials as its target market, Rio Tinto was looking for partners to recover valuable metals such as cobalt and copper from the wastewater generated at mines. These metals were typically trapped in the water, creating harmful waste and resulting in lost revenue. “We thought this was a great innovation challenge and posted it on our website to scout for companies to partner with who can help us solve this water challenge,” said Nick Gurieff, principal advisor for mine closure, in an interview with MIT’s Industrial Liaison Program in 2023. At SiTration, mining was not yet a market focus, but Smith couldn’t help noticing that Rio Tinto’s needs were in alignment with what his young company offered. SiTration submitted its proposal in August 2022. Gurieff said SiTration’s tunable membrane set it apart. The companies formed a business partnership in June 2023, with SiTration adjusting its membrane to handle mine wastewater and incorporating Rio Tinto feedback to refine the technology. After running tests with water from mine sites, SiTration will begin building a small-scale critical-materials recovery unit, followed by larger-scale systems processing up to 100 cubic meters of water an hour.SiTration’s focused technology development with Rio Tinto puts it in a good position for future market growth, Smith says. “Every ounce of effort and resource we put into developing our product is geared towards creating real-world value. Having an industry-leading partner constantly validating our progress is a tremendous advantage.”It’s a long time from the days when Smith began tinkering with tiny holes in silicon in Grossman’s DMSE lab. Now, they work together as business partners who are scaling up technology to meet a global need. Their joint passion for applying materials innovation to tough problems has served them well. “Materials science and engineering is an engine for a lot of the innovation that is happening today,” Grossman says. “When you look at all of the challenges we face to make the transition to a more sustainable planet, you realize how many of these are materials challenges.” More

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      in Environment

      Two MIT films nominated for New England Emmy Awards

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      Two films produced by MIT were honored with Emmy nominations by the National Academy of Television Arts & Sciences Boston/New England Chapter. Both “We Are the Forest” and “No Drop to Spare” illustrate international conversations the MIT community is having about the environment and climate change.“We Are the Forest,” produced by MIT Video Productions (MVP) at MIT Open Learning, was one of six nominees in the Education/Schools category. The documentary highlights the cultural and scientific exchange of the MIT Festival Jazz Ensemble, MIT Wind Ensemble, and MIT Vocal Jazz Ensemble in the Brazilian Amazon. The excursion depicted in the film was part of the ongoing work of Frederick Harris Jr., MIT director of wind and jazz ensembles and senior lecturer in music, to combine Brazilian music and environmental research.“No Drop to Spare,” created by the Department of Mechanical Engineering (MechE), was nominated in the Environment/Science and Video Essayist categories. The film, produced by John Freidah, MechE senior producer and creative lead, follows a team of researchers from the K. Lisa Yang Global Engineering and Research (GEAR) Center working in Kenya, Morocco, and Jordan to deploy affordable, user-driven smart irrigation technology.“We Are the Forest” tells the story of 80 MIT student musicians who traveled to Manaus, Brazil in March 2023. Together with Indigenous Brazilian musicians and activists, the students played music, created instruments with found objects from the rainforest, and connected their musical practice to nature and culture. The trip and the documentary culminated with the concert “Hearing Amazônia: Art and Resistance.”“We have an amazing team who are excited to tell the stories of so many great things that happen at MIT,” says Clayton Hainsworth, director for MVP. “It’s a true pleasure when we get to partner with the Institute’s community on these video projects — from Fred [Harris], with his desire for outreach of the music curriculum, giving students new perspectives and getting beyond the lab; to students getting to experience the world and seeing how that affects their next steps as they go out and make an impact.”The documentary was produced by Hainsworth, directed by Jean Dunoyer, staff editor at MVP, and filmed by Myles Lowery, field production videographer at MVP. Hainsworth credits Dunoyer with refining the story’s main themes: the universality of music as a common human language, and the ways that Indigenous communities can teach and inform the rest of the globe about the environment and the challenges we are all facing.“The film highlights the reach of how MIT touches the world and, more importantly, how the world touches MIT,” says Hainsworth, adding that the work was generously supported by A. Neil Pappalardo ’64 and Jane Pappalardo. “No Drop to Spare” evoked a similar sentiment from Freidah. “What I liked about this story was the potential for great impact,” says Freidah, discussing the MechE film’s production process. “It was global, it was being piloted in three different places in the world, with three different end users, and had three different applications. You sort of go in with an idea in mind of what the story might be, then things bubble up. In this story, as with so many stories, what rose to the top was the students and the impact they were having on the real world and end users.” Freidah has worked with Amos Winter SM ’05, PhD ’11, associate professor of mechanical engineering and MIT GEAR Center principal investigator, to highlight other impact global projects in the past, including producing a video in 2016. That film, “Water is Life,” explores the development of low-cost desalination systems in India. While the phrase “it’s an honor to be nominated” might seem cliched, it remains often used because the sentiment almost always rings true. Although neither film triumphed at this year’s awards ceremony, Freidah says there’s much to be celebrated in the final product. “Seeing the effect this piece had, and how it highlighted our students, that’s the success story — but it’s always nice also to receive recognition from outside.”The 47th Boston/New England Emmy Awards Ceremony took place on June 8 at the Marriott Boston Copley Place. A list of nominees and winners can be found on the National Academy of Television Arts and Sciences Boston/New England Chapter website.  More

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      in Energy

      Startup aims to transform the power grid with superconducting transmission lines

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      Last year in Woburn, Massachusetts, a power line was deployed across a 100-foot stretch of land. Passersby wouldn’t have found much interesting about the installation: The line was supported by standard utility poles, the likes of which most of us have driven by millions of times. In fact, the familiarity of the sight is a key part of the technology’s promise.The lines are designed to transport five to 10 times the amount of power of conventional transmission lines, using essentially the same footprint and voltage level. That will be key to helping them overcome the regulatory hurdles and community opposition that has made increasing transmission capacity nearly impossible across large swaths of the globe, particularly in America and Europe, where new power distribution systems play a vital role in the shift to renewable energy and the resilience of the grid.The lines are the product of years of work by the startup VEIR, which was co-founded by Tim Heidel ’05, SM ’06, SM ’09, PhD ’10. They make use of superconducting cables and a proprietary cooling system that will enable initial transmission capacity up to 400 megawatts and, in future versions, up to several gigawatts.“We can deploy much higher power levels at much lower voltage, and so we can deploy the same high power but with a footprint and visual impact that is far less intrusive, and therefore can overcome a lot of the public opposition as well as siting and permitting barriers,” Heidel says.VEIR’s solution comes at a time when more than 10,000 renewable energy projects at various stages of development are seeking permission to connect to U.S. grids. The White House has said the U.S. must more than double existing regional transmission capacity in order to reach 2035 decarbonization goals.All of this comes as electricity demand is skyrocketing amid the increasing use of data centers and AI, and the electrification of everything from passenger vehicles to home heating systems.Despite those trends, building high-power transmission lines remains stubbornly difficult.“Building high-power transmission infrastructure can take a decade or more, and there’s been quite a few examples of projects that folks have had to abandon because they realize that there’s just so much opposition, or there’s too much complexity to pull it off cost effectively,” Heidel says. “We can drop down in voltage but carry the same amount of power because we can build systems that operate at much higher current levels, and that’s how our lines are able to melt into the background and avoid the same opposition.”Heidel says VEIR has built a pipeline of interested customers including utilities, data center operators, industrial companies, and renewable energy developers. VEIR is aiming to complete its first commercial-scale pilot carrying high power in 2026.A career in energyOver more than a decade at MIT, Heidel went from learning about the fundamentals of electrical engineering to studying the electric grid and the power sector more broadly. That journey included earning a bachelor’s, master’s, and PhD from MIT’s Department of Electrical Engineering and Computer Science as well as a master’s in MIT’s Technology and Policy Program, which he earned while working toward his PhD.“I got the energy bug and started to focus exclusively on energy and climate in graduate school,” Heidel says.Following his PhD, Heidel was named research director of MIT’s Future of the Electric Grid study, which was completed in 2011.“That was a fantastic opportunity at the outset of my career to survey the entire landscape and understand challenges facing the power grid and the power sector more broadly,” Heidel says. “It gave me a good foundation for understanding the grid, how it works, who’s involved, how decisions get made, how expansion works, and it looked out over the next 30 years.”After leaving MIT, Heidel worked at the Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) and then at Bill Gates’ Breakthrough Energy Ventures (BEV) investment firm, where he continued studying transmission.“Just about every single decarbonization scenario and study that’s been published in the last two decades concludes that to achieve aggressive greenhouse gas emissions reductions, we’re going to have to double or triple the scale of power grids around the world,” Heidel says. “But when we looked at the data on how fast grids were being expanded, the ease with which transmission lines could be built, the cost of building new transmission, just about every indicator was heading in the wrong direction. Transmission was getting more expensive over time and taking longer to build. We desperately need to find a new solution.”Unlike traditional transmission lines made from steel and aluminum, VEIR’s transmission lines leverage decades of progress in the development of high-temperature superconducting tapes and other materials. Some of that progress has been driven by the nuclear fusion industry, which incorporates superconducting materials into some of their nuclear reactor designs.But the core innovation at VEIR is the cooling system. VEIR co-founder and advisor Steve Ashworth developed the rough idea for the cooling system more than 15 years ago at Los Alamos National Laboratory as part of a larger Department of Energy-funded research project. When the project was shut down, the idea was largely forgotten.Heidel and others at Breakthrough Energy Ventures became aware of the innovation in 2019 while researching transmission. Today VEIR’s system is passively cooled with nitrogen, which runs through a vacuum-insulated pipe that surrounds a superconducting cable. Heat exchange units are also used on some transmission towers.Heidel says transmission lines designed to carry that much power are typically far bigger than VEIR’s design, and other attempts at shrinking the footprint of high-power lines were limited to short distances underground.“High power requires high voltage, and high voltage requires tall towers and wide right of ways, and those tall towers and those wide right of ways are deeply unpopular,” Heidel says. “That is a universal truth across just about the entire world.”Moving power around the worldVEIR’s first alternating current (AC) overhead product line is capable of transmission capacities up to 400 megawatts and voltages of up to 69 kilovolts, and the company plans to scale to higher voltage and higher-power products in the future, including direct current (DC) lines.VEIR will sell its equipment to the companies installing transmission lines, with a primary focus on the U.S. market.In the longer term, Heidel believes VEIR’s technology is needed as soon as possible to meet rising electricity demands and new renewable energy projects around the globe. 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      in Energy

      Students research pathways for MIT to reach decarbonization goals

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      A number of emerging technologies hold promise for helping organizations move away from fossil fuels and achieve deep decarbonization. The challenge is deciding which technologies to adopt, and when.MIT, which has a goal of eliminating direct campus emissions by 2050, must make such decisions sooner than most to achieve its mission. That was the challenge at the heart of the recently concluded class 4.s42 (Building Technology — Carbon Reduction Pathways for the MIT Campus).The class brought together undergraduate and graduate students from across the Institute to learn about different technologies and decide on the best path forward. It concluded with a final report as well as student presentations to members of MIT’s Climate Nucleus on May 9.“The mission of the class is to put together a cohesive document outlining how MIT can reach its goal of decarbonization by 2050,” says Morgan Johnson Quamina, an undergraduate in the Department of Civil and Environmental Engineering. “We’re evaluating how MIT can reach these goals on time, what sorts of technologies can help, and how quickly and aggressively we’ll have to move. The final report details a ton of scenarios for partial and full implementation of different technologies, outlines timelines for everything, and features recommendations.”The class was taught by professor of architecture Christoph Reinhart but included presentations by other faculty about low- and zero-carbon technology areas in their fields, including advanced nuclear reactors, deep geothermal energy, carbon capture, and more.The students’ work served as an extension of MIT’s Campus Decarbonization Working Group, which Reinhart co-chairs with Director of Sustainability Julie Newman. The group is charged with developing a technology roadmap for the campus to reach its goal of decarbonizing its energy systems.Reinhart says the class was a way to leverage the energy and creativity of students to accelerate his group’s work.“It’s very much focused on establishing a vision for what could happen at MIT,” Reinhart says. “We are trying to bring these technologies together so that we see how this [decarbonization process] would actually look on our campus.”A class with impactThroughout the semester, every Thursday from 9 a.m. to 12 p.m., around 20 students gathered to explore different decarbonization technology pathways. They also discussed energy policies, methods for evaluating risk, and future electric grid supply changes in New England.“I love that this work can have a real-world impact,” says Emile Germonpre, a master’s student in the Department of Nuclear Science and Engineering. “You can tell people aren’t thinking about grades or workload — I think people would’ve loved it even if the workload was doubled. Everyone is just intrinsically motivated to help solve this problem.”The classes typically began with an introduction to one of 10 different technologies. The introductions covered technical maturity, ease of implementation, costs, and how to model the technology’s impact on campus emissions. Students were then split into teams to evaluate each technology’s feasibility.“I’ve learned a lot about decarbonization and climate change,” says Johnson Quamina. “As an undergrad, I haven’t had many focused classes like this. But it was really beneficial to learn about some of these technologies I hadn’t even heard of before. It’s awesome to be contributing to the community like this.”As part of the class, students also developed a model that visualizes each intervention’s effect on emissions, allowing users to select interventions or combinations of interventions to see how they shape emissions trajectories.“We have a physics-based model that takes into account every building,” says Reinhart. “You can look at variants where we retrofit buildings, where we add rooftop photovoltaics, nuclear, carbon capture, and adopting different types of district underground heating systems. The point is you can start to see how fast we could do something like this and what the real game-changers are.”The class also designed and conducted a preliminary survey, to be expanded in the fall, that captures the MIT community’s attitudes towards the different technologies. Preliminary results were shared with the Climate Nucleus during students’ May 9 presentations.“I think it’s this unique and wonderful intersection of the forward-looking and innovative nature of academia with real world impact and specificity that you’d typically only find in industry,” Germonpre says. “It lets you work on a tangible project, the MIT campus, while exploring technologies that companies today find too risky to be the first mover on.”From MIT’s campus to the worldThe students recommended MIT form a building energy team to audit and retrofit all campus buildings. They also suggested MIT order a comprehensive geological feasibility survey to support planning regarding shallow and deep borehole fields for harvesting underground heat. A third recommendation was to communicate with the MIT community as well as with regulators and policymakers in the area about the deployment of nuclear batteries and deep geothermal boreholes on campus.The students’ modeling tool can also help members of the working group explore various decarbonization pathways. For instance, installing rooftop photovoltaics now would effectively reduce emissions, but installing them in a few decades, when the regional electricity grid is expected to be reducing its reliance on fossil fuels anyways, would have a much smaller impact.“When you have students working together, the recommendations are a little less filtered, which I think is a good thing,” Reinhart says. “I think there’s a real sense of urgency in the class. For certain choices, we have to basically act now.”Reinhart plans to do more activities related to the Working Group and the class’ recommendations in the fall, and he says he’s currently engaged with the Massachusetts Governor’s Office to explore doing something similar for the state.Students say they plan to keep working on the survey this summer and continue studying their technology areas. In the longer term, they believe the experience will help them in their careers.“Decarbonization is really important, and understanding how we can implement new technologies on campuses or in buildings provides me with a more well-rounded vision for what I could design in my career,” says Johnson Quamina, who wants to work as a structural or environmental engineer but says the class has also inspired her to consider careers in energy.The students’ findings also have implications beyond MIT campus. In accordance with MIT’s 2015 climate plan that committed to using the campus community as a “test bed for change,” the students’ recommendations also hold value for organizations around the world.“The mission is definitely broader than just MIT,” Germonpre says. “We don’t just want to solve MIT’s problem. We’ve dismissed technologies that were too specific to MIT. The goal is for MIT to lead by example and help certain technologies mature so that we can accelerate their impact.” More