Chemical engineering

Subterms

    Latest story

    100 Shares99 Views

    A new biodegradable material to replace certain microplastics

    by

    Microplastics are an environmental hazard found nearly everywhere on Earth, released by the breakdown of tires, clothing, and plastic packaging. Another significant source of microplastics is tiny beads that are added to some cleansers, cosmetics, and other beauty products.In an effort to cut off some of these microplastics at their source, MIT researchers have developed a class of biodegradable materials that could replace the plastic beads now used in beauty products. These polymers break down into harmless sugars and amino acids.“One way to mitigate the microplastics problem is to figure out how to clean up existing pollution. But it’s equally important to look ahead and focus on creating materials that won’t generate microplastics in the first place,” says Ana Jaklenec, a principal investigator at MIT’s Koch Institute for Integrative Cancer Research.These particles could also find other applications. In the new study, Jaklenec and her colleagues showed that the particles could be used to encapsulate nutrients such as vitamin A. Fortifying foods with encapsulated vitamin A and other nutrients could help some of the 2 billion people around the world who suffer from nutrient deficiencies.Jaklenec and Robert Langer, an MIT Institute Professor and member of the Koch Institute, are the senior authors of the paper, which appears today in Nature Chemical Engineering. The paper’s lead author is Linzixuan (Rhoda) Zhang, an MIT graduate student in chemical engineering.Biodegradable plasticsIn 2019, Jaklenec, Langer, and others reported a polymer material that they showed could be used to encapsulate vitamin A and other essential nutrients. They also found that people who consumed bread made from flour fortified with encapsulated iron showed increased iron levels.However, since then, the European Union has classified this polymer, known as BMC, as a microplastic and included it in a ban that went into effect in 2023. As a result, the Bill and Melinda Gates Foundation, which funded the original research, asked the MIT team if they could design an alternative that would be more environmentally friendly.The researchers, led by Zhang, turned to a type of polymer that Langer’s lab had previously developed, known as poly(beta-amino esters). These polymers, which have shown promise as vehicles for gene delivery and other medical applications, are biodegradable and break down into sugars and amino acids.By changing the composition of the material’s building blocks, researchers can tune properties such as hydrophobicity (ability to repel water), mechanical strength, and pH sensitivity. After creating five different candidate materials, the MIT team tested them and identified one that appeared to have the optimal composition for microplastic applications, including the ability to dissolve when exposed to acidic environments such as the stomach.The researchers showed that they could use these particles to encapsulate vitamin A, as well as vitamin D, vitamin E, vitamin C, zinc, and iron. Many of these nutrients are susceptible to heat and light degradation, but when encased in the particles, the researchers found that the nutrients could withstand exposure to boiling water for two hours.They also showed that even after being stored for six months at high temperature and high humidity, more than half of the encapsulated vitamins were undamaged.To demonstrate their potential for fortifying food, the researchers incorporated the particles into bouillon cubes, which are commonly consumed in many African countries. They found that when incorporated into bouillon, the nutrients remained intact after being boiled for two hours.“Bouillon is a staple ingredient in sub-Saharan Africa, and offers a significant opportunity to improve the nutritional status of many billions of people in those regions,” Jaklenec says.In this study, the researchers also tested the particles’ safety by exposing them to cultured human intestinal cells and measuring their effects on the cells. At the doses that would be used for food fortification, they found no damage to the cells.Better cleansingTo explore the particles’ ability to replace the microbeads that are often added to cleansers, the researchers mixed the particles with soap foam. This mixture, they found, could remove permanent marker and waterproof eyeliner from skin much more effectively than soap alone.Soap mixed with the new microplastic was also more effective than a cleanser that includes polyethylene microbeads, the researchers found. They also discovered that the new biodegradable particles did a better job of absorbing potentially toxic elements such as heavy metals.“We wanted to use this as a first step to demonstrate how it’s possible to develop a new class of materials, to expand from existing material categories, and then to apply it to different applications,” Zhang says.With a grant from Estée Lauder, the researchers are now working on further testing the microbeads as a cleanser and potentially other applications, and they plan to run a small human trial later this year. They are also gathering safety data that could be used to apply for GRAS (generally regarded as safe) classification from the U.S. Food and Drug Administration and are planning a clinical trial of foods fortified with the particles.The researchers hope their work could help to significantly reduce the amount of microplastic released into the environment from health and beauty products.“This is just one small part of the broader microplastics issue, but as a society we’re beginning to acknowledge the seriousness of the problem. This work offers a step forward in addressing it,” Jaklenec says. “Polymers are incredibly useful and essential in countless applications in our daily lives, but they come with downsides. This is an example of how we can reduce some of those negative aspects.”The research was funded by the Gates Foundation and the U.S. National Science Foundation. More

    More stories

    • 113 Shares149 Views

      in Environment

      A new catalyst can turn methane into something useful

      by

      Although it is less abundant than carbon dioxide, methane gas contributes disproportionately to global warming because it traps more heat in the atmosphere than carbon dioxide, due to its molecular structure.MIT chemical engineers have now designed a new catalyst that can convert methane into useful polymers, which could help reduce greenhouse gas emissions.“What to do with methane has been a longstanding problem,” says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and the senior author of the study. “It’s a source of carbon, and we want to keep it out of the atmosphere but also turn it into something useful.”The new catalyst works at room temperature and atmospheric pressure, which could make it easier and more economical to deploy at sites of methane production, such as power plants and cattle barns.Daniel Lundberg PhD ’24 and MIT postdoc Jimin Kim are the lead authors of the study, which appears today in Nature Catalysis. Former postdoc Yu-Ming Tu and postdoc Cody Ritt also authors of the paper.Capturing methaneMethane is produced by bacteria known as methanogens, which are often highly concentrated in landfills, swamps, and other sites of decaying biomass. Agriculture is a major source of methane, and methane gas is also generated as a byproduct of transporting, storing, and burning natural gas. Overall, it is believed to account for about 15 percent of global temperature increases.At the molecular level, methane is made of a single carbon atom bound to four hydrogen atoms. In theory, this molecule should be a good building block for making useful products such as polymers. However, converting methane to other compounds has proven difficult because getting it to react with other molecules usually requires high temperature and high pressures.To achieve methane conversion without that input of energy, the MIT team designed a hybrid catalyst with two components: a zeolite and a naturally occurring enzyme. Zeolites are abundant, inexpensive clay-like minerals, and previous work has found that they can be used to catalyze the conversion of methane to carbon dioxide.In this study, the researchers used a zeolite called iron-modified aluminum silicate, paired with an enzyme called alcohol oxidase. Bacteria, fungi, and plants use this enzyme to oxidize alcohols.This hybrid catalyst performs a two-step reaction in which zeolite converts methane to methanol, and then the enzyme converts methanol to formaldehyde. That reaction also generates hydrogen peroxide, which is fed back into the zeolite to provide a source of oxygen for the conversion of methane to methanol.This series of reactions can occur at room temperature and doesn’t require high pressure. The catalyst particles are suspended in water, which can absorb methane from the surrounding air. For future applications, the researchers envision that it could be painted onto surfaces.“Other systems operate at high temperature and high pressure, and they use hydrogen peroxide, which is an expensive chemical, to drive the methane oxidation. But our enzyme produces hydrogen peroxide from oxygen, so I think our system could be very cost-effective and scalable,” Kim says.Creating a system that incorporates both enzymes and artificial catalysts is a “smart strategy,” says Damien Debecker, a professor at the Institute of Condensed Matter and Nanosciences at the University of Louvain, Belgium.“Combining these two families of catalysts is challenging, as they tend to operate in rather distinct operation conditions. By unlocking this constraint and mastering the art of chemo-enzymatic cooperation, hybrid catalysis becomes key-enabling: It opens new perspectives to run complex reaction systems in an intensified way,” says Debecker, who was not involved in the research.Building polymersOnce formaldehyde is produced, the researchers showed they could use that molecule to generate polymers by adding urea, a nitrogen-containing molecule found in urine. This resin-like polymer, known as urea-formaldehyde, is now used in particle board, textiles and other products.The researchers envision that this catalyst could be incorporated into pipes used to transport natural gas. Within those pipes, the catalyst could generate a polymer that could act as a sealant to heal cracks in the pipes, which are a common source of methane leakage. The catalyst could also be applied as a film to coat surfaces that are exposed to methane gas, producing polymers that could be collected for use in manufacturing, the researchers say.Strano’s lab is now working on catalysts that could be used to remove carbon dioxide from the atmosphere and combine it with nitrate to produce urea. That urea could then be mixed with the formaldehyde produced by the zeolite-enzyme catalyst to produce urea-formaldehyde.The research was funded by the U.S. Department of Energy. More

    • 50 Shares109 Views

      in Energy

      Ensuring a durable transition

      by

      To fend off the worst impacts of climate change, “we have to decarbonize, and do it even faster,” said William H. Green, director of the MIT Energy Initiative (MITEI) and Hoyt C. Hottel Professor, MIT Department of Chemical Engineering, at MITEI’s Annual Research Conference.“But how the heck do we actually achieve this goal when the United States is in the middle of a divisive election campaign, and globally, we’re facing all kinds of geopolitical conflicts, trade protectionism, weather disasters, increasing demand from developing countries building a middle class, and data centers in countries like the U.S.?”Researchers, government officials, and business leaders convened in Cambridge, Massachusetts, Sept. 25-26 to wrestle with this vexing question at the conference that was themed, “A durable energy transition: How to stay on track in the face of increasing demand and unpredictable obstacles.”“In this room we have a lot of power,” said Green, “if we work together, convey to all of society what we see as real pathways and policies to solve problems, and take collective action.”The critical role of consensus-building in driving the energy transition arose repeatedly in conference sessions, whether the topic involved developing and adopting new technologies, constructing and siting infrastructure, drafting and passing vital energy policies, or attracting and retaining a skilled workforce.Resolving conflictsThere is “blowback and a social cost” in transitioning away from fossil fuels, said Stephen Ansolabehere, the Frank G. Thompson Professor of Government at Harvard University, in a panel on the social barriers to decarbonization. “Companies need to engage differently and recognize the rights of communities,” he said.Nora DeDontney, director of development at Vineyard Offshore, described her company’s two years of outreach and negotiations to bring large cables from ocean-based wind turbines onshore.“Our motto is, ‘community first,’” she said. Her company works to mitigate any impacts towns might feel because of offshore wind infrastructure construction with projects, such as sewer upgrades; provides workforce training to Tribal Nations; and lays out wind turbines in a manner that provides safe and reliable areas for local fisheries.Elsa A. Olivetti, professor in the Department of Materials Science and Engineering at MIT and the lead of the Decarbonization Mission of MIT’s new Climate Project, discussed the urgent need for rapid scale-up of mineral extraction. “Estimates indicate that to electrify the vehicle fleet by 2050, about six new large copper mines need to come on line each year,” she said. To meet the demand for metals in the United States means pushing into Indigenous lands and environmentally sensitive habitats. “The timeline of permitting is not aligned with the temporal acceleration needed,” she said.Larry Susskind, the Ford Professor of Urban and Environmental Planning in the MIT Department of Urban Studies and Planning, is trying to resolve such tensions with universities playing the role of mediators. He is creating renewable energy clinics where students train to participate in emerging disputes over siting. “Talk to people before decisions are made, conduct joint fact finding, so that facilities reduce harms and share the benefits,” he said.Clean energy boom and pressureA relatively recent and unforeseen increase in demand for energy comes from data centers, which are being built by large technology companies for new offerings, such as artificial intelligence.“General energy demand was flat for 20 years — and now, boom,” said Sean James, Microsoft’s senior director of data center research. “It caught utilities flatfooted.” With the expansion of AI, the rush to provision data centers with upwards of 35 gigawatts of new (and mainly renewable) power in the near future, intensifies pressure on big companies to balance the concerns of stakeholders across multiple domains. Google is pursuing 24/7 carbon-free energy by 2030, said Devon Swezey, the company’s senior manager for global energy and climate.“We’re pursuing this by purchasing more and different types of clean energy locally, and accelerating technological innovation such as next-generation geothermal projects,” he said. Pedro Gómez Lopez, strategy and development director, Ferrovial Digital, which designs and constructs data centers, incorporates renewable energy into their projects, which contributes to decarbonization goals and benefits to locales where they are sited. “We can create a new supply of power, taking the heat generated by a data center to residences or industries in neighborhoods through District Heating initiatives,” he said.The Inflation Reduction Act and other legislation has ramped up employment opportunities in clean energy nationwide, touching every region, including those most tied to fossil fuels. “At the start of 2024 there were about 3.5 million clean energy jobs, with ‘red’ states showing the fastest growth in clean energy jobs,” said David S. Miller, managing partner at Clean Energy Ventures. “The majority (58 percent) of new jobs in energy are now in clean energy — that transition has happened. And one-in-16 new jobs nationwide were in clean energy, with clean energy jobs growing more than three times faster than job growth economy-wide”In this rapid expansion, the U.S. Department of Energy (DoE) is prioritizing economically marginalized places, according to Zoe Lipman, lead for good jobs and labor standards in the Office of Energy Jobs at the DoE. “The community benefit process is integrated into our funding,” she said. “We are creating the foundation of a virtuous circle,” encouraging benefits to flow to disadvantaged and energy communities, spurring workforce training partnerships, and promoting well-paid union jobs. “These policies incentivize proactive community and labor engagement, and deliver community benefits, both of which are key to building support for technological change.”Hydrogen opportunity and challengeWhile engagement with stakeholders helps clear the path for implementation of technology and the spread of infrastructure, there remain enormous policy, scientific, and engineering challenges to solve, said multiple conference participants. In a “fireside chat,” Prasanna V. Joshi, vice president of low-carbon-solutions technology at ExxonMobil, and Ernest J. Moniz, professor of physics and special advisor to the president at MIT, discussed efforts to replace natural gas and coal with zero-carbon hydrogen in order to reduce greenhouse gas emissions in such major industries as steel and fertilizer manufacturing.“We have gone into an era of industrial policy,” said Moniz, citing a new DoE program offering incentives to generate demand for hydrogen — more costly than conventional fossil fuels — in end-use applications. “We are going to have to transition from our current approach, which I would call carrots-and-twigs, to ultimately, carrots-and-sticks,” Moniz warned, in order to create “a self-sustaining, major, scalable, affordable hydrogen economy.”To achieve net zero emissions by 2050, ExxonMobil intends to use carbon capture and sequestration in natural gas-based hydrogen and ammonia production. Ammonia can also serve as a zero-carbon fuel. Industry is exploring burning ammonia directly in coal-fired power plants to extend the hydrogen value chain. But there are challenges. “How do you burn 100 percent ammonia?”, asked Joshi. “That’s one of the key technology breakthroughs that’s needed.” Joshi believes that collaboration with MIT’s “ecosystem of breakthrough innovation” will be essential to breaking logjams around the hydrogen and ammonia-based industries.MIT ingenuity essentialThe energy transition is placing very different demands on different regions around the world. Take India, where today per capita power consumption is one of the lowest. But Indians “are an aspirational people … and with increasing urbanization and industrial activity, the growth in power demand is expected to triple by 2050,” said Praveer Sinha, CEO and managing director of the Tata Power Co. Ltd., in his keynote speech. For that nation, which currently relies on coal, the move to clean energy means bringing another 300 gigawatts of zero-carbon capacity online in the next five years. Sinha sees this power coming from wind, solar, and hydro, supplemented by nuclear energy.“India plans to triple nuclear power generation capacity by 2032, and is focusing on advancing small modular reactors,” said Sinha. “The country also needs the rapid deployment of storage solutions to firm up the intermittent power.” The goal is to provide reliable electricity 24/7 to a population living both in large cities and in geographically remote villages, with the help of long-range transmission lines and local microgrids. “India’s energy transition will require innovative and affordable technology solutions, and there is no better place to go than MIT, where you have the best brains, startups, and technology,” he said.These assets were on full display at the conference. Among them a cluster of young businesses, including:the MIT spinout Form Energy, which has developed a 100-hour iron battery as a backstop to renewable energy sources in case of multi-day interruptions;startup Noya that aims for direct air capture of atmospheric CO2 using carbon-based materials;the firm Active Surfaces, with a lightweight material for putting solar photovoltaics in previously inaccessible places;Copernic Catalysts, with new chemistry for making ammonia and sustainable aviation fuel far more inexpensively than current processes; andSesame Sustainability, a software platform spun out of MITEI that gives industries a full financial analysis of the costs and benefits of decarbonization.The pipeline of research talent extended into the undergraduate ranks, with a conference “slam” competition showcasing students’ summer research projects in areas from carbon capture using enzymes to 3D design for the coils used in fusion energy confinement.“MIT students like me are looking to be the next generation of energy leaders, looking for careers where we can apply our engineering skills to tackle exciting climate problems and make a tangible impact,” said Trent Lee, a junior in mechanical engineering researching improvements in lithium-ion energy storage. “We are stoked by the energy transition, because it’s not just the future, but our chance to build it.” More

    • 100 Shares179 Views

      in Security

      Linzixuan (Rhoda) Zhang wins 2024 Collegiate Inventors Competition

      by

      Linzixuan (Rhoda) Zhang, a doctoral candidate in the MIT Department of Chemical Engineering, recently won the 2024 Collegiate Inventors Competition, medaling in both the Graduate and People’s Choice categories for developing materials to stabilize nutrients in food with the goal of improving global health.  The annual competition, organized by the National Inventors Hall of Fame and United States Patent and Trademark Office (USPTO), celebrates college and university student inventors. The finalists present their inventions to a panel of final-round judges composed of National Inventors Hall of Fame inductees and USPTO officials. No stranger to having her work in the limelight, Zhang is a three-time winner of the Koch Institute Image Awards in 2022, 2023, and 2024, as well as a 2022 fellow at the MIT Abdul Latif Jameel Water and Food Systems Lab.  “Rhoda is an exceptionally dedicated and creative student. Her well-deserved award recognizes the potential of her research on nutrient stabilization, which could have a significant impact on society,” says Ana Jaklenec, one of Zhang’s advisors and a principal investigator at MIT’s Koch Institute for Integrative Cancer Research. Zhang is also advised by David H. Koch (1962) Institute Professor Robert Langer. Frameworks for global healthIn a world where nearly 2 billion people suffer from micronutrient deficiencies, particularly iron, the urgency for effective solutions has never been greater. Iron deficiency is especially harmful for vulnerable populations such as children and pregnant women, since it can lead to weakened immune systems and developmental delays. The World Health Organization has highlighted food fortification as a cost-effective strategy, yet many current methods fall short. Iron and other nutrients can break down during processing or cooking, and synthetic additives often come with high costs and environmental drawbacks. Zhang, along with her teammate, Xin Yang, a postdoc associate at Koch Institute, set out to innovate new technologies for nutrient fortification that are effective, accessible, and sustainable, leading to the invention nutritional metal-organic frameworks (NuMOFs) and the subsequent launch of MOFe Coffee, the world’s first iron-fortified coffee. NuMOFs not only protect essential nutrients such as iron while in food for long periods of time, but also make them more easily absorbed and used once consumed.The inspiration for the coffee came from the success of iodized salt, which significantly reduced iodine deficiency worldwide. Because coffee and tea are associated with low iron absorption, iron fortification would directly address the challenge.However, replicating the success of iodized salt for iron fortification has been extremely challenging due to the micronutrient’s high reactivity and the instability of iron(II) salts. As researchers with backgrounds in material science, chemistry, and food technology, Zhang and Yang leveraged their expertise to develop a solution that could overcome these technical barriers. The fortified coffee serves as a practical example of how NuMOFs can help people increase their iron intake by engaging in a habit that’s already part of their daily routine, with significant potential benefits for women, who are disproportionately affected by iron deficiency. The team plans to expand the technology to incorporate additional nutrients to address a wider array of nutritional deficiencies and improve health equity globally.Fast-track to addressing global health improvementsLooking ahead, Zhang and Yang in the Jaklenec Group are focused on both product commercialization and ongoing research, refining MOFe Coffee to enhance nutrient stability and ensuring the product remains palatable while maximizing iron absorption.Winning the CIC competition means that Zhang, Yang, and the team can fast-track their patent application with the USPTO. The team hopes that their fast-tracked patent will allow them to attract more potential investors and partners, which is crucial for scaling their efforts. A quicker patent process also means that the team can bring the technology to market faster, helping improve global nutrition and health for those who need it most. “Our goal is to make a real difference in addressing micronutrient deficiencies around the world,” says Zhang.   More

    • 88 Shares149 Views

      in Environment

      Making agriculture more resilient to climate change

      by

      As Earth’s temperature rises, agricultural practices will need to adapt. Droughts will likely become more frequent, and some land may no longer be arable. On top of that is the challenge of feeding an ever-growing population without expanding the production of fertilizer and other agrochemicals, which have a large carbon footprint that is contributing to the overall warming of the planet.Researchers across MIT are taking on these agricultural challenges from a variety of angles, from engineering plants that sound an alarm when they’re under stress to making seeds more resilient to drought. These types of technologies, and more yet to be devised, will be essential to feed the world’s population as the climate changes.“After water, the first thing we need is food. In terms of priority, there is water, food, and then everything else. As we are trying to find new strategies to support a world of 10 billion people, it will require us to invent new ways of making food,” says Benedetto Marelli, an associate professor of civil and environmental engineering at MIT.Marelli is the director of one of the six missions of the recently launched Climate Project at MIT, which focus on research areas such as decarbonizing industry and building resilient cities. Marelli directs the Wild Cards mission, which aims to identify unconventional solutions that are high-risk and high-reward.Drawing on expertise from a breadth of fields, MIT is well-positioned to tackle the challenges posed by climate change, Marelli says. “Bringing together our strengths across disciplines, including engineering, processing at scale, biological engineering, and infrastructure engineering, along with humanities, science, and economics, presents a great opportunity.”Protecting seeds from droughtMarelli, who began his career as a biomedical engineer working on regenerative medicine, is now developing ways to boost crop yields by helping seeds to survive and germinate during drought conditions, or in soil that has been depleted of nutrients. To achieve that, he has devised seed coatings, based on silk and other polymers, that can envelop and nourish seeds during the critical germination process.

      A new seed-coating process could facilitate agriculture on marginal arid lands by enabling the seeds to retain any available water.

      In healthy soil, plants have access to nitrogen, phosphates, and other nutrients that they need, many of which are supplied by microbes that live in the soil. However, in soil that has suffered from drought or overfarming, these nutrients are lacking. Marelli’s idea was to coat the seeds with a polymer that can be embedded with plant-growth-promoting bacteria that “fix” nitrogen by absorbing it from the air and making it available to plants. The microbes can also make other necessary nutrients available to plants.For the first generation of the seed coatings, he embedded these microbes in coatings made of silk — a material that he had previously shown can extend the shelf life of produce, meat, and other foods. In his lab at MIT, Marelli has shown that the seed coatings can help germinating plants survive drought, ultraviolet light exposure, and high salinity.Now, working with researchers at the Mohammed VI Polytechnic University in Morocco, he is adapting the approach to crops native to Morocco, a country that has experienced six consecutive years of drought due a drop in rainfall linked to climate change.For these studies, the researchers are using a biopolymer coating derived from food waste that can be easily obtained in Morocco, instead of silk.“We’re working with local communities to extract the biopolymers, to try to have a process that works at scale so that we make materials that work in that specific environment.” Marelli says. “We may come up with an idea here at MIT within a high-resource environment, but then to work there, we need to talk with the local communities, with local stakeholders, and use their own ingenuity and try to match our solution with something that could actually be applied in the local environment.”Microbes as fertilizersWhether they are experiencing drought or not, crops grow much better when synthetic fertilizers are applied. Although it’s essential to most farms, applying fertilizer is expensive and has environmental consequences. Most of the world’s fertilizer is produced using the Haber-Bosch process, which converts nitrogen and hydrogen to ammonia at high temperatures and pressures. This energy intensive process accounts for about 1.5 percent of the world’s greenhouse gas emissions, and the transportation required to deliver it to farms around the world adds even more emissions.Ariel Furst, the Paul M. Cook Career Development Assistant Professor of Chemical Engineering at MIT, is developing a microbial alternative to the Haber-Bosch process. Some farms have experimented with applying nitrogen-fixing bacteria directly to the roots of their crops, which has shown some success. However, the microbes are too delicate to be stored long-term or shipped anywhere, so they must be produced in a bioreactor on the farm.

      MIT chemical engineers devised a metal-organic coating that protects bacterial cells from damage without impeding their growth or function.

      To overcome those challenges, Furst has developed a way to coat the microbes with a protective shell that prevents them from being destroyed by heat or other stresses. The coating also protects microbes from damage caused by freeze-drying — a process that would make them easier to transport.The coatings can vary in composition, but they all consist of two components. One is a metal such as iron, manganese, or zinc, and the other is a polyphenol — a type of plant-derived organic compound that includes tannins and other antioxidants. These two components self-assemble into a protective shell that encapsulates bacteria.

      Play video

      Mighty Microbes: The Power of Protective PolymersVideo: Chemistry Shorts

      “These microbes would be delivered with the seeds, so it would remove the need for fertilizing mid-growing. It also reduces the cost and provides more autonomy to the farmers and decreases carbon emissions associated with agriculture,” Furst says. “We think it’ll be a way to make agriculture completely regenerative, so to bring back soil health while also boosting crop yields and the nutrient density of the crops.”Furst has founded a company called Seia Bio, which is working on commercializing the coated microbes and has begun testing them on farms in Brazil. In her lab, Furst is also working on adapting the approach to coat microbes that can capture carbon dioxide from the atmosphere and turn it into limestone, which helps to raise the soil pH.“It can help change the pH of soil to stabilize it, while also being a way to effectively perform direct air capture of CO2,” she says. “Right now, farmers may truck in limestone to change the pH of soil, and so you’re creating a lot of emissions to bring something in that microbes can do on their own.”Distress sensors for plantsSeveral years ago, Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT, began to explore the idea of using plants themselves as sensors that could reveal when they’re in distress. When plants experience drought, attack by pests, or other kinds of stress, they produce hormones and other signaling molecules to defend themselves.Strano, whose lab specializes in developing tiny sensors for a variety of molecules, wondered if such sensors could be deployed inside plants to pick up those distress signals. To create their sensors, Strano’s lab takes advantage of the special properties of single-walled carbon nanotubes, which emit fluorescent light. By wrapping the tubes with different types of polymers, the sensors can be tuned to detect specific targets, giving off a fluorescent signal when the target is present.For use in plants, Strano and his colleagues created sensors that could detect signaling molecules such as salicylic acid and hydrogen peroxide. They then showed that these sensors could be inserted into the underside of plant leaves, without harming the plants. Once embedded in the mesophyll of the leaves, the sensors can pick up a variety of signals, which can be read with an infrared camera.

      Sensors that detect plant signaling molecules can reveal when crops are experiencing too much light or heat, or attack from insects or microbes.

      These sensors can reveal, in real-time, whether a plant is experiencing a variety of stresses. Until now, there hasn’t been a way to get that information fast enough for farmers to act on it.“What we’re trying to do is make tools that get information into the hands of farmers very quickly, fast enough for them to make adaptive decisions that can increase yield,” Strano says. “We’re in the middle of a revolution of really understanding the way in which plants internally communicate and communicate with other plants.”This kind of sensing could be deployed in fields, where it could help farmers respond more quickly to drought and other stresses, or in greenhouses, vertical farms, and other types of indoor farms that use technology to grow crops in a controlled environment.Much of Strano’s work in this area has been conducted with the support of the U.S. Department of Agriculture (USDA) and as part of the Disruptive and Sustainable Technologies for Agricultural Precision (DiSTAP) program at the Singapore-MIT Alliance for Research and Technology (SMART), and sensors have been deployed in tests in crops at a controlled environment farm in Singapore called Growy.“The same basic kinds of tools can help detect problems in open field agriculture or in controlled environment agriculture,” Strano says. “They both suffer from the same problem, which is that the farmers get information too late to prevent yield loss.”Reducing pesticide usePesticides represent another huge financial expense for farmers: Worldwide, farmers spend about $60 billion per year on pesticides. Much of this pesticide ends up accumulating in water and soil, where it can harm many species, including humans. But, without using pesticides, farmers may lose more than half of their crops.Kripa Varanasi, an MIT professor of mechanical engineering, is working on tools that can help farmers measure how much pesticide is reaching their plants, as well as technologies that can help pesticides adhere to plants more efficiently, reducing the amount that runs off into soil and water.Varanasi, whose research focuses on interactions between liquid droplets and surfaces, began to think about applying his work to agriculture more than a decade ago, after attending a conference at the USDA. There, he was inspired to begin developing ways to improve the efficiency of pesticide application by optimizing the interactions that occur at leaf surfaces.“Billions of drops of pesticide are being sprayed on every acre of crop, and only a small fraction is ultimately reaching and staying on target. This seemed to me like a problem that we could help to solve,” he says.Varanasi and his students began exploring strategies to make drops of pesticide stick to leaves better, instead of bouncing off. They found that if they added polymers with positive and negative charges, the oppositely charged droplets would form a hydrophilic (water-attracting) coating on the leaf surface, which helps the next droplets applied to stick to the leaf.

      AgZen has developed a system for farming that can monitor exactly how much of the sprayed chemicals adheres to plants, in real time, as the sprayer drives through a field.

      Later, they developed an easier-to-use technology in which a surfactant is added to the pesticide before spraying. When this mixture is sprayed through a special nozzle, it forms tiny droplets that are “cloaked” in surfactant. The surfactant helps the droplets to stick to the leaves within a few milliseconds, without bouncing off.In 2020, Varanasi and Vishnu Jayaprakash SM ’19, PhD ’22 founded a company called AgZen to commercialize their technologies and get them into the hands of farmers. They incorporated their ideas for improving pesticide adhesion into a product called EnhanceCoverage.During the testing for this product, they realized that there weren’t any good ways to measure how many of the droplets were staying on the plant. That led them to develop a product known as RealCoverage, which is based on machine vision. It can be attached to any pesticide sprayer and offer real-time feedback on what percentage of the pesticide droplets are sticking to and staying on every leaf.RealCoverage was used on 65,000 acres of farmland across the United States in 2024, from soybeans in Iowa to cotton in Georgia. Farmers who used the product were able to reduce their pesticide use by 30 to 50 percent, by using the data to optimize delivery and, in some cases, even change what chemicals were sprayed.He hopes that the EnhanceCoverage product, which is expected to become available in 2025, will help farmers further reduce their pesticide use.“Our mission here is to help farmers with savings while helping them achieve better yields. We have found a way to do all this while also reducing waste and the amount of chemicals that we put into our atmosphere and into our soils and into our water,” Varanasi says. “This is the MIT approach: to figure out what are the real issues and how to come up with solutions. Now we have a tool and I hope that it’s deployed everywhere and everyone gets the benefit from it.” More

    • 75 Shares159 Views

      in Environment

      Translating MIT research into real-world results

      by

      Inventive solutions to some of the world’s most critical problems are being discovered in labs, classrooms, and centers across MIT every day. Many of these solutions move from the lab to the commercial world with the help of over 85 Institute resources that comprise MIT’s robust innovation and entrepreneurship (I&E) ecosystem. The Abdul Latif Jameel Water and Food Systems Lab (J-WAFS) draws on MIT’s wealth of I&E knowledge and experience to help researchers commercialize their breakthrough technologies through the J-WAFS Solutions grant program. By collaborating with I&E programs on campus, J-WAFS prepares MIT researchers for the commercial world, where their novel innovations aim to improve productivity, accessibility, and sustainability of water and food systems, creating economic, environmental, and societal benefits along the way.The J-WAFS Solutions program launched in 2015 with support from Community Jameel, an international organization that advances science and learning for communities to thrive. Since 2015, J-WAFS Solutions has supported 19 projects with one-year grants of up to $150,000, with some projects receiving renewal grants for a second year of support. Solutions projects all address challenges related to water or food. Modeled after the esteemed grant program of MIT’s Deshpande Center for Technological Innovation, and initially administered by Deshpande Center staff, the J-WAFS Solutions program follows a similar approach by supporting projects that have already completed the basic research and proof-of-concept phases. With technologies that are one to three years away from commercialization, grantees work on identifying their potential markets and learn to focus on how their technology can meet the needs of future customers.“Ingenuity thrives at MIT, driving inventions that can be translated into real-world applications for widespread adoption, implantation, and use,” says J-WAFS Director Professor John H. Lienhard V. “But successful commercialization of MIT technology requires engineers to focus on many challenges beyond making the technology work. MIT’s I&E network offers a variety of programs that help researchers develop technology readiness, investigate markets, conduct customer discovery, and initiate product design and development,” Lienhard adds. “With this strong I&E framework, many J-WAFS Solutions teams have established startup companies by the completion of the grant. J-WAFS-supported technologies have had powerful, positive effects on human welfare. Together, the J-WAFS Solutions program and MIT’s I&E ecosystem demonstrate how academic research can evolve into business innovations that make a better world,” Lienhard says.Creating I&E collaborationsIn addition to support for furthering research, J-WAFS Solutions grants allow faculty, students, postdocs, and research staff to learn the fundamentals of how to transform their work into commercial products and companies. As part of the grant requirements, researchers must interact with mentors through MIT Venture Mentoring Service (VMS). VMS connects MIT entrepreneurs with teams of carefully selected professionals who provide free and confidential mentorship, guidance, and other services to help advance ideas into for-profit, for-benefit, or nonprofit ventures. Since 2000, VMS has mentored over 4,600 MIT entrepreneurs across all industries, through a dynamic and accomplished group of nearly 200 mentors who volunteer their time so that others may succeed. The mentors provide impartial and unbiased advice to members of the MIT community, including MIT alumni in the Boston area. J-WAFS Solutions teams have been guided by 21 mentors from numerous companies and nonprofits. Mentors often attend project events and progress meetings throughout the grant period.“Working with VMS has provided me and my organization with a valuable sounding board for a range of topics, big and small,” says Eric Verploegen PhD ’08, former research engineer in MIT’s D-Lab and founder of J-WAFS spinout CoolVeg. Along with professors Leon Glicksman and Daniel Frey, Verploegen received a J-WAFS Solutions grant in 2021 to commercialize cold-storage chambers that use evaporative cooling to help farmers preserve fruits and vegetables in rural off-grid communities. Verploegen started CoolVeg in 2022 to increase access and adoption of open-source, evaporative cooling technologies through collaborations with businesses, research institutions, nongovernmental organizations, and government agencies. “Working as a solo founder at my nonprofit venture, it is always great to have avenues to get feedback on communications approaches, overall strategy, and operational issues that my mentors have experience with,” Verploegen says. Three years after the initial Solutions grant, one of the VMS mentors assigned to the evaporative cooling team still acts as a mentor to Verploegen today.Another Solutions grant requirement is for teams to participate in the Spark program — a free, three-week course that provides an entry point for researchers to explore the potential value of their innovation. Spark is part of the National Science Foundation’s (NSF) Innovation Corps (I-Corps), which is an “immersive, entrepreneurial training program that facilitates the transformation of invention to impact.” In 2018, MIT received an award from the NSF, establishing the New England Regional Innovation Corps Node (NE I-Corps) to deliver I-Corps training to participants across New England. Trainings are open to researchers, engineers, scientists, and others who want to engage in a customer discovery process for their technology. Offered regularly throughout the year, the Spark course helps participants identify markets and explore customer needs in order to understand how their technologies can be positioned competitively in their target markets. They learn to assess barriers to adoption, as well as potential regulatory issues or other challenges to commercialization. NE-I-Corps reports that since its start, over 1,200 researchers from MIT have completed the program and have gone on to launch 175 ventures, raising over $3.3 billion in funding from grants and investors, and creating over 1,800 jobs.Constantinos Katsimpouras, a research scientist in the Department of Chemical Engineering, went through the NE I-Corps Spark program to better understand the customer base for a technology he developed with professors Gregory Stephanopoulos and Anthony Sinskey. The group received a J-WAFS Solutions grant in 2021 for their microbial platform that converts food waste from the dairy industry into valuable products. “As a scientist with no prior experience in entrepreneurship, the program introduced me to important concepts and tools for conducting customer interviews and adopting a new mindset,” notes Katsimpouras. “Most importantly, it encouraged me to get out of the building and engage in interviews with potential customers and stakeholders, providing me with invaluable insights and a deeper understanding of my industry,” he adds. These interviews also helped connect the team with companies willing to provide resources to test and improve their technology — a critical step to the scale-up of any lab invention.In the case of Professor Cem Tasan’s research group in the Department of Materials Science and Engineering, the I-Corps program led them to the J-WAFS Solutions grant, instead of the other way around. Tasan is currently working with postdoc Onur Guvenc on a J-WAFS Solutions project to manufacture formable sheet metal by consolidating steel scrap without melting, thereby reducing water use compared to traditional steel processing. Before applying for the Solutions grant, Guvenc took part in NE I-Corps. Like Katsimpouras, Guvenc benefited from the interaction with industry. “This program required me to step out of the lab and engage with potential customers, allowing me to learn about their immediate challenges and test my initial assumptions about the market,” Guvenc recalls. “My interviews with industry professionals also made me aware of the connection between water consumption and steelmaking processes, which ultimately led to the J-WAFS 2023 Solutions Grant,” says Guvenc.After completing the Spark program, participants may be eligible to apply for the Fusion program, which provides microgrants of up to $1,500 to conduct further customer discovery. The Fusion program is self-paced, requiring teams to conduct 12 additional customer interviews and craft a final presentation summarizing their key learnings. Professor Patrick Doyle’s J-WAFS Solutions team completed the Spark and Fusion programs at MIT. Most recently, their team was accepted to join the NSF I-Corps National program with a $50,000 award. The intensive program requires teams to complete an additional 100 customer discovery interviews over seven weeks. Located in the Department of Chemical Engineering, the Doyle lab is working on a sustainable microparticle hydrogel system to rapidly remove micropollutants from water. The team’s focus has expanded to higher value purifications in amino acid and biopharmaceutical manufacturing applications. Devashish Gokhale PhD ’24 worked with Doyle on much of the underlying science.“Our platform technology could potentially be used for selective separations in very diverse market segments, ranging from individual consumers to large industries and government bodies with varied use-cases,” Gokhale explains. He goes on to say, “The I-Corps Spark program added significant value by providing me with an effective framework to approach this problem … I was assigned a mentor who provided critical feedback, teaching me how to formulate effective questions and identify promising opportunities.” Gokhale says that by the end of Spark, the team was able to identify the best target markets for their products. He also says that the program provided valuable seminars on topics like intellectual property, which was helpful in subsequent discussions the team had with MIT’s Technology Licensing Office.Another member of Doyle’s team, Arjav Shah, a recent PhD from MIT’s Department of Chemical Engineering and a current MBA candidate at the MIT Sloan School of Management, is spearheading the team’s commercialization plans. Shah attended Fusion last fall and hopes to lead efforts to incorporate a startup company called hydroGel.  “I admire the hypothesis-driven approach of the I-Corps program,” says Shah. “It has enabled us to identify our customers’ biggest pain points, which will hopefully lead us to finding a product-market fit.” He adds “based on our learnings from the program, we have been able to pivot to impact-driven, higher-value applications in the food processing and biopharmaceutical industries.” Postdoc Luca Mazzaferro will lead the technical team at hydroGel alongside Shah.In a different project, Qinmin Zheng, a postdoc in the Department of Civil and Environmental Engineering, is working with Professor Andrew Whittle and Lecturer Fábio Duarte. Zheng plans to take the Fusion course this fall to advance their J-WAFS Solutions project that aims to commercialize a novel sensor to quantify the relative abundance of major algal species and provide early detection of harmful algal blooms. After completing Spark, Zheng says he’s “excited to participate in the Fusion program, and potentially the National I-Corps program, to further explore market opportunities and minimize risks in our future product development.”Economic and societal benefitsCommercializing technologies developed at MIT is one of the ways J-WAFS helps ensure that MIT research advances will have real-world impacts in water and food systems. Since its inception, the J-WAFS Solutions program has awarded 28 grants (including renewals), which have supported 19 projects that address a wide range of global water and food challenges. The program has distributed over $4 million to 24 professors, 11 research staff, 15 postdocs, and 30 students across MIT. Nearly half of all J-WAFS Solutions projects have resulted in spinout companies or commercialized products, including eight companies to date plus two open-source technologies.Nona Technologies is an example of a J-WAFS spinout that is helping the world by developing new approaches to produce freshwater for drinking. Desalination — the process of removing salts from seawater — typically requires a large-scale technology called reverse osmosis. But Nona created a desalination device that can work in remote off-grid locations. By separating salt and bacteria from water using electric current through a process called ion concentration polarization (ICP), their technology also reduces overall energy consumption. The novel method was developed by Jongyoon Han, professor of electrical engineering and biological engineering, and research scientist Junghyo Yoon. Along with Bruce Crawford, a Sloan MBA alum, Han and Yoon created Nona Technologies to bring their lightweight, energy-efficient desalination technology to the market.“My feeling early on was that once you have technology, commercialization will take care of itself,” admits Crawford. The team completed both the Spark and Fusion programs and quickly realized that much more work would be required. “Even in our first 24 interviews, we learned that the two first markets we envisioned would not be viable in the near term, and we also got our first hints at the beachhead we ultimately selected,” says Crawford. Nona Technologies has since won MIT’s $100K Entrepreneurship Competition, received media attention from outlets like Newsweek and Fortune, and hired a team that continues to further the technology for deployment in resource-limited areas where clean drinking water may be scarce. Food-borne diseases sicken millions of people worldwide each year, but J-WAFS researchers are addressing this issue by integrating molecular engineering, nanotechnology, and artificial intelligence to revolutionize food pathogen testing. Professors Tim Swager and Alexander Klibanov, of the Department of Chemistry, were awarded one of the first J-WAFS Solutions grants for their sensor that targets food safety pathogens. The sensor uses specialized droplets that behave like a dynamic lens, changing in the presence of target bacteria in order to detect dangerous bacterial contamination in food. In 2018, Swager launched Xibus Systems Inc. to bring the sensor to market and advance food safety for greater public health, sustainability, and economic security.“Our involvement with the J-WAFS Solutions Program has been vital,” says Swager. “It has provided us with a bridge between the academic world and the business world and allowed us to perform more detailed work to create a usable application,” he adds. In 2022, Xibus developed a product called XiSafe, which enables the detection of contaminants like salmonella and listeria faster and with higher sensitivity than other food testing products. The innovation could save food processors billions of dollars worldwide and prevent thousands of food-borne fatalities annually.J-WAFS Solutions companies have raised nearly $66 million in venture capital and other funding. Just this past June, J-WAFS spinout SiTration announced that it raised an $11.8 million seed round. Jeffrey Grossman, a professor in MIT’s Department of Materials Science and Engineering, was another early J-WAFS Solutions grantee for his work on low-cost energy-efficient filters for desalination. The project enabled the development of nanoporous membranes and resulted in two spinout companies, Via Separations and SiTration. SiTration was co-founded by Brendan Smith PhD ’18, who was a part of the original J-WAFS team. Smith is CEO of the company and has overseen the advancement of the membrane technology, which has gone on to reduce cost and resource consumption in industrial wastewater treatment, advanced manufacturing, and resource extraction of materials such as lithium, cobalt, and nickel from recycled electric vehicle batteries. The company also recently announced that it is working with the mining company Rio Tinto to handle harmful wastewater generated at mines.But it’s not just J-WAFS spinout companies that are producing real-world results. Products like the ECC Vial — a portable, low-cost method for E. coli detection in water — have been brought to the market and helped thousands of people. The test kit was developed by MIT D-Lab Lecturer Susan Murcott and Professor Jeffrey Ravel of the MIT History Section. The duo received a J-WAFS Solutions grant in 2018 to promote safely managed drinking water and improved public health in Nepal, where it is difficult to identify which wells are contaminated by E. coli. By the end of their grant period, the team had manufactured approximately 3,200 units, of which 2,350 were distributed — enough to help 12,000 people in Nepal. The researchers also trained local Nepalese on best manufacturing practices.“It’s very important, in my life experience, to follow your dream and to serve others,” says Murcott. Economic success is important to the health of any venture, whether it’s a company or a product, but equally important is the social impact — a philosophy that J-WAFS research strives to uphold. “Do something because it’s worth doing and because it changes people’s lives and saves lives,” Murcott adds.As J-WAFS prepares to celebrate its 10th anniversary this year, we look forward to continued collaboration with MIT’s many I&E programs to advance knowledge and develop solutions that will have tangible effects on the world’s water and food systems.Learn more about the J-WAFS Solutions program and about innovation and entrepreneurship at MIT. More

    • 113 Shares179 Views

      in Energy

      MIT engineers design tiny batteries for powering cell-sized robots

      by

      A tiny battery designed by MIT engineers could enable the deployment of cell-sized, autonomous robots for drug delivery within in the human body, as well as other applications such as locating leaks in gas pipelines.The new battery, which is 0.1 millimeters long and 0.002 millimeters thick — roughly the thickness of a human hair — can capture oxygen from air and use it to oxidize zinc, creating a current of up to 1 volt. That is enough to power a small circuit, sensor, or actuator, the researchers showed.“We think this is going to be very enabling for robotics,” says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and the senior author of the study. “We’re building robotic functions onto the battery and starting to put these components together into devices.”Ge Zhang PhD ’22 and Sungyun Yang, an MIT graduate student, are the lead author of the paper, which appears in Science Robotics.Powered by batteriesFor several years, Strano’s lab has been working on tiny robots that can sense and respond to stimuli in their environment. One of the major challenges in developing such tiny robots is making sure that they have enough power.Other researchers have shown that they can power microscale devices using solar power, but the limitation to that approach is that the robots must have a laser or another light source pointed at them at all times. Such devices are known as “marionettes” because they are controlled by an external power source. Putting a power source such as a battery inside these tiny devices could free them to roam much farther.“The marionette systems don’t really need a battery because they’re getting all the energy they need from outside,” Strano says. “But if you want a small robot to be able to get into spaces that you couldn’t access otherwise, it needs to have a greater level of autonomy. A battery is essential for something that’s not going to be tethered to the outside world.”To create robots that could become more autonomous, Strano’s lab decided to use a type of battery known as a zinc-air battery. These batteries, which have a longer lifespan than many other types of batteries due to their high energy density, are often used in hearing aids.The battery that they designed consists of a zinc electrode connected to a platinum electrode, embedded into a strip of a polymer called SU-8, which is commonly used for microelectronics. When these electrodes interact with oxygen molecules from the air, the zinc becomes oxidized and releases electrons that flow to the platinum electrode, creating a current.In this study, the researchers showed that this battery could provide enough energy to power an actuator — in this case, a robotic arm that can be raised and lowered. The battery could also power a memristor, an electrical component that can store memories of events by changing its electrical resistance, and a clock circuit, which allows robotic devices to keep track of time.The battery also provides enough power to run two different types of sensors that change their electrical resistance when they encounter chemicals in the environment. One of the sensors is made from atomically thin molybdenum disulfide and the other from carbon nanotubes.“We’re making the basic building blocks in order to build up functions at the cellular level,” Strano says.Robotic swarmsIn this study, the researchers used a wire to connect their battery to an external device, but in future work they plan to build robots in which the battery is incorporated into a device.“This is going to form the core of a lot of our robotic efforts,” Strano says. “You can build a robot around an energy source, sort of like you can build an electric car around the battery.”One of those efforts revolves around designing tiny robots that could be injected into the human body, where they could seek out a target site and then release a drug such as insulin. For use in the human body, the researchers envision that the devices would be made of biocompatible materials that would break apart once they were no longer needed.The researchers are also working on increasing the voltage of the battery, which may enable additional applications.The research was funded by the U.S. Army Research Office, the U.S. Department of Energy, the National Science Foundation, and a MathWorks Engineering Fellowship. More

    • 75 Shares149 Views

      in Energy

      Reducing carbon emissions from long-haul trucks

      by

      People around the world rely on trucks to deliver the goods they need, and so-called long-haul trucks play a critical role in those supply chains. In the United States, long-haul trucks moved 71 percent of all freight in 2022. But those long-haul trucks are heavy polluters, especially of the carbon emissions that threaten the global climate. According to U.S. Environmental Protection Agency estimates, in 2022 more than 3 percent of all carbon dioxide (CO2) emissions came from long-haul trucks.The problem is that long-haul trucks run almost exclusively on diesel fuel, and burning diesel releases high levels of CO2 and other carbon emissions. Global demand for freight transport is projected to as much as double by 2050, so it’s critical to find another source of energy that will meet the needs of long-haul trucks while also reducing their carbon emissions. And conversion to the new fuel must not be costly. “Trucks are an indispensable part of the modern supply chain, and any increase in the cost of trucking will be felt universally,” notes William H. Green, the Hoyt Hottel Professor in Chemical Engineering and director of the MIT Energy Initiative.For the past year, Green and his research team have been seeking a low-cost, cleaner alternative to diesel. Finding a replacement is difficult because diesel meets the needs of the trucking industry so well. For one thing, diesel has a high energy density — that is, energy content per pound of fuel. There’s a legal limit on the total weight of a truck and its contents, so using an energy source with a lower weight allows the truck to carry more payload — an important consideration, given the low profit margin of the freight industry. In addition, diesel fuel is readily available at retail refueling stations across the country — a critical resource for drivers, who may travel 600 miles in a day and sleep in their truck rather than returning to their home depot. Finally, diesel fuel is a liquid, so it’s easy to distribute to refueling stations and then pump into trucks.Past studies have examined numerous alternative technology options for powering long-haul trucks, but no clear winner has emerged. Now, Green and his team have evaluated the available options based on consistent and realistic assumptions about the technologies involved and the typical operation of a long-haul truck, and assuming no subsidies to tip the cost balance. Their in-depth analysis of converting long-haul trucks to battery electric — summarized below — found a high cost and negligible emissions gains in the near term. Studies of methanol and other liquid fuels from biomass are ongoing, but already a major concern is whether the world can plant and harvest enough biomass for biofuels without destroying the ecosystem. An analysis of hydrogen — also summarized below — highlights specific challenges with using that clean-burning fuel, which is a gas at normal temperatures.Finally, the team identified an approach that could make hydrogen a promising, low-cost option for long-haul trucks. And, says Green, “it’s an option that most people are probably unaware of.” It involves a novel way of using materials that can pick up hydrogen, store it, and then release it when and where it’s needed to serve as a clean-burning fuel.Defining the challenge: A realistic drive cycle, plus diesel values to beatThe MIT researchers believe that the lack of consensus on the best way to clean up long-haul trucking may have a simple explanation: Different analyses are based on different assumptions about the driving behavior of long-haul trucks. Indeed, some of them don’t accurately represent actual long-haul operations. So the first task for the MIT team was to define a representative — and realistic — “drive cycle” for actual long-haul truck operations in the United States. Then the MIT researchers — and researchers elsewhere — can assess potential replacement fuels and engines based on a consistent set of assumptions in modeling and simulation analyses.To define the drive cycle for long-haul operations, the MIT team used a systematic approach to analyze many hours of real-world driving data covering 58,000 miles. They examined 10 features and identified three — daily range, vehicle speed, and road grade — that have the greatest impact on energy demand and thus on fuel consumption and carbon emissions. The representative drive cycle that emerged covers a distance of 600 miles, an average vehicle speed of 55 miles per hour, and a road grade ranging from negative 6 percent to positive 6 percent.The next step was to generate key values for the performance of the conventional diesel “powertrain,” that is, all the components involved in creating power in the engine and delivering it to the wheels on the ground. Based on their defined drive cycle, the researchers simulated the performance of a conventional diesel truck, generating “benchmarks” for fuel consumption, CO2 emissions, cost, and other performance parameters.Now they could perform parallel simulations — based on the same drive-cycle assumptions — of possible replacement fuels and powertrains to see how the cost, carbon emissions, and other performance parameters would compare to the diesel benchmarks.The battery electric optionWhen considering how to decarbonize long-haul trucks, a natural first thought is battery power. After all, battery electric cars and pickup trucks are proving highly successful. Why not switch to battery electric long-haul trucks? “Again, the literature is very divided, with some studies saying that this is the best idea ever, and other studies saying that this makes no sense,” says Sayandeep Biswas, a graduate student in chemical engineering.To assess the battery electric option, the MIT researchers used a physics-based vehicle model plus well-documented estimates for the efficiencies of key components such as the battery pack, generators, motor, and so on. Assuming the previously described drive cycle, they determined operating parameters, including how much power the battery-electric system needs. From there they could calculate the size and weight of the battery required to satisfy the power needs of the battery electric truck.The outcome was disheartening. Providing enough energy to travel 600 miles without recharging would require a 2 megawatt-hour battery. “That’s a lot,” notes Kariana Moreno Sader, a graduate student in chemical engineering. “It’s the same as what two U.S. households consume per month on average.” And the weight of such a battery would significantly reduce the amount of payload that could be carried. An empty diesel truck typically weighs 20,000 pounds. With a legal limit of 80,000 pounds, there’s room for 60,000 pounds of payload. The 2 MWh battery would weigh roughly 27,000 pounds — significantly reducing the allowable capacity for carrying payload.Accounting for that “payload penalty,” the researchers calculated that roughly four electric trucks would be required to replace every three of today’s diesel-powered trucks. Furthermore, each added truck would require an additional driver. The impact on operating expenses would be significant.Analyzing the emissions reductions that might result from shifting to battery electric long-haul trucks also brought disappointing results. One might assume that using electricity would eliminate CO2 emissions. But when the researchers included emissions associated with making that electricity, that wasn’t true.“Battery electric trucks are only as clean as the electricity used to charge them,” notes Moreno Sader. Most of the time, drivers of long-haul trucks will be charging from national grids rather than dedicated renewable energy plants. According to Energy Information Agency statistics, fossil fuels make up more than 60 percent of the current U.S. power grid, so electric trucks would still be responsible for significant levels of carbon emissions. Manufacturing batteries for the trucks would generate additional CO2 emissions.Building the charging infrastructure would require massive upfront capital investment, as would upgrading the existing grid to reliably meet additional energy demand from the long-haul sector. Accomplishing those changes would be costly and time-consuming, which raises further concern about electrification as a means of decarbonizing long-haul freight.In short, switching today’s long-haul diesel trucks to battery electric power would bring major increases in costs for the freight industry and negligible carbon emissions benefits in the near term. Analyses assuming various types of batteries as well as other drive cycles produced comparable results.However, the researchers are optimistic about where the grid is going in the future. “In the long term, say by around 2050, emissions from the grid are projected to be less than half what they are now,” says Moreno Sader. “When we do our calculations based on that prediction, we find that emissions from battery electric trucks would be around 40 percent lower than our calculated emissions based on today’s grid.”For Moreno Sader, the goal of the MIT research is to help “guide the sector on what would be the best option.” With that goal in mind, she and her colleagues are now examining the battery electric option under different scenarios — for example, assuming battery swapping (a depleted battery isn’t recharged but replaced by a fully charged one), short-haul trucking, and other applications that might produce a more cost-competitive outcome, even for the near term.A promising option: hydrogenAs the world looks to get off reliance on fossil fuels for all uses, much attention is focusing on hydrogen. Could hydrogen be a good alternative for today’s diesel-burning long-haul trucks?To find out, the MIT team performed a detailed analysis of the hydrogen option. “We thought that hydrogen would solve a lot of the problems we had with battery electric,” says Biswas. It doesn’t have associated CO2 emissions. Its energy density is far higher, so it doesn’t create the weight problem posed by heavy batteries. In addition, existing compression technology can get enough hydrogen fuel into a regular-sized tank to cover the needed distance and range. “You can actually give drivers the range they want,” he says. “There’s no issue with ‘range anxiety.’”But while using hydrogen for long-haul trucking would reduce carbon emissions, it would cost far more than diesel. Based on their detailed analysis of hydrogen, the researchers concluded that the main source of incurred cost is in transporting it. Hydrogen can be made in a chemical facility, but then it needs to be distributed to refueling stations across the country. Conventionally, there have been two main ways of transporting hydrogen: as a compressed gas and as a cryogenic liquid. As Biswas notes, the former is “super high pressure,” and the latter is “super cold.” The researchers’ calculations show that as much as 80 percent of the cost of delivered hydrogen is due to transportation and refueling, plus there’s the need to build dedicated refueling stations that can meet new environmental and safety standards for handling hydrogen as a compressed gas or a cryogenic liquid.Having dismissed the conventional options for shipping hydrogen, they turned to a less-common approach: transporting hydrogen using “liquid organic hydrogen carriers” (LOHCs), special organic (carbon-containing) chemical compounds that can under certain conditions absorb hydrogen atoms and under other conditions release them.LOHCs are in use today to deliver small amounts of hydrogen for commercial use. Here’s how the process works: In a chemical plant, the carrier compound is brought into contact with hydrogen in the presence of a catalyst under elevated temperature and pressure, and the compound picks up the hydrogen. The “hydrogen-loaded” compound — still a liquid — is then transported under atmospheric conditions. When the hydrogen is needed, the compound is again exposed to a temperature increase and a different catalyst, and the hydrogen is released.LOHCs thus appear to be ideal hydrogen carriers for long-haul trucking. They’re liquid, so they can easily be delivered to existing refueling stations, where the hydrogen would be released; and they contain at least as much energy per gallon as hydrogen in a cryogenic liquid or compressed gas form. However, a detailed analysis of using hydrogen carriers showed that the approach would decrease emissions but at a considerable cost.The problem begins with the “dehydrogenation” step at the retail station. Releasing the hydrogen from the chemical carrier requires heat, which is generated by burning some of the hydrogen being carried by the LOHC. The researchers calculate that getting the needed heat takes 36 percent of that hydrogen. (In theory, the process would take only 27 percent — but in reality, that efficiency won’t be achieved.) So out of every 100 units of starting hydrogen, 36 units are now gone.But that’s not all. The hydrogen that comes out is at near-ambient pressure. So the facility dispensing the hydrogen will need to compress it — a process that the team calculates will use up 20-30 percent of the starting hydrogen.Because of the needed heat and compression, there’s now less than half of the starting hydrogen left to be delivered to the truck — and as a result, the hydrogen fuel becomes twice as expensive. The bottom line is that the technology works, but “when it comes to really beating diesel, the economics don’t work. It’s quite a bit more expensive,” says Biswas. In addition, the refueling stations would require expensive compressors and auxiliary units such as cooling systems. The capital investment and the operating and maintenance costs together imply that the market penetration of hydrogen refueling stations will be slow.A better strategy: onboard release of hydrogen from LOHCsGiven the potential benefits of using of LOHCs, the researchers focused on how to deal with both the heat needed to release the hydrogen and the energy needed to compress it. “That’s when we had the idea,” says Biswas. “Instead of doing the dehydrogenation [hydrogen release] at the refueling station and then loading the truck with hydrogen, why don’t we just take the LOHC and load that onto the truck?” Like diesel, LOHC is a liquid, so it’s easily transported and pumped into trucks at existing refueling stations. “We’ll then make hydrogen as it’s needed based on the power demands of the truck — and we can capture waste heat from the engine exhaust and use it to power the dehydrogenation process,” says Biswas.In their proposed plan, hydrogen-loaded LOHC is created at a chemical “hydrogenation” plant and then delivered to a retail refueling station, where it’s pumped into a long-haul truck. Onboard the truck, the loaded LOHC pours into the fuel-storage tank. From there it moves to the “dehydrogenation unit” — the reactor where heat and a catalyst together promote chemical reactions that separate the hydrogen from the LOHC. The hydrogen is sent to the powertrain, where it burns, producing energy that propels the truck forward.Hot exhaust from the powertrain goes to a “heat-integration unit,” where its waste heat energy is captured and returned to the reactor to help encourage the reaction that releases hydrogen from the loaded LOHC. The unloaded LOHC is pumped back into the fuel-storage tank, where it’s kept in a separate compartment to keep it from mixing with the loaded LOHC. From there, it’s pumped back into the retail refueling station and then transported back to the hydrogenation plant to be loaded with more hydrogen.Switching to onboard dehydrogenation brings down costs by eliminating the need for extra hydrogen compression and by using waste heat in the engine exhaust to drive the hydrogen-release process. So how does their proposed strategy look compared to diesel? Based on a detailed analysis, the researchers determined that using their strategy would be 18 percent more expensive than using diesel, and emissions would drop by 71 percent.But those results need some clarification. The 18 percent cost premium of using LOHC with onboard hydrogen release is based on the price of diesel fuel in 2020. In spring of 2023 the price was about 30 percent higher. Assuming the 2023 diesel price, the LOHC option is actually cheaper than using diesel.Both the cost and emissions outcomes are affected by another assumption: the use of “blue hydrogen,” which is hydrogen produced from natural gas with carbon capture and storage. Another option is to assume the use of “green hydrogen,” which is hydrogen produced using electricity generated from renewable sources, such as wind and solar. Green hydrogen is much more expensive than blue hydrogen, so then the costs would increase dramatically.If in the future the price of green hydrogen drops, the researchers’ proposed plan would shift to green hydrogen — and then the decline in emissions would no longer be 71 percent but rather close to 100 percent. There would be almost no emissions associated with the researchers’ proposed plan for using LHOCs with onboard hydrogen release.Comparing the options on cost and emissionsTo compare the options, Moreno Sader prepared bar charts showing the per-mile cost of shipping by truck in the United States and the CO2 emissions that result using each of the fuels and approaches discussed above: diesel fuel, battery electric, hydrogen as a cryogenic liquid or compressed gas, and LOHC with onboard hydrogen release. The LOHC strategy with onboard dehydrogenation looked promising on both the cost and the emissions charts. In addition to such quantitative measures, the researchers believe that their strategy addresses two other, less-obvious challenges in finding a less-polluting fuel for long-haul trucks.First, the introduction of the new fuel and trucks to use it must not disrupt the current freight-delivery setup. “You have to keep the old trucks running while you’re introducing the new ones,” notes Green. “You cannot have even a day when the trucks aren’t running because it’d be like the end of the economy. Your supermarket shelves would all be empty; your factories wouldn’t be able to run.” The researchers’ plan would be completely compatible with the existing diesel supply infrastructure and would require relatively minor retrofits to today’s long-haul trucks, so the current supply chains would continue to operate while the new fuel and retrofitted trucks are introduced.Second, the strategy has the potential to be adopted globally. Long-haul trucking is important in other parts of the world, and Moreno Sader thinks that “making this approach a reality is going to have a lot of impact, not only in the United States but also in other countries,” including her own country of origin, Colombia. “This is something I think about all the time.” The approach is compatible with the current diesel infrastructure, so the only requirement for adoption is to build the chemical hydrogenation plant. “And I think the capital expenditure related to that will be less than the cost of building a new fuel-supply infrastructure throughout the country,” says Moreno Sader.Testing in the lab“We’ve done a lot of simulations and calculations to show that this is a great idea,” notes Biswas. “But there’s only so far that math can go to convince people.” The next step is to demonstrate their concept in the lab.To that end, the researchers are now assembling all the core components of the onboard hydrogen-release reactor as well as the heat-integration unit that’s key to transferring heat from the engine exhaust to the hydrogen-release reactor. They estimate that this spring they’ll be ready to demonstrate their ability to release hydrogen and confirm the rate at which it’s formed. And — guided by their modeling work — they’ll be able to fine-tune critical components for maximum efficiency and best performance.The next step will be to add an appropriate engine, specially equipped with sensors to provide the critical readings they need to optimize the performance of all their core components together. By the end of 2024, the researchers hope to achieve their goal: the first experimental demonstration of a power-dense, robust onboard hydrogen-release system with highly efficient heat integration.In the meantime, they believe that results from their work to date should help spread the word, bringing their novel approach to the attention of other researchers and experts in the trucking industry who are now searching for ways to decarbonize long-haul trucking.Financial support for development of the representative drive cycle and the diesel benchmarks as well as the analysis of the battery electric option was provided by the MIT Mobility Systems Center of the MIT Energy Initiative. Analysis of LOHC-powered trucks with onboard dehydrogenation was supported by the MIT Climate and Sustainability Consortium. Sayandeep Biswas is supported by a fellowship from the Martin Family Society of Fellows for Sustainability, and Kariana Moreno Sader received fellowship funding from MathWorks through the MIT School of Science. More

    • 75 Shares159 Views

      in Environment

      School of Engineering welcomes new faculty

      by

      The School of Engineering welcomes 15 new faculty members across six of its academic departments. This new cohort of faculty members, who have either recently started their roles at MIT or will start within the next year, conduct research across a diverse range of disciplines.Many of these new faculty specialize in research that intersects with multiple fields. In addition to positions in the School of Engineering, a number of these faculty have positions at other units across MIT. Faculty with appointments in the Department of Electrical Engineering and Computer Science (EECS) report into both the School of Engineering and the MIT Stephen A. Schwarzman College of Computing. This year, new faculty also have joint appointments between the School of Engineering and the School of Humanities, Arts, and Social Sciences and the School of Science.“I am delighted to welcome this cohort of talented new faculty to the School of Engineering,” says Anantha Chandrakasan, chief innovation and strategy officer, dean of engineering, and Vannevar Bush Professor of Electrical Engineering and Computer Science. “I am particularly struck by the interdisciplinary approach many of these new faculty take in their research. They are working in areas that are poised to have tremendous impact. I look forward to seeing them grow as researchers and educators.”The new engineering faculty include:Stephen Bates joined the Department of Electrical Engineering and Computer Science as an assistant professor in September 2023. He is also a member of the Laboratory for Information and Decision Systems (LIDS). Bates uses data and AI for reliable decision-making in the presence of uncertainty. In particular, he develops tools for statistical inference with AI models, data impacted by strategic behavior, and settings with distribution shift. Bates also works on applications in life sciences and sustainability. He previously worked as a postdoc in the Statistics and EECS departments at the University of California at Berkeley (UC Berkeley). Bates received a BS in statistics and mathematics at Harvard University and a PhD from Stanford University.Abigail Bodner joined the Department of EECS and Department of Earth, Atmospheric and Planetary Sciences as an assistant professor in January. She is also a member of the LIDS. Bodner’s research interests span climate, physical oceanography, geophysical fluid dynamics, and turbulence. Previously, she worked as a Simons Junior Fellow at the Courant Institute of Mathematical Sciences at New York University. Bodner received her BS in geophysics and mathematics and MS in geophysics from Tel Aviv University, and her SM in applied mathematics and PhD from Brown University.Andreea Bobu ’17 will join the Department of Aeronautics and Astronautics as an assistant professor in July. Her research sits at the intersection of robotics, mathematical human modeling, and deep learning. Previously, she was a research scientist at the Boston Dynamics AI Institute, focusing on how robots and humans can efficiently arrive at shared representations of their tasks for more seamless and reliable interactions. Bobu earned a BS in computer science and engineering from MIT and a PhD in electrical engineering and computer science from UC Berkeley.Suraj Cheema will join the Department of Materials Science and Engineering, with a joint appointment in the Department of EECS, as an assistant professor in July. His research explores atomic-scale engineering of electronic materials to tackle challenges related to energy consumption, storage, and generation, aiming for more sustainable microelectronics. This spans computing and energy technologies via integrated ferroelectric devices. He previously worked as a postdoc at UC Berkeley. Cheema earned a BS in applied physics and applied mathematics from Columbia University and a PhD in materials science and engineering from UC Berkeley.Samantha Coday joins the Department of EECS as an assistant professor in July. She will also be a member of the MIT Research Laboratory of Electronics. Her research interests include ultra-dense power converters enabling renewable energy integration, hybrid electric aircraft and future space exploration. To enable high-performance converters for these critical applications her research focuses on the optimization, design, and control of hybrid switched-capacitor converters. Coday earned a BS in electrical engineering and mathematics from Southern Methodist University and an MS and a PhD in electrical engineering and computer science from UC Berkeley.Mitchell Gordon will join the Department of EECS as an assistant professor in July. He will also be a member of the MIT Computer Science and Artificial Intelligence Laboratory. In his research, Gordon designs interactive systems and evaluation approaches that bridge principles of human-computer interaction with the realities of machine learning. He currently works as a postdoc at the University of Washington. Gordon received a BS from the University of Rochester, and MS and PhD from Stanford University, all in computer science.Kaiming He joined the Department of EECS as an associate professor in February. He will also be a member of the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL). His research interests cover a wide range of topics in computer vision and deep learning. He is currently focused on building computer models that can learn representations and develop intelligence from and for the complex world. Long term, he hopes to augment human intelligence with improved artificial intelligence. Before joining MIT, He was a research scientist at Facebook AI. He earned a BS from Tsinghua University and a PhD from the Chinese University of Hong Kong.Anna Huang SM ’08 will join the departments of EECS and Music and Theater Arts as assistant professor in September. She will help develop graduate programming focused on music technology. Previously, she spent eight years with Magenta at Google Brain and DeepMind, spearheading efforts in generative modeling, reinforcement learning, and human-computer interaction to support human-AI partnerships in music-making. She is the creator of Music Transformer and Coconet (which powered the Bach Google Doodle). She was a judge and organizer for the AI Song Contest. Anna holds a Canada CIFAR AI Chair at Mila, a BM in music composition, and BS in computer science from the University of Southern California, an MS from the MIT Media Lab, and a PhD from Harvard University.Yael Kalai PhD ’06 will join the Department of EECS as a professor in September. She is also a member of CSAIL. Her research interests include cryptography, the theory of computation, and security and privacy. Kalai currently focuses on both the theoretical and real-world applications of cryptography, including work on succinct and easily verifiable non-interactive proofs. She received her bachelor’s degree from the Hebrew University of Jerusalem, a master’s degree at the Weizmann Institute of Science, and a PhD from MIT.Sendhil Mullainathan will join the departments of EECS and Economics as a professor in July. His research uses machine learning to understand complex problems in human behavior, social policy, and medicine. Previously, Mullainathan spent five years at MIT before joining the faculty at Harvard in 2004, and then the University of Chicago in 2018. He received his BA in computer science, mathematics, and economics from Cornell University and his PhD from Harvard University.Alex Rives will join the Department of EECS as an assistant professor in September, with a core membership in the Broad Institute of MIT and Harvard. In his research, Rives is focused on AI for scientific understanding, discovery, and design for biology. Rives worked with Meta as a New York University graduate student, where he founded and led the Evolutionary Scale Modeling team that developed large language models for proteins. Rives received his BS in philosophy and biology from Yale University and is completing his PhD in computer science at NYU.Sungho Shin will join the Department of Chemical Engineering as an assistant professor in July. His research interests include control theory, optimization algorithms, high-performance computing, and their applications to decision-making in complex systems, such as energy infrastructures. Shin is a postdoc at the Mathematics and Computer Science Division at Argonne National Laboratory. He received a BS in mathematics and chemical engineering from Seoul National University and a PhD in chemical engineering from the University of Wisconsin-Madison.Jessica Stark joined the Department of Biological Engineering as an assistant professor in January. In her research, Stark is developing technologies to realize the largely untapped potential of cell-surface sugars, called glycans, for immunological discovery and immunotherapy. Previously, Stark was an American Cancer Society postdoc at Stanford University. She earned a BS in chemical and biomolecular engineering from Cornell University and a PhD in chemical and biological engineering at Northwestern University.Thomas John “T.J.” Wallin joined the Department of Materials Science and Engineering as an assistant professor in January. As a researcher, Wallin’s interests lay in advanced manufacturing of functional soft matter, with an emphasis on soft wearable technologies and their applications in human-computer interfaces. Previously, he was a research scientist at Meta’s Reality Labs Research working in their haptic interaction team. Wallin earned a BS in physics and chemistry from the College of William and Mary, and an MS and PhD in materials science and engineering from Cornell University.Gioele Zardini joined the Department of Civil and Environmental Engineering as an assistant professor in September. He will also join LIDS and the Institute for Data, Systems, and Society. Driven by societal challenges, Zardini’s research interests include the co-design of sociotechnical systems, compositionality in engineering, applied category theory, decision and control, optimization, and game theory, with society-critical applications to intelligent transportation systems, autonomy, and complex networks and infrastructures. He received his BS, MS, and PhD in mechanical engineering with a focus on robotics, systems, and control from ETH Zurich, and spent time at MIT, Stanford University, and Motional. More