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    China-based emissions of three potent climate-warming greenhouse gases spiked in past decade

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    When it comes to heating up the planet, not all greenhouse gases are created equal. They vary widely in their global warming potential (GWP), a measure of how much infrared thermal radiation a greenhouse gas would absorb over a given time frame once it enters the atmosphere. For example, measured over a 100-year period, the GWP of methane is about 28 times that of carbon dioxide (CO2), and the GWPs of a class of greenhouse gases known as perfluorocarbons (PFCs) are thousands of times that of CO2. The lifespans in the atmosphere of different greenhouse gases also vary widely. Methane persists in the atmosphere for around 10 years; CO2 for over 100 years, and PFCs for up to tens of thousands of years.Given the high GWPs and lifespans of PFCs, their emissions could pose a major roadblock to achieving the aspirational goal of the Paris Agreement on climate change — to limit the increase in global average surface temperature to 1.5 degrees Celsius above preindustrial levels. Now, two new studies based on atmospheric observations inside China and high-resolution atmospheric models show a rapid rise in Chinese emissions over the last decade (2011 to 2020 or 2021) of three PFCs: tetrafluoromethane (PFC-14) and hexafluoroethane (PFC-116) (results in PNAS), and perfluorocyclobutane (PFC-318) (results in Environmental Science & Technology).Both studies find that Chinese emissions have played a dominant role in driving up global emission levels for all three PFCs.The PNAS study identifies substantial PFC-14 and PFC-116 emission sources in the less-populated western regions of China from 2011 to 2021, likely due to the large amount of aluminum industry in these regions. The semiconductor industry also contributes to some of the emissions detected in the more economically developed eastern regions. These emissions are byproducts from aluminum smelting, or occur during the use of the two PFCs in the production of semiconductors and flat panel displays. During the observation period, emissions of both gases in China rose by 78 percent, accounting for most of the increase in global emissions of these gases.The ES&T study finds that during 2011-20, a 70 percent increase in Chinese PFC-318 emissions (contributing more than half of the global emissions increase of this gas) — originated primarily in eastern China. The regions with high emissions of PFC-318 in China overlap with geographical areas densely populated with factories that produce polytetrafluoroethylene (PTFE, commonly used for nonstick cookware coatings), implying that PTFE factories are major sources of PFC-318 emissions in China. In these factories, PFC-318 is formed as a byproduct.“Using atmospheric observations from multiple monitoring sites, we not only determined the magnitudes of PFC emissions, but also pinpointed the possible locations of their sources,” says Minde An, a postdoc at the MIT Center for Global Change Science (CGCS), and corresponding author of both studies. “Identifying the actual source industries contributing to these PFC emissions, and understanding the reasons for these largely byproduct emissions, can provide guidance for developing region- or industry-specific mitigation strategies.”“These three PFCs are largely produced as unwanted byproducts during the manufacture of otherwise widely used industrial products,” says MIT professor of atmospheric sciences Ronald Prinn, director of both the MIT Joint Program on the Science and Policy of Global Change and CGCS, and a co-author of both studies. “Phasing out emissions of PFCs as early as possible is highly beneficial for achieving global climate mitigation targets and is likely achievable by recycling programs and targeted technological improvements in these industries.”Findings in both studies were obtained, in part, from atmospheric observations collected from nine stations within a Chinese network, including one station from the Advanced Global Atmospheric Gases Experiment (AGAGE) network. For comparison, global total emissions were determined from five globally distributed, relatively unpolluted “background” AGAGE stations, as reported in the latest United Nations Environment Program and World Meteorological Organization Ozone Assessment report. More

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      Q&A: What past environmental success can teach us about solving the climate crisis

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      Susan Solomon, MIT professor of Earth, atmospheric, and planetary sciences (EAPS) and of chemistry, played a critical role in understanding how a class of chemicals known as chlorofluorocarbons were creating a hole in the ozone layer. Her research was foundational to the creation of the Montreal Protocol, an international agreement established in the 1980s that phased out products releasing chlorofluorocarbons. Since then, scientists have documented signs that the ozone hole is recovering thanks to these measures.Having witnessed this historical process first-hand, Solomon, the Lee and Geraldine Martin Professor of Environmental Studies, is aware of how people can come together to make successful environmental policy happen. Using her story, as well as other examples of success — including combating smog, getting rid of DDT, and more — Solomon draws parallels from then to now as the climate crisis comes into focus in her new book, “Solvable: How we Healed the Earth and How we can do it Again.”Solomon took a moment to talk about why she picked the stories in her book, the students who inspired her, and why we need hope and optimism now more than ever.Q: You have first-hand experience seeing how we’ve altered the Earth, as well as the process of creating international environmental policy. What prompted you to write a book about your experiences?A: Lots of things, but one of the main ones is the things that I see in teaching. I have taught a class called Science, Politics and Environmental Policy for many years here at MIT. Because my emphasis is always on how we’ve actually fixed problems, students come away from that class feeling hopeful, like they really want to stay engaged with the problem.It strikes me that students today have grown up in a very contentious and difficult era in which they feel like nothing ever gets done. But stuff does get done, even now. Looking at how we did things so far really helps you to see how we can do things in the future.Q: In the book, you use five different stories as examples of successful environmental policy, and then end talking about how we can apply these lessons to climate change. Why did you pick these five stories?A: I picked some of them because I’m closer to those problems in my own professional experience, like ozone depletion and smog. I did other issues partly because I wanted to show that even in the 21st century, we’ve actually got some stuff done — that’s the story of the Kigali Amendment to the Montreal Protocol, which is a binding international agreement on some greenhouse gases.Another chapter is on DDT. One of the reasons I included that is because it had an enormous effect on the birth of the environmental movement in the United States. Plus, that story allows you to see how important the environmental groups can be.Lead in gasoline and paint is the other one. I find it a very moving story because the idea that we were poisoning millions of children and not even realizing it is so very, very sad. But it’s so uplifting that we did figure out the problem, and it happened partly because of the civil rights movement, that made us aware that the problem was striking minority communities much more than non-minority communities.Q: What surprised you the most during your research for the book?A: One of the things that that I didn’t realize and should have, was the outsized role played by one single senator, Ed Muskie of Maine. He made pollution control his big issue and devoted incredible energy to it. He clearly had the passion and wanted to do it for many years, but until other factors helped him, he couldn’t. That’s where I began to understand the role of public opinion and the way in which policy is only possible when public opinion demands change.Another thing about Muskie was the way in which his engagement with these issues demanded that science be strong. When I read what he put into congressional testimony I realized how highly he valued the science. Science alone is never enough, but it’s always necessary. Over the years, science got a lot stronger, and we developed ways of evaluating what the scientific wisdom across many different studies and many different views actually is. That’s what scientific assessment is all about, and it’s crucial to environmental progress.Q: Throughout the book you argue that for environmental action to succeed, three things must be met which you call the three Ps: a threat much be personal, perceptible, and practical. Where did this idea come from?A: My observations. You have to perceive the threat: In the case of the ozone hole, you could perceive it because those false-color images of the ozone loss were so easy to understand, and it was personal because few things are scarier than cancer, and a reduced ozone layer leads to too much sun, increasing skin cancers. Science plays a role in communicating what can be readily understood by the public, and that’s important to them perceiving it as a serious problem.Nowadays, we certainly perceive the reality of climate change. We also see that it’s personal. People are dying because of heat waves in much larger numbers than they used to; there are horrible problems in the Boston area, for example, with flooding and sea level rise. People perceive the reality of the problem and they feel personally threatened.The third P is practical: People have to believe that there are practical solutions. It’s interesting to watch how the battle for hearts and minds has shifted. There was a time when the skeptics would just attack the whole idea that the climate was changing. Eventually, they decided ‘we better accept that because people perceive it, so let’s tell them that it’s not caused by human activity.’ But it’s clear enough now that human activity does play a role. So they’ve moved on to attacking that third P, that somehow it’s not practical to have any kind of solutions. This is progress! So what about that third P?What I tried to do in the book is to point out some of the ways in which the problem has also become eminently practical to deal with in the last 10 years, and will continue to move in that direction. We’re right on the cusp of success, and we just have to keep going. People should not give in to eco despair; that’s the worst thing you could do, because then nothing will happen. If we continue to move at the rate we have, we will certainly get to where we need to be.Q: That ties in very nicely with my next question. The book is very optimistic; what gives you hope?A: I’m optimistic because I’ve seen so many examples of where we have succeeded, and because I see so many signs of movement right now that are going to push us in the same direction.If we had kept conducting business as usual as we had been in the year 2000, we’d be looking at 4 degrees of future warming. Right now, I think we’re looking at 3 degrees. I think we can get to 2 degrees. We have to really work on it, and we have to get going seriously in the next decade, but globally right now over 30 percent of our energy is from renewables. That’s fantastic! Let’s just keep going.Q: Throughout the book, you show that environmental problems won’t be solved by individual actions alone, but requires policy and technology driving. What individual actions can people take to help push for those bigger changes?A: A big one is choose to eat more sustainably; choose alternative transportation methods like public transportation or reducing the amount of trips that you make. Older people usually have retirement investments, you can shift them over to a social choice funds and away from index funds that end up funding companies that you might not be interested in. You can use your money to put pressure: Amazon has been under a huge amount of pressure to cut down on their plastic packaging, mainly coming from consumers. They’ve just announced they’re not going to use those plastic pillows anymore. I think you can see lots of ways in which people really do matter, and we can matter more.Q: What do you hope people take away from the book?A: Hope for their future and resolve to do the best they can getting engaged with it. More

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      in Environment

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

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

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      in Environment

      How to increase the rate of plastics recycling

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

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      in Energy

      Reducing carbon emissions from long-haul trucks

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      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

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      in Energy

      Getting to systemic sustainability

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      Add up the commitments from the Paris Agreement, the Glasgow Climate Pact, and various commitments made by cities, countries, and businesses, and the world would be able to hold the global average temperature increase to 1.9 degrees Celsius above preindustrial levels, says Ani Dasgupta, the president and chief executive officer of the World Resources Institute (WRI).While that is well above the 1.5 C threshold that many scientists agree would limit the most severe impacts of climate change, it is below the 2.0 degree threshold that could lead to even more catastrophic impacts, such as the collapse of ice sheets and a 30-foot rise in sea levels.However, Dasgupta notes, actions have so far not matched up with commitments.“There’s a huge gap between commitment and outcomes,” Dasgupta said during his talk, “Energizing the global transition,” at the 2024 Earth Day Colloquium co-hosted by the MIT Energy Initiative and MIT Department of Earth, Atmospheric and Planetary Sciences, and sponsored by the Climate Nucleus.Dasgupta noted that oil companies did $6 trillion worth of business across the world last year — $1 trillion more than they were planning. About 7 percent of the world’s remaining tropical forests were destroyed during that same time, he added, and global inequality grew even worse than before.“None of these things were illegal, because the system we have today produces these outcomes,” he said. “My point is that it’s not one thing that needs to change. The whole system needs to change.”People, climate, and natureDasgupta, who previously held positions in nonprofits in India and at the World Bank, is a recognized leader in sustainable cities, poverty alleviation, and building cultures of inclusion. Under his leadership, WRI, a global research nonprofit that studies sustainable practices with the goal of fundamentally transforming the world’s food, land and water, energy, and cities, adopted a new five-year strategy called “Getting the Transition Right for People, Nature, and Climate 2023-2027.” It focuses on creating new economic opportunities to meet people’s essential needs, restore nature, and rapidly lower emissions, while building resilient communities. In fact, during his talk, Dasgupta said that his organization has moved away from talking about initiatives in terms of their impact on greenhouse gas emissions — instead taking a more holistic view of sustainability.“There is no net zero without nature,” Dasgupta said. He showed a slide with a graphic illustrating potential progress toward net-zero goals. “If nature gets diminished, that chart becomes even steeper. It’s very steep right now, but natural systems absorb carbon dioxide. So, if the natural systems keep getting destroyed, that curve becomes harder and harder.”A focus on people is necessary, Dasgupta said, in part because of the unequal climate impacts that the rich and the poor are likely to face in the coming years. “If you made it to this room, you will not be impacted by climate change,” he said. “You have resources to figure out what to do about it. The people who get impacted are people who don’t have resources. It is immensely unfair. Our belief is, if we don’t do climate policy that helps people directly, we won’t be able to make progress.”Where to start?Although Dasgupta stressed that systemic change is needed to bring carbon emissions in line with long-term climate goals, he made the case that it is unrealistic to implement this change around the globe all at once. “This transition will not happen in 196 countries at the same time,” he said. “The question is, how do we get to the tipping point so that it happens at scale? We’ve worked the past few years to ask the question, what is it you need to do to create this tipping point for change?”Analysts at WRI looked for countries that are large producers of carbon, those with substantial tropical forest cover, and those with large quantities of people living in poverty. “We basically tried to draw a map of, where are the biggest challenges for climate change?” Dasgupta said.That map features a relative handful of countries, including the United States, Mexico, China, Brazil, South Africa, India, and Indonesia. Dasgupta said, “Our argument is that, if we could figure out and focus all our efforts to help these countries transition, that will create a ripple effect — of understanding technology, understanding the market, understanding capacity, and understanding the politics of change that will unleash how the rest of these regions will bring change.”Spotlight on the subcontinentDasgupta used one of these countries, his native India, to illustrate the nuanced challenges and opportunities presented by various markets around the globe. In India, he noted, there are around 3 million projected jobs tied to the country’s transition to renewable energy. However, that number is dwarfed by the 10 to 12 million jobs per year the Indian economy needs to create simply to keep up with population growth.“Every developing country faces this question — how to keep growing in a way that reduces their carbon footprint,” Dasgupta said.Five states in India worked with WRI to pool their buying power and procure 5,000 electric buses, saving 60 percent of the cost as a result. Over the next two decades, Dasgupta said, the fleet of electric buses in those five states is expected to increase to 800,000.In the Indian state of Rajasthan, Dasgupta said, 59 percent of power already comes from solar energy. At times, Rajasthan produces more solar than it can use, and officials are exploring ways to either store the excess energy or sell it to other states. But in another state, Jharkhand, where much of the country’s coal is sourced, only 5 percent of power comes from solar. Officials in Jharkhand have reached out to WRI to discuss how to transition their energy economy, as they recognize that coal will fall out of favor in the future, Dasgupta said.“The complexities of the transition are enormous in a country this big,” Dasgupta said. “This is true in most large countries.”The road aheadDespite the challenges ahead, the colloquium was also marked by notes of optimism. In his opening remarks, Robert Stoner, the founding director of the MIT Tata Center for Technology and Design, pointed out how much progress has been made on environmental cleanup since the first Earth Day in 1970. “The world was a very different, much dirtier, place in many ways,” Stoner said. “Our air was a mess, our waterways were a mess, and it was beginning to be noticeable. Since then, Earth Day has become an important part of the fabric of American and global society.”While Dasgupta said that the world presently lacks the “orchestration” among various stakeholders needed to bring climate change under control, he expressed hope that collaboration in key countries could accelerate progress.“I strongly believe that what we need is a very different way of collaborating radically — across organizations like yours, organizations like ours, businesses, and governments,” Dasgupta said. “Otherwise, this transition will not happen at the scale and speed we need.” More

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      in Environment

      MIT scholars will take commercial break with entrepreneurial scholarship

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      Two MIT scholars, each with a strong entrepreneurial drive, have received 2024 Kavanaugh Fellowship awards, advancing their quest to turn pioneering research into profitable commercial enterprises.The Kavanaugh Translational Fellows Program gives scholars training to lead organizations that will bring their research to market. PhD candidates Grant Knappe and Arjav Shah are this year’s recipients. Knappe is developing a drug delivery platform for an emerging class of medicines called nucleic acid therapeutics. Shah is using hydrogel microparticles to clean up water polluted by heavy metals and other contaminants.Knappe and Shah will begin their fellowship with years of entrepreneurial expertise under their belts. They’ve developed and refined their business plans through MIT’s innovation ecosystem, including the Sandbox, the Legatum Center, the Venture Mentoring Service, the National Science Foundation’s I-Corps Program, and Blueprint by The Engine. Now, the yearlong Kavanaugh Fellowship will give the scholars time to focus exclusively on testing their business plans and exercising decision-making skills — critical to startup success — with the guidance of MIT mentors.“It’s a testament to the support and direction they’ve received from the MIT community that their entrepreneurial aspirations have evolved and matured over time,” says Michael J. Cima, program director for the Kavanaugh program and the David H. Koch Professor of Engineering in the Department of Materials Science and Engineering.Founded in 2016, the Kavanaugh program was instrumental in helping past fellows launch several robust startups, including low-carbon cement manufacturer Sublime Systems and SiTration, which is using a new type of filtration membrane to extract critical materials such as lithium.A safer way to deliver breakthrough medicinesNucleic acid therapeutics, including mRNA and CRISPR, are disrupting today’s clinical landscape thanks to their promise of targeting disease treatment according to genetic blueprints. But the first methods of delivering these molecules to the body used viruses as their transport, raising patient safety concerns.“Humans have figured out how to engineer certain viruses found in nature to deliver specific cargoes [for disease treatment],” says Knappe. “But because they look like viruses, the human immune system sees them as a danger signal and creates an immune reaction that can be harmful to patients.”Given the safety profile issues of viral delivery, researchers turned to non-viral technologies that use lipid nanoparticle technology, a mixture of different lipid-like materials, assembled into particles to protect the mRNA therapeutic from getting degraded before it reaches a cell of interest. “Because they don’t look like viruses there, the immune system generally tolerates them,” adds Knappe.Recent data show lipid nanoparticles can now target the lung, opening the potential for novel treatments of deadly cancers and other diseases.Knappe’s work in MIT’s Bathe BioNanoLab focused on building such a non-viral delivery platform based on a different technology: nucleic acid nanoparticles, which combine the attractive components of both viral and non-viral systems. Knappe will spend his Kavanaugh Fellowship year developing proof-of-concept data for his drug delivery method and building the team and funding needed to commercialize the technology.A PhD candidate in the Department of Chemical Engineering (ChemE), Knappe was initially attracted to MIT because of its intellectual openness. “You can work with any faculty member in other departments. I wasn’t restricted to the chemical engineering faculty,” says Knappe, whose supervisor, Professor Mark Bathe, is in the Department of Biological Engineering.Knappe, who is from New Jersey, welcomes the challenges that will come in his Kavanaugh year, including the need to pinpoint the right story that will convince venture capitalists and other funders to bet on his technology. Attracting talent is also top of mind. “How do you convince really talented people that have a lot of opportunities to work on what you work on? Building the first team is going to be critical,” he says. The network Knappe has been building in his years at MIT is paying dividends now.Targeting “forever chemicals” in waterThat network includes Shah. The two fellows met when they worked on the MIT Science Policy Review, a student-run journal concerned with the intersection of science, technology, and policy. Knappe and Shah did not compete directly academically but used their biweekly coffee walks as a welcome sounding board. Naturally, they were pleased when they found out they had both been chosen for the Kavanaugh Fellowship. So far, they have been too busy to celebrate over a beer.“We are good collaborators with research, as well,” says Shah. “Now we’re going on this entrepreneurial journey together. It’s been exciting.”Shah is a PhD candidate in ChemE’s Chemical Engineering Practice program. He got interested in the global imperative for cleaner water at a young age. His hometown of Surat is the heart of India’s textile industry. “Growing up, it wasn’t hard to see the dye-colored water flowing into your rivers and streams,” Shah says. “Playing a role in fostering positive change in water treatment fills me with a profound sense of purpose.”Shah’s work, broadly, is to clean toxic chemicals called micropollutants from water in an efficient and sustainable manner. “It’s humanly impossible to turn a blind eye to our water problems,” he says, which can be categorized as accessibility, availability, and quality. Water problems are global and complex, not just because of the technological challenges but also sociopolitical ones, he adds.Manufactured chemicals called per- and polyfluoroalkyl substances (PFAS), or “forever chemicals,” are in the news these days. PFAS, which go into making nonstick cookware and waterproof clothing, are just one of more than 10,000 such emerging contaminants that have leached into water streams. “These are extremely difficult to remove using existing systems because of their chemical diversity and low concentrations,” Shah says. “The concentrations are akin to dropping an aspirin tablet in an Olympic-sized swimming pool.” But no less toxic for that.In the lab at MIT, Shah is working with Devashish Gokhale, a fellow PhD student, and Patrick S. Doyle, the Robert T. Haslam (1911) Professor of Chemical Engineering, to commercialize an innovative microparticle technology, hydroGel, to remove these micropollutants in an effective, facile, and sustainable manner. Hydrogels are a broad class of polymer materials that can hold large quantities of water.“Our materials are like Boba beads. We are trying to save the world with our Boba beads,” says Shah with a laugh. “And we have functionalized these particles with tunable chemistries to target different micropollutants in a single unit operation.”Due to its outsized environmental impact, industrial water is the first application Shah is targeting. Today, wastewater treatment emits more than 3 percent of global carbon dioxide emissions, which is more than the shipping industry’s emissions, for example. The current state of the art for removing micropollutants in the industry is to use activated carbon filters. “[This technology] comes from coal, so it’s unsustainable,” Shah says. And the activated carbon filters are hard to reuse. “Our particles are reusable, theoretically infinitely.”“I’m very excited to be able to take advantage of the mentorship we have from the Kavanaugh team to take this technology to its next inflection point, so that we are ready to go out in the market and start making a huge impact,” he says.A dream communityShah and Knappe have become adept at navigating the array of support and mentorship opportunities MIT has to offer. Shah worked with a small team of seasoned professionals in the water space from the MIT Venture Mentoring Service. “They’ve helped us every step of the way as we think about commercializing the technology,” he says.Shah worked with MIT Sandbox, which provides a seed grant to help find the right product-market fit. He is also a fellow with the Legatum Center for Development and Entrepreneurship, which focuses on entrepreneurship in emerging countries in growth markets.“We’re exploring the potential for this technology and its application in a lot of different markets, including India. Because that’s close to my heart,” Shah says. “The Legatum community has been unique, where you can have those extremely hard conversations, confront yourself with those fears, and then talk it out with the group of fellows.”The Abdul Latif Jameel Water and Food Systems Lab, or J-WAFS, has been an integral part of Shah’s journey with research and commercialization support through its Solutions Grant and a travel award to the Stockholm World Water Week in August 2023.Knappe has also taken advantage of many innovation programs, including MIT’s Blueprint by the Engine, which helps researchers explore commercial opportunities of their work, plus programs outside of MIT but with strong on-campus ties such as Nucleate Activator and Frequency Bio.It was during one of these programs that he was inspired by two postdocs working in Bathe’s lab and spinning out biotech startups from their research, Floris Engelhardt and James Banal. Engelhardt helped spearhead Kano Therapeutics, and Banal launched Cache DNA.“I was passively absorbing and watching everything that they were going through and what they were excited about and challenged with. I still talk to them pretty regularly to this day,” Knappe says. “It’s been really great to have them as continual mentors, throughout my PhD and as I transition out of the lab.”Shah says he is grateful not only for being selected for the Kavanaugh Fellowship but to MIT as a community. “MIT has been more than a dream come true,” he says. He will have the opportunity to explore a different side of the institution as he enters the MBA program at MIT Sloan School of Management this fall. Shah expects this program, along with his Kavanaugh training, will supply the skills he needs to scale the business so it can make a difference in the world.“I always keep coming back to the question ‘How does what I do matter to the person on the street?’ This guides me to look at the bigger picture, to contextualize my research to solving important problems,” Shah says. “So many great technologies are being worked on each day, but only a minuscule fraction make it to the market.”Knappe is equally dedicated to serving a larger purpose. “With the right infrastructure, between basic fundamental science, conducted in academia, funded by government, and then translated by companies, we can make products that could improve everyone’s life across the world,” he says.Past Kavanaugh Fellows are credited with spearheading commercial outfits that have indeed made a difference. This year’s fellows are poised to follow their lead. But first they will have that beer together to celebrate. More

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      in Security

      Repurposed beer yeast may offer a cost-effective way to remove lead from water

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      Every year, beer breweries generate and discard thousands of tons of surplus yeast. Researchers from MIT and Georgia Tech have now come up with a way to repurpose that yeast to absorb lead from contaminated water.Through a process called biosorption, yeast can quickly absorb even trace amounts of lead and other heavy metals from water. The researchers showed that they could package the yeast inside hydrogel capsules to create a filter that removes lead from water. Because the yeast cells are encapsulated, they can be easily removed from the water once it’s ready to drink.“We have the hydrogel surrounding the free yeast that exists in the center, and this is porous enough to let water come in, interact with yeast as if they were freely moving in water, and then come out clean,” says Patricia Stathatou, a former postdoc at the MIT Center for Bits and Atoms, who is now a research scientist at Georgia Tech and an incoming assistant professor at Georgia Tech’s School of Chemical and Biomolecular Engineering. “The fact that the yeast themselves are bio-based, benign, and biodegradable is a significant advantage over traditional technologies.”The researchers envision that this process could be used to filter drinking water coming out of a faucet in homes, or scaled up to treat large quantities of water at treatment plants.MIT graduate student Devashish Gokhale and Stathatou are the lead authors of the study, which appears today in the journal RSC Sustainability. Patrick Doyle, the Robert T. Haslam Professor of Chemical Engineering at MIT, is the senior author of the paper, and Christos Athanasiou, an assistant professor of aerospace engineering at Georgia Tech and a former visiting scholar at MIT, is also an author.Absorbing leadThe new study builds on work that Stathatou and Athanasiou began in 2021, when Athanasiou was a visiting scholar at MIT’s Center for Bits and Atoms. That year, they calculated that waste yeast discarded from a single brewery in Boston would be enough to treat the city’s entire water supply.Through biosorption, a process that is not fully understood, yeast cells can bind to and absorb heavy metal ions, even at challenging initial concentrations below 1 part per million. The MIT team found that this process could effectively decontaminate water with low concentrations of lead. However, one key obstacle remained, which was how to remove yeast from the water after they absorb the lead.In a serendipitous coincidence, Stathatou and Athanasiou happened to present their research at the AIChE Annual Meeting in Boston in 2021, where Gokhale, a student in Doyle’s lab, was presenting his own research on using hydrogels to capture micropollutants in water. The two sets of researchers decided to join forces and explore whether the yeast-based strategy could be easier to scale up if the yeast were encapsulated in hydrogels developed by Gokhale and Doyle.“What we decided to do was make these hollow capsules — something like a multivitamin pill, but instead of filling them up with vitamins, we fill them up with yeast cells,” Gokhale says. “These capsules are porous, so the water can go into the capsules and the yeast are able to bind all of that lead, but the yeast themselves can’t escape into the water.”The capsules are made from a polymer called polyethylene glycol (PEG), which is widely used in medical applications. To form the capsules, the researchers suspend freeze-dried yeast in water, then mix them with the polymer subunits. When UV light is shone on the mixture, the polymers link together to form capsules with yeast trapped inside.Each capsule is about half a millimeter in diameter. Because the hydrogels are very thin and porous, water can easily pass through and encounter the yeast inside, while the yeast remain trapped.In this study, the researchers showed that the encapsulated yeast could remove trace lead from water just as rapidly as the unencapsulated yeast from Stathatou and Athanasiou’s original 2021 study.Scaling upLed by Athanasiou, the researchers tested the mechanical stability of the hydrogel capsules and found that the capsules and the yeast inside can withstand forces similar to those generated by water running from a faucet. They also calculated that the yeast-laden capsules should be able to withstand forces generated by flows in water treatment plants serving several hundred residences.“Lack of mechanical robustness is a common cause of failure of previous attempts to scale-up biosorption using immobilized cells; in our work we wanted to make sure that this aspect is thoroughly addressed from the very beginning to ensure scalability,” Athanasiou says.After assessing the mechanical robustness of the yeast-laden capsules, the researchers constructed a proof-of-concept packed-bed biofilter, capable of treating trace lead-contaminated water and meeting U.S. Environmental Protection Agency drinking water guidelines while operating continuously for 12 days.This process would likely consume less energy than existing physicochemical processes for removing trace inorganic compounds from water, such as precipitation and membrane filtration, the researchers say.This approach, rooted in circular economy principles, could minimize waste and environmental impact while also fostering economic opportunities within local communities. Although numerous lead contamination incidents have been reported in various locations in the United States, this approach could have an especially significant impact in low-income areas that have historically faced environmental pollution and limited access to clean water, and may not be able to afford other ways to remediate it, the researchers say.“We think that there’s an interesting environmental justice aspect to this, especially when you start with something as low-cost and sustainable as yeast, which is essentially available anywhere,” Gokhale says.The researchers are now exploring strategies for recycling and replacing the yeast once they’re used up, and trying to calculate how often that will need to occur. They also hope to investigate whether they could use feedstocks derived from biomass to make the hydrogels, instead of fossil-fuel-based polymers, and whether the yeast can be used to capture other types of contaminants.“Moving forward, this is a technology that can be evolved to target other trace contaminants of emerging concern, such as PFAS or even microplastics,” Stathatou says. “We really view this as an example with a lot of potential applications in the future.”The research was funded by the Rasikbhai L. Meswani Fellowship for Water Solutions, the MIT Abdul Latif Jameel Water and Food Systems Lab (J-WAFS), and the Renewable Bioproducts Institute at Georgia Tech. More

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      in Energy

      Q&A: Claire Walsh on how J-PAL’s King Climate Action Initiative tackles the twin climate and poverty crises

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      The King Climate Action Initiative (K-CAI) is the flagship climate change program of the Abdul Latif Jameel Poverty Action Lab (J-PAL), which innovates, tests, and scales solutions at the nexus of climate change and poverty alleviation, together with policy partners worldwide.

      Claire Walsh is the associate director of policy at J-PAL Global at MIT. She is also the project director of K-CAI. Here, Walsh talks about the work of K-CAI since its launch in 2020, and describes the ways its projects are making a difference. This is part of an ongoing series exploring how the MIT School of Humanities, Arts, and Social Sciences is addressing the climate crisis.

      Q: According to the King Climate Action Initiative (K-CAI), any attempt to address poverty effectively must also simultaneously address climate change. Why is that?

      A: Climate change will disproportionately harm people in poverty, particularly in low- and middle-income countries, because they tend to live in places that are more exposed to climate risk. These are nations in sub-Saharan Africa and South and Southeast Asia where low-income communities rely heavily on agriculture for their livelihoods, so extreme weather — heat, droughts, and flooding — can be devastating for people’s jobs and food security. In fact, the World Bank estimates that up to 130 million more people may be pushed into poverty by climate change by 2030.

      This is unjust because these countries have historically emitted the least; their people didn’t cause the climate crisis. At the same time, they are trying to improve their economies and improve people’s welfare, so their energy demands are increasing, and they are emitting more. But they don’t have the same resources as wealthy nations for mitigation or adaptation, and many developing countries understandably don’t feel eager to put solving a problem they didn’t create at the top of their priority list. This makes finding paths forward to cutting emissions on a global scale politically challenging.

      For these reasons, the problems of enhancing the well-being of people experiencing poverty, addressing inequality, and reducing pollution and greenhouse gases are inextricably linked.

      Q: So how does K-CAI tackle this hybrid challenge?

      A: Our initiative is pretty unique. We are a competitive, policy-based research and development fund that focuses on innovating, testing, and scaling solutions. We support researchers from MIT and other universities, and their collaborators, who are actually implementing programs, whether NGOs [nongovernmental organizations], government, or the private sector. We fund pilots of small-scale ideas in a real-world setting to determine if they hold promise, followed by larger randomized, controlled trials of promising solutions in climate change mitigation, adaptation, pollution reduction, and energy access. Our goal is to determine, through rigorous research, if these solutions are actually working — for example, in cutting emissions or protecting forests or helping vulnerable communities adapt to climate change. And finally, we offer path-to-scale grants which enable governments and NGOs to expand access to programs that have been tested and have strong evidence of impact.

      We think this model is really powerful. Since we launched in 2020, we have built a portfolio of over 30 randomized evaluations and 13 scaling projects in more than 35 countries. And to date, these projects have informed the scale ups of evidence-based climate policies that have reached over 15 million people.

      Q: It seems like K-CAI is advancing a kind of policy science, demanding proof of a program’s capacity to deliver results at each stage. 

      A: This is one of the factors that drew me to J-PAL back in 2012. I majored in anthropology and studied abroad in Uganda. From those experiences I became very passionate about pursuing a career focused on poverty reduction. To me, it is unfair that in a world full of so much wealth and so much opportunity there exists so much extreme poverty. I wanted to dedicate my career to that, but I’m also a very detail-oriented nerd who really cares about whether a program that claims to be doing something for people is accomplishing what it claims.

      It’s been really rewarding to see demand from governments and NGOs for evidence-informed policymaking grow over my 12 years at J-PAL. This policy science approach holds exciting promise to help transform public policy and climate policy in the coming decades.  

      Q: Can you point to K-CAI-funded projects that meet this high bar and are now making a significant impact?

      A: Several examples jump to mind. In the state of Gujarat, India, pollution regulators are trying to cut particulate matter air pollution, which is devastating to human health. The region is home to many major industries whose emissions negatively affect most of the state’s 70 million residents.

      We partnered with state pollution regulators — kind of a regional EPA [Environmental Protection Agency] — to test an emissions trading scheme that is used widely in the U.S. and Europe but not in low- and middle-income countries. The government monitors pollution levels using technology installed at factories that sends data in real time, so the regulator knows exactly what their emissions look like. The regulator sets a cap on the overall level of pollution, allocates permits to pollute, and industries can trade emissions permits.

      In 2019, researchers in the J-PAL network conducted the world’s first randomized, controlled trial of this emissions trading scheme and found that it cut pollution by 20 to 30 percent — a surprising reduction. It also reduced firms’ costs, on average, because the costs of compliance went down. The state government was eager to scale up the pilot, and in the past two years, two other cities, including Ahmedabad, the biggest city in the state, have adopted the concept.

      We are also supporting a project in Niger, whose economy is hugely dependent on rain-fed agriculture but with climate change is experiencing rapid desertification. Researchers in the J-PAL network have been testing training farmers in a simple, inexpensive rainwater harvesting technique, where farmers dig a half-moon-shaped hole called a demi-lune right before the rainy season. This demi-lune feeds crops that are grown directly on top of it, and helps return land that resembled flat desert to arable production.

      Researchers found that training farmers in this simple technology increased adoption from 4 percent to 94 percent and that demi-lunes increased agricultural output and revenue for farmers from the first year. K-CAI is funding a path-to-scale grant so local implementers can teach this technique to over 8,000 farmers and build a more cost-effective program model. If this takes hold, the team will work with local partners to scale the training to other relevant regions of the country and potentially other countries in the Sahel.

      One final example that we are really proud of, because we first funded it as a pilot and now it’s in the path to scale phase: We supported a team of researchers working with partners in Bangladesh trying to reduce carbon emissions and other pollution from brick manufacturing, an industry that generates 17 percent of the country’s carbon emissions. The scale of manufacturing is so great that at some times of year, Dhaka (the capital of Bangladesh) looks like Mordor.

      Workers form these bricks and stack hundreds of thousands of them, which they then fire by burning coal. A team of local researchers and collaborators from our J-PAL network found that you can reduce the amount of coal needed for the kilns by making some low-cost changes to the manufacturing process, including stacking the bricks in a way that increases airflow in the kiln and feeding the coal fires more frequently in smaller rather than larger batches.

      In the randomized, controlled trial K-CAI supported, researchers found that this cut carbon and pollution emissions significantly, and now the government has invited the team to train 1,000 brick manufacturers in Dhaka in these techniques.

      Q: These are all fascinating and powerful instances of implementing ideas that address a range of problems in different parts of the world. But can K-CAI go big enough and fast enough to take a real bite out of the twin poverty and climate crisis?

      A: We’re not trying to find silver bullets. We are trying to build a large playbook of real solutions that work to solve specific problems in specific contexts. As you build those up in the hundreds, you have a deep bench of effective approaches to solve problems that can add up in a meaningful way. And because J-PAL works with governments and NGOs that have the capacity to take the research into action, since 2003, over 600 million people around the world have been reached by policies and programs that are informed by evidence that J-PAL-affiliated researchers produced. While global challenges seem daunting, J-PAL has shown that in 20 years we can achieve a great deal, and there is huge potential for future impact.

      But unfortunately, globally, there is an underinvestment in policy innovation to combat climate change that may generate quicker, lower-cost returns at a large scale — especially in policies that determine which technologies get adopted or commercialized. For example, a lot of the huge fall in prices of renewable energy was enabled by early European government investments in solar and wind, and then continuing support for innovation in renewable energy.

      That’s why I think social sciences have so much to offer in the fight against climate change and poverty; we are working where technology meets policy and where technology meets real people, which often determines their success or failure. The world should be investing in policy, economic, and social innovation just as much as it is investing in technological innovation.

      Q: Do you need to be an optimist in your job?

      A: I am half-optimist, half-pragmatist. I have no control over the climate change outcome for the world. And regardless of whether we can successfully avoid most of the potential damages of climate change, when I look back, I’m going to ask myself, “Did I fight or not?” The only choice I have is whether or not I fought, and I want to be a fighter. More