It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Tuesday, August 01, 2023
School meals would be even healthier if compliant with US nutrition standards, study finds
Aligning student meals to the 2020-2025 Dietary Guidelines for Americans would further support children’s well-being and cut healthcare costs into adulthood, say Friedman School of Nutrition Science and Policy researchers
IMAGE: FULLY SYNCHRONIZING SCHOOL MEALS WITH THE DIETARY GUIDELINES FOR AMERICANS, 2020-2025 COULD POSITIVELY IMPACT HUNDREDS OF THOUSANDS OF CHILDREN INTO THEIR ADULTHOOD, WITH THE ADDED BENEFIT OF SAVING BILLIONS IN LIFETIME MEDICAL COSTSview more
CREDIT: ALONSO NICHOLS/TUFTS UNIVERSITY
Today’s school meals are much healthier than they were for the parents of American kids, but still 1 in 4 school meals are of poor nutritional quality. The latest Dietary Guidelines for Americans (DGA), in place for 2020-25, call for meals with less sugar and salt and with more whole grains.
Fully synchronizing school meals with these new standards could positively impact hundreds of thousands of children into their adulthood, with the added benefit of saving billions in lifetime medical costs, investigators from the Friedman School of Nutrition Science and Policy at Tufts University report July 31 in The American Journal of Clinical Nutrition. By modeling the national implementation of updated school lunch guidelines, the research team found even incomplete compliance by schools would lead to overall reductions in short- and long-term health issues for participating K-12 students.
“On average, school meals are healthier than the food American children consume from any other source including at home, but we’re at a critical time to further strengthen their nutrition,” says senior author Dariush Mozaffarian, a cardiologist and Jean Mayer Professor of Nutrition at the Friedman School. “Our findings suggest a real positive impact on long-term health and healthcare costs with even modest updates to the current school meal nutrition standards.”
The researchers utilized a simulation model to derive a data-driven estimate of three changes to the school meal program, including limiting percent of energy from added sugar to lower than 10% of total energy per meal, requiring all grain foods to be whole grain, and lowering sodium content to the Chronic Disease Risk Reduction amount for sodium intake in the 2020-2025 DGA. A portion (35%) of these dietary changes were estimated to continue into adulthood. If all schools fully complied with the new standards, these were estimated to prevent more than 10,600 deaths per year due to fewer diet-related diseases, saving over $19 billion annually in healthcare-related costs during later adulthood. The worst-case estimate, in which schools remained with their current food offerings, saved a little over half as many lives and healthcare dollars.
School meals aligning to new dietary guidelines for added sugars, sodium, and whole grains would have modest, but important, short-term health benefits for children. For example, these changes were estimated to reduce elementary and middle school students’ body mass index (BMI) by 0.14 and systolic blood pressure by 0.13 mm Hg. Benefits were about half as large for high school students because fewer older students eat school-provided meals.
“Using a comparative risk assessment model, our estimations are based on the best available, nationally representative data on children and adults and the best available evidence on how dietary changes in childhood relate to BMI and blood pressure, how dietary changes persist into adulthood, and how diet influences disease in adulthood,” says first author Lu Wang, a postdoctoral fellow at the Friedman School. “Our new results indicate that even small changes to strengthen school nutrition policies can help students live longer, healthier lives.”
The study’s findings, which cannot prove the outcomes they describe but are derived from a mathematical model based on the best available demographic and health data, are timely given the United States Department of Agriculture’s recent commitment to updating the school meal nutrition standards to align with the 2020-2025 dietary guidelines. The price to fully implement new school meal standards is yet to be determined, but previous alignments suggest it would add at least another $1 billion nationally to the cost of these programs, or only about 5 percent of the total predicted annual long-term healthcare savings this change would yield.
Research reported in this article was supported by an award from the National Institutes of Health's National Heart, Lung, and Blood Institute (R01HL115189) and the Center for Science in the Public Interest. Complete information on authors, funders, methodology, and conflicts of interest is available in the published paper. The content is solely the responsibility of the authors and does not necessarily represent the official views of the funders.
IMAGE: CONCRETE IS THE MOST IMPORTANT BUILDING MATERIAL ON EARTH, BUT ITS PRODUCTION CAUSES A MASSIVE AMOUNT OF GLOBAL CARBON EMISSIONS. JOIN GEORGE AS HE DISCOVERS HOW A SURPRISING DISCOVERY IN 1973 COULD DRAMATICALLY CHANGE HOW WE MAKE CONCRETE FOREVER. HTTPS://YOUTU.BE/FET92F1C730view more
CREDIT: THE AMERICAN CHEMICAL SOCIETY
WASHINGTON, July 31, 2023 — Concrete is the most important building material on Earth, but its production causes a MASSIVE amount of global carbon emissions. Join George as he discovers how a surprising discovery in 1973 could dramatically change how we make concrete forever. https://youtu.be/fEt92F1c730
Reactions is a video series produced by the American Chemical Society and PBS Digital Studios. Subscribe to Reactions at http://bit.ly/ACSReactions and follow us on Twitter @ACSReactions.
The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.
To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.
IMAGE: THIS MAP OF RED OAK SEED SOURCES PROVIDES AN EXAMPLE OF A MAJOR THREAT TO AN IMPORTANT EFFORT AGAINST CLIMATE CHANGE: MAJOR GOVERNMENT AND PRIVATE FUNDING IS BEING INVESTED IN PLANTING TREES AS A POWERFUL TOOL TO FIGHT LOCAL AND GLOBAL WARMING. BUT NEW RESEARCH IN THE JOURNAL BIOSCIENCE, FROM WHICH THIS MAP IS ADAPTED, SHOWS A TROUBLING BOTTLENECK THAT COULD THREATEN THESE EFFORTS: U.S. TREE NURSERIES DON’T GROW CLOSE TO ENOUGH TREES—NOR HAVE THE SPECIES DIVERSITY NEEDED—TO MEET AMBITIOUS PLANTING GOALS.view more
CREDIT: ADAPTED FROM PETER CLARK/BIOSCIENCE
The REPLANT Act provides money for the US Forest Service to plant more than a billion trees in the next nine years. The World Economic Forum aims to help plant a trillion trees around the world by 2030. Many US cities have plans to shade their streets with millions of trees. Major government and private funding is being invested in planting trees as a powerful tool to fight climate change, protect water, clean air, and cool cities. In short, trees are hot.
But new research shows a troubling bottleneck that could threaten these efforts: U.S. tree nurseries don’t grow close to enough trees—nor have the species diversity needed—to meet ambitious plans.
The study was published in the journal Bioscience on July 31, 2023.
Seedling Scarcity
“Trees are this amazing natural solution to a lot of our challenges, including climate change. We urgently need to plant many millions of them,” says University of Vermont scientist Tony D’Amato who co-led the new research. “But what this paper points out is that we are woefully underserved by any kind of regional or national scale inventory of seedlings to get the job done.”
A team of 13 scientists, led by D’Amato and UVM post-doctoral scientist Peter Clark, studied 605 plant nurseries across twenty northern states. Only 56 of these grow and sell seedlings in the volumes needed for conservation and reforestation and only 14 of them were government-operated, they report. The team was more dismayed to discover an “overwhelming scarcity of seedlings,” they write, from different species and “seed collection zones”—trees adapted to local conditions and climate. In essence, forest nurseries tended to maintain a limited inventory of a select few species, electing to prioritize those valued for commercial timber production over species required for conservation, ecological restoration, or climate adaptation. Moreover, many areas had no locally adapted tree stock available. (See map for example.) And within the seedlings available, there were not enough types of trees and “future-climate-suitable” genetics to meet goals for conservation and forest restoration in a hot future.
“The world is thinking about a warming climate—can we plant towards that warming climate? We know we’re losing ecologically important species across North America and around the world. So, the goal is: can we restore these trees or replace them with similar species? It’s a powerful idea,” says UVM’s Peter Clark, the lead author on the new study. “But—despite the excitement and novelty of that idea in many policy and philanthropy circles—when push comes to shove, it's very challenging on the ground to actually find either the species or the seed sources needed.”
“The number of seedlings is a challenge,” Clark says, “but finding the diversity we need to restore ecologically complex forests—not just a few industrial workhorse species commonly used for commercial timber operations, like white pine—is an even bigger bottleneck.”
One extreme example is red spruce. This ecologically important species along hundreds of miles of eastern North America has been under stress for decades from climate change, pests, and land clearing. Yet, in their 20-state survey, the team only found two tree nurseries that had inventory of red spruce, a species from which many millions of seedlings are needed to meet restoration goals. “Remarkably, only 800 red spruce seedlings were commercially available for purchase in 2022,” the team reports in their new Bioscience study, “—enough to reforest less than one hectare.”
“It really points to just how bare the cupboard is when it comes to the diversity of options,” says Tony D’Amato, director of the Forestry Program in UVM’s Rubenstein School of Environment and Natural Resources, “but also the quantity that's needed to make any meaningful impact.”
Increased Investment
The team argues that dramatic increases in both seedling production and diversity at many regional nurseries will be central to any successful campaign to address climate change with tree planting. However, the novelty and risk involved, “likely generates uncertainty among forest nurseries, hampering investment,” they write. This appears to be especially true in regions, like the Northeast, where nurseries have declined over recent decades, the study reports, and where speculative investment—in growing new, future-climate-adapted, non-timber species and seedlots—may carry high financial risk.
Additionally, seedlings brought in from outside a region may be less likely to succeed. The new study reports that the vast majority (80%) of seedlings in the northern states, where the study was conducted, are produced in the North Central states—and very few in the Northeastern states. “Such concentration of production will hinder tree planting efforts,” they write, “because species and seed sources likely originate from similar geographic or bioclimatic zones.” On top of this challenge, seedlings are sensitive to stress. A misalignment between when seedlings are available—say in a southern nursery months before northern soils are frost free—and when they are needed, may doom their chances.
The team of researchers—including scientists from UVM; the USDA’s Northern Forest Research Stations in Minnesota, Michigan and New Hampshire; Minnesota Department of Natural Resources; Wisconsin Department of Natural Resources; Michigan Department of Natural Resources; University of Minnesota; the USDA’s Northern Institute of Applied Climate Science; and The Nature Conservancy (Albany, NY)—recommend a series of improvements from improved policy and financing to better training and expanded research.
For example, today government agencies, such as the US Forest Service and many US state governments, lack clear policies about the movement of tree species and tree genetics. They often rely on seed zones established in the 1970s based on historical climate conditions, not future ones—even though up-to-date guidelines for moving species under a warming climate are becoming available. Additionally, much forest policy and research has been framed around species important for timber production—rather than efforts to diversify species and climate-adapted seed-sourcing.
The team of scientists suggest that expanded federal and state investment will be needed to boost both public tree nurseries and seed collection efforts. “This strategy may stimulate production from private nurseries once a stable demand is apparent,” they write. In 2023, the federal government made an investment of $35 million in expanding federal nursery capacity. “However, given the existing (and growing) reforestation backlog, declines in nursery infrastructure, and complex needs for diverse seeds and seedlings, it is likely that substantially more public investment in the form of grants, loans, and cost-share programs will be needed to reinvigorate, diversify, and expand forest nurseries,” they write.
“People want trillions of trees,” says the University of Vermont’s Peter Clark, “but often, on the ground, it’s one old farmer walking around to collect acorns. There’s a massive disconnect.”
University of Vermont forest scientists Peter Clark and Tony D'Amato at an experimental forest in Vemont. They led new research showing a troubling bottleneck that could threaten efforts to fight climate change with tree planting: U.S. tree nurseries don’t grow close to enough trees—nor have the species diversity needed—to meet ambitious planting goals.
IMAGE: THIS BEVERAGE WITH 5% RICE FLOUR IN COCONUT WATER (LEFT) BECAME SLIGHTLY DARKER AND STICKIER AFTER BEING TREATED WITH HEAT (RIGHT).view more
CREDIT: DIANA C. CASTRO-RODRÍGUEZ
Whether they’re made from soybeans, almonds, oats, or just sourced straight from the cow, milk products must go through heat treatment to prevent harmful bacterial growth and keep them safe. But understanding how these processes affect new, plant-based milk formulations could make the beverages more pleasant to drink as well. Researchers reporting in ACS Omega have discovered how pasteurization and sterilization affects the look and feel of one such drink made from coconut and rice.
Despite the ubiquity of dairy-based foods, many people have some form of lactose intolerance — up to 36% of Americans, according to the National Institutes of Health. As a result, many turn to lactose-free, plant-based alternatives, some of which have added health benefits. For example, one drink under development combines rice flour and coconut water: Rice is hypoallergenic and high in fiber, and coconut water is hydrating and low in calories. To understand how heat treatment might alter this beverage, Jorge Yáñez-Fernández, Diana Castro-Rodríguez and colleagues wanted to test the formulation against two different high-temperature processing steps.
The team used three versions of the beverage, containing either 2%, 5% or 8% rice flour, with coconut water comprising the rest. These were heated either by pasteurization in a water bath at 140 degrees Fahrenheit or by sterilization in an autoclave at almost 250 degrees Fahrenheit. After these treatments, the team found that the starches in the rice flour gelatinized and underwent the Maillard reaction, producing a slightly darkened color and stickier fluid for all three versions. Additionally, the drinks’ acidities increased, and there were fewer sugars, which may alter the way they taste. The team plans to use these results to inform future research into similar, dairy-free, “functional beverages,” including those that could one day contain probiotic, lactic-acid bacteria.
The authors acknowledge funding from the Instituto Politecnico Nacional of Mexico.
The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.
To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.
“Role of Thermal Process on the Physicochemical and Rheological Properties and Antioxidant Capacity of a New Functional Beverage Based on Coconut Water and Rice Flour”
ARTICLE PUBLICATION DATE
28-Jul-2023
Plant-based protein intake may reduce kidney disease risk
IMAGE: VISUAL ABSTRACT FOR "ASSOCIATION OF PLANT PROTEIN INTAKE WITH RISK OF INCIDENT CKD: A UK BIOBANK STUDY" BY GA YOUNG HEO ET AL: HTTPS://WWW.AJKD.ORG/ARTICLE/S0272-63862300742-4/FULLTEXT IN THIS LARGE, PROSPECTIVE COHORT STUDY, GREATER DIETARY PLANT PROTEIN INTAKE WAS ASSOCIATED WITH A LOWER RISK OF INCIDENT CKD. FURTHER, INTERVENTIONAL STUDIES DEMONSTRATING KIDNEY PROTECTIVE BENEFITS OF PLANT PROTEIN INTAKE ARE WARRANTED.view more
CREDIT: AJKD 2023
Plant-based diets confer various health benefits, including lowering the risk of cardiovascular disease and certain cancers. However, the relationship between plant protein intake and the risk of chronic kidney disease (CKD) remains unclear. This study led by Ga Young Heo aimed to investigate the association between plant protein intake and the development of CKD. Using the UK biobank study data, the researchers found that participants with a higher plant protein intake had a lower risk of developing CKD. This finding suggests that a higher dietary intake of plant-based protein may be beneficial for kidney health and provide insight into dietary interventions to prevent CKD in primary care settings.
ARTICLE TITLE: Association of Plant Protein Intake With Risk of Incident CKD: A UK Biobank Study
AUTHORS: Ga Young Heo, MD, Hee Byung Koh, MD, Hyo Jeong Kim, MD, Kyung Won Kim, MD, Chan-Young Jung, MD, Hyung Woo Kim, MD, Tae Ik Chang, MD, PhD, Jung Tak Park, MD, PhD, Tae-Hyun Yoo, MD, PhD, Shin-Wook Kang, MD, PhD, and Seung Hyeok Han, MD, PhD
RICHLAND, Wash. – A novel method to extract lignin could help spin wheat straw into gold. Lignin produced using the new method was color-neutral, odorless and homogenous, an advance that could make this carbon-neutral material a more viable candidate for development of high-value products.
Reporting in the Proceedings of the National Academy of Sciences, the Washington State University researchers extracted up to 93% lignin with up to 98% purity from wheat straw, producing a significant amount of material in a uniform way that could make it more attractive for industry use.
“This method allows us to extract lignin from plant material in its native form and at a high yield,” said Xiao Zhang, professor in WSU’s Gene and Linda Voiland School of Chemical Engineering and Bioengineering, who led the work. “We were able to demonstrate to industry that it is possible to make color-neutral and odorless lignin, and we can make quite a bit of the material to begin evaluating its applications.”
Lignin is the second most abundant renewable carbon source, making up about 30% of the non-fossil fuel-based carbon on Earth. It is in all vascular plants, where it forms cell walls and provides plants with rigidity. Lignin allows trees to stand, gives vegetables their firmness and makes up about 20%-35% of the weight of wood. The material holds great promise as a precursor for biobased materials and fuels, but it is also notoriously difficult to extract from plants.
The material is usually separated during papermaking and biorefining, but these processes often contaminate and significantly alter lignin’s chemical and physical properties, decreasing its value. So most lignin is either burned to produce fuel and electricity or used in low-value products, such as for cement additives or as a binder in animal feed. Producing a more homogenous lignin provides the opportunity to pursue high-value material development to replace petroleum-derived plastics and polymers.
“Because of its heterogeneity, lignin can’t be used as a valuable material despite centuries of effort,” said Zhang, who holds a joint appointment with Pacific Northwest National Laboratory. “The saying has been that ‘you can make anything out of lignin, except money.’ There’s so much heterogeneity in the molecules that nobody can reliably make things out of it.”
In their work, the researchers used a solvent to separate the lignin from wheat straw and were able to preserve and control its key properties, producing a more uniform molecule with a consistent molecular weight that makes it more useful for industry. The lignin extracted was light-colored, which is more like the lignin that exists in nature.
Because it is an electron-rich compound, the lignin had a strong affinity for the solvent, and the electron interactions allowed the researchers to extract it with minimal chemical reactions, which protected its natural molecular structure that is so often easily damaged in chemical separations.
WSU’s Office of Commercialization has filed a provisional patent and will assist the researchers for the scale-up and eventual commercialization of this technology. To make it more viable for industry applications, the research team is working to decrease the lengthy processing time and the amount of purification chemicals needed.
The work was done in collaboration with Edoardo Apra, a computational scientist from PNNL, and Professor Art Ragauskas from University of Tennessee, Knoxville. It was supported by the National Science Foundation and the U.S. Department of Agriculture National Institute of Food and Agriculture as well as WSU’s Commercialization Gap fund.
Lignin with controlled structural properties by N-heterocycle-based deep eutectic solvent extraction
ARTICLE PUBLICATION DATE
4-Aug-2023
MIT engineers create an energy-storing supercapacitor from ancient materials
Made of cement, carbon black, and water, the device could provide cheap and scalable energy storage for renewable energy sources
ANCIENT PEOPLES COULD HAVE DONE THIS
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
IMAGE: SINCE THE NEW “SUPERCAPACITOR” CONCRETE WOULD RETAIN ITS STRENGTH, A HOUSE WITH A FOUNDATION MADE OF THIS MATERIAL COULD STORE A DAY’S WORTH OF ENERGY PRODUCED BY SOLAR PANELS OR WINDMILLS, AND ALLOW IT TO BE USED WHENEVER IT’S NEEDED.view more
CREDIT: IMAGE COURTESY OF FRANZ-JOSEF ULM, ADMIR MASIC, AND YANG-SHAO HORN
CAMBRIDGE, Mass. --Two of humanity's most ubiquitous historical materials, cement and carbon black (which resembles very fine charcoal), may form the basis for a novel, low-cost energy storage system, according to a new study. The technology could facilitate the use of renewable energy sources such as solar, wind, and tidal power by allowing energy networks to remain stable despite fluctuations in renewable energy supply.
The two materials, the researchers found, can be combined with water to make a supercapacitor — an alternative to batteries — that could provide storage of electrical energy. As an example, the MIT researchers who developed the system say that their supercapacitor could eventually be incorporated into the concrete foundation of a house, where it could store a full day’s worth of energy while adding little (or no) to the cost of the foundation and still providing the needed structural strength. The researchers also envision a concrete roadway that could provide contactless recharging for electric cars as they travel over that road.
The simple but innovative technology is described in a forthcoming paper in the journal PNAS, in a paper by MIT professors Franz-Josef Ulm, Admir Masic, and Yang-Shao Horn, and four others at MIT and at the Wyss Institute.
Capacitors are in principle very simple devices, consisting of two electrically conductive plates immersed in an electrolyte and separated by a membrane. When a voltage is applied across the capacitor, positively charged ions from the electrolyte accumulate on the negatively charged plate, while the positively charged plate accumulates negatively charged ions. Since the membrane in between the plates blocks charged ions from migrating across, this separation of charges creates an electric field between the plates, and the capacitor becomes charged. The two plates can maintain this pair of charges for a long time and then deliver them very quickly when needed. Supercapacitors are simply capacitors that can store exceptionally large charges.
The amount of power a capacitor can store depends on the total surface area of its conductive plates. The key to the new supercapacitors developed by this team comes from a method of producing a cement-based material with an extremely high internal surface area due to a dense, interconnected network of conductive material within its bulk volume. The researchers achieved this by introducing carbon black — which is highly conductive — into a concrete mixture along with cement powder and water, and letting it cure. The water naturally forms a branching network of openings within the structure as it reacts with cement, and the carbon migrates into these spaces to make wire-like structures within the hardened cement. These structures have a fractal-like structure, with larger branches sprouting smaller branches, and those sprouting even smaller branchlets, and so on, ending up with an extremely large surface area within the confines of a relatively small volume. The material is then soaked in a standard electrolyte material, such as potassium chloride, a kind of salt, which provides the charged particles that accumulate on the carbon structures. Two electrodes made of this material, separated by a thin space or an insulating layer, form a very powerful supercapacitor, the researchers found.
The two plates of the capacitor function just like the two poles of a rechargeable battery of equivalent voltage: When connected to a source of electricity, as with a battery, energy gets stored in the plates, and then when connected to a load, the electrical current flows back out to provide power.
“The material is fascinating,” Masic says, “because you have the most-used manmade material in the world, cement, that is combined with carbon black, that is a well-known historical material — the Dead Sea Scrolls were written with it. You have these at least two-millennia-old materials that when you combine them in a specific manner you come up with a conductive nanocomposite, and that’s when things get really interesting.”
As the mixture sets and cures, he says, “The water is systematically consumed through cement hydration reactions, and this hydration fundamentally affects nanoparticles of carbon because they are hydrophobic (water repelling).” As the mixture evolves, “the carbon black is self-assembling into a connected conductive wire,” he says. The process is easily reproducible, with materials that are inexpensive and readily available anywhere in the world. And the amount of carbon needed is very small — as little as 3 percent by volume of the mix — to achieve a percolated carbon network, Masic says.
Supercapacitors made of this material have great potential to aid in the world’s transition to renewable energy, Ulm says. The principal sources of emissions-free energy, wind, solar, and tidal power, all produce their output at variable times that often do not correspond to the peaks in electricity usage, so ways of storing that power are essential. “There is a huge need for big energy storage,” he says, and existing batteries are too expensive and mostly rely on materials such as lithium, whose supply is limited, so cheaper alternatives are badly needed. “That’s where our technology is extremely promising, because cement is ubiquitous,” Ulm says.
The team calculated that a block of nanocarbon-black-doped concrete that is 45 cubic meters (or yards) in size — equivalent to a cube about 3.5 meters across — would have enough capacity to store about 10 kilowatt-hours of energy, which is considered the average daily electricity usage for a household. Since the concrete would retain its strength, a house with a foundation made of this material could store a day’s worth of energy produced by solar panels or windmills and allow it to be used whenever it’s needed. And, supercapacitors can be charged and discharged much more rapidly than batteries.
After a series of tests used to determine the most effective ratios of cement, carbon black, and water, the team demonstrated the process by making small supercapacitors, about the size of some button-cell batteries, about 1 centimeter across and 1 millimeter thick, that could each be charged to 1 volt, comparable to a 1-volt battery. They then connected three of these to demonstrate their ability to light up a 3-volt light-emitting diode (LED). Having proved the principle, they now plan to build a series of larger versions, starting with ones about the size of a typical 12-volt car battery, then working up to a 45-cubic-meter version to demonstrate its ability to store a house-worth of power.
There is a tradeoff between the storage capacity of the material and its structural strength, they found. By adding more carbon black, the resulting supercapacitor can store more energy, but the concrete is slightly weaker, and this could be useful for applications where the concrete is not playing a structural role or where the full strength-potential of concrete is not required. For applications such as a foundation, or structural elements of the base of a wind turbine, the “sweet spot” is around 10 percent carbon black in the mix, they found.
Another potential application for carbon-cement supercapacitors is for building concrete roadways that could store energy produced by solar panels alongside the road and then deliver that energy to electric vehicles traveling along the road using the same kind of technology used for wirelessly rechargeable phones. A related type of car-recharging system is already being developed by companies in Germany and the Netherlands, but using standard batteries for storage.
Initial uses of the technology might be for isolated homes or buildings or shelters far from grid power, which could be powered by solar panels attached to the cement supercapacitors, the researchers say.
Ulm says that the system is very scalable, as the energy-storage capacity is a direct function of the volume of the electrodes. “You can go from 1-millimeter-thick electrodes to 1-meter-thick electrodes, and by doing so basically you can scale the energy storage capacity from lighting an LED for a few seconds, to powering a whole house,” he says.
Depending on the properties desired for a given application, the system could be tuned by adjusting the mixture. For a vehicle-charging road, very fast charging and discharging rates would be needed, while for powering a home “you have the whole day to charge it up,” so slower-charging material could be used, Ulm says.
“So, it’s really a multifunctional material,” he adds. Besides its ability to store energy in the form of supercapacitors, the same kind of concrete mixture can be used as a heating system, by simply applying electricity to the carbon-laced concrete.
Ulm sees this as “a new way of looking toward the future of concrete as part of the energy transition.”
The research team also included postdocs Nicolas Chanut and Damian Stefaniuk at MIT’s Department of Civil and Environmental Engineering, James Weaver at the Wyss Institute for Biologically Inspired Engineering, and Yunguang Zhu in MIT’s Department of Mechanical Engineering. The work was supported by the MIT Concrete Sustainability Hub, with sponsorship by the Concrete Advancement Foundation.
MIT engineers have created a “supercapacitor” made of ancient, abundant materials, that can store large amounts of energy. Made of just cement, water, and carbon black (which resembles powdered charcoal), the device could form the basis for inexpensive systems that store intermittently renewable energy, such as solar or wind energy.
CREDIT
Image courtesy of Franz-Josef Ulm, Admir Masic, and Yang-Shao Horn
