GT/ Cloud engineering could be more effective ‘painkiller’ for global warming than previously thought
Energy & green technology biweekly vol.68, 17th April — 3rd May
TL;DR
- Cloud ‘engineering’ emerges as a potentially potent tool for climate cooling due to increased cloud cover, according to recent research findings.
- Wirelessly connected devices, serving various purposes from machinery monitoring to agricultural sensing, lack reliable power sources in remote areas, prompting the search for alternative energy solutions.
- A novel type of battery presents a promising solution for powering wireless devices, addressing the challenge of inaccessible electrical sources.
- Researchers achieve a significant milestone with a 16.94% power conversion efficiency in a new four-terminal organic solar cell design, incorporating a transparent ultrathin silver electrode.
- Efficient extraction of protein from brewers’ spent grain reaches over 80%, potentially impacting resource utilization in brewing byproduct management.
- Nanoscale imaging reveals the corrosive effects on ruthenium dioxide crystals, a crucial element in hydrogen production, highlighting the need for more durable catalysts.
- Carbon dioxide and lignin, a wood component, form the basis of a novel alternative to petroleum-based plastics, offering a sustainable solution with low-cost byproducts.
- Groundbreaking progress in battery technology introduces a novel cathode material for rechargeable magnesium batteries, enabling efficient operation even at low temperatures.
- Engineered bacteria produce a plastic modifier enhancing renewably sourced plastic’s processability, fracture resistance, and biodegradability, opening avenues for greener plastic production.
- Machine learning connects low-magnitude microearthquakes to subsurface rock permeability, potentially improving geothermal energy extraction techniques. Additionally, research explores using depleted oil and natural gas reservoirs for carbon-free hydrogen fuel storage, advancing clean energy solutions.
- And more!
Green Technology Market
Green technology is an applicable combination of advanced tools and solutions to conserve natural resources and environment, minimize or mitigate negative impacts from human activities on the environment, and ensure sustainability development. Green technology is also referred to as clean technology or environmental technology which includes technologies, such as IoT, AI, analytics, blockchain, digital twin, security, and cloud, which collect, integrate, and analyze data from various real-time data sources, such as sensors, cameras, and Global Positioning System (GPS).
Green technology, also known as sustainable technology, protects the environment by using various forms of sustainable energy. Some of the best examples of green technologies include solar panels, LED lighting, wind energy, electric vehicles, vertical farming, and composting.
The global Green Technology and Sustainability market size to grow from USD 11.2 billion in 2020 to USD 36.6 billion by 2025, at a Compound Annual Growth Rate (CAGR) of 26.6% during the forecast period. The growing consumer and industrial interest for the use of clean energy resources to conserve environment and increasing use of Radio Frequency Identification sensors across industries are driving the adoption of green technology and sustainability solutions and services in the market.
Latest Research
Substantial cooling effect from aerosol-induced increase in tropical marine cloud cover
by Ying Chen, Jim Haywood, Yu Wang, Florent Malavelle, George Jordan, Amy Peace, Daniel G. Partridge, Nayeong Cho, Lazaros Oreopoulos, Daniel Grosvenor, Paul Field, Richard P. Allan, Ulrike Lohmann in Nature Geoscience
Cloud ‘engineering’ could be more effective for climate cooling than previously thought, because of the increased cloud cover produced, new research shows.
In a study, researchers at the University of Birmingham found that marine cloud brightening (MCB), also known as marine cloud engineering, works primarily by increasing the amount of cloud cover, accounting for 60–90% of the cooling effect. Previous models used to estimate the cooling effects of MCB have focused on the ability of aerosol injection to produce a brightening effect on the cloud, which in turn increases the amount of sunlight reflected back into space.
The practice of MCB has attracted much attention in recent years as a way of offsetting the global warming effects caused by humans and buying some time while the global economy decarbonises. It works by spraying tiny particles, or aerosols, into the atmosphere where they mix with clouds and with the primary aim of increasing the amount of sunlight that clouds can reflect.
Experiments with the technique are already being used in Australia in an attempt to reduce bleaching on the Great Barrier Reef. However the ways in which MCB creates a cooling effect, and the ways in which clouds will respond to aerosols, are still poorly understood, because of variable effects such as the confounding from co-varying meteorological conditions.
To investigate the phenomenon, the researchers created a ‘natural experiment’, using aerosol injection from the effusive eruption of Kilauea volcano in Hawaii to study the interactions between these natural aerosols, clouds, and climate.
Using machine learning and historic satellite and meteorological data, the team created a predictor to show that how the cloud would behave during periods when the volcano was inactive. This predictor enabled them to identify clearly the impacts on the clouds that had been directly caused by the volcanic aerosols.
They were able to show that the cloud cover relatively increased by up to 50% during the periods of volcanic activity, producing a cooling effect of up to -10 W m-2 regionally. Global heating and cooling is measured in watts per square metre, with a negative figure indicating cooling. Note that doubling CO2 would lead to a warming effect of +3.7 W m-2 approximately on a global average. The research was carried out in collaboration with the Met Office, the Universities of Edinburgh, Reading and Leeds, ETH Zurich in Switzerland, and the University of Maryland and NASA in USA.
Lead author, Dr Ying Chen, of the University of Birmingham, said: “Our findings show that marine cloud brightening could be more effective as a climate intervention than climate models have suggested previously. Of course, while it could be useful, MCB does not address the underlying causes of global warming from greenhouse gases produced by human activity. It should therefore be regarded as a ‘painkiller’, rather than a solution, and we must continue to improve fundamental understanding of aerosol’s impacts on clouds, further research on global impacts and risks of MCB, and search for ways to decarbonise human activities.”
Direct conversion of thermal energy to stored electrochemical energy via a self-charging pyroelectrochemical cell
by Tim Kowalchik, Fariha Khan, Danielle Horlacher, Shad Roundy, Roseanne Warren in Energy & Environmental Science
Today wirelessly connected devices are performing an expanding array of applications, such as monitoring the condition of engines and machinery and remote sensing in agricultural settings. Systems known as the “Internet of Things” (IoT), hold much potential for improving the efficiency and safety of the equipment.
Yet stumbling blocks remain for IoT, thwarting many potential applications. How do you power these devices in situations where and when reliable electrical sources are not practically available?
Research from the University of Utah’s College of Engineering points to a possible solution in the form of a novel type of battery called a pyroelectrochemical cell (PEC). The device was developed and tested in the research labs of Roseanne Warren and Shad Roundy, both associate professors of mechanical engineering.
“It’s our idea for an integrated device that could harvest ambient thermal energy and convert it directly into stored electrochemical energy in the form of a supercapacitor or battery with applications for the Internet of things and distributed sensors,” said Warren, the senior author on a new study that demonstrates a proof of concept.
“We’re talking very low levels of energy harvesting, but the ability to have sensors that can be distributed and not need to be recharged in the field is the main advantage,” she added. “We explored the basic physics of it and found that it could generate a charge with an increase in temperature or a decrease in temperature.”
The device is charged by changing temperatures in the surrounding environment, whether it’s inside a car or aircraft or just under the soil in an agricultural environment. In theory, the PEC could power sensors for IoT applications that would otherwise be impractical to recharge. A solar cell would work fine in some situations, according to Roundy, a co-author of the study.
“But in a lot of environments, you run into two problems,” said Roundy. “One is that it gets dirty over time. Solar cells have to be kept clean. So in these types of applications, they get dirty and their power degrades. And then there are a lot of applications where you just don’t have sunlight available. For example, we work on soil sensors that we put just under the top surface of the soil. You’re not going to get any sunlight.”
The PEC uses a pyroelectric composite material, as the separator in an electrochemical cell. The material consists of porous polyvinylidene fluoride (PVDF) and barium titanate nanoparticles. This material’s electrical properties change as it’s heated or cooled, which decreases or increases the polarization of the pyroelectric separator Changing temperatures create an electric field inside the cell, pushing ions around and enabling the cell store to energy.
“It stores electricity in what’s called an electric double layer, which stores the charge in positive and negative layers of ions. This is a glorified capacitor,” said lead author Tim Kowalchik, a graduate student in Warren’s lab. “When you heat and cool the system and you’re storing electrochemical energy, you’re changing the amount of positive or negative ions that are in those layers.”
The new study tested the lab’s theory of how the cell would operate.
“We had a predicted model of function that included what we called an ‘orientation effect’ in the paper,” Kowalchik said. “If we change the reverse the orientation of separator in the cell, it should drive ions the other way. This is a change we can make to the system that will show a different result that we can gather.”
The team’s experiments were set up to determine if the cells would respond as they predicted. Besides the orientation effect, there were heating vs. cooling effects that needed to be tested.
“If you heat the thing one way, you should get something to happen. If you cool it first, you should get something to happen and that should show up differently,” Kowalchik said. “We did that with a process called amperometry. You put a voltage across it and you hold that voltage constant and measure current. Your energy into the system is constant if nothing changes; if there is energy going into the system, the current changes.”
The cell did respond as the team theorized it would, but can it work outside a lab? That’s the next question Warren seeks to address. One of her students is now undertaking circuit modeling to design a cell and optimize its function.
“Now we start to change different parameters,” Warren said. “How can we improve the energy harvesting and storage and the combination of the two? And then after that would be a real-world field demonstration.”
The cell could produce up to 100 microjoules per square centimeter from a single heating/cooling cycle, which is not much energy, but enough to be useful for IoT purposes, according to the research.
“You want to monitor the condition of your car, the condition of machines, the condition of plants and soil and those kinds of things. Those types of sensors are generally going to be quite a bit lower power than your smartwatch or your phone, which have a display and they’re transmitting a lot of data,” Roundy said. “The sensors we’re talking about might just give periodic updates and they operate autonomously. They don’t have an interface or a screen.”
Four‐Terminal Tandem Based on a PM6:L8‐BO Transparent Solar Cell and a 7 nm Ag Layer Intermediate Electrode
by Francisco Bernal‐Texca, Jordi Martorell in Solar RRL
Researchers at ICFO have fabricated a new four-terminal organic solar cell with a tandem configuration with a 16.94% power conversion efficiency (PCE). The new device is composed by a highly transparent front cell that incorporates a transparent ultrathin silver (Ag) electrode of only 7nm, which ensures its efficient operation.
Two-terminal tandem organic solar cells (OSCs) represent one of the most promising approaches to address the transmission and thermalization losses in single-junction solar cells. These organic solar cells consist of front and rear subcells with varying bandgaps, enabling broader absorption and use of the solar spectrum. However, achieving optimal performance in such configurations demands a sufficient current balance between the two subcells. Moreover, fabricating tandem organic solar cells of these types are challenging because they need a robust interconnection layer capable of facilitating efficient charge recombination while maintaining high transparency.
The four-terminal tandem configuration has emerged as a highly efficient alternative strategy in solar cell design. Unlike the two-terminal approach, this configuration features separate electrical connections for the transparent front cell and the opaque back cell. Consequently, the issue of electrical current matching is no longer a limiting factor. This setup enables greater flexibility in selecting the bandgaps of each cell of the tandem, thereby optimizing photon absorption and enhancing the overall efficiency of solar energy production.
Now, in a new study, ICFO researchers Francisco Bernal-Texca, and Prof. Jordi Martorell describe the fabrication of a four-terminal tandem organic solar cell that has achieved a 16.94% power conversion efficiency (PCE). Central to this achievement is the fabrication of an ultrathin transparent silver electrode, a critical component that played a pivotal role in optimizing the performance of the tandem solar cell.
To fabricate the new device, the researchers first explored the organic materials destined for the photoactive layer of both cells. They examined the effectiveness of three distinct blends for the front cell, which is designed to harvest the high-energy photons. The blend that performed the best, named PM6:L8-BO, was finally chosen. For the back opaque cell, the researchers decided to use the PTB7-Th:O6T-4F blend, with a narrow bandgap, which makes it better suited to absorb the infrared part of the spectrum (low-energy photons).
After choosing the blends, the researchers used a numerical approach to design the four-tandem OSC’s final structure. They used the matrix formalism combined with the conventional inverse problem-solving methodology to find the optimal performance and the final configuration of the solar device.
The fabrication of an ultra-thin transparent silver electrode with a thickness of only 7nm was the key ingredient in the current research. This element was placed at the back of the front cell, ensuring a good light transmission to power the back cell. Conventional top Ag electrodes utilized for transparent solar cell applications typically range in thickness from 9 to 15 nm.
Its production demanded meticulous control of laboratory conditions to ensure precision and consistency. The electrode was then stacked with three dielectric layers alternating tungsten trioxide (WO3) and lithium fluoride (LiF). This photonic multilayer structure has a crucial role, because it is positioned between the two cells to facilitate efficient and uniform light distribution. “This structure exhibits a high transmission in the 750–1000 nm range and a high reflectivity in the 500–700 nm range,” researchers wrote.
“The development of a transparent silver intermediate electrode is crucial for the efficient operation of the solar cell. It must present a delicate balance, being transparent enough to allow light to reach the back cell while maintaining high electrical conductivity to ensure the optimal performance of the front cell,” said Francisco Bernal, ICFO researcher and first author of the study. “Being able to fabricate an electrode of only 7nm without observing losses in the front transparent cells is a significant advancement in the field of transparent cells.”
The researchers tested the photovoltaic performance of the device under 1 sun of illumination with a solar simulator and measured its quantum efficiency. The device achieved a 16,94% of power conversion efficiency which, to date, would be the highest reached for a four-terminal tandem organic cell. The authors of the study remark that the current official record in efficiency for organic tandem devices is 14,2% and that the last reported PCE for 4-terminal organic tandems is 6.5% .
“Our research holds potential applications in photoelectochemical cells (PEC), addressing crucial electrical requirements such as providing the necessary voltage to surpass established for driving water splitting or CO2 reduction reactions like in SOREC2 project,” explains Prof. Jordi Martorell, researcher at ICFO and SOREC2 project coordinator. “The methodology for the design and implementation of the four-terminal tandem structure could be applied to design news systems where an adequate distribution of light in the elements is crucial for the performance of a certain device.”
The researchers are currently directing their focus towards refining, tuning and enhancing the methodology and structural design tailored for applications such as solar fuels, where tandem devices hold widespread applicability. By optimizing the methodology and design strategies, researchers aim to unlock the full potential of these devices in harnessing solar energy for diverse and sustainable energy conversion processes, such as CO2 conversion and valorization.
Recovery of antioxidative protein hydrolysates with functional properties from fermented brewer’s spent grain via microwave-assisted three phase partitioning
by Kong Fei Chai, Wei Ning Chen in Innovative Food Science & Emerging Technologies
Researchers from Nanyang Technological University, Singapore (NTU Singapore), have created a method that extracts over 80 per cent of the available protein in grain leftovers from brewing beer, commonly known as brewers’ spent grain.
Brewers’ spent grain (BSG) is the solid residue from malted barley after brewing beer. It is the most significant byproduct of the beer brewing industry, making up 85 per cent of the total waste. Globally, about 36.4 million tons of spent grain are produced every year[1].
This spent grain is typically discarded after its primary use in brewing beer. While some efforts are made to repurpose BSG in applications such as animal feed, biofuel production, or composting, a substantial portion still ends up in landfills, generating greenhouse gases such as methane and carbon dioxide.
After exploring new use cases for the BSG proteins, the researchers from NTU’s Food Science and Technology programme say their protein extraction method could help reduce waste. The extracted proteins could then be used to enrich diets and even for cosmetic purposes, feeding into growing consumer preferences towards sustainably sourced and eco-friendly goods, with 66 per cent of global consumers expressing readiness to pay premium prices for products from sustainable brands[2].
The researchers extracted up to 200 grams of protein from one kilogram of BSG, indicating its potential as a protein source. The Singapore Health Promotion Board recommends that the average woman requires 40 grams of protein daily, while an average adult man needs 56 grams daily.
The researchers note that BSG proteins are safe for human consumption and of high quality, making them suitable for direct use in supplements and for enhancing the protein content of plant-based foods.
Given the importance of plant-based foods in providing essential proteins to our diets, incorporating BSG protein into these foods has the potential to enhance their nutritional value significantly. This addition could assist individuals in meeting their daily protein requirements more effectively.
This would also help mitigate a possible protein shortage due to a forecast 73 per cent increase in meat consumption by the year 2050[3] following rapid global population growth, according to the Food and Agriculture Organisation of the UN (FAO).
The proteins extracted by the NTU researchers were found to be rich in antioxidants, which could not only protect human skin from pollutants but could also extend the shelf life of cosmetics like body lotions and moisturisers.
This could present an eco-friendly alternative to conventional cosmetic components such as parabens, which disrupt hormone function in aquatic organisms, and petroleum-based ingredients, known to contribute environmental pollution during extraction and production processes.
Lead author Professor William Chen, Director of NTU’s Food Science and Technology (FST) programme, who led the study, said: “Our study, which presents more sustainable and efficient ways to add value to brewers’ spent grain disposal, is a crucial step towards mitigating its contribution to greenhouse emissions and reducing environmental strain, while also enriching the global food supply chain. Demonstrating that the protein-rich qualities of brewers’ spent grain could be successfully extracted and funnelled into supplements and enriching plant-based proteins to make them more attractive to the consumer addresses two global pressure points — food wastage and food shortage.” Prof Chen is also the Director of the Singapore Agri-food Innovation Lab (SAIL) and Director of the Singapore Future Ready Food Safety Hub (FRESH).
First author of the study, Dr Chai Kong Fei, Senior Research Fellow at NTU’s FST programme, said:”The protein extracted from brewers’ spent grain from the NTU-developed method has been shown to not only have potential to be included in our diets, but they could also serve in another industry — cosmetics. Due to their natural exfoliating properties and abundance of antioxidants, we feel they could be incorporated into various skincare formulations, from moisturisers to body lotions, offering an alternative to chemicals such as preservatives, which have been shown to cause damage to wildlife and the environment after being washed down our sinks.”
Several NTU industry partners have received the NTU innovation positively. Ms Mirte Gosker, Managing Director of The Good Food Institute Asia Pacific, said: “Innovative applications of underutilised grains like those being brewed up at NTU have the potential to reduce Singapore’s dependence on raw-material imports, provide an additional revenue source for local producers, and help entrepreneurs craft more nutrient-dense plant-based meats. Amid rising food demand pressures, protein extraction from agricultural side streams is field primed and ready to be tapped.”
The study, which presents an innovation that promotes a sustainable food tech solution that reduces waste, reflects NTU’s commitment to mitigate our environmental impact, one of four humanity’s grand challenges that the University seeks to address through its NTU 2025 strategic plan.
The NTU FST Programme collaborated with Heineken Asia Pacific, the producer of Tiger Beer, using the brewers’ spent grain in the study. To extract the protein from the spent grain, the researchers first sterilised it before using Rhizopus oligosporus, a food-grade fungus commonly used to ferment soybeans to produce tempeh, a soy-based food popular in Southeast Asia. The three-day fermentation process helps break down the BSG’s complex structure, making its protein content more easily extractable.
The fermented BSG is then dried, ground into a powder, sieved, and spun in a centrifuge to separate the protein, which would float to the top from the rest of the mixture. Once extracted, the protein could be added to foods to boost their protein content or combined with lotions or creams to boost their moisturising and antioxidant properties.
Prof Chen added: “Our method presents an innovative way to repurpose beer waste into a valuable protein source for global nutrition. Beyond mere innovation, our work embodies a narrative of turning what was once considered waste into a vital resource, a symbol of sustainability, and a solution to one of humanity’s most pressing challenges: protein scarcity. Our endeavour underscores NTU’s pioneering role in food technology science and our commitment to addressing real-world problems with ingenuity and foresight.”
Dissolution Heterogeneity Observed in Anisotropic Ruthenium Dioxide Nanocrystals via Liquid-Phase Transmission Electron Microscopy
by S. Avery Vigil, Ivan A. Moreno-Hernandez in Journal of the American Chemical Society
Left unchecked, corrosion can rust out cars and pipes, take down buildings and bridges, and eat away at our monuments.
Corrosion can also damage devices that could be key to a clean energy future. And now, Duke University researchers have captured extreme close-ups of that process in action.
“By studying how and why renewable energy devices break down over time, we might be able to extend their lifetime,” said chemistry professor and senior author Ivan Moreno-Hernandez.
In his lab at Duke sits a miniature version of one such device. Called an electrolyzer, it separates hydrogen out of water, using electricity to power the reaction. When the electricity to power electrolysis comes from renewable sources such as wind or solar, the hydrogen gas it churns out is considered a promising source of clean fuel, because it takes no fossil fuels to produce and it burns without creating any planet-warming carbon dioxide.
A number of countries have plans to scale up their production of so-called “green hydrogen” to help curb their dependence on fossil fuels, particularly in industries like steel- and cement-making. But before hydrogen can go mainstream, some big obstacles need to be overcome. Part of the trouble is electrolyzers require rare metal catalysts to function, and these are prone to corrosion. They’re not the same after a year of operation than they were in the beginning.
In a study, Moreno-Hernandez and his Ph.D. student Avery Vigil used a technique called liquid phase transmission electron microscopy to study the complex chemical reactions that go on between these catalysts and their environment that cause them to decay.
You might remember from high school that to make hydrogen gas, an electrolyzer splits water into its constituent hydrogen and oxygen molecules. For the current study, the team focused on a catalyst called ruthenium dioxide that speeds up the oxygen half of the reaction, since that’s the bottleneck in the process.
“We essentially put these materials through a stress test,” Vigil said.
They zapped nanocrystals of ruthenium dioxide with high-energy radiation, and then watched the changes wrought by the acidic environment inside the cell. To take pictures of such tiny objects, they used a transmission electron microscope, which shoots a beam of electrons through nanocrystals suspended inside a super-thin pocket of liquid to create time-lapse images of the chemistry taking place at 10 frames per second. The result: desktop-worthy close-ups of virus-sized crystals, more than a thousand times finer than a human hair, as they get oxidized and dissolve into the acidic liquid around them.
“We’re actually able to see the process of this catalyst breaking down with nanoscale resolution,” Moreno-Hernandez said.
Over the course of five minutes, the crystals broke down fast enough to “render a real device useless in a matter of hours,” Vigil said. Zooming in hundreds of thousands of times, the videos reveal subtle defects in the crystals’ 3D shapes that create areas of strain, causing some to break down faster than others. By minimizing such imperfections, the researchers say it could one day be possible to design renewable energy devices that last two to three times longer than they currently do.
“So instead of being stable for, say, two years, an electrolyzer could last six years. That could have a massive impact on renewable technologies,” Moreno-Hernandez said.
CO2 and Lignin‐Based Sustainable Polymers with Closed‐Loop Chemical Recycling
by Arijit Ghorai, Hoyong Chung in Advanced Functional Materials
Modern life relies on plastic. This lightweight, adaptable product is a cornerstone of packaging, medical equipment, the aerospace and automotive industries and more. But plastic waste remains a problem as it degrades in landfills and pollutes oceans.
FAMU-FSU College of Engineering researchers have created a potential alternative to traditional petroleum-based plastic that is made from carbon dioxide (CO2) and lignin, a component of wood that is a low-cost byproduct of paper manufacturing and biofuel production.
“Our study takes the harmful greenhouse gas CO2 and makes it into a useful raw material to produce degradable polymers or plastics,” said Hoyong Chung, an associate professor in chemical and biomedical engineering at the college. “We are not only reducing CO2 emissions, but we are producing a sustainable polymer product using the CO2.”
This study is the first to demonstrate the direct synthesis of what’s known as a cyclic carbonate monomer — a molecule made of carbon and oxygen atoms that can be linked with other molecules — made from CO2 and lignin. By linking multiple monomers together, scientists can create synthetic polymers, long-chained molecules that can be designed to fill all manner of applications.
The material developed by Chung and his research team is fully degradable at the end of its life without producing microplastics and toxic substances. It can be synthesized at lower pressures and temperatures. And the polymer can be recycled without losing its original properties.
Using depolymerization, the researchers can convert polymers to pure monomers, which are the building blocks of polymers. This is the key to the high quality of the recycled material. The monomers can be recycled indefinitely and produce a high-quality polymer as good as the original, an improvement over previously developed and currently used polymer materials in which repeated heat exposure from melting reduces quality and allows for limited recycling.
“We can readily degrade the polymer via depolymerization, and the degraded product can synthesize the same polymer again,” Chung said. “This is more cost effective and keeps it from losing original properties of polymers over multiple recycling. This is considered a breakthrough in material science, as it enables the realization of a true circular economy.”
The newly developed material could be used for low-cost, short lifespan plastic products in such sectors as construction, agriculture, packaging, cosmetics, textiles, diapers and disposable kitchenware. With further development, Chung anticipates its use in highly specialized polymers for biomedical and energy storage applications.
Securing cation vacancies to enable reversible Mg insertion/extraction in rocksalt oxides
by Tomoya Kawaguchi, Masaya Yasuda, Natsumi Nemoto, Kohei Shimokawa, Hongyi Li, Norihiko L. Okamoto, Tetsu Ichitsubo in Journal of Materials Chemistry
Researchers at Tohoku University have made a groundbreaking advancement in battery technology, developing a novel cathode material for rechargeable magnesium batteries (RMBs) that enables efficient charging and discharging even at low temperatures. This innovative material, leveraging an enhanced rock-salt structure, promises to usher in a new era of energy storage solutions that are more affordable, safer, and higher in capacity.
The study showcases a considerable improvement in magnesium (Mg) diffusion within a rock-salt structure, a critical advancement since the denseness of atoms in this configuration had previously impeded Mg migration. By introducing a strategic mixture of seven different metallic elements, the research team created a crystal structure abundant in stable cation vacancies, facilitating easier Mg insertion and extraction.
This represents the first utilization of rocksalt oxide as a cathode material for RMBs. The high-entropy strategy employed by the researchers allowed the cation defects to activate the rocksalt oxide cathode.
The development also addresses a key limitation of RMBs — the difficulty of Mg transport within solid materials. Until now, high temperatures were necessary to enhance Mg mobility in conventional cathode materials, such as those with a spinel structure. However, the material unveiled by Tohoku University researchers operates efficiently at just 90°C, demonstrating a significant reduction in the required operating temperature.
Tomoya Kawaguchi, a professor at Tohoku University’s Institute for Materials Research (IMR), notes the broader implications of the study.
“Lithium is scarce and unevenly distributed, whereas magnesium is abundantly available, offering a more sustainable and cost-effective alternative for lithium-ion batteries. Magnesium batteries, featuring the newly developed cathode material, are poised to play a pivotal role in various applications, including grid storage, electric vehicles, and portable electronic devices, contributing to the global shift towards renewable energy and reduced carbon footprints.”
Kawaguchi collaborated with Tetsu Ichitsubo, also a professor at IMR, who states, “By harnessing the intrinsic benefits of magnesium and overcoming previous material limitations, this research paves the way for the next generation of batteries, promising significant impacts on technology, the environment, and society.”
Microbial Platform for Tailor-made Production of a Biodegradable Polylactide Modifier: Ultrahigh-Molecular-Weight Lactate-Based Polyester LAHB
by Sangho Koh, Sho Furutate, Yusuke Imai, Toshihiko Kanda, Shinji Tanaka, Yuichi Tominaga, Shunsuke Sato, Seiichi Taguchi in ACS Sustainable Chemistry & Engineering
Engineered bacteria can produce a plastic modifier that makes renewably sourced plastic more processable, more fracture resistant and highly biodegradable even in sea water. The Kobe University development provides a platform for the industrial-scale, tunable production of a material that holds great potential for turning the plastic industry green.
Plastic is a hallmark of our civilization. It is a family of highly formable (hence the name), versatile and durable materials, most of which are also persistent in nature and therefore a significant source of pollution. Moreover, many plastics are produced from crude oil, a non-renewable resource. Engineers and researchers worldwide are searching for alternatives, but none have been found that exhibit the same advantages as conventional plastics while avoiding their problems. One of the most promising alternatives is polylactic acid, which can be produced from plants, but it is brittle and does not degrade well.
To overcome these difficulties, Kobe University bioengineers around TAGUCHI Seiichi together with the biodegradable polymer manufacturing company Kaneka Corporation decided to mix polylactic acid with another bioplastic, called LAHB, which has a range of desirable properties, but most of all it is biodegradable and mixes well with polylactic acid. However, in order to produce LAHB, they needed to engineer a strain of bacteria that naturally produces a precursor, by systematically manipulating the organism’s genome through the addition of new genes and the deletion of interfering ones.
Researchers now report that they could thus create a bacterial plastic factory that produces chains of LAHB in high amounts, using just glucose as feedstock. In addition, they also show that by modifying the genome, they could control the length of the LAHB chain and thus the properties of the resulting plastic. They were thus able to produce LAHB chains up to ten times longer than with conventional methods, which they call “ultra-high molecular weight LAHB.”
Most importantly, by adding LAHB of this unprecedented length to polylactic acid, they could create a material that exhibits all the properties the researchers had aimed for. The resulting highly transparent plastic is much better moldable and more shock resistant than pure polylactic acid, and also biodegrades in seawater within a week. Taguchi comments on this achievement, saying “By blending polylactic acid with LAHB, the multiple problems of polylactic acid can be overcome in one fell swoop, and the so modified material is expected to become an environmentally sustainable bioplastic that satisfies the conflicting needs of physical robustness and biodegradability.”
The Kobe University bioengineers, however, dream bigger. The strain of bacteria they used in this work is in principle able to use CO2 as a raw material. It should thus be possible to synthesize useful plastics directly from the greenhouse gas. Taguchi explains, “Through the synergy of multiple projects, we aim to realize a biomanufacturing technology that effectively links microbial production and material development.”
Crustal permeability generated through microearthquakes is constrained by seismic moment
by Pengliang Yu, Ankur Mali, Thejasvi Velaga, Alex Bi, Jiayi Yu, Chris Marone, Parisa Shokouhi, Derek Elsworth in Nature Communications
Using machine learning, researchers at Penn State have tied low-magnitude microearthquakes to the permeability of subsurface rocks beneath the Earth, a discovery that could have implications for improving geothermal energy transfer.
Generating geothermal energy requires a permeable subsurface to efficiently release heat when cold fluids are forced into the rock. This research reveals the optimum times for efficient energy transfer by exposing the link to microearthquakes, which are monitored on the surface through seismometers.
Using funding from the U.S. Department of Energy (DOE) and two datasets from the EGS Collab and Utah FORGE demonstration projects, researchers used machine learning to extract the “noise” found in the data that obscured the link. Researchers then used machine learning to create a model from one site and successfully applied it to the other — a process called transfer learning — suggesting that the link was formed based on general physics of subsurface rocks. That means it’s likely to be universally true for all geothermal energy sites, the researchers said.
“Success of transfer learning confirms the generalizability of the models,” said Pengliang Yu, postdoctoral scholar at Penn State and lead author of the study. “This suggests seismic monitoring could broadly be used to improve geothermal energy transfer efficiencies across a wide range of sites.”
Increasing rock permeability is critical to a range of energy extraction methods, Yu said. Rock permeability impacts traditional fossil fuel recovery as well as renewable energies including hydrogen production. Hydrofracturing methods introduce cold fluids into the subsurface through porous rock, which creates high pressures that break the rock in tension or shear. This process creates microearthquakes similar to naturally occurring earthquakes, but at a much smaller scale. By increasing the permeability of the rock, energies such as heat and hydrocarbons are able to more easily reach the surface.
Yu said their algorithm showed a direct link, meaning the rock became the most permeable when the seismic activity was strongest.
Identifying the link between seismic activity and rock permeability improves the ability to extract energy while ensuring microquakes stay below the threshold that could cause damage or be observed by the public.
“Machine learning played a key role in uncovering the relationship between seismic activity and rock permeability” said co-author Parisa Shokouhi, professor of engineering science and mechanics in the College of Engineering. “It helped identify the important attributes of the seismic data for predicting rock permeability evolution. We constrained the machine learning algorithm to ensure a physically meaningful model. In return, the model prediction revealed a previously unknown physical link between seismic data and rock permeability.”
Increasing the availability of geothermal energy would lessen dependence on fossil fuels, the researchers said. Additionally, they noted that linking rock permeability to microquakes can be useful in monitoring gas movement for carbon sequestration and the production and storage of subsurface hydrogen.
The research is part of a larger DOE-funded project to decrease the cost and increase production of geothermal energy and use machine learning to better understand and predict earthquakes, including microquakes.
“Yu’s work is part of our effort to advance geothermal exploration and geothermal energy production using machine learning methods, said co-author Chris Marone, professor of geosciences at Penn State. “Our lab studies show clear connections between the evolution of elastic properties prior to lab earthquakes, and we are excited to see that similar relationships are observed in nature.”
Nuclear magnetic resonance and molecular simulation study of H2 and CH4 adsorption onto shale and sandstone for hydrogen geological storage
by Tuan A. Ho, Son T. Dang, Nabankur Dasgupta, Aditya Choudhary, Chandra S. Rai, Yifeng Wang in International Journal of Hydrogen Energy
Imagine a vast volume of porous sandstone reservoir, once full of oil and natural gas, now full of a different, carbon-free fuel — hydrogen.
Scientists at Sandia National Laboratories are using computer simulations and laboratory experiments to see if depleted oil and natural gas reservoirs can be used for storing this carbon-free fuel. Hydrogen is an important clean fuel: It can be made by splitting water using solar or wind power, it can be used to generate electricity and power heavy industry, and it could be used to power fuel-cell-based vehicles. Additionally, hydrogen could be stored for months and used when energy needs outpace the supply delivered by renewable energy sources.
“Hydrogen would be good for seasonal and long-term storage,” said Sandia chemical engineer Tuan Ho, who is leading the research. “If you think of solar energy, in the summer you can produce a lot of electricity, but you don’t need a lot for heating. The excess can be turned into hydrogen and stored until winter.”
However, hydrogen contains much less “bang” in a set volume than carbon-based fuels such as natural gas or propane and is much more difficult to compress, Ho said. This means storing huge amounts of hydrogen in metal tanks on the surface is just not feasible, he added.
Hydrogen can be stored underground in salt caverns, but salt deposits are not widespread across the U.S., said Don Conley, the manager for Sandia’s underground hydrogen storage work. Therefore, Ho’s team is studying if hydrogen stored in depleted oil and gas reservoirs will get stuck in the rock, leak out, or get contaminated.
First, Ho’s team studied if hydrogen would get stuck in the sandstone or shale that forms the body and seal around many oil and gas reservoirs or leak out. Sandstone is composed of sand-sized grains of minerals and rocks that have been compressed over eons; sandstone has a lot of gaps between particles and thus can store water in aquifers or form oil and gas reservoirs. Shale is mud compressed into rock and is made up of much smaller particles of clay-rich minerals. Thus, shale can form a seal around sandstone, trapping oil and natural gas.
“You want the hydrogen to stay where you inject it,” Ho said. “You don’t want it to migrate away from the storage zone and get lost. That’s just a waste of money, which is a big concern for any storage facility.”
Ho’s collaborators at the University of Oklahoma used experiments to study how hydrogen interacts with samples of sandstone and shale. They found that hydrogen does not stay inside sandstone after it is pumped out, but up to 10% of the adsorbed gas got stuck inside the shale sample, Ho said. These results were confirmed by Ho’s computer simulations.
Taking a closer look at a specific type of clay that is common in the shale around oil and gas reservoirs, Ho conducted computer simulations of the molecular interactions between layers of montmorillonite clay, water and hydrogen. He found that hydrogen does not prefer to go into the watery gaps between mineral layers of that kind of clay.
This means that the loss of hydrogen in clay due to getting stuck or moving through it would be tiny, Ho said. This is quite positive for underground storage of hydrogen. These findings on clay were published last year in the journal Sustainable Energy and Fuels. Additional absorption experiments are being conducted at Stevens Institute of Technology and the University of Oklahoma to confirm the molecular simulation results, Ho said.
Using both experiments and simulation, Ho’s team found that residual natural gas can be released from the rock into the hydrogen when hydrogen is injected into a depleted natural gas reservoir. This means that when the hydrogen is removed for use, it will contain a small amount of natural gas, Ho said.
“That’s not terrible because natural gas still has energy, but it contains carbon, so when this hydrogen is burned, it will produce a small amount of carbon dioxide,” Ho said. “It’s something we need to be aware of.”
Ho’s team, principally Sandia postdoctoral researcher Aditya Choudhary, is currently studying the effects of hydrogen on a depleted oil reservoir and how leftover oil might contaminate or interact with hydrogen gas using both molecular simulations and experiments.
The findings from Ho’s research can be used to inform and guide large field-scale tests of underground hydrogen storage, said Conley, the manager for Sandia’s portion of the Department of Energy Office of Fossil Energy and Carbon Management’s Subsurface Hydrogen Assessment, Storage, and Technology Acceleration project. The SHASTA project plans to conduct such a field-scale test in the future to demonstrate the feasibility of depleted oil and natural gas reservoirs for hydrogen storage, he added. Additional research is needed to understand how microorganisms and other chemicals in depleted petroleum reservoirs might interact with stored hydrogen, Ho said.
“If we want to create a hydrogen economy, we really need widely distributed means of storing large quantities of hydrogen,” Conley said. “Storage in salt is excellent where it exists, but it can’t be the sole option. So, we’re turning to depleted oil and gas reservoirs and aquifers as more geologically distributed means of storing large quantities of hydrogen. It’s all in the name of decarbonizing the energy sector.”
Subscribe to Paradigm!
Medium. Twitter. Telegram. Telegram Chat. Reddit. LinkedIn.
Main Sources
Research articles
