Energy & green technology biweekly vol.16, 14th January — 29th January
TL;DR
- Scientists have developed a way to maximize hydrogen yields from biowaste, within few milliseconds. The method uses rapid photo-pyrolysis to produce hydrogen gas and solid conductive carbon from banana peels.
- A research team has set a new record in the power conversion efficiency of solar cells made using perovskite and organic materials. Their latest work demonstrated a power conversion efficiency of 23.6%, approaching that of conventional silicon solar cells. This technological breakthrough paves the way for flexible, light-weight, low cost and ultra-thin photovoltaic cells for wide-ranging applications.
- Scientists have boosted the efficiency and scalability of perovskite solar cells by replacing their electron-transport layers with a thin layer of quantum dots.
- Researchers used the characteristics of owl wings to inform airfoil design and significantly reduce trailing-edge noise. The team used noise calculation and analysis software to conduct a series of detailed theoretical studies of simplified airfoils with characteristics reminiscent of owl wings. They applied their findings to suppress the noise of rotating machinery. Improving the flow conditions around the trailing edge and optimizing the shape of the edge suppressed the noise.
- Australian researchers have developed a smart and super-efficient new way of capturing carbon dioxide and converting it to solid carbon, to help advance the decarbonisation of heavy industries.
- Researchers have developed a free, user-friendly tool that makes use of multiple computational models to help solid waste systems achieve their environmental goals in the most cost-efficient way possible.
- Decommissioning and clean-up are ongoing at the Fukushima Daiichi Nuclear Power Plant; however, many difficult problems remain unaddressed. Chief amongst these problems is the retrieval and management of fuel debris.
- Lanthanum trihydride, a compound of lanthanum and hydrogen, when lightly doped with oxygen shows potential as an efficient hydrogen carrier, according to a new study. Hydride ion (H — ) conductors are expected to be used in chemical reactors and energy storage systems. However, the low H — conductivity at room temperature introduces certain technical limitations. These limitations may now be overcome with this latest innovation by the researchers.
- Britain’s towns and cities have the potential to support an urban agricultural revolution that would help meet the dietary needs of a growing population, boost the nation’s health and wellbeing, as well as reduce reliance on imports, a new study reveals.
- More than 70 million tons of carbon were prevented from being released into the atmosphere under a deforestation emissions reduction scheme in Indonesia — but researchers point out this is only 3 per cent of the total required by Indonesia’s Nationally Defined Contribution (NDC) under the Paris Agreement.
- 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.
The blockchain segment is estimated to grow at the highest CAGR: Energy-intensive cryptocurrency mining has caused a spike in carbon emission, and hence blockchain is capable of driving innovation in the field of green technology.
Latest News
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- Nissan and Renault Reboot Their Alliance for the Electric Age
- Entergy to weigh renewable energy options to power LNG export facility expansion
- TransAlta plans 180MW/360MWh battery energy storage project
- Xcel asked to upgrade solar interconnection process
- PG&E proposes 6.4 GWh battery energy storage plan to California regulators
- Vistra releases Moss Landing incident findings
- Amp Energy to develop 800 MWh of battery storage capacity
- EDP Renewables repowers wind farm with 2 MW turbines
- MidAmerican plans to add 2 GW of wind energy resources in Iowa
- U.K. Wind Energy Hits Record, Bringing Relief to Power Costs
- Cost of Emitting Carbon Soars in Europe With U.K. Hitting Record
- Texas Governor Abbott Turns to Bitcoin Miners to Bolster the Grid and His Re-Election
- Steelmaker SSAB Plans to Cut Carbon Far Faster Than Before
- Active Ownership Vs. Active Returns: The Norway Sovereign Wealth Fund Dilemma
- Musk Calls Biden ‘A Damp Sock Puppet’ As Tesla Shares Tank
- Tesla Notches Record Profit On Sales Surge–But EV Competition Is Building
- Motoring Organizations Welcome U.K. Highway Code Changes That See Pedestrians Given Priority On Roads
- Bentley To Spend $3.4 Billion To Become All-Electric By 2030
- Masdar Works To Bring Clean Energy To Oil-Rich Gulf Region And Beyond
- A $1 Trillion Stock Owner Sticks to ESG Path Despite Fed Moves
- China Built More Offshore Wind In 2021 Than Every Other Country Built In 5 Years
- GM Pouring $7 Billion Into New EV Plants In Michigan
- Maritime Blue’s Third Wave Includes Plastic Alternatives, Sustainable Seafood Snacks And Electric Outboards
- High-Speed Las Vegas Train Back On Track As U.S. Reviews L.A. Extension
- Chris Boardman Appointed As England’s First Cycling And Walking Commissioner
- Gulf of Mexico Offshore Oil Lease Plan Voided by U.S. Judge
- Barcelona-Based Startup Blue Hybrid Meat Alternative Might Be The Solution To The Industry’s Blues
- Michigan Startup’s Gemini Battery Powers Tesla For 752 Miles On A Single Charge
- Japan’s Mitsubishi, energy body join Gates’ nuclear project
- Invest strategically in wind and solar farms in Africa, study recommends
- Radical overhaul of construction industry needed if UK to have any chance of net zero by 2050
- ‘Game changer’ e-moped batteries spread from Taiwan across Asia
- The Biggest Future Trends In Agriculture And Food Production
- Your Natural Gas Stove Is Fueling Climate Change And Harming Your Health — And It’s Worse Than Scientists Thought
Latest Research
Banana split: biomass splitting with flash light irradiation
by Wanderson O. Silva, Bhawna Nagar, Mathieu Soutrenon, Hubert H. Girault in Chemical Science
As the world’s energy demands increase, so does our consumption of fossil fuels. The result is a massive rise in greenhouse gases emissions with severely adverse environmental effects. To address this, scientists have been searching for alternative, renewable sources of energy.
A main candidate is hydrogen produced from organic waste, or “biomass,” of plants and animals. Biomass also absorbs, removes, and stores CO2 from the atmosphere, while biomass decomposition can also bring us ways to negative emissions or greenhouse gases removal. But even though biomass heralds a way forward, there is still the question of the best way to maximize its conversion into energy.
There are currently two main methods for converting biomass into energy: gasification and pyrolysis. Gasification puts solid or liquid biomass at temperatures around 1000°C, converting it into gas and solid compounds; the gas is called “syngas” while the solid is “biochar.”
Syngas is a mix of hydrogen, methane, carbon monoxide and other hydrocarbons, and those are what are used as “biofuel” to generate power. On the other hand, biochar is often regarded as a solid carbon waste, although it can be used in agriculture applications. The other method, biomass pyrolysis, is similar to gasification except that biomass is heated at lower temperatures, between 400–800°C and at pressures up to 5 bar in an inert atmosphere. There are three types of pyrolysis: conventional, fast, and flash pyrolysis. Out of all three, the first two take the longest time, and have the most char production.
Flash pyrolysis takes place at 600°C and produces the most syngas and has the lowest residence time. Unfortunately, it also needs specialized reactors that can handle high temperatures and pressures.
Now, scientists led by Professor Hubert Girault at EPFL’s School of Basic Sciences have developed a new method for biomass photo-pyrolysis that produces not only valuable syngas, but also a biochar of solid carbon that can be repurposed in other applications.
The method performs flash light pyrolysis using a Xenon lamp, commonly used for curing metallic inks for printed electronics. Girault’s group has also used the system in the last few years for other purposes, like synthesizing nanoparticles.
The lamp’s white flash light provides a high-power energy source as well as short pulses that promote photo-thermal chemical reactions. The idea is to generate a powerful flash light shot, which the biomass absorbs and which instantaneously triggers a photothermal biomass conversion into syngas and biochar.
This flashing technique was used on different sources of biomass: banana peels, corn cobs, orange peels, coffee beans and coconut shells, all of which were initially dried at 105°C for 24 hours and then ground and sieved to a thin powder. The powder was then placed in a stainless-steel reactor with a standard glass window at ambient pressure and under an inert atmosphere. The Xenon lamp flashes, and the whole conversion process is over in few milliseconds.
“Each kg of dried biomass can generate around 100 liters of hydrogen and 330g of biochar, which is up to 33wt.% of the original dried banana peel mass,” says Bhawna Nagar, who worked on the study. The method also had a positive calculated energy outcome of 4.09 MJ·per kg of dried biomass.
What stands out in this method is that both its end products, hydrogen and solid-carbon biochar, are valuable. The hydrogen can be used as green fuel, while the carbon biochar, can either be buried and used as a fertilizer or it can be used to manufacture conductive electrodes.
“The relevance of our work is further heightened by the fact that we are indirectly capturing CO2stores from the atmosphere for years,” says Nagar. “We have converted that into useful end products in no time using a Xenon flash lamp.”
Monolithic perovskite/organic tandem solar cells with 23.6% efficiency enabled by reduced voltage losses and optimized interconnecting layer
by Wei Chen, Yudong Zhu, Jingwei Xiu, Guocong Chen, Haoming Liang, Shunchang Liu, Hansong Xue, Erik Birgersson, Jian Wei Ho, Xinshun Qin, Jingyang Lin, Ruijie Ma, Tao Liu, Yanling He, Alan Man-Ching Ng, Xugang Guo, Zhubing He, He Yan, Aleksandra B. Djurišić, Yi Hou in Nature Energy
A team of researchers from the National University of Singapore (NUS) has set a new record in the power conversion efficiency of solar cells made using perovskite and organic materials. This technological breakthrough paves the way for flexible, light-weight, low cost and ultra-thin photovoltaic cells which are ideal for powering vehicles, boats, blinds and other applications.
“Technologies for clean and renewable energy are extremely important for carbon reduction. Solar cells that directly convert solar energy into electricity are among the most promising clean energy technologies. High power conversion efficiency of solar cells is critical for generating more electrical power using a limited area and this, in turn, reduces the total cost of generating solar energy,” explained lead researcher Presidential Young Professor Hou Yi, who is from the NUS Department of Chemical and Biomolecular Engineering and also leading a “Perovskite-based Multi-junction Solar Cells group” at the Solar Energy Research Institute of Singapore at NUS.
“The main motivation of this study is to improve the power conversion efficiency of perovskite/organic tandem solar cells. In our latest work, we have demonstrated a power conversion efficiency of 23.6% — this is the best performance for this type of solar cells to date,” added Dr Chen Wei, Research Fellow at the NUS Department of Chemical and Biomolecular Engineering and the first author of this work.
This achievement is significant leap from the current power conversion rate of about 20% reported by other studies on perovskite/organic tandem solar cells, and is approaching the power conversion rate of 26.7% of silicon solar cells, which is the dominating solar technology in the current solar photovoltaic (PV) market.
Solar cell technology has achieved tremendous growth in recent years as a sustainable energy source. The reliability, efficiency, durability, and price of solar cells have a crucial impact on the commercial potential and large-scale implementation of solar energy projects around the world.
The conventional solar cells being used in solar power plants are based on a single-junction architecture. The practical power conversion efficiency of single-junction solar cells is limited to about 27% in industrial production. To push the frontiers of solar energy production will require novel solutions for solar cells to perform better in power conversion.
In order to raise the power conversion efficiency of solar cells to go beyond 30%, stacks of two or more absorber layers (multi-junction cells) are required. Tandem solar cells, which are made using two different types of photovoltaic materials, is a hot area of research.
In their latest project, Assistant Professor Hou and his team break new ground in the field of perovskite/organic tandem solar cells. Their discovery opens the door to thin-film tandem solar cells that are light and bendable, which could have wide-ranging applications such as for solar-powered blinds, vehicles, boats and other mobile devices.
A tandem solar cell comprises two or more subcells electrically connected using interconnecting layers (ICLs). The ICL plays a critical role in determining the performance and reproducibility of a device. An effective ICL should be chemically inert, electrically conductive and optically transparent.
Although perovskite/organic tandem solar cells are attractive for next-generation thin-film photovoltaics, their efficiency lags behind other types of tandem solar cells. To address this technological challenge, Asst Prof Hou and his team developed a novel and effective ICL that reduces voltage, optical and electrical losses within the tandem solar cell. This innovation significantly improves the efficiency of the perovskite/organic tandem solar cells, achieving a power conversion rate of 23.6%.
“Our study shows the great potential of perovskite-based tandem solar cells for future commercial application of photovoltaic technology. Building on our new discovery, we hope to further improve the performance of our tandem solar cells and scale up this technology,” said Asst Prof Hou.
Aeroacoustic investigation of asymmetric oblique trailing-edge serrations enlighted by owl wings
by Lei Wang, Xiaomin Liu in Physics of Fluids
Trailing-edge noise is the dominant source of sound from aeronautical and turbine engines like those in airplanes, drones, and wind turbines. Suppressing this noise pollution is a major environmental goal for some urban areas.
Researchers from Xi’an Jiaotong University used the characteristics of owl wings to inform airfoil design and significantly reduce the trailing-edge noise.
“Nocturnal owls produce about 18 decibels less noise than other birds at similar flight speeds due to their unique wing configuration,” said author Xiaomin Liu. “Moreover, when the owl catches prey, the shape of the wings is also constantly changing, so the study of the wing edge configuration during owl flight is of great significance.”
Trailing-edge noise is generated when airflow passes along the back of an airfoil. The flow forms a turbulent layer of air along the upper and lower surfaces of the airfoil, and when that layer of air flows back through the trailing edge, it scatters and radiates noise.
Previous studies explored serrated trailing edges, finding that the serrations effectively reduce the noise of rotating machinery. However, the noise reduction was not universal, depending heavily on the final application.
“At present, the blade design of rotating turbomachinery has gradually matured, but the noise reduction technology is still at a bottleneck,” said Liu. “The noise reduction capabilities of conventional sawtooth structures are limited, and some new nonsmooth trailing-edge structures need to be proposed and developed to further tap the potential of bionic noise reduction.”
The team used noise calculation and analysis software to conduct a series of detailed theoretical studies of simplified airfoils with characteristics reminiscent of owl wings. They applied their findings to suppress the noise of rotating machinery.
Improving the flow conditions around the trailing edge and optimizing the shape of the edge suppressed the noise. Interestingly, asymmetric serrations reduced the noise more than their symmetric counterparts.
Noise reduction varied with different operating conditions, so the scientists emphasized that the airfoil designs should be further evaluated based on the specific application. For example, wind turbines have complex incoming flow environments, which require a more general noise reduction technology. Examining noise reduction techniques under the influence of different incoming flows would make their conclusions more universal.
The researchers believe their work will serve as an important guide for airfoil design and noise control.
Conformal quantum dot–SnO 2 layers as electron transporters for efficient perovskite solar cells
by Minjin Kim, Jaeki Jeong, Haizhou Lu, et al in Science
Perovskites are hybrid compounds made from metal halides and organic constituents. They show great potential in a range of applications, e.g. LED lights, lasers, and photodetectors, but their major contribution is in solar cells, where they are poised to overtake the market from their silicon counterparts.
One of the obstacles facing the commercialization of perovskite solar cells is that their power-conversion efficiency and operational stability drop as they scale up, making it a challenge to maintain high performance in a complete solar cell. The problem is partly with the cell’s electron-transport layer, which ensures that the electrons produced when the cell absorbs light will transfer efficiently to the device’s electrode. In perovskite solar cells, the electron-transport layer is made with mesoporous titanium dioxide, which shows low electron mobility, and is also susceptible to adverse, photocatalytic events under ultraviolet light.
In a new publication, scientists led by Professor Michael Grätzel at EPFL and Dr Dong Suk Kim at the Korea Institute of Energy Research have found an innovative way to increase the performance and maintain it at a high level in perovskite solar cells even at large scales. The innovative idea was to replace the electron-transport layer with a thin layer of quantum dots.
Quantum dots are nanometer-sized particle that act as semiconductors, and emit light of specific wavelengths (colors) when they illuminated. Their unique optical properties make quantum dots ideal for use in a variety of optical applications, including photovoltaic devices.
The scientists replaced the titanium dioxide electron-transport layer of their perovskite cells with a thin layer of polyacrylic acid-stabilized tin(IV) oxide quantum dots, and found that it enhanced the devices’ light-capturing capacity, while also suppressing nonradiative recombination, an efficiency-sapping phenomenon that sometimes takes on the interface between the electron-transport layer and the actual perovskite layer.
By using the quantum dot layer, the researchers found that perovskite solar cells of 0.08 square centimeters attained a record power-conversion efficiency of 25.7% (certified 25.4%) and high operational stability, while facilitating the scale-up. When increasing the surface area of the solar cells to 1, 20, and 64 square centimeters, power-conversion efficiency measured at 23.3, 21.7, and 20.6% respectively.
Direct conversion of CO2 to solid carbon by Ga-based liquid metals
by Karma Zuraiqi, Ali Zavabeti, Jonathan Clarke-Hannaford, Billy James Murdoch, Kalpit Shah, Michelle J. S. Spencer, Chris F. McConville, Torben Daeneke, Ken Chiang in Energy & Environmental Science
Australian researchers have developed a smart and super-efficient new way of capturing carbon dioxide and converting it to solid carbon, to help advance the decarbonisation of heavy industries.
The carbon dioxide utilisation technology from researchers at RMIT University in Melbourne, Australia, is designed to be smoothly integrated into existing industrial processes.
Decarbonisation is an immense technical challenge for heavy industries like cement and steel, which are not only energy-intensive but also directly emit CO2 as part of the production process. The new technology offers a pathway for instantly converting carbon dioxide as it is produced and locking it permanently in a solid state, keeping CO2 out of the atmosphere.
Co-lead researcher Associate Professor Torben Daeneke said the work built on an earlier experimental approach that used liquid metals as a catalyst.
“Our new method still harnesses the power of liquid metals but the design has been modified for smoother integration into standard industrial processes,” Daeneke said. “As well as being simpler to scale up, the new tech is radically more efficient and can break down CO2 to carbon in an instant. “We hope this could be a significant new tool in the push towards decarbonisation, to help industries and governments deliver on their climate commitments and bring us radically closer to net zero.”
A provisional patent application has been filed for the technology and researchers have recently signed a $AUD2.6 million agreement with Australian environmental technology company ABR, who are commercialising technologies to decarbonise the cement and steel manufacturing industries.
Co-lead researcher Dr Ken Chiang said the team was keen to hear from other companies to understand the challenges in difficult-to-decarbonise industries and identify other potential applications of the technology.
“To accelerate the sustainable industrial revolution and the zero carbon economy, we need smart technical solutions and effective research-industry collaborations,” Chiang said.
The steel and cement industries are each responsible for about 7% of total global CO2 emissions (International Energy Agency), with both sectors expected to continue growing over coming decades as demand is fuelled by population growth and urbanisation.
Technologies for carbon capture and storage (CCS) have largely focused on compressing the gas into a liquid and injecting it underground, but this comes with significant engineering challenges and environmental concerns. CCS has also drawn criticism for being too expensive and energy-intensive for widespread use.
Daeneke, an Australian Research Council DECRA Fellow, said the new approach offered a sustainable alternative, with the aim of both preventing CO2 emissions and delivering value-added reutilisation of carbon.
“Turning CO2 into a solid avoids potential issues of leakage and locks it away securely and indefinitely,” he said. “And because our process does not use very high temperatures, it would be feasible to power the reaction with renewable energy.”
The RMIT team, with lead author and PhD researcher Karma Zuraiqi, employed thermal chemistry methods widely used by industry in their development of the new CCS tech. The “bubble column” method starts with liquid metal being heated to about 100–120C. Carbon dioxide is injected into the liquid metal, with the gas bubbles rising up just like bubbles in a champagne glass. As the bubbles move through the liquid metal, the gas molecule splits up to form flakes of solid carbon, with the reaction taking just a split second.
“It’s the extraordinary speed of the chemical reaction we have achieved that makes our technology commercially viable, where so many alternative approaches have struggled,” Chiang said.
The next stage in the research is scaling up the proof-of-concept to a modularized prototype the size of a shipping container, in collaboration with industry partner ABR. ABR Project Director David Ngo said the RMIT process turns a waste product into a core ingredient in the next generation of cement blends.
“Climate change will not be solved by one single solution, however, the collaboration between ABR and RMIT will yield an efficient and effective technology for our net-zero goals,” Ngo said.
The team is also investigating potential applications for the converted carbon, including in construction materials.
“Ideally the carbon we make could be turned into a value-added product, contributing to the circular economy and enabling the CCS technology to pay for itself over time,” Daeneke said.
Volatilization of B4C control rods in Fukushima Daiichi nuclear reactors during meltdown: B–Li isotopic signatures in cesium-rich microparticles
by Kazuki Fueda, Ryu Takami, Kenta Minomo, Kazuya Morooka, Kenji Horie, Mami Takehara, Shinya Yamasaki, Takumi Saito, Hiroyuki Shiotsu, Toshihiko Ohnuki, Gareth T.W. Law, Bernd Grambow, Rodney C. Ewing, Satoshi Utsunomiya in Journal of Hazardous Materials
Decommissioning and clean-up are ongoing at the Fukushima Daiichi Nuclear Power Plant (FDNPP); however, many difficult problems remain unaddressed. Chief amongst these problems is the retrieval and management of fuel debris. Fuel debris is the name given to the solidified mixture of melted nuclear fuel and other materials that now lie at the base of each of the damaged reactors (reactor Units 1–3). This material is highly radioactive and it has potential to generate enough neutrons to trigger successive nuclear fission reactions (uranium-235 breaks into two elements after capturing neutrons, emitting enormous amounts of energy, radiation, and more neutrons). Successive fission reactions would present a serious safety and material management risk.
One of the materials in nuclear reactors that can lower the number of neutrons interacting with uranium-235 is boron carbide (B4C). This was used as the control rod material in the FDNPP reactors, and it may now remain within the fuel debris. If so, it may limit fission events within the fuel debris.
On March 11th 2011, the control rods were inserted into the FDNPP reactors to stop the fission reactions immediately after the earthquake, but the later tsunami destroyed the reactor cooling systems. Fuel temperatures soon became high enough (>2000 °C) to cause reactor meltdowns. Currently, the fuel debris material from each reactor is cooled and stable; however, careful assessment of these materials, including not only their inventories of radioactive elements but as well their boron content, a neutron absorber, is needed to ascertain if successive fission reactions and associated neutron flux could occur in the fuel debris during its removal. Many important questions remain: was boron from the control rods lost at high temperature during the meltdown? If so, does enough boron remain in the fuel debris to limit successive fission reactions within this material? These questions must be answered to support safe decommissioning.
Despite the importance of this topic, the state and stability of the FDNPP control rod material has remained unknown until now. However, work now provides vital evidence that indicates that most of the control rod boron remains in at least two of the damaged FDNPP reactors (Units 2 and/or 3).
The study was an international effort involving scientists from Japan, Finland, France, and the USA. Dr. Satoshi Utsunomiya and graduate student Kazuki Fueda of Kyushu University led the study. Using electron microscopy and secondary ion mass spectrometry (SIMS), the team has been able to report the first-ever measurements of boron and lithium chemistry from radioactive Cs-rich microparticles (CsMPs). CsMPs formed inside FDNPP reactor units 2 and/or 3 during the meltdowns. These microscopic particles were then emitted into the environment, and the particles hold vital clues about the extent and types of meltdown processes. The team’s new results on boron-11/boron-10 isotopic ratios (~4.2) clearly indicate that most of the boron inside the CsMPs is derived from the FDNPP control rods and not from other sources (e.g., boron from the seawater that was used to cool the reactors). Dr Utsunomiya states that the presence of boron in the CsMPs “provides direct evidence of volatilization of the control rods, indicating that they were severely damaged
In the study the team also combined their new data with past knowledge on CsMP emissions. From this, they have been able to estimate the total amount of boron released from the FDNPP reactors was likely very small: 0.024–62 g.
Prof. Gareth Law, a co-author from the University of Helsinki emphasized that this “is a tiny fraction of the reactor’s overall boron inventory, and this may mean that essentially all of the control rod boron remains inside the reactors.” The team hopes that this should prevent excessive fission reactions in the fuel debris. Utsunomiya stresses that “FDNPP decommissioning, and specifically fuel debris removal must be planned so that the extensive fission reactions do not occur. Our international team has successfully provided the first direct evidence of volatilization of B4C during the FDNPP meltdowns, but critically, our new data indicated that large quantities of boron, which adsorbs neutrons, likely remains within the fuel debris.”
Prof. Rod Ewing, a co-author from Stanford University acknowledged the importance of these new findings but highlighted that the team’s measurements now need to be “extended in follow-up studies, where the occurrence and distribution of boron species should be characterized across a wide range of debris fragments.”
Solid waste optimization life‐cycle framework in Python (SwolfPy)
by Mojtaba Sardarmehni, Pedro H. Chagas Anchieta, James W. Levis in Journal of Industrial Ecology
Researchers from North Carolina State University have developed a free, user-friendly tool that makes use of multiple computational models to help solid waste systems achieve their environmental goals in the most cost-efficient way possible.
Waste management systems do more than simply put solid waste into landfills. These systems need to not only safely store or recycle solid waste, but also must minimize any health risks associated with the waste, minimize environmental risks associated with air or water pollution, and minimize the release of greenhouse gases (GHGs) that can be produced as solid waste is processed or decomposes.
“The challenge is that there are a host of things waste management systems can do to accomplish these goals,” says James Levis, co-author of a paper on the new tool and a research assistant professor of civil, construction and environmental engineering at NC State. “And many of those actions have trade-offs, in terms of cost, environmental impact, technical challenges, and so on.
“To address this, we’ve created an open-source tool called the Solid Waste Optimization Life-cycle in Python (SwolfPy), which allows users to assess all of these options in one place. This can help users determine the best course of action for any specific set of circumstances. And, because it is open-source, the solid waste community can develop additional features over time to make the tool even more useful in guiding decision-making.”
“SwolfPy is a dynamic tool,” says Mojtaba Sardarmehni, corresponding author of the paper and a Ph.D. student at NC State. “For example, if someone develops a better model for one of its components, the open-source platform will allow users to update SwolfPy.”
The SwolfPy framework includes a collection of process models and a user-interface that allows users to plug in data relevant to their circumstances. SwolfPy will then run the numbers and do two things. First, it gives users a concise snapshot of their current overall operations, and what that means for their cost and environmental goals. Second, SwolfPy gives users the best combination — or combinations — of processes that would allow them to meet their target numbers for cost, GHG emissions, and so on.
But users don’t have to use the default models included in SwolfPy. Users can also choose to develop process models tailored to their specific projects and connect those models to SwolfPy; or users can use a combination of the default models and customized models. Regardless of which suite of models they choose, SwolfPy allows users to plug their target numbers into the user-interface, and SwolfPy will let them know which combination of processes will get them closest to their goals.
“To be clear, there isn’t always one best solution,” Sardarmehni says. “For example, there may be one combination of processes that is most cost-effective, while a second option is less cost-effective, but does a better job of reducing GHG emissions. What SwolfPy does is identify the range of best possible options for users, depending on how they prioritize their goals.”
“We think SwolfPy will be a useful tool for waste management companies, government decision makers who deal with solid waste issues, state policymakers and the research community,” Levis says.
SwolfPy is already freely available online at:
“We’re open to hearing from people in the solid waste community who have ideas or questions about how SwolfPy can be used, as well as what can be done to continue fine-tuning it as a practical tool,” Levis says.
Room-Temperature Fast H– Conduction in Oxygen-Substituted Lanthanum Hydride
by Keiga Fukui, Soshi Iimura, Albert Iskandarov, Tomofumi Tada, Hideo Hosono in Journal of the American Chemical Society
Fossil fuels such as coal, oil, and natural gas cannot last forever. Therefore, gradually decreasing our dependency on fossil fuels seems critical. Whereas alternative sources of energy such as solar or tidal energy can fill in the gap to some extent, they come with certain practical limitations. For example, utilizing solar energy requires the use of solar panels with large surface areas, thus making it a relatively expensive energy alternative.
In the recent past, scientists have explored multiple possibilities in an attempt to harness energy from various other sources. One such example includes the use of hydrogen-based energy systems. In this regard, lanthanum hydride, a compound of hydrogen and the metallic element lanthanum, has attracted quite a lot of attention. Because of its unique material properties, lanthanum hydride allows for superior hydride ion (H-) conductivity under certain conditions, which is the prerequisite for the efficient operation of chemical reactors and energy storage systems. However, most H- conductors show low H- conductivity at room temperature, which limits their application.
In a new study, researchers from Tokyo Institute of Technology (Tokyo Tech) have now come up with a technological innovation that can be used to overcome this limitation and design the next generation of energy carriers. The research team, led by Prof. Hideo Hosono, senior author of the study and Honorary Professor, Tokyo Tech, has successfully prepared and characterized a hydrogen-rich lanthanum hydride, with the chemical formula “LaH3−2xOx,” which shows a H- conductivity that is higher by three orders of magnitude when compared with the best conductor available. Their trick was to control the concentration of oxygen in LaH3−2xOx.
The researchers used a two-step process to prepare LaH3−2xOx. The high-density LaH3−2xOx pellet prepared using the first high-pressure synthesis step had a large amount of hydrogen deficiency. Next, the researchers exposed these pellets to hydrogen gas atmosphere at an elevated temperature (400 °C) for an extended duration (10 hours) to fill the hydrogen vacancy. It resulted in the formation of “LaH2.8O0.1,” a novel material showing high ionic conductivity even at room temperature.
Elaborating the concept behind their research, Prof. Hosono says, “Our study was driven by the idea that minimizing the amount of substituted O2− used to suppress the electronic conduction in LaH3−y should ideally make fast H− conduction in LaH3−2xOx at room temperature possible.”
Quite interestingly, the hydrogen-rich LaH3−2xOx also exhibited a low activation barrier — an energy hurdle that it must overcome to successfully function as an efficient ionic conductor. In terms of the actual measurement, this low activation barrier was somewhere between 0.3 and 0.4 eV. Moreover, the low activation barrier was independently confirmed using computerized simulations. The simulations also showed that the H- ions far from O2− ions were highly mobile and some of them traveled long distances by knocking each other out, suggesting the presence of strong repulsive Coulombic interactions ideal for fast H- conduction.
It seems there is good reason for Prof. Hosono to observe optimistically, “Hydrogen-rich LaH3−2xOx is a promising candidate for next-generation hydrogen carriers and can promote fossil fuel replacement!”
Potential of urban green spaces for supporting horticultural production: a national scale analysis
by Lael E Walsh, Bethan R Mead, Charlotte A Hardman, Daniel Evans, Lingxuan Liu, Natalia Falagán, Sofia Kourmpetli, Jess Davies in Environmental Research Letters
Britain’s towns and cities have the potential to support an urban agricultural revolution that would help meet the dietary needs of a growing population, boost the nation’s health and wellbeing, as well as reduce reliance on imports, a new study reveals.
In the first national-level study of its kind, a team of researchers led by scientists at Lancaster University set out to discover if there is sufficient green space, such as private gardens, parks and other recreational areas, within our towns and cities to grow enough fresh food to feed local populations.
The UK relies heavily on imports to meet its demand for fresh food, with more than a third of food coming from overseas. This can leave the nation exposed to disruptions in supply chains, such as those recently experienced with Brexit and Covid-19, leaving some shelves empty. And climate change presents another rising threat to these supplies, as much of our fresh fruit and veg comes from drought-prone regions.
“Britain is a densely-populated country that is highly reliant on imported fresh fruit and vegetables, and meeting the dietary needs of a growing urban population in a sustainable manner is a significant challenge,” said Professor Jess Davies, Principal Investigator of the study. “Finding ways in which Britain could increase food self-sufficiency is of increasing importance for securing our future food supply.
“Urban agriculture and more people ‘growing their own’ could play an important role in reducing our reliance on imports, and bolster resilience against disruptions in supply, without converting areas of nature to agriculture, or further intensifying farming. But it was not clear what the extent of that role could be at a national scale, until now.”
The research team used Ordnance Survey master maps to identify outdoor urban green spaces and calculated the productive potential of these areas using figures from existing domestic agriculture.
Private gardens and amenity space, such as landscaping and lawns, makes up most urban green space, followed by parks and other recreational areas such as sports fields. Currently only around 1% of urban green space is taken up by allotments dedicated for food production. The researchers considered all urban green spaces as potentially suitable for agriculture.
The study found if all urban green spaces were converted to food production, and used efficiently, they would collectively have the capacity to support food output eight times that of the current UK fruit and vegetable production. However, the researchers recognise that this is at the ‘extreme upper limit’ and that achievable outputs would be lower due to factors such as: some green spaces not being desirable or available for conversion, the level of available skills and knowledge, resources and variable growing conditions.
“These estimates are at the extreme upper limit for growing in British towns and cities,” said Dr Lael Walsh, lead author for the study and researcher with the Rurban Revolution project at Lancaster University. “However, even if only a small percentage of this area is suitable and available for urban agriculture, it could still represent a significant contribution to national supplies of fresh fruit and veg.
“We found that urban green spaces are significantly under-used for food growing and that there is huge untapped capacity in our towns and cities for people to grow more given support through targeted national policies. This could prove to be beneficial for improving access to healthier foods as well as boosting wellbeing through better connectedness to nature.”
The study also looked at 26 urban conurbations of differing sizes across England, Scotland and Wales and revealed that all those towns and cities analysed had the potential to meet the fresh fruit and vegetable dietary needs of their local populations.
Based on World Health Organisation guidelines, individuals need 400g of fruit and vegetables a day — which equates to 146kg a year. The assessment found that conversion of urban green spaces to food production could, at the higher end, produce 281kg of fruit and vegetables per person each year.
Carbon emissions reductions from Indonesia’s moratorium on forest concessions are cost-effective yet contribute little to Paris pledges
Ben Groom, Charles Palmer, Lorenzo Sileci. . Proceedings of the National Academy of Sciences
More than 70 million tons of carbon were prevented from being released into the atmosphere under a deforestation emissions reduction scheme in Indonesia — but researchers point out this is only 3 per cent of the total required by Indonesia’s Nationally Defined Contribution (NDC) under the Paris Agreement.
Indonesia is home to the world’s third largest span of tropical rainforest and is one of the largest greenhouse gas emitters — from 2000–2016 it was responsible for around a quarter of global emissions from deforestation, forest degradation, peatland decomposition and fires.
In 2011 Norway began a partnership with Indonesia to reduce carbon emissions from deforestation through a moratorium on granting new licences for palm oil, logging and timber concessions. The partnership, part of the international framework for Reducing Emissions from Deforestation and Forest Degradation (REDD+) established at COP13, saw Norway pledge $1billion to Indonesia as a performance based payment for carbon emissions reductions in the forestry sector. Under the REDD+ approach Norway committed to pay $5 per ton of carbon if the forest-rich tropical country reduced its emissions from deforestation.
The study, by a group of researchers including Professor Ben Groom, Dragon Capital Chair in Biodiversity Economics at the University of Exeter Business School, analysed the effectiveness of the scheme, and asked whether Norway received good carbon value for its money.
The researchers compared satellite data from 2004–2018 on forest cover inside the moratorium area, initially spanning 69 million hectares of forest land, with a control area outside the moratorium. They divided forest cover throughout Indonesia into 400,000 grid squares and then matched grid squares inside and outside the moratorium area, ensuring they were comparing similar areas of forested land. The impact was measured by comparing trends before and after the 2010 moratorium.
The researchers calculated that the moratorium had resulted in 67.8–86.9 million tons of carbon emissions reductions, with dryland forest inside the moratorium area having on average 0.65% higher forest cover compared with similar areas outside the moratorium.But on peatlands, which are huge natural stores of carbon, the study found that the moratorium had zero effect. The researchers said that while they found the scheme had been moderately successfully, the impact was “tiny” compared with the nationally determined contributions (NDCs) for carbon reduction set out in the Paris Agreement.
“Our estimates suggest a 3–4 per cent annual contribution to Indonesia’s NDC of a 29% emissions reduction by 2030, which is only a small dent in Indonesia’s overall commitment,” said Professor Groom.
“This is a problem because in Indonesia around 65 per cent of emissions are from forest areas so the forest sector is a very important place to stop emissions coming from if they’re going to meet their NDC commitments for the Paris Agreement. “The scale of the finance needs to be much bigger for implementation to be effective.”
In 2019 Norway agreed to pay Indonesia $56.2 million for preventing the estimated emission of 11.23 million tons of carbon in 2017. This estimate of performance used the average deforestation rates for the whole of Indonesia rather than just the moratorium area, so is not an accurate measure of whether the programme was effective, said the researchers.
Using well-established policy impact methods to estimate carbon emissions reductions, the researchers calculated that over the period 2011–17 the moratorium was more effective than this calculation suggests, meaning that for $56m Norway effectively bought carbon emissions reductions at a rate of less than $1 per ton.
“We find that Norway should probably been paying a lot more because the impact starts much earlier, from 2013 we estimate some modest but statistically significant changes, yet the payment was only calculated for 2017, with no proper counterfactual.” said Professor Groom.
While the carbon pricing was a “good deal” for Norway and global emissions reductions, Professor Groom adds that the agreement, which ended in 2021, could be seen as unfair towards Indonesia.
“Norway is looking for ways to invest its wealth by investing in this global public good: carbon emissions reductions. In the end there should be more efforts like Norway’s in the world.
“However, the global benefits of mitigating climate change, which economists measure using the social cost of carbon, is far greater than the $5 per ton they were paying — the US government uses $50 per ton, New York State $125 per ton, many argue it is higher still- so while Norway got a good deal, and cost-effective carbon policy is important, it wasn’t necessarily fair from an Indonesian perspective not to get a greater share of the global benefits. Maybe perceptions of fairness were driving the failure in this otherwise positive bilateral arrangement.”
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