TL;DR
- New prototype tech can double the power harvested from ocean waves, an advance that could finally make wave energy a viable renewable alternative.
- Electric vehicles require power to be available anywhere and anytime without delay to recharge, but solar and wind are intermittent energy sources that are not available on demand. And the electricity they do generate needs to be stored for later use and not go to waste. New research reveals a more stable way to store this important energy.
- To fully harness the potential of sunlight, scientists have been trying to maximize the amount of energy that can be extracted from the sun. Researchers now describe how pairing metal halide perovskites with conventional silicon leads to a more powerful solar cell that overcomes the 26% practical efficiency limit of using silicon cells alone. Perovskites fulfill all the optoelectronic requirements for a photovoltaic cell, and they can be manufactured using existing processes.
- A research group is developing polymers that can be broken down into their constituent parts; thus, when the catalyst for depolymerization is absent or removed, the polymers will be highly stable and their thermal and mechanical properties can be tuned to meet the needs of various applications.
- Hydrogen produced from renewable energy sources with the help of electric power is deemed a key to the energy transition: It can be used to chemically store wind and solar energy in a CO2-neutral way. Researchers have studied water electrolysis processes on the surface of an iridium oxide catalyst.
- Researchers have devised a new ‘greener’ method to make a key compound in fertilizer, and that may pave the way to a more sustainable agricultural practice as global food demand rises.
- We usually think of solar, or photovoltaic (PV), cells fixed to roofs, converting sunlight into electricity, but bringing that technology indoors could further boost the energy efficiency of buildings and energize swaths of wireless smart technologies such as smoke alarms, cameras and temperature sensors, also called Internet of Things (IoT) devices. Now, a new study suggests that a straightforward approach for capturing light indoors may be within reach.
- Researchers have developed a climate-friendly alternative to conventional cement. Carbon dioxide (CO2) emissions can be reduced during production by up to two thirds when a previously unused overburden from bauxite mining is used as a raw material. The alternative was found to be just as stable as the traditional Portland cement.
- The future connection between human waste, sanitation technology and sustainable agriculture is becoming more evident. According to a new study, countries could be moving closer to using human waste as fertilizer, closing the loop to more circular, sustainable economies.
- Researchers work on physicochemical properties and antioxidant activity of wood vinegar and tar fraction in bio-oil produced from hazelnut shells pyrolysis at 400 degrees Celsius to 1,000 C. They found the wood vinegar and tar left over after burning the shells contained the most phenolic substances, which laid a foundation for the subsequent research on antioxidant properties.
- 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
- How Europe could slash its cooling footprint with chilled water: District cooling, a method of cooling buildings where chilled water from a central facility passes through pipes to multiple buildings, allowing to be cooled without needing their own energy-hungry air conditioning systems.
- US utility plans to switch 1200 vehicles to electric by 2030: The nation’s largest public utility plans to switch out 1,200 of its vehicles for electric ones by 2030, furthering its role in that market for a power supplier that also plans to help add charging stations across the region.
- How Sweden Delivered The World’s First Fossil Fuel-Free Steel: Sweden has delivered the world’s first shipment of steel produced without the use of fossil fuels, a major milestone on the road towards cutting carbon emissions from industry.
- Canadian utility creates marketplace for DER households using blockchain technology: Canada’s largest municipally-owned electric utility has launched a pilot program that allows customers with distributed energy resources (DERs) to participate in an energy marketplace using blockchain technology.
- As Henri Strikes, Scientists Reveal Europe Floods Made Up To Nine Times More Likely By Climate Change: Extreme rainfall of the sort that caused devastating floods across Europe last month has been made both more severe and more likely by climate change, a team of scientists has revealed.
- Climate change is an infrastructure problem — map of electric vehicle chargers shows one reason why: The U.S. has around 43,000 public EV charging stations, with about 106,000 outlets. Each outlet can charge only one vehicle at a time, and even fast-charging outlets take an hour to provide 180–240 miles’ worth of charge; most take much longer.
- Climate report underscores urgency of advancing battery storage for renewables: The recent report from the UN’s Intergovernmental Panel on Climate Change clearly outlines that climate change is widespread, intensifying, and ‘unequivocally’ caused by human activities.
- A Methane Hunter Finds Leaking Gas That Threatens EU’s Climate Goals: A special infrared camera captured more than 70 plumes from pipes, oil fields and storage units operated by one of the European Union’s biggest oil and gas producers.
- Investors Get Serious About Nuclear Fusion, Energy’s Eternal Grail: Enthusiastic for the prospect of carbon-free power, funders poured $300 million into private fusion companies in 2020.
- Wave-powered SeaRAY preps for Hawaii trial: An autonomous, wave-powered, renewable energy device — called the SeaRAY autonomous offshore power system (AOPS) — could power offshore work and help protect our oceans and climate, too.
- UK government sees future in low-carbon fuel, but what’s the reality? The UK’s long-awaited hydrogen strategy has set out the government’s plans for “a world-leading hydrogen economy” that it says would generate £900 million (US$1.2 million) and create over 9,000 jobs by 2030.
- The coal price has skyrocketed in 2021: What it means for net zero: The rise in prices can be attributed squarely to a resurgence of demand after the depths of the pandemic.
- Distilleries need blend of green energy and storage to reach net zero: Distilleries of all sizes should combine renewable energy with some form of heat or electrical energy storage, a new study says.
- A fleet-footed focus to improve electric vehicle uptake in Australia: Australia’s transport sector accounts for almost 20% of the country’s CO₂ emissions, making it a key battleground in efforts to reduce the impact of climate change.
- Silicon nanowire offers efficient high-temperature thermoelectric system: Berkeley Lab has developed a cost-effective thermoelectric waste-heat recovery system to reduce electricity-related carbon emissions.
- Stretchable sweat-powered battery developed for wearable tech: Scientists from Nanyang Technological University have developed a soft and stretchable battery that is powered by human perspiration.
- With redesigned ‘brains,’ W88 nuclear warhead reaches milestone: Sandia National Laboratories and its nuclear security enterprise partners recently completed the first production unit of a weapon assembly responsible for key operations of the W88 nuclear warhead.
- ‘Thermal switches’ dynamically moderate heat of electronic devices: Purdue University engineers have developed a “thermal switch” made up of compressible graphene foam, that dynamically adjusts to temperatures of the device to maintain consistent thermal management.
- Water consumption and conservation evaluated in the coal power industry in China: Coal power is still a main source of power generation for China. Effective water conservation is urgent for the sustainable development of this industry.
- Offshore wind could help solve California’s reliability problem, report finds: Offshore wind development offers an answer to California’s reliability problem, and could greatly help the state reach its net-zero goals.
- North Star Renewables secures $131M loan to build offshore wind farm support vessels: The company has secured a $131 million loan to build a new fleet of offshore wind farm support vessels in the UK.
- Guidehouse Insights forecast: AI-driven DER integration could reach $481M annually by 2030: A new report analyzed the potential for AI-enabled DER integration and predicted 10 percent annual growth rates topping more than $480 million by 2030.
- Kokam to supply Tahiti utility with 15MW battery system to replace reserve diesel generators: South Korean lithium-ion battery system manufacturer Kokam has entered into a contract to supply a Tahiti utility with a 15 MW/10.4 MWh battery energy storage system (BESS).
- U.K. Oil Field Work Delayed With Environment Debate Raging: Siccar Point Energy Ltd. is delaying work on its Cambo oil field in the U.K.
- More Transmission Or Local Solar? To Quickly Cut Emissions, We Need Both: A clean energy CEO says we need more transmission and local resources like rooftop solar to decarbonize our electricity supply.
- GM’s $1.8 Billion Chevy Bolt Recall Shows Why Automakers’ EV Rollouts Could Be ‘On Fire’: The significance of GM’s recall of the Chevy Bolt goes far beyond Detroit.
- Winning Solutions To Single-Use Plastic Bags Are Being Tested By Some Major Retailers: The single-use plastic bag is out and several sustainable alternatives are in at some CVS Health, Target and Walmart stores.
Latest Research
Study of a novel rotational speed amplified dual turbine wheel wave energy converter
by Han Xiao, Zhenwei Liu, Ran Zhang, Andrew Kelham, Xiangyang Xu, Xu Wang in Applied Energy
Researchers have developed prototype technology that can double the power harvested from ocean waves, in an advance that could finally make wave energy a viable renewable alternative.
The untapped potential of ocean wave energy is vast — it has been estimated that the power of coastal waves around the world each year is equivalent to annual global electricity production. But the challenges of developing technologies that can efficiently extract that natural power and withstand the harsh ocean environment have kept wave energy stuck at experimental stage.
Now a research team led by RMIT University has created a wave energy converter that is twice as efficient at harvesting power as any similar technologies developed to date. The innovation relies on a world-first, dual-turbine design.
Lead researcher Professor Xu Wang said wave energy was one of the most promising sources of clean, reliable and renewable power.
“While wind and solar dominate the renewable market, they are available only 20–30% of the time,” Wang said. Wave energy is available 90% of the time on average and the potential power contained in offshore waves is immense”.
“Our prototype technology overcomes some of the key technical challenges that have been holding back the wave energy industry from large-scale deployment. With further development, we hope this technology could be the foundation for a thriving new renewable energy industry delivering massive environmental and economic benefits.”
One of the most popular experimental approaches is to harvest wave energy through a buoy-type converter known as a “point absorber,” which is ideal for offshore locations.
This technology, which harvests energy from the up and down movement of waves, is generally cost-effective to manufacture and install.
But it needs to be precisely synchronized with incoming wave movement to efficiently harvest the energy. This usually involves an array of sensors, actuators and control processors, adding complexity to the system that can cause underperformance, as well as reliability and maintenance issues.
The RMIT-created prototype needs no special synching tech, as the device naturally floats up and down with the swell of the wave.
“By always staying in sync with the movement of the waves, we can maximise the energy that’s harvested,” Wang said.
“Combined with our unique counter-rotating dual turbine wheels, this prototype can double the output power harvested from ocean waves, compared with other experimental point absorber technologies.”
The simple and economical device has been developed by RMIT engineering researchers in collaboration with researchers from Beihang University in China.
Two turbine wheels, which are stacked on top of each other and rotate in opposite directions, are connected to a generator through shafts and a belt-pulley driven transmission system. The generator is placed inside a buoy above the waterline to keep it out of corrosive seawater and extend the lifespan of the device.
The prototype has been successfully tested at lab scale and the research team is keen to collaborate with industry partners to test a full-scale model, and work towards commercial viability.
“We know it works in our labs, so the next steps are to scale this technology up and test it in a tank or in real-life ocean conditions,” Wang said.
“Tapping into our wave energy resource could not only help us cut carbon emissions and create new green energy jobs, it also has great potential for addressing other environmental problems.”
“For example, as the frequency of drought increases, wave energy could be used to power carbon-neutral desalination plants and supply fresh water for the agriculture industry — a smart adaptation to the challenge of a changing climate.”
Symmetry-breaking design of an organic iron complex catholyte for a long cyclability aqueous organic redox flow battery
by Xiang Li, Peiyuan Gao, Yun-Yu Lai, J. David Bazak, Aaron Hollas, Heng-Yi Lin, Vijayakumar Murugesan, Shuyuan Zhang, Chung-Fu Cheng, Wei-Yao Tung, Yueh-Ting Lai, Ruozhu Feng, Jin Wang, Chien-Lung Wang, Wei Wang, Yu Zhu in Nature Energy
The sale of electric vehicles (EV’s) has grown exponentially in the past few years as is the need for renewable energy sources to power them, such as solar and wind. There were nearly 1.8 million registered electric vehicles in the U.S. as of 2020, which is more than three times as many in 2016, according to the International Energy Agency (IEA).
Electric vehicles require power to be available anywhere and anytime without delay to recharge, but solar and wind are intermittent energy sources that are not available on demand. And the electricity they do generate needs to be stored for later use and not go to waste. That’s where Dr. Yu Zhu, a professor in The University of Akron’s School of Polymer Science and Polymer Engineering, and his research team come in, by developing a more stable way to store this important energy.
Just as the gas station today, electricity power stations need a storage system to keep the electricity for EV constantly charging. Low cost, scalable redox flow batteries (RFB) are among the most suitable technology for such a system; however, current RFBs use high-cost and environmentally hazardous active materials (electrolytes). Recently, water-soluble organic materials have been proposed as future electrolytes in the RFBs (namely aqueous organic RFBs, or AORFBs). Organic-based electrolytes can be obtained from renewable sources and manufactured with very low cost. However, the lack of stable water-soluble organic electrolyte materials, particularly the positive electrolyte (catholyte), is a major hurdle of AORFBs.
Zhu’s research group, in collaboration with scientists in Pacific Northwestern National Laboratory led by Dr. Wei Wang, successfully developed the most stable catholyte (positive electrolyte) to date in AORFBs and demonstrated cells that kept more than 90% of capacity over 6,000 cycles, projecting more than 16 years of uninterrupted service in a pace of one cycle per day. Their research included contributions from Zhu’s doctoral students Xiang Li and Yun-Yu Lai.
“Development of high-performance RFBs will enrich the category of electricity energy storage systems and complement the shortcoming of intermittent renewable energy sources, therefore largely improving the usability of electricity powered facilities, such as vehicles,” says Zhu. “To significantly improve the performance of aqueous organic RFBs, the urgency of developing new catholyte is crucial.”
The team not only demonstrated a state of art catholyte in AORFBs, but also provided a brand-new strategy to design water soluble catholyte to enhance their solubility (energy density) in water. Instead of attaching a hydrophilic functional group to improve the solubility of the molecules, the researchers change the symmetry of molecules, which results in a dramatic enhancement of solubility. With the new design strategy, the team plans to design new materials they can further mature the RFBs.
A patent application has been submitted based on the technology developed in this research.
Perovskite/silicon tandem photovoltaics: Technological disruption without business disruption
by Christina Kamaraki, Matthew T. Klug, Thomas Green, Laura Miranda Perez, Christopher Case in Applied Physics Letters
Many countries around the world are committed to reducing emissions or reaching net-zero emissions to meet the United Nations’ climate goals of maintaining temperature increases below 1.5 degrees Celsius by 2050. Renewable energy technologies, particularly solar energy panels, will play a significant role in achieving these goals.
To fully harness the potential of sunlight — the world’s most abundant energy resource — scientists have been trying for decades to maximize the amount of energy that can be extracted from the sun. Researchers from Oxford PV describe how pairing metal halide perovskites with conventional silicon leads to a more powerful solar cell that overcomes the 26% practical efficiency limit of using silicon cells alone.
“We identified perovskites as the perfect partner for a tandem system with silicon,” said author Laura Miranda Pérez.
From a materials perspective, perovskites fulfill all the optoelectronic requirements for a photovoltaic cell, and they can be manufactured using existing processes. These features make perovskite a perfect plug-and-play addition to silicon technology as it can be deposited as a layer onto a conventional silicon solar cell.
“We’re proving the potential of perovskite-on-silicon tandem technology through the continuous achievement of world-record efficiencies, with our current record at 29.52%,” said Miranda Pérez.
The elemental composition of the perovskite material is readily available within existing supply chains, providing a clear pathway to scale up the technology quickly to meet the ambitious solar energy targets needed to tackle climate change. Also, the higher power output of perovskite-on-silicon tandem cells could offset the carbon footprint embodied in the production of high-purity silicon required for photovoltaic cells.
Consequently, the researchers found adding perovskite onto existing silicon photovoltaics is the fastest way to improve silicon performance as it bypasses the industry disruptions associated with the introduction of a brand-new technology. The researchers focused on tandem solar cells for seven years, and the group is now very close to starting mass commercial production in its factory in Brandenburg, Germany.
“We want to help people understand the huge potential of perovskite-on-silicon tandem technology to boost the efficiency of solar installations and to help the world reach the goal of providing sustainable energy for all,” said Miranda Pérez.
Indoor light energy harvesting for battery‐powered sensors using small photovoltaic modules
by Andrew Shore, John Roller, Jennifer Bergeson, Behrang H. Hamadani in Energy Science & Engineering
Any time you turn on a light at home or in the office, you are expending energy. But what if flipping the light switch meant producing energy too?
We usually think of solar, or photovoltaic (PV), cells fixed to roofs, converting sunlight into electricity, but bringing that technology indoors could further boost the energy efficiency of buildings and energize swaths of wireless smart technologies such as smoke alarms, cameras and temperature sensors, also called Internet of Things (IoT) devices. Now, a study from the National Institute of Standards and Technology (NIST) suggests that a straightforward approach for capturing light indoors may be within reach. NIST researchers tested the indoor charging ability of small modular PV devices made of different materials and then hooked up the lowest efficiency module — composed of silicon — to a wireless temperature sensor.
The team’s results demonstrate that the silicon module, absorbing only light from an LED, supplied more power than the sensor consumed in operation. This outcome suggests that the device could run continuously while lights remain on, which would do away with the need for someone to manually exchange or recharge the battery.
“People in the field have assumed it’s possible to power IoT devices with PV modules in the long term, but we haven’t really seen the data to support that before now, so this is kind of a first step to say that we can pull it off,” said Andrew Shore, a NIST mechanical engineer and lead author of the study.
Most buildings are lit by a mix of both the sun and artificial light sources during the day. At dusk, the latter could continue to supply energy to devices. However, light from common indoor sources, such as LEDs, spans a narrower spectrum of light than the wider bands emitted by the sun, and some solar cell materials are better at capturing these wavelengths than others.
To find out exactly how a few different materials would stack up, Shore and his colleagues tested PV mini modules made of gallium indium phosphide (GaInP), gallium arsenide (GaAs) — two materials geared toward white LED light — and silicon, a less efficient but more affordable and commonplace material.
The researchers placed the centimeters-wide modules underneath a white LED, housed inside an opaque black box to block out external light sources. The LED produced light at a fixed intensity of 1000 lux, comparable to light levels in a well-lit room, for the duration of the experiments. For the silicon and GaAs PV modules, soaking in indoor light proved less efficient than sunshine, but the GaInP module performed far better under the LED than sunlight. Both the GaInP and GaAs modules significantly outpaced silicon indoors, converting 23.1% and 14.1% of the LED light into electrical power, respectively, compared with silicon’s 9.3% power conversion efficiency.
Coming as no surprise to the researchers, the rankings were the same for a charging test in which they timed how long it took the modules to fill a half-charged 4.18-volt battery, with silicon coming in last by a margin of more than a day and a half.
The team was interested in learning if the silicon module, despite its poor performance relative to its top-shelf competitors, could generate enough power to run a low-demand IoT device.
Their IoT device of choice for the next experiment was a temperature sensor that they hooked up to the silicon PV module, placed once more under an LED. Upon turning the sensor on, the researchers found that it was able to feed temperature readings wirelessly to a computer nearby, powered by the silicon module alone. After two hours, they switched off the light in the black box and the sensor continued to run, its battery depleting at half the rate it took to charge.
“Even with a less efficient mini module, we found that we could still supply more power than the wireless sensor consumed,” Shore said.
The researchers’ findings suggest that an already ubiquitous material in outdoor PV modules could be repurposed for indoor devices with low-capacity batteries. The results are particularly applicable to commercial buildings where lights are on around the clock. But how well would PV-powered devices run in spaces that are only lit intermittently throughout the day or shut off at night? And how much of a factor would ambient light pouring in from outside be? Homes and office spaces aren’t black boxes after all.
The team plans to tackle both questions, first by setting up light-measuring devices in NIST’s Net-Zero Energy Residential Test Facility to gain an understanding of what light is available throughout the day in an average residence, Shore said. Then they’ll replicate the lighting conditions of the net-zero house in the lab to find out how PV-powered IoT devices perform in a residential scenario.
Feeding their data into computer models will also be important for predicting how much power PV modules would produce indoors given a certain level of light, a key capability for cost-effective implementation of the technology.
“We’re turning on our lights all the time and as we move more toward computerized commercial buildings and homes, PV could be a way to harvest some of the wasted light energy and improve our energy efficiency,” Shore said.
Olefin metathesis-based chemically recyclable polymers enabled by fused-ring monomers
by Devavrat Sathe, Junfeng Zhou, Hanlin Chen, Hsin-Wei Su, Wei Xie, Tze-Gang Hsu, Briana R. Schrage, Travis Smith, Christopher J. Ziegler, Junpeng Wang in Nature Chemistry
Plastics sustainability has come a long way in recent years thanks in large part to scientific advances. But even as plastics become more and more environmentally friendly, the world continues to be polluted as many industries rely on them for their widely used products.
The latest research from Dr. Junpeng Wang, assistant professor in UA’s School of Polymer Science and Polymer Engineering has a solution to reduce such waste and clear a scientific pathway for a more sustainable future that can appeal to the rubber, tire, automobile and electronics industries. Although this work is supported by UA, Wang recently earned a National Science Foundation CAREER Award that will support future developments from this research.
The problem at hand: Synthetic polymers, including rubber and plastics, are used in nearly every aspect of daily life. The dominance of synthetic polymers is largely driven by their excellent stability and versatile mechanical properties. However, due to their high durability, waste materials composed of these polymers have accumulated in the land and oceans, causing serious concerns for the ecosystem.
In addition, since over 90% of these polymers are derived from finite natural resources, such as petroleum and coal, the production of these materials is unsustainable if they cannot be recycled and reused.
A promising solution to address the challenges in plastics sustainability is to replace current polymers with recyclable ones in order to achieve a circular use of materials. Despite the progress made thus far, few recyclable polymers exhibit the excellent thermal stability and high-performance mechanical properties of traditional polymers. The recyclable materials Wang and his team have developed are unique in the superior thermal stability and versatile mechanical properties.
“We are particularly interested in chemically recyclable polymers that can be broken down into the constituents (monomers) from which they are made,” says Wang. “The recycled monomers can be reused to produce the polymers, allowing for a circular use of materials, which not only helps to preserve the finite natural resources used in plastics production, but also addresses the issue of unwanted end-of-life accumulation of plastic objects.”
The key in the design of chemically recyclable polymers is to identify the right monomer. Through careful computational calculation, the researchers identified a targeting monomer. They then prepared the monomer and polymers through chemical synthesis, using abundantly available starting materials.
Wang’s research group, including polymer science graduate students and a postdoctoral scientist, aims to address those challenges by developing polymers that can be broken down into their constituent parts. When the catalyst for depolymerization is absent or removed, the polymers will be highly stable and their thermal and mechanical properties can be tuned to meet the needs of various applications.
“The chemically recyclable polymers we developed show excellent thermal stability and robust mechanical properties and can be used to prepare both rubber and plastics,” says Wang. “We expect this material to be an attractive candidate to replace current polymers. Our molecular design is guided by computation, highlighting the transformational power of integrating computation and experimental work. Compared to other recyclable polymers that have been demonstrated, the new polymers we demonstrate show much better stability and more versatile mechanical properties. When a catalyst is added, the polymer can be degraded into the constituent monomer for recycling.”
Next for Wang’s research group is to expand the scope of the chemically recyclable polymers and to develop carbon-fiber reinforced polymer composites. The team will also analyze the economic performance of this industrial process and life-cycle analysis for commercialization of the polymers.
Increased Ir–Ir Interaction in Iridium Oxide during the Oxygen Evolution Reaction at High Potentials Probed by Operando Spectroscopy
by Steffen Czioska, Alexey Boubnov, Daniel Escalera-López, Janis Geppert, Alexandra Zagalskaya, Philipp Röse, Erisa Saraçi, Vitaly Alexandrov, Ulrike Krewer, Serhiy Cherevko, Jan-Dierk Grunwaldt in ACS Catalysis
Hydrogen produced from renewable energy sources with the help of electric power is deemed a key to the energy transition: It can be used to chemically store wind and solar energy in a CO2-neutral way. Researchers have studied water electrolysis processes on the surface of an iridium oxide catalyst.
Using energy from solar modules and wind turbines, water can be split by electrolysis into its constituents hydrogen and oxygen without producing any dangerous emissions. As the availability of energy from renewable sources varies when producing green, i.e. CO2-neutral, hydrogen, it is very important to know the behavior of the catalysts under high loading and dynamic conditions.
“At high currents, strong oxygen bubble evolution can be observed on the anode, which aggravates measurement. It has made it impossible so far to obtain a reliable measurement signal,” says the first author of the study, Dr. Steffen Czioska from KIT’s Institute for Chemical Technology and Polymer Chemistry (ITCP).
By combining various techniques, the researchers have now succeeded in fundamentally investigating the surface of the iridium oxide catalyst under dynamic operation conditions. “For the first time, we have studied the behavior of the catalyst on the atomic level in spite of strong bubble evolution,” Czioska says.
For catalysis, researchers from KIT’s ITCP, the Institute of Catalysis Research and Technology, and the Electrochemical Technologies Group of the Institute for Applied Materials combined X-ray absorption spectroscopy for the highly precise investigation of modifications on the atomic level with other analysis methods. “We have observed regular processes on the catalyst surface during the reaction, because all irregularities were filtered out — similar to slow speed shooting on a road at night — and we have also pursued dynamic processes,” Czioska says. “Our study reveals highly unexpected structural modifications connected to a stabilization of the catalyst at high voltages under dynamic loading,” the chemist adds. Iridium oxide dissolution is reduced, the material remains stable.
Understanding of the processes on the catalyst surface paves the way to further investigation of catalysts at high electric potentials and will contribute to the development of improved and more efficient catalysts meeting the needs of the energy transition, Czioska points out. The study is part of the “Dynakat” priority program funded by the German Research Foundation. This collaboration of more than 30 research groups from all over Germany is coordinated by Professor Jan-Dierk Grunwaldt from ITCP.
Green hydrogen is deemed an environmentally compatible chemical energy storage material and, hence, an important element in the decarbonization of e.g. steel and chemical industries. According to the National Hydrogen Strategy adopted by the Federal Government in 2020, reliable, affordable, and sustainable production of hydrogen will be the basis for its future use.
Selective electrocatalytic synthesis of urea with nitrate and carbon dioxide
by Chade Lv, Lixiang Zhong, Hengjie Liu, Zhiwei Fang, Chunshuang Yan, Mengxin Chen, Yi Kong, Carmen Lee, Daobin Liu, Shuzhou Li, Jiawei Liu, Li Song, Gang Chen, Qingyu Yan, Guihua Yu in Nature Sustainability
A team of international scientists led by Nanyang Technological University, Singapore (NTU Singapore) has devised a new ‘greener’ method to make a key compound in fertiliser, and that may pave the way to a more sustainable agricultural practice as global food demand rises.
Devised by NTU researchers, the method produces a compound known as ‘urea’, which is a natural product found in the urine of mammals, and an essential compound for fertilisers that is mass-produced industrially to increase crop yields.
However, the current Haber-Bosch process used to make urea is energy-intensive, requiring temperatures of 500 degrees Celsius and pressures of two hundred times sea-level atmospheric pressure. It creates significant CO2 emissions, contributing to approximately 2 percent of global energy annually.
Seeking a more sustainable and energy-efficient method, the team found a way to greatly improve an existing alternative approach to urea production known as electrocatalysis — using electricity to drive chemical reactions in a solution.
Using the nanomaterial indium hydroxide as a catalyst, the researchers reacted nitrate and carbon dioxide and found that the process formed urea five times more efficiently than previously reported attempts using electrocatalysis, specifically by causing the chemical reaction to take place in a ‘highly selective’ manner.
Co-lead author of the study, Professor Alex Yan from the NTU School of Materials Science and Engineering (MSE) said, “Our method essentially manipulates the chemical reaction process to become ‘highly selective’. By picking a better catalyst, we helped the nitrate ions and carbon dioxide molecules to optimally position themselves to facilitate urea formation, while suppressing the creation of unnecessary by-products like hydrogen, leading to higher efficiency and better urea yields.”
This new method to produce urea may inspire the future design of sustainable chemistry approaches and contribute to ‘greener’ agricultural practices to feed the world’s growing population, say the research team. The study reflects the university’s commitment to address humanity’s grand challenges on sustainability as part of the NTU 2025 strategic plan, which seeks to accelerate the translation of research discoveries into innovations that mitigate our impact on the environment.
As a proof of concept, the scientists tested the efficiency of their devised method in the lab and found that the approach achieved a urea yield of 53.4 per cent, which is competitive with the current Haber-Bosch industrial method, that was first demonstrated in 1910.
The Haber-Bosch, a two-step thermal process, is fossil fuel reliant and can only happen at specific high temperatures, and high-pressure conditions. First, nitrogen and hydrogen are combined to make ammonia. Carbon dioxide is then bonded with it to make urea. By comparison, the new NTU approach is more environmentally friendly and simpler. It uses nitrate — a compound with bonds that require less energy to break — carbon dioxide, and hydrogen to directly trigger urea formation under room temperature.
The new method is simple enough to be adopted at both large and small scales, say the research team. The electrocatalytic device could be easily operated by farmers to generate their own urea for fertilisers. The method could also one day be powered entirely by renewable energy.
First author of the research, Dr Lyu Chade, Research Fellow from the NTU School of MSE said, “With advances in solar technology, we may potentially use sunlight to power the electrocatalysis process in future, which can further help lower global emissions.”
As the next steps, the research team is aiming to achieve even higher yield results and to refine the catalytic selectivity, by exploring catalysts that would trigger faster reactions. They also plan to find a way to power the process using solar energy and to create a prototype device to demonstrate scaled up urea production.
Production of low-CO2 cements using abundant bauxite overburden “Belterra Clay”
by Leonardo Boiadeiro Ayres Negrão, Herbert Pöllmann, Marcondes Lima da Costa in Sustainable Materials and Technologies
Researchers at the Martin Luther University Halle-Wittenberg (MLU) in Germany and the Brazilian University of Pará have developed a climate-friendly alternative to conventional cement. Carbon dioxide (CO2) emissions can be reduced during production by up to two thirds when a previously unused overburden from bauxite mining is used as a raw material. The alternative was found to be just as stable as the traditional Portland cement.
Houses, factories, staircases, bridges, dams — none of these structures can be built without cement. According to estimates, almost six billion tonnes of cement were produced worldwide in 2020. Cement is not only an important building material, it is also responsible for around eight per cent of humanmade CO2 emissions.
“Portland cement is traditionally made using various raw materials, including limestone, which are burned to form so-called clinker,” explains Professor Herbert Pöllmann from MLU’s Institute of Geosciences and Geography. “In the process, the calcium carbonate is converted into calcium oxide, releasing large quantities of carbon dioxide.”
Since CO2 is a greenhouse gas, researchers have been looking for alternatives to Portland cement for several years.
One promising solution is calcium sulphoaluminate cement, in which a large portion of the limestone is replaced by bauxite. However, bauxite is a sought-after raw material in aluminium production and not available in unlimited quantities. Together with Brazilian mineralogists, the MLU team has now found an alternative to the alternative, so to speak: They do not use pure bauxite, but rather an overburden: Belterra clay. “This layer of clay can be up to 30 metres thick and covers the bauxite deposits in the tropical regions of the earth, for example in the Amazon basin,” explains Pöllmann. “It contains enough minerals with an aluminium content to ensure good quality cement. It is also available in large quantities and can be processed without additional treatment.” Another advantage: The Belterra clay has to be removed anyway, so it does not have to be extracted only for cement production.
Even though cement cannot be entirely produced without calcium carbonate, at least 50 to 60 percent of the limestone can be replaced by Belterra clay. The process has another environmentally relevant advantage: the burning process only requires 1,250 degrees Celsius (2282° Fahrenheit) — 200 degrees (392° Fahrenheit) less than for Portland cement. “Our method not only releases less CO2 during the chemical conversion, but also when heating the rotary kilns,” says Pöllmann. By coupling these effects, CO2 emissions can be reduced by up to two thirds during cement production.
In extensive laboratory tests, the mineralogists were able to prove that their alternative cement meets all the quality requirements placed on traditional Portland cement. Further research projects will now investigate whether there are also overburden sources in Germany suitable for cement production. “Raw materials containing clay minerals with a lower aluminium content could be used particularly in construction projects where lower-grade concrete is sufficient,” explains Pöllmann. “There is still huge potential here to further reduce carbon dioxide emissions.”
Influence of pyrolysis temperature on bio-oil produced from hazelnut shells: Physico-chemical properties and antioxidant activity of wood vinegar and tar fraction
by Aihui Chen, Xifeng Liu, Haibin Zhang, Hao Wu, Dong Xu, Bo Li, Chenxi Zhao in Journal of Renewable and Sustainable Energy
Biomass is attracting growing interest from researchers as a source of renewable, sustainable, and clean energy. It can be converted into bio-oil by thermochemical methods, such as gasification, liquefaction, and pyrolysis, and used to produce fuels, chemicals, and biomaterials.
Researchers from Heilongjiang Academy of Agricultural Machinery Sciences in China share their work on the physicochemical properties and antioxidant activity of wood vinegar and tar fraction in bio-oil produced from hazelnut shells pyrolysis at 400 degrees Celsius to 1,000 C.
Wood vinegar is often used in agricultural fields as insect repellent, fertilizer, and plant growth promoter or inhibitor, and can be applied as an odor remover, wood preservative, and animal feed additive.
“After these results, wood vinegar and tar obtained from residual hazelnut shells could be considered as potential source of renewable energy dependent on their own characteristics,” said author Liu Xifeng.
The researchers found the wood vinegar and tar left over after burning the shells contained the most phenolic substances, which laid a foundation for the subsequent research on antioxidant properties.
The experiments were conducted in a tube furnace pyrolysis reactor, and hazelnut shells samples weighing 20 grams were placed in the waiting area of a quartz tube in advance. When the target temperature was reached and stable, the raw materials were pushed to the reaction region and heated for 20 minutes.
The biochar was determined as the ratio of pyrolytic char and biomass weight, and the bio-oil yield was calculated by the increased weight of the condenser.
To separate two fractions of bio-oil sufficiently, the liquid product was centrifuged at 3,200 revolutions per minute for eight minutes, and the aqueous fraction was called wood vinegar. The separated tar fraction remained stationary for 24 hours without the appearance of the aqueous phase.
The wood vinegar and tar were respectively stored in a sealed tube and preserved in a refrigerator at 4 C for experimental analysis, and the gas yield was calculated by considering their combined volume.
The researchers found the pyrolysis temperature had a significant effect on the yield and properties of wood vinegar and tar fraction in bio-oil obtained from hazelnut shells. Wood vinegar was the dominant liquid fraction with maximal yield of 31.23 weight percent obtained at 700 C, attributable to the high concentration of water.
This research sets the groundwork for further applications of bio-oil from waste hazelnut shell pyrolysis, and its application in antioxidant activity has been extended.
Defining Nutrient Colocation Typologies for Human-Derived Supply and Crop Demand To Advance Resource Recovery
by Desarae Echevarria, John T. Trimmer, Roland D. Cusick, Jeremy S. Guest in Environmental Science & Technology
The future connection between human waste, sanitation technology and sustainable agriculture is becoming more evident. According to research directed by University of Illinois Urbana-Champaign civil and environmental engineering professor Jeremy Guest, countries could be moving closer to using human waste as fertilizer, closing the loop to more circular, sustainable economies.
A new study characterizes the spatial distribution of human urine-derived nutrients — nitrogen, phosphorus and potassium — and agricultural fertilizer demand to define supply-demand location typologies, their prevalence across the globe and the implications for resource recovery.
“The total amount of nitrogen, phosphorus and potassium largely remains constant in our bodies, once we stop growing,” said Guest, who also serves as the acting associate director for research at the Institute for Sustainability, Energy, and Environment at the U. of I. “Whatever comes in through food and drink must come out in our urine, feces and sweat. Knowing that, we can estimate how much of each of these nutrients is in a population’s bodily waste if we know their diet.”
Previous studies by Guest and others have assessed the potential for recovering the nutrients from human waste across the globe and identified locations with a surplus of human waste-derived nutrients relative to the local demand for agricultural fertilizers.
“The new study is the first to describe human waste-derived nutrient supply-demand location relationships using a single mathematical equation,” Guest said. “The quality of sanitation infrastructure varies greatly across the globe, as do people’s diets and the availability of land suitable for agriculture. Having the means to characterize and quantitatively compare a location’s nutrient-recovery potential can go a long way to better inform decision-makers when it comes to future sanitation and agriculture policy.”
The team performed extensive numerical and geographic analyses of dietary, population, sanitation and agricultural data from 107 countries to accomplish this quantitative characterization at the global scale. The investigation revealed three distinct supply-demand typologies: countries with a co-located supply-demand; countries with a dislocated supply-demand; and countries with diverse supply-demand proximities.
The United States and Australia, for example, fall under the dislocated supply-demand typology. They have intensive agriculture in areas far from large cities, thus the human waste-derived nutrient supply is far away from where it is needed, Guest said. Even with advanced sanitation infrastructure in place, this means that nutrients would need to be transported over large distances, either as heavy fluids or converted into concentrated crystalline products. Economically speaking, Guest said, it would make sense to work with a concentrated product to implement a human waste-derived fertilizer in these countries.
The study reports that in countries with co-located supply-demand typologies like India, Nigeria and Uganda, human populations are more substantively in the proximity of agricultural areas, making local reuse possible. In many communities with co-located supply-demand, however, there is a need for improved sanitation infrastructure. Guest said implementing a human waste-derived fertilizer program could be highly beneficial to sanitation and agriculture in these places.
Countries like Brazil, Mexico, China and Russia exhibit a continuum of co-location to dislocation of nutrient supply and demand. The study reports that policymakers would need to approach human waste-derived nutrient use with more regionalized strategies and a range of local reuse and transport approaches. “Higher income countries in this group may have the infrastructure and economic support for various technologies, but those with limited financial resources would require prioritization of resource-recovery technology in some areas,” Guest said.
“Higher HDI-scoring countries like the U.S., Western Europe and Australia tend to fall in the dislocated supply-demand typology and lower HDI-scoring countries tend to fit the co-located supply-demand typology. Of course, there are exceptions, but we did not expect to find such a strong correlation,” Guest said.
The team hopes this research will help clarify the salient economic, sanitation and agricultural characteristics of countries across the globe so that decision-makers can prioritize investment, policies and technologies that will advance goals for a circular economy and the provision of sanitation to all, Guest said.
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