GT/ New faster charging hydrogen fuel cell developed
Energy & green technology biweekly vol.30, 29th July — 14th August
TL;DR
- A new design for solid-state hydrogen storage could significantly reduce charging times.
- Researchers recently announced that they have figured out how to engineer a biofilm that harvests the energy in evaporation and converts it to electricity. This biofilm has the potential to revolutionize the world of wearable electronics, powering everything from personal medical sensors to personal electronics.
- Scientists have created a novel technology that can help to tackle climate change and address the global energy crisis.
- The production of ammonia, a major ingredient in fertilizers, involves greenhouse gas emissions. Scientists have quantified ways to reduce carbon impacts in this process.
- A new study indicates that decarbonization pathways should incorporate more efficient electric heating technologies and more renewable energy sources to minimize strain on the U.S. electric grid during peaks in electricity usage from heating in the winter.
- Researchers have developed a new enzyme engineering platform to improve plastic degrading enzymes through directed evolution.
- Engineers have designed and successfully tested a more efficient wind sensor for use on drones, balloons and other autonomous aircraft.
- Sneezing out mucus may be one of the oldest ways for organisms to get rid of unwanted waste. A group of researchers found that sponges, one of the oldest multicellular organisms in existence, ‘sneeze’ to unclog their internal filter systems that they use to capture nutrients from the water. Additionally, authors find that other animals who live with the sponges use their mucus as food.
- A team of researchers has developed a water-activated disposable paper battery. The researchers suggest that it could be used to power a wide range of low-power, single-use disposable electronics — such as smart labels for tracking objects, environmental sensors and medical diagnostic devices — and minimize their environmental impact.
- The concrete industry is just one of many looking at new manufacturing methods to reduce its carbon footprint. These efforts are essential to fulfilling the Paris Agreement, which asks each of its signees to achieve a net-zero carbon economy by 2050. However, a new study focusing exclusively on Japan concludes that improved manufacturing technologies will only get the industry within eighty percent of its goal. Using a dynamic material flows analysis model, the study claim that the other twenty percent will have to come from changes in how concrete is consumed and managed, putting expectations on the buyer as well as the seller.
- 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 Research
Design optimization of a magnesium-based metal hydride hydrogen energy storage system
by Puchanee Larpruenrudee, Nick S. Bennett, YuanTong Gu, Robert Fitch, Mohammad S. Islam in Scientific Reports
Researchers from the University of Technology Sydney (UTS) and Queensland University of Technology (QUT) have developed a new method to improve solid-state hydrogen fuel cell charging times.
Hydrogen is gaining significant attention as an efficient way to store ‘green energy’ from renewables such as wind and solar. Compressed gas is the most common form of hydrogen storage, however it can also be stored in a liquid or solid state.
Dr Saidul Islam, from the University of Technology Sydney, said solid hydrogen storage, and in particular metal hydride, is attracting interest because it is safer, more compact, and lower cost than compressed gas or liquid, and it can reversibly absorb and release hydrogen.
“Metal hydride hydrogen storage technology is ideal for onsite hydrogen production from renewable electrolysis. It can store the hydrogen for extended periods and once needed, it can be converted as gas or a form of thermal or electric energy when converted through a fuel cell,” said Dr Islam.
“Applications include hydrogen compressors, rechargeable batteries, heat pumps and heat storage, isotope separation and hydrogen purification. It can also be used to store hydrogen in space, to be used in satellites and other ‘green’ space technology,” he said.
However, a problem with metal hydride for hydrogen energy storage has been its low thermal conductivity, which leads to slow charging and discharging times. To address this the researchers developed a new method to improve solid-state hydrogen charging and discharging times. First author Puchanee Larpruenrudee, a PhD candidate in the UTS School of Mechanical and Mechatronic Engineering, said faster heat removal from the solid fuel cell results in faster charging times.
“Several internal heat exchangers have been designed for use with metal hydride hydrogen storage. These include straight tubes, helical coil or spiral tubes, U-shape tubes, and fins. Using a helical coil significantly improves heat and mass transfer inside the storage.
“This is due to the secondary circulation and having more surface area for heat removal from the metal hydride powder to the cooling fluid. Our study further developed a helical coil to increase heat transfer performance.”
The researchers developed a semi-cylindrical coil as an internal heat exchanger, which significantly improved heat transfer performance. The hydrogen charging time was reduced by 59% when using the new semi-cylindrical coil compared to a traditional helical coil heat exchanger.
They are now working on the numerical simulation of the hydrogen desorption process, and continuing to improve absorption times. The semi-cylindrical coil heat exchanger will be further developed for this purpose.
Finally, the researchers aim to develop a new design for hydrogen energy storage, which will combine other types of heat exchangers. They hope to also work with industry partners to investigate real tank performance based on the new heat exchanger.
Microbial biofilms for electricity generation from water evaporation and power to wearables
by Xiaomeng Liu, Toshiyuki Ueki, Hongyan Gao, Trevor L. Woodard, Kelly P. Nevin, Tianda Fu, Shuai Fu, Lu Sun, Derek R. Lovley, Jun Yao in Nature Communications
Researchers at the University of Massachusetts Amherst recently announced that they have figured out how to engineer a biofilm that harvests the energy in evaporation and converts it to electricity. This biofilm has the potential to revolutionize the world of wearable electronics, powering everything from personal medical sensors to personal electronics.
“This is a very exciting technology,” says Xiaomeng Liu, graduate student in electrical and computer engineering in UMass Amherst’s College of Engineering and the paper’s lead author. “It is real green energy, and unlike other so-called ‘green-energy’ sources, its production is totally green.”
That’s because this biofilm — a thin sheet of bacterial cells about the thickness of a sheet of paper — is produced naturally by an engineered version of the bacteria Geobacter sulfurreducens. G. sulfurreducens is known to produce electricity and has been used previously in “microbial batteries” to power electrical devices. But such batteries require that G. sulfurreducens is properly cared for and fed a constant diet. By contrast, this new biofilm, which can supply as much, if not more, energy than a comparably sized battery, works, and works continuously, because it is dead. And because it’s dead, it doesn’t need to be fed.
“It’s much more efficient,” says Derek Lovley, Distinguished Professor of Microbiology at UMass Amherst and one of the paper’s senior authors. “We’ve simplified the process of generating electricity by radically cutting back on the amount of processing needed. We sustainably grow the cells in a biofilm, and then use that agglomeration of cells. This cuts the energy inputs, makes everything simpler and widens the potential applications.”
The secret behind this new biofilm is that it makes energy from the moisture on your skin. Though we daily read stories about solar power, at least 50% of the solar energy reaching the earth goes toward evaporating water. “This is a huge, untapped source of energy,” says Jun Yao, professor of electrical and computer engineering at UMass, and the paper’s other senior author. Since the surface of our skin is constantly moist with sweat, the biofilm can “plug-in” and convert the energy locked in evaporation into enough energy to power small devices.
“The limiting factor of wearable electronics,” says Yao, “has always been the power supply. Batteries run down and have to be changed or charged. They are also bulky, heavy, and uncomfortable.” But a clear, small, thin flexible biofilm that produces a continuous and steady supply of electricity and which can be worn, like a Band-Aid, as a patch applied directly to the skin, solves all these problems.
What makes this all work is that G. sulfurreducens grows in colonies that look like thin mats, and each of the individual microbes connects to its neighbors through a series of natural nanowires. The team then harvests these mats and uses a laser to etch small circuits into the films. Once the films are etched, they’re sandwiched between electrodes and finally sealed in a soft, sticky, breathable polymer that you can apply directly to your skin. Once this tiny battery is “plugged in” by applying it to your body, it can power small devices.
“Our next step is to increase the size of our films to power more sophisticated skin-wearable electronics,” says Yao, and Liu points out that one of the goals is to power entire electronic systems, rather than single devices.
Airfoil Anemometer With Integrated Flexible Piezo-Capacitive Pressure Sensor
by Arun K. Ramanathan, Leon M. Headings, Marcelo J. Dapino in Frontiers in Materials
Engineers have designed and successfully tested a more efficient wind sensor for use on drones, balloons and other autonomous aircraft.
These wind sensors — called anemometers — are used to monitor wind speed and direction. As demand for autonomous aircraft increases, better wind sensors are needed to make it easier for these vehicles to both sense weather changes and perform safer take-offs and landings, according to researchers. Such enhancements could improve how people use their local airspace, whether it be through drones delivering packages or passengers one day flying on unmanned aircraft, said Marcelo Dapino, co-author of the study and a professor in mechanical and aerospace engineering at The Ohio State University.
“Our ability to use the airspace to move or transport things in an efficient manner has huge societal implications,” said Dapino. “But to operate these flying objects, precise wind measurements must be available in real time whether the vehicle is manned or unmanned.” Besides helping aerial objects cross long distances, accurate wind measurements are also important for energy forecasting and optimizing the performance of wind turbines, he said.
Conventional anemometers vary in how they collect their data, but all of them have limitations, said Dapino. Because anemometers can be expensive to make, consume high amounts of energy, and have a high aerodynamic drag — meaning the instrument opposes the aircraft’s motion through the air — many types are ill-suited for small aircraft. But the Ohio State team’s anemometer is lightweight, low-energy, low-drag and more sensitive to changes in pressure than conventional types.
Leon Headings, co-author of the study and a senior research associate in mechanical and aerospace engineering at Ohio State, said the instrument was fabricated from smart materials — matter with properties that can be controlled, enabling them to sense and react to their environment. The team used an electric polymer called polyvinylidene fluoride (PVDF). Used extensively in architectural coatings and lithium ion batteries, PVDF can be piezoelectric, which means that it produces electrical energy when a pressure is applied to it. This energy can be used to power the device. The measured voltage or change in capacitance of a piece of flexible PVDF film can be correlated to the wind speed.
The PVDF sensor is incorporated into an airfoil, similar to an airplane wing, which reduces aerodynamic drag. Because the airfoil is free to rotate like a wind vane, it can be used to measure the direction of the wind.
But to test how their device would fare once subjected to Earth’s atmosphere, researchers designed a two-pronged experiment. First, the pressure sensor was tested in a sealed chamber to determine its sensitivity. Then, the sensor was incorporated into an airfoil and tested in a wind tunnel. The results showed that the sensor measures both pressure and wind speed extremely well. A small digital magnetometer compass integrated into the airfoil provides precise wind direction data by measuring the absolute orientation of the airfoil relative to the Earth’s magnetic field.
But more research needs to be done to move the wind sensor concept from a controlled research environment to commercial applications. As his team continues to work with PVDF and other advanced materials to improve sensor technology, Dapino hopes that their work will eventually lead to technology that can be used outside of aircraft, such as for wind turbines for clean, efficient and readily available energy for the public.
“These are very advanced materials and they can be used in many applications,” said Dapino. “We would like to build on those applications to bring compact wind energy generation to the home.”
Bacteria–photocatalyst sheet for sustainable carbon dioxide utilization
by Qian Wang, Shafeer Kalathil, Chanon Pornrungroj, Constantin D. Sahm, Erwin Reisner in Nature Catalysis
Scientists have created a novel technology that can help to tackle climate change.
Northumbria University’s Dr Shafeer Kalathil is among a team of academics behind the project, which uses a chemical process that converts sunlight, water and carbon dioxide into acetate and oxygen to produce high-value fuels and chemicals powered by renewable energy. As part of the process, bacteria are grown on a synthetic semiconductor device known as a photocatalyst sheet, which means that the conversion can take place without the assistance of organic additives, creation of toxins or use of electricity. The aim of the project is to curtail the rise in atmospheric CO2 levels, secure much-needed green energy supplies and alleviate the global dependence on fossil fuels.
Dr Kalathil, Vice Chancellor’s Senior Fellow, is working on the project with Erwin Reisner, Professor of Energy and Sustainability at the University of Cambridge, DrQian Wang, associate professor at Nagoya University in Japan, and partners from Newcastle University.
Dr Kalathil said: “Several incidents have demonstrated the fragility of the global energy supply, such as recent soaring gas prices in UK, the outbreak of conflicts and civil wars in the Middle East and the ecological and humanitarian threat of a nuclear meltdown in Fukushima, Japan. The search for alternative energy sources is therefore of major global importance.
“Our research directly addresses the global energy crisis and climate change facing today’s society. We need to develop new technologies to address these grand challenges without further polluting the planet we live on.
“There has been an increase in electricity generation from renewable sources such as wind and solar, but these are intermittent in nature. To fill the gap when the wind doesn’t blow or the sun doesn’t shine, we need technologies that can create storable fuels and sustainable chemicals. Our research addresses this challenge head on. “As well as securing additional much-needed energy supplies, our sustainable technology can reduce greenhouse gas emissions and play a key role in the global drive to achieve net zero.”
Dr Kalathil, who is heavily involved with the HBBE, said: “The aims of the HBBE fit with what we’re trying to achieve with our research — to address key environmental concerns facing our society today and in the future. This emerging field of research represents an interdisciplinary approach that combines the strengths of microbes, synthetic materials and analytical techniques for chemical transformation, and provides an excellent platform to produce high-value, environmentally friendly fuels and chemicals at scale. We’re already in discussions with international chemical manufacturers and cosmetics producers, and the ultimate aim is to develop our technology on a commercial scale.”
Techno-economic performances and life cycle greenhouse gas emissions of various ammonia production pathways including conventional, carbon-capturing, nuclear-powered, and renewable production
by Kyuha Lee, Xinyu Liu, Pradeep Vyawahare, Pingping Sun, Amgad Elgowainy, Michael Wang in Green Chemistry
Scientists evaluate how to make ammonia production more sustainable.
Ever wondered about the carbon impact of growing your dinner? Scientists have just come up with a new way to calculate part of it. A major ingredient in the production of fertilizers for the world’s food production, ammonia also contributes significantly to the world’s greenhouse gas emissions and fossil fuel use. Recently, scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have modeled how much it would cost to use more environmentally friendly methods that emit less carbon to produce ammonia.
Ammonia is principally made by reforming natural gas, a process that contributes to the atmospheric emissions of both carbon dioxide and methane. “The ultimate goal is to use renewable or nuclear energy and clean hydrogen to produce it instead,” said Argonne senior scientist Amgad Elgowainy. Elgowainy and his colleagues used Argonne’s Greenhouse gases, Regulated Emissions, and Energy use in Technologies (GREET®) model to estimate the environmental impact of ammonia production from various energy sources. Then, they used a technoeconomic model to look at the cost of two different ways that ammonia could be produced more sustainably.
The first way avoids some of the carbon release by capturing a certain percent of the carbon produced and then storing it in geologic formations. This technology pathway can be implemented at relatively low cost, as the total cost to produce the ammonia increases by only about 20%. In the other near zero-carbon pathway, water is electrolyzed to produce hydrogen, which is then paired with nitrogen to produce ammonia.
Using renewable or nuclear energy to split water via electrolysis gives us a way of producing ammonia with almost no carbon impact, Elgowainy said. That said, the cost of doing so is currently higher than the carbon capture pathway.”
According to Elgowainy, there is significant room for cost reduction of the electrolysis technology that could eventually make the water electrolysis pathway more cost competitive.
“Research in this area could end up changing the market significantly, but it will take investment in developing and scaling up the production of the electrolysis technologies,” he said. ”With the cost reduction and efficiency improvements to meet DOE’s target of $1/kg of clean hydrogen, the electrolysis pathway could enable a close-to-carbon-free and affordable way of producing ammonia.”
Inefficient Building Electrification Will Require Massive Buildout of Renewable Energy and Seasonal Energy Storage
by Jonathan J. Buonocore, Parichehr Salimifard, Zeyneb Magavi, Joseph G. Allen in Scientific Reports
Direct fossil fuel consumption by buildings, burned in water heaters, furnaces, and other heating sources, account for nearly 10 percent of greenhouse gas emissions in the United States. Switching to an electric system that powers heating through renewable energy sources, rather than coal, oil, and natural gas — the process known as building electrification or building decarbonization — is a crucial step towards achieving global net-zeroclimate goals.
However, most building decarbonization models have not accounted for seasonal fluctuations in energy demand for heating or cooling. This makes it difficult to predict what an eventual switch to cleaner, all-electric heating in buildings could mean for the nation’s electrical grid, especially during peaks in energy use.
A new study by researchers at Boston University School of Public Health (BUSPH), Harvard T.H. Chan School of Public Health (Harvard Chan School), Oregon State University (OSU), and the nonprofit Home Energy Efficiency Team (HEET) examined these seasonal changes in energy demand, and found that monthly energy consumption varies substantially and is highest in the winter months. The study presented novel modeling of multiple building electrification scenarios, and found that this seasonal surge in winter energy demand will be difficult to satisfy through current renewable sources, if buildings switch to low-efficiency electrified heating. The findings emphasize the need for buildings to install more efficient home-heating technologies, such as ground source heat pumps.
“Our research reveals the degree of fluctuation in building energy demand and the benefits of using extremely efficient heating technologies when electrifying buildings,” says study lead and corresponding author Dr. Jonathan Buonocore, Assistant Professor of Environmental Health at BUSPH. “Historically, this fluctuation in building energy demand has been managed largely by gas, oil, and wood, all of which can be stored throughout the year and used during the winter. Electrified buildings, and the electrical system that supports them, will have to provide this same service of providing reliable heating in winter. More efficient electric heating technologies will reduce the electrical load put on the grid and improve the ability for this heating demand to be met with non-combustion renewables.”
For the study, Buonocore and colleagues analyzed building energy data from March 2010 to February 2020, and found that US total monthly average for energy consumption — based on the current use of fossil fuels, as well as future use of electricity in the winter — varies by a factor of 1.6x, with the lowest demand in May, and the highest demand in January. The researchers modeled these seasonal fluctuations in what they call the “Falcon Curve’’ — since a graph of the change in monthly energy consumption represents the shape of a falcon. The data shows that winter heating demand drives energy consumption to its highest levels in December and January, with a secondary peak in July and August due to cooling, and the lowest levels in April, May, September, and October.
The researchers also calculated the amount of additional renewable energy, specifically wind and solar energy, that would need to be generated to meet this increased demand in electricity. Without storage, demand response, or other tactics to manage grid load, to meet winter heating peaks, buildings would require a 28x increase in January wind generation or a 303x increase in January solar energy. But with more efficient renewables, such as air source heat pumps (ASHPs) or ground source heat pumps (GSHPs), buildings would only require 4.5x more winter wind generation, or 36x more solar energy — thus “flattening” the Falcon Curve as less new energy demand is placed on the electrical grid.
“This work really shows that technologies on both the demand and the supply side have a strong role to play in decarbonization,” says study coauthor Dr. Parichehr Salimifard, Assistant Professor of College of Engineering at Oregon State University. Examples of these technologies on the energy supply side are geothermal building heating and renewable energy technologies that can provide energy at all hours, she says — such as renewables coupled with long-term storage, distributed energy resources (DERs) at all scales, and geothermal electricity generation where possible.
“These can be coupled with technologies on demand side — i.e., in buildings — such as passive and active building energy efficiency measures, peak-shaving, and energy storage in buildings. These building-level technologies can both reduce the overall building energy demand by reducing both baseline and maximum energy demand as well as smooth the fluctuations in building energy demand, and consequently flatten the Falcon Curve.”
“The Falcon Curve draws our attention to a key relationship between the choice of building electrification technology and the impact of building electrification on our power grid,” says study coauthor Zeyneb Magavi, co-executive director of HEET, a non-profit climate solutions incubator.
Magavi cautions that this research does not yet quantify this relationship based on measured seasonal efficiency curves for specific technologies, or for more granular time scales or regions, or assess the numerous strategies and technologies that can help address the challenge. All of which must be considered in decarbonization planning. Yet, Magavi says, this research clearly does indicate that, “Using a strategic combination of heat pump technologies (air-source, ground-source, and networked), as well as long-term energy storage, will help us electrify buildings more efficiently, economically, and equitably. The Falcon curve shows us a faster path to a clean, healthy energy future.”
“Our research makes clear that, when accounting for seasonal fluctuations in energy consumption apparent in the Falcon Curve, the drive to electrify our buildings must be coupled with a commitment to energy-efficient technologies to ensure building decarbonization efforts maximize climate and health benefits,” says study senior author Dr. Joseph G. Allen, Associate Professor of Exposure Assessment Science and Director of the Healthy Buildings program at Harvard Chan School.
“Our work here shows a pathway for building electrification that avoids relying on fossil fuels, and avoids renewable combustion fuels, which still can produce air pollution, and possibly perpetuate disparities in air pollution exposure, despite being climate neutral,” says Buonocore. “Avoiding issues like this is why it is important for public health experts to be involved in energy and climate policymaking.”
Directed evolution of an efficient and thermostable PET depolymerase
by Elizabeth L. Bell, Ross Smithson, Siobhan Kilbride, Jake Foster, Florence J. Hardy, Saranarayanan Ramachandran, Aleksander A. Tedstone, Sarah J. Haigh, Arthur A. Garforth, Philip J. R. Day, Colin Levy, Michael P. Shaver, Anthony P. Green in Nature Catalysis
Researchers from the Manchester Institute of Biotechnology (MIB) have developed a new enzyme engineering platform to improve plastic degrading enzymes through directed evolution.
To illustrate the utility of their platform, they have engineered an enzyme that can successfully degrade poly(ethylene) terephthalate (PET), the plastic commonly used in plastic bottles. In recent years, the enzymatic recycling of plastics has emerged as an attractive and environmentally friendly strategy to help alleviate the problems associated with plastic waste. Although there are a number of existing methods for recycling plastics, enzymes could potentially offer a more cost-effective and energy efficient alternative. In addition, they could be used to selectively breakdown specific components of mixed plastic waste streams that are currently difficult to recycle using existing technologies.
Although promising as a technology, there are considerable hurdles that need to be overcome for enzymatic plastic recycling to be used widely on a commercial scale. One challenge, for instance, is that natural enzymes with the ability to break down plastics typically are less effective and are unstable under the conditions needed for an industrial-scale process.
To address these limitations, researchers from The University of Manchester have reported a new enzyme engineering platform that can quickly improve the properties of plastic degrading enzymes to help make them more suitable for plastic recycling at large scales. Their integrated and automated platform can successfully assess the plastic degradation ability of around 1000 enzyme variants per day.
Dr Elizabeth Bell, who led the experimental work at the MIB, says of the platform; “The accumulation of plastic in the environment is a major global challenge. For this reason, we were keen to use our enzyme evolution capabilities to enhance the properties of plastic degrading enzymes to help alleviate some of these problems. We are hopeful that in the future our scalable platform will allow us to quickly develop new and specific enzymes are suitable for use in large-scale plastic recycling processes.”
To test their platform, they went on to develop a new enzyme, HotPETase, through the directed evolution of IsPETase. IsPETase is a recently discovered enzyme produced by the bacterium Ideonella sakaiensis, which can use PET as a carbon and energy source.
While IsPETase has the natural ability to degrade some semi-crystalline forms of PET, the enzyme is unstable at temperatures above 40°C, far below desirable process conditions. This low stability means that reactions must be run at temperatures below the glass transition temperature of PET (~65°C), which leads to low depolymerisation rates.
To address this limitation, the team developed a thermostable enzyme, HotPETase, which is active at 70°C, which is above the glass transition temperature of PET. This enzyme can depolymerise semi-crystalline PET more rapidly than previously reported enzymes and can selectively deconstruct the PET component of a laminated packaging material, highlighting the selectivity that can be achieved by enzymatic recycling.
Professor Anthony Green, Lecturer in Organic Chemistry, said: “The development of HotPETase nicely illustrates the capabilities of our enzyme engineering platform. We are now excited to work with process engineers and polymer scientists to test our enzyme in real world applications. Moving forward, we are hopeful that our platform will prove useful for developing more efficient, stable, and selective enzymes for recycling a wide range of plastic materials.”
The development of robust plastic degrading enzymes such as HotPETase, along with the availability of a versatile enzyme engineering platform, make important contributions towards the development of a biotechnological solution to the plastic waste challenge. To move this promising technology forward will now require a collaborative and multidisciplinary effort involving biotechnologists, process engineers and polymer scientists from across the academic and industrial communities. With the world facing an ever-mounting waste problem, biotechnology could provide an environmentally sustainable solution.
Sponges sneeze mucus to shed particulate waste from their seawater inlet pores
by Niklas A. Kornder, Yuki Esser, Daniel Stoupin, Sally P. Leys, Benjamin Mueller, Mark J.A. Vermeij, Jef Huisman, Jasper M. de Goeij in Current Biology
Sneezing out mucus may be one of the oldest ways for organisms to get rid of unwanted waste. A group of researchers found that sponges, one of the oldest multicellular organisms in existence, “sneeze” to unclog their internal filter systems that they use to capture nutrients from the water. Additionally, authors find that other animals who live with the sponges use their mucus as food.
“Our data suggest that sneezing is an adaptation that sponges evolved to keep themselves clean,” says Jasper de Goeij, a marine biologist at the University of Amsterdam and the senior author of the paper.
While the field has known about this behavior for years, the authors of this paper show that these sneezes get rid of materials the sponges cannot use. “Let’s be clear: sponges don’t sneeze like humans do. A sponge sneeze takes about half an hour to complete. But both sponge and human sneezes exist as a waste disposal mechanism,” says de Goeij.
Sponges gather food for themselves by filtering out organic matter from the water. They draw in and eject water from different openings, and sometimes the sponges will suck in particles that are too big. “These are sponges; they can’t just walk to somewhere else when the water around them gets too dirty for them to handle,” says de Goeij. This is when the “sneezing” mechanism comes in handy.
While the mucus may be waste to sponges, the fishes who live around them think otherwise. “We also observed fish and other animals feeding off of the sponge mucus as food,” says Niklas Kornder, the first author of the study and a doctoral researcher in de Goeij’s research group. “Some organic matter exists in the water surrounding the coral reef, but most of it is not concentrated enough for other animals to eat. Sponges transform this material into eatable mucus,” says Kornder.
The paper recorded “sneezing” behavior in two species of sponges, the Caribbean tube sponge Aplysina archeri and another Indo-Pacific species of the genus Chelonaplysilla. “We actually think that most, if not all, sponges sneeze. I’ve seen mucus accumulate on different sponges while diving and in pictures taken by other scientists for other purposes,” says Kornder.
“Our findings highlight opportunities to better understand material cycling in some of the most ancient Metazoans,” say the authors in the paper.
There are still many aspects about sponge “sneezes” that remain open questions. “In the videos, you can see that the mucus moves along defined paths on the surface of the sponge before accumulating. I have some hypotheses, but more analysis is needed to find out what is happening,” says Kornder.
“There are a lot of scientists that think that sponges are very simple organisms, but more often than not we are amazed by the flexibility that they show to adapt to their environment,” says de Goeij.
Efficient use of cement and concrete to reduce reliance on supply-side technologies for net-zero emissions
by Takuma Watari, Zhi Cao, Sho Hata, Keisuke Nansai in Nature Communications
The concrete industry is just one of many looking at new manufacturing methods to reduce its carbon footprint. These efforts are essential to fulfilling the Paris Agreement, which asks each of its signees to achieve a net-zero carbon economy by 2050. However, a new study from researchers in Japan and Belgium and focusing exclusively on Japan concludes that improved manufacturing technologies will only get the industry within eighty percent of its goal. Using a dynamic material flows analysis model, the study claim that the other twenty percent will have to come from changes in how concrete is consumed and managed, putting expectations on the buyer as well as the seller.
Electric cars, fluorescent lights, water-saving shower heads, these are all examples of efforts to lower our carbon footprint. However, the energy savings are made from the supply side, with companies developing new technologies that reduce the amount of energy consumed for the same amount of use. Notably, they put little demand on the user, who can use the product no differently than before.
The same holds true for concrete, the most consumed human-made material in the world. Many studies have shown the potential for making the concrete industry more energy efficient through esoteric efforts like “clinker-to-cement ratio reduction,” “cement substitution with alternative binders,” and “carbon capture and utilization.” The problem, explains Dr. Takuma Watari, a researcher at the Japan National Institute for Environmental Studies and lead of the new study, is that supply-side efforts are not enough if nations are serious about achieving net-zero carbon emissions.
“We found that supply-side efforts can at best achieve 80% of the needed reductions. Our research has shown that for net-zero emissions, both supply-side and demand-side strategies are necessary,” he said.
That conclusion came after exhausting all options on the supply side. Watari and his colleagues realized, after examining the cement and concrete cycle in Japan from 1950 to today, that the concrete industry has already implemented effective technologies to reduce its carbon footprint to the point that it cannot be expected to solely take the responsibility.
“We must change not only how concrete is made, but also how it is used,” he said.
Extending the service life of buildings and infrastructure through new design as well as enhancing their multi-purpose use will reduce the demand for concrete. Consumers of concrete, the authors argue, need to view their consumption with more of the recycle, reuse, and reduce attitude applied to household waste. Obvious targets, they continued, are not just homes, but infrastructure for medical care, transportation, schools and stores. Policies are needed to encourage these consumers to change their behavior. Much like how “energy efficiency” has influenced consumption, societies need to embrace “material efficiency,” which is influenced by design and use, when making their purchases. The irony, notes Watari, is that the concrete industry, while incentivized to reduce carbon consumption on the supply side, has little motivation in changing habits on the demand side.
“Current profits are directly related to the volume sold. This gives little reason for the industry to promote efficient material use. The change needs to come from policy,” he said.
With appropriate changes to the demand side, the study states that not only will the concrete and cement cycle become more environmentally friendly and the goal of net-zero carbon by 2050 be realized, but there will be benefits for the use of scarce resources such as water as well.
“The most important finding of our study is that there is no ‘silver bullet’ solution. Everyone needs to contribute. Right now, there is too much emphasis on supply-side strategies. To realize net-zero emissions, architects, urban planners, and general consumers must contribute,” said Watari.
Water activated disposable paper battery
by Alexandre Poulin, Xavier Aeby, Gustav Nyström in Scientific Reports
The battery, devised by Gustav Nyström and his team, is made of at least one cell measuring one centimeter squared and consisting of three inks printed onto a rectangular strip of paper. Salt, in this case simply sodium chloride or table salt, is dispersed throughout the strip of paper and one of its shorter ends has been dipped in wax. An ink containing graphite flakes, which acts as the positive end of the battery (the cathode), is printed onto one of the flat sides of the paper while an ink containing zinc powder, which acts as the negative end of the battery (the anode), is printed onto the reverse side of the paper. Yet another ink containing graphite flakes and carbon black is printed on both sides of the paper, on top of the other two inks. This ink makes up the current collectors connecting the positive and negative ends of the battery to two wires, which are located at the wax-dipped end of the paper.
When a small amount of water is added, the salts within the paper dissolve and charged ions are released, thus making the electrolyte ionically conductive. These ions activate the battery by dispersing through the paper, resulting in zinc in the ink at the anode being oxidized thereby releasing electrons. By closing the (external) circuit these electrons can then be transferred from the zinc-containing anode — via the graphite- and carbon black-containing ink, the wires and the device — to the graphite cathode where they are transferred to — and hence reduce — oxygen from ambient air. These redox reactions (reduction and oxidation) thus generate an electrical current that can be used to power an external electrical device.
To demonstrate the ability of their battery to run low-power electronics, Nyström’s team combined two cells into one battery to increase the operating voltage and used it to power an alarm clock with a liquid crystal display. Analysis of the performance of a one-cell battery revealed that after two drops of water were added, the battery activated within 20 seconds and, when not connected to an energy-consuming device, reached a stable voltage of 1.2 volts. The voltage of a standard AA alkaline battery is 1.5 volts. After one hour, the one-cell battery’s performance decreased significantly due to the paper drying. However, after the researchers added two extra drops of water, the battery maintained a stable operating voltage of 0.5 volts for more than one additional hour.
The researchers propose that the biodegradability of paper and zinc could enable their battery to minimize the environmental impact of disposable, low-power electronics. “What’s special about our new battery is that, in contrast many metal air batteries using a metal foil that is gradually consumed as the battery is depleted, our design allows to add only the amount of zinc to the ink that is actually needed for the specific application,” says Nyström. Metal foils were more difficult to control and not always fully consumed leading to a waste of materials. So the more zinc the ink contains, the longer the battery is able to operate.
A more critical point of the battery’s current design with water activation, Nyström adds, is the time it takes for the battery to dry out. “But I am sure this can be engineered differently to get around this problem.” For environmental sensing applications at a certain humidity or in wet environments, however, the drying of the paper would not be an issue.
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