By combining visible light and electrochemistry, researchers have enhanced the conversion of carbon dioxide into valuable products and stumbled upon a surprising discovery. The team found that visible light significantly improved an important chemical attribute called selectivity, opening new avenues not only for CO2 conversion but also for many other chemical reactions used in catalysis research and chemical manufacturing.&nbsp;One way that chemists recycle CO2 into valuable products is through a process called electrochemical reduction, where a stream of CO2 gas moves through an electrolysis cell that breaks the CO2 and water down into carbon monoxide and hydrogen, which then can be used to make new desired hydrocarbon products, said University of Illinois Urbana-Champaign <a href="https://chemistry.illinois.edu/">chemistry</a> professor <a href="https://chemistry.illinois.edu/jain">Prashant Jain</a>. “However, the reaction is sluggish, and the process requires large electrodes containing a lot of expensive catalyst material such as gold or copper, so our lab has been pursuing ways to speed up the process so that less catalyst material is required, making it a more viable option for the alternative fuels industry.”The new study, led by Jain and former graduate student Francis Alcorn and published in the Proceedings of the National Academy of Sciences, details a method that combines the action of visible light with electrodes coated in nanoparticles of gold-copper alloy to induce CO2 reduction at a much higher rate and allow for more controlled selectivity than seen with current methods.&nbsp;“These new electrodes act like tiny antennae that seek out photons in the visible light range and couple them with the chemical reaction pathway,” Jain said.In the lab, the electrodes are immersed in a solution of CO2, water and an electrolyte to enhance conductivity. The team then applies a voltage across the electrode while a visible light laser illuminates its surface. The resulting reaction rapidly produces carbon monoxide — from splitting the CO2 — and hydrogen, which comes from splitting water molecules.&nbsp;“We were very excited to see the boost in productivity when visible light was used. However, we were not expecting to find that using visible light would have a major impact on chemical selectivity, which is the important advance here,” Jain said.&nbsp;In catalysis, chemical selectivity is the ability of a chemical reaction to favor or target one type of pathway or molecule over another. In this study, the researchers found that the water-splitting reaction that forms hydrogen gas was selectively enhanced by using light. This led the team to experiment further and model their results with the help of Northwestern University chemistry professor <a href="https://chemistry.northwestern.edu/people/core-faculty/profiles/george-schatz.html">George Schatz</a> and postdoctoral researcher Sajal Kumar Giri.&nbsp;“The results suggest that visible light offers a unique opportunity to adjust the ratio of carbon monoxide to hydrogen gas produced, a crucial factor for the industrial production of synthetic gas,” Jain said. “This finding paves the way for a more sustainable and efficient energy future.”<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1730418918413-231345.jpg" style="width: 832px;" class="fr-fic fr-dib">This graphic shows a map of the charge transfer (yellow for positive and cyan for negative) in the reaction at 25, 26 and 90 femtoseconds. Gold atoms are shown in brown, hydrogen in light pink, carbon in green and oxygen in red. Graphic by the Jain laboratory at Illinois and the Schatz group at Northwestern University.Using light to help boost chemical reactions is not without its controversy, though, Jain said. Because adding light to a chemical reaction will also add heat, it was essential for the team to run careful measurements and control experiments to determine if it was simply the heating effect of light that led to faster reaction rates and selectivity.&nbsp;“We ran experiments with and without the laser at the exact same temperature produced by light excitation and ruled out heating as being responsible,” Jain said. “Rather, electric fields and directed charge flow induced by light excitation were responsible for the enhanced productivity and increased selectivity of water splitting, which is captured in the simulations by our collaborators,” Jain said.&nbsp;The team still has some challenges to face&nbsp;as they forge ahead. For instance, the repeated use of the nanoparticle-based electrode will inevitably lead to degradation over time, especially under a scaled-up scenario&nbsp;required for industrial application. Additionally, the overall energy efficiency of the process and light management will need further research and improvement.“What we found with this study presents completely new ways of thinking about electrochemistry and catalysis,” Jain said. “By using light, we enhance the activity of this catalyst, but surprisingly, we also change the selectivity. This will open up new chemical pathways that make different products. And why stop at CO2 reduction or water splitting? This could be applied to many other catalytic reactions important to the chemical industry.”Illinois Researchers Maya Chattoraj and Rachel Nixon also contributed to this study. The National Science Foundation, the U.S. Department of Energy, the Robert C. and Carolyn J. Springborn Endowment and the Future Interdisciplinary Research Explorations Grant supported this research.&nbsp;

A new study from the University of Illinois captures energy from the visible light spectrum to power up carbon dioxide recycling. Image courtesy the National Science Foundation

By combining visible light and electrochemistry, researchers have enhanced the conversion of carbon dioxide into valuable products and stumbled upon a surprising discovery.

Visible light energy yields two-for-one deal when added to CO2 recycling process

In this episode, we discuss how MIT researchers cracked the code for affordable, sustainable, and scalable hydrogen production using commonly found materials and a secret alloy!

Podcast: Turning Scrap Soda Cans & Coffee To Sustainable Car Fuel

This article was discussed in our <a href="https://www.wevolver.com/profile/the.next.byte" rel="noopener noreferrer" target="_blank">Next Byte podcast</a>.&nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/60fd7e2c-4154-4104-8c57-a3377abb0ca4?dark=false" class="fr-draggable" data-gtm-yt-inspected-23="true" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe> The full article will continue below.<hr>A sustainable source for clean energy may lie in old soda cans and seawater.MIT engineers have found that when the aluminum in soda cans is exposed in its pure form and mixed with seawater, the solution bubbles up and naturally produces hydrogen — a gas that can be subsequently used to power an engine or fuel cell without generating carbon emissions. What’s more, this simple reaction can be sped up by adding a common stimulant: caffeine.In a study <a href="https://www.cell.com/cell-reports-physical-science/fulltext/S2666-3864(24)00399-0" target="_blank">appearing today in the journal Cell Reports Physical Science</a>, the researchers show they can produce hydrogen gas by dropping pretreated, pebble-sized aluminum pellets into a beaker of filtered seawater. The aluminum is pretreated with a rare-metal alloy that effectively scrubs aluminum into a pure form that can react with seawater to generate hydrogen. The salt ions in the seawater can in turn attract and recover the alloy, which can be reused to generate more hydrogen, in a sustainable cycle.<iframe width="640" height="360" src="https://www.youtube.com/embed/QIowXoHPeFk?&amp;wmode=opaque&amp;enablejsapi=1&amp;origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true" data-gtm-yt-inspected-23="true" id="21089365" title="A sustainable way to generate hydrogen fuel">&nbsp;&nbsp;</iframe>A pebble-sized pellet of aluminum, dropped into a beaker of filtered seawater, produces hydrogen gas that bubbles up and out of the container within a few minutes. MIT engineers are optimizing this simple chemical reaction as an efficient and sustainable way to generate hydrogen fuel, which they envision can be used to power an engine or fuel cell aboard marine vessels and underwater vehicles.The team found that this reaction between aluminum and seawater successfully produces hydrogen gas, though slowly. On a lark, they tossed into the mix some coffee grounds and found, to their surprise, that the reaction picked up its pace.In the end, the team discovered that a low concentration of imidazole — an active ingredient in caffeine — is enough to significantly speed up the reaction, producing the same amount of hydrogen in just five minutes, compared to two hours without the added stimulant.The researchers are developing a small reactor that could run on a marine vessel or underwater vehicle. The vessel would hold a supply of aluminum pellets (recycled from old soda cans and other aluminum products), along with a small amount of gallium-indium and caffeine. These ingredients could be periodically funneled into the reactor, along with some of the surrounding seawater, to produce hydrogen on demand. The hydrogen could then fuel an onboard engine to drive a motor or generate electricity to power the ship.“This is very interesting for maritime applications like boats or underwater vehicles because you wouldn’t have to carry around seawater — it’s readily available,” says study lead author Aly Kombargi, a PhD student in MIT’s Department of Mechanical Engineering. “We also don’t have to carry a tank of hydrogen. Instead, we would transport aluminum as the ‘fuel,’ and just add water to produce the hydrogen that we need.”The study’s co-authors include Enoch Ellis, an undergraduate in chemical engineering; Peter Godart PhD ’21, who has founded a company to recycle aluminum as a source of hydrogen fuel; and Douglas Hart, MIT professor of mechanical engineering.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzIxOTUzNzIxNzYwLU1JVC1TZWF3YXRlci1IeWRyb2dlbi0wMi1wcmVzcy5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 100%px;" class="fr-fic fr-dib">A researcher demonstrates “activating” aluminum by dipping an aluminum pellet in a mixture of gallium-indium. Photo: Tony Pulsone<h2>Shields up</h2>The MIT team, led by Hart, is developing efficient and sustainable methods to produce hydrogen gas, which is seen as a “green” energy source that could power engines and fuel cells without generating climate-warming emissions.One drawback to fueling vehicles with hydrogen is that some designs would require the gas to be carried onboard like traditional gasoline in a tank — a risky setup, given hydrogen’s volatile potential. Hart and his team have instead looked for ways to power vehicles with hydrogen without having to constantly transport the gas itself.They found a possible workaround in aluminum — a naturally abundant and stable material that, when in contact with water, undergoes a straightforward chemical reaction that generates hydrogen and heat.The reaction, however, comes with a sort of Catch-22: While aluminum can generate hydrogen when it mixes with water, it can only do so in a pure, exposed state. The instant aluminum meets with oxygen, such as in air, the surface immediately forms a thin, shield-like layer of oxide that prevents further reactions. This barrier is the reason hydrogen doesn’t immediately bubble up when you drop a soda can in water.In previous work, using fresh water, the team found they could pierce aluminum’s shield&nbsp;and keep the reaction with water going by pretreating the aluminum with a small amount of rare metal alloy made from a specific concentration of gallium and indium. The alloy serves as an “activator,” scrubbing away any oxide buildup and creating a pure aluminum surface that is free to react with water. When they ran the reaction in fresh, de-ionized water, they found that one pretreated pellet of aluminum produced 400 milliliters of hydrogen in just five minutes. They estimate that just 1 gram of pellets would generate 1.3 liters of hydrogen in the same amount of time.But to further scale up the system would require a significant supply of gallium indium, which is relatively expensive and rare.“For this idea&nbsp;to be cost-effective and sustainable, we had to work on recovering this alloy postreaction,” Kombargi says.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzIxOTUzNzQ3MTk2LU1JVC1TZWF3YXRlci1IeWRyb2dlbi0wMy1wcmVzcy5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 100%px;" class="fr-fic fr-dib">Aly Kombargi holds a jar of aluminum pellets as they start to react in seawater. Photo: Tony Pulsone<h2>By the sea</h2>In the team’s new work, they found they could retrieve and reuse gallium indium using a solution of ions. The ions — atoms or molecules with an electrical charge — protect the metal alloy from reacting with water and help it to precipitate into a form that can be scooped out and reused. &nbsp;&nbsp;“Lucky for us, seawater is an ionic solution that is very cheap and available,” says Kombargi, who tested the idea with seawater from a nearby beach. “I literally went to Revere Beach with a friend and we grabbed our bottles and filled them, and then I just filtered out algae and sand, added aluminum to it, and it worked with the same consistent results.”He found that hydrogen indeed bubbled up when he added aluminum to a beaker of filtered seawater. And he was able to scoop out the gallium indium afterward. But the reaction happened much more slowly than it did in fresh water. It turns out that the ions in seawater act to shield gallium indium, such that it can coalesce and be recovered after the reaction. But the ions have a similar effect on aluminum, building up a barrier that slows its reaction with water.As they looked for ways to speed up the reaction in seawater, the researchers tried out various and unconventional ingredients.“We were just playing around with things in the kitchen, and found that when we&nbsp;added coffee grounds into seawater and dropped aluminum pellets in, the reaction was quite fast compared to just seawater,” Kombargi says.To see what might explain the speedup, the team reached out to colleagues in MIT’s chemistry department, who suggested they try imidazole — an active ingredient in caffeine, which happens to have a molecular structure that can pierce through aluminum (allowing the material to continue reacting with water), while leaving gallium indium’s ionic shield intact.“That was our big win,” Kombargi says. “We had everything we wanted: recovering the gallium indium, plus the fast and efficient reaction.”The researchers believe they have the essential ingredients to run a sustainable hydrogen reactor. They plan to test it first in marine and underwater vehicles. They’ve calculated that such a reactor, holding about 40 pounds of aluminum pellets, could power a small underwater glider for about 30 days by pumping in surrounding seawater and generating hydrogen to power a motor.“We’re showing a new way to produce hydrogen fuel, without carrying hydrogen but carrying aluminum as the ‘fuel,’” Kombargi says. “The next part is to figure out how to use this for trucks, trains, and maybe airplanes. Perhaps, instead of having to carry water as well, we could extract water from the ambient humidity to produce hydrogen. That’s down the line.”

MIT engineers Aly Kombargi (left) and Niko Tsakiris (right) work on a new hydrogen reactor, designed to produce hydrogen gas by mixing aluminum pellets with seawater. Photo: Tony Pulsone

MIT engineers have developed a fast and sustainable method for producing hydrogen fuel using aluminum, saltwater, and coffee grounds.

A recipe for zero-emissions fuel: Soda cans, seawater, and caffeine

The production of cement, metals and many chemical commodities requires extremely high temperatures of over a thousand degrees Celsius. At present, this heat is usually obtained by combusting fossil fuels: coal or natural gas, which emit large amounts of greenhouse gases. Heating with renewable electricity is not an alternative, as this would be inefficient at these high temperatures. Although much of our economy and society will need to become carbon neutral in the coming decades, these industrial processes are likely to continue to be powered by fossil fuels for the near future. They are considered difficult to decarbonise. &nbsp; &nbsp;Researchers at ETH Zurich have now demonstrated, in the lab, a way to make these industries independent of fossil fuels. Using solar radiation, they have engineered a device that can deliver heat at the high temperatures needed for the production processes. The team led by Emiliano Casati, a scientist in the Energy and Process Systems Engineering Group, and Aldo Steinfeld, Professor of Renewable Energy Carriers, has developed a thermal trap. It consists of a quartz rod coupled to a ceramic absorber which, thanks to its optical properties, can efficiently absorb sunlight and convert it into heat.&nbsp; &nbsp; &nbsp;In their lab-scale experiments, the team used a quartz rod measuring 7.5 centimetres in diameter and 30 centimetres in length. They exposed it to artificial light with an intensity equivalent to 135 times that of sunlight, reaching temperatures of up to 1050 degrees Celsius. Previous studies by other researchers have achieved a maximum of 170 degrees with such thermal traps.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1717028136435-image.imageformat.1286.1508405936.jpg" style="width: 100%px;" class="fr-fic fr-dib">Illustration of the experimental thermal trap. It consists of a quartz rod (inside) and a ceramic absorber (outside). Solar radiation enters at the front, heat is generated in the rear area. (Visualizations: Casati E et al. Device 2024, edited)Large-scale solar concentrating technologies are already established at an industrial scale for solar power generation, for example in Spain, the US and in China. These plants typically operate at up to 600 degrees. At higher temperatures, heat loss by radiation increases and reduces the efficiency of the plants. A major advantage of the thermal trap developed by ETH Zurich researchers is that it minimises radiative heat losses.<h2>High-temperature solar plants</h2>Our approach significantly improves the efficiency of solar absorption,” says Casati. “We are, therefore, confident that this technology supports the deployment of high-temperature solar plants.” However, detailed technical and economic analyses are still pending, he says. Such analysis is beyond the scope of the current experimental study, which the researchers have published in the scientific journal <a href="https://doi.org/10.1016/j.device.2024.100399" target="_blank">external pageDevicecall_made</a>.Casati is continuing his research to optimise the process. The technology could one day make it possible to use solar energy not only to generate electricity, but also to decarbonise energy-intensive industries on a large scale. “To combat climate change, we need to decarbonise energy in general," says Casati. “People often think of energy in terms of electricity, but we actually use about half of our energy in the form of heat.”<hr><h2 id="isPasted">Reference &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;</h2>Casati E, Allgoewer L, Steinfeld A: Solar thermal trapping at 1,000°C and above. Device, 15. May 2024, doi: <a href="https://doi.org/10.1016/j.device.2024.100399" target="_blank">external page10.1016/j.device.2024.100399</a>

The main component of the thermal trap is a cylinder made of quartz. In the experiments, it reached a temperature of 1050 degrees Celsius and glowed at this heat. (Photograph: ETH Zurich / Emiliano Casati)

Instead of burning coal or oil to produce cement or steel, in the future solar energy could be used for this purpose. Researchers at ETH Zurich have developed a thermal trap that can absorb concentrated sunlight and deliver heat at over thousand degrees Celsius.

Using solar energy to generate heat at high temperatures

Catalysts are chemistry’s hard-working little helpers. They accelerate reactions and reduce the energy required for a reaction to take place. The more specific and effective a catalyst is, the more effectively any undesirable side reactions are suppressed. In nature, enzymes have the job of specifically boosting the required metabolic processes from among the almost infinite reaction possibilities of the chemical soup within cells. In chemical plants, metal catalysts are usually employed to increase product yield.The researchers working on the Swiss Cat+ technology platform at ETH Zurich, led by Paco Laveille, have now developed a fully digitalised and automated method that enables them to find new and better metal catalysts much faster than before. Their process consists of a combination of artificial intelligence (AI) for calculating promising catalyst compositions and an automated synthesis and test laboratory.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1708443779398-1708443779398.png" style="width: 766px;" class="fr-fic fr-dib">With this infrastructure, it took the team less than six weeks to successfully develop around 150 catalysts compositions for producing methanol from CO2. The best catalysts are cost-effective and exhibit high conversion rates with a low proportion of byproducts. “This new method saves a huge amount of time,” Laveille says. “With a conventional approach, our experiments would have taken years.”Methanol is regarded as one of the key elements for a sustainable hydrocarbon economy. A close chemical relative of ethanol (i.e. drinking alcohol), the substance can be used both as a fuel and as a raw material for the production of organic compounds such as medicines, plastics or paints. Because it is a liquid, methanol is much easier to transport and store than gaseous hydrogen and methane, two other sources of energy. What’s more, using methanol in the existing supply infrastructure and engines of today’s petrol technology requires only minor modifications.<h2>Narrowing down the possibilities through clever preselection</h2>In the search for optimum catalysts for methanol production, there’s one big problem: theoretically, atoms can be combined in an almost infinite number of ways to form a catalyst. “The chemical space in which we’re searching for catalysts comprises around 1020 possibilities – that’s one hundred billion billion. So we’re literally looking for a needle in the chemical haystack,” explains Christophe Copéret, a professor at the Laboratory of Inorganic Chemistry at ETH Zurich and co-initiator of the Swiss Cat+ project.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1708443805162-image.imageformat.1286.1743801613.jpg" style="width: 766px;" class="fr-fic fr-dib">Precision scale of the robotic system. The system transfers solid and liquid raw chemicals into the glass vials in which the synthesis takes place. (Photograph: ETH Zurich / Michel Büchel)To narrow down the huge range of possibilities, the researchers made a preselection based on experience and economic requirements. A catalyst that can be used on a large scale needs to be not only effective but also inexpensive. For that reason, the main active ingredients for the catalyst were limited to three comparatively cheap metals: iron, copper and cobalt.In addition to these main metals, the researchers considered three elements that are traditionally added to catalysts in small quantities for the purposes of doping, as well as potassium, which is also contained in many catalysts. As to carrier materials, the researchers limited themselves to four typical metal oxides. Multiplied by the different mixing ratios, this still resulted in 20 million possible combinations.<h2>Taking iterative steps with AI-supported statistics</h2>At this point, the researchers brought an AI algorithm into play that uses what is known as Bayesian optimisation to find the best possible solutions. This special form of statistics is particularly suitable when only a small amount of data is available. Unlike in classical statistics, the probability doesn’t derive from the relative frequency as calculated from numerous experiments. Instead, the calculation takes into account the probability that can be expected based on the current state of knowledge.In the initial round, the algorithm randomly selected 24 catalyst compositions that met the specifications drawn up for the purposes of limiting the complexity. These catalysts were produced directly using the Swiss Cat+ automated laboratory infrastructure and then tested.<h2>Delivering lots of highly reliable results quickly</h2>The results of this initial selection served the researchers as the starting point for an AI prediction; the catalyst compositions thus predicted were in turn automatically synthesised and tested. For this first demonstration test, the scientists had their integrated system complete a total of six such rounds.The fact that the results improved between rounds not in a linear fashion, but rather by leaps and bounds, was entirely intentional: not only does the algorithm optimise the results of earlier rounds, it also includes an exploratory component that feeds completely new compositions into each round and learns about the chemical space. This is how the researchers prevented the calculations from getting stuck in an optimisation dead end amongst all the possibilities.<h2>Generating data beyond petrochemicals</h2>In this first project, though, the researchers’ primary concern wasn’t to come up with the best possible catalyst for methanol synthesis. “At present, knowledge about catalysts for fuel production is based predominantly on expertise from the oil industry,” Copéret says. “When it comes to reactions for use in the sustainable energy industry, reliable data is still largely lacking.” However, AI algorithms and human research intelligence need that data before they can search in a more targeted way in the vast space of chemical possibilities. “And that’s precisely the kind of high-quality, reproducible data our AI-assisted robot laboratory now delivers. It’s certain to take catalyst research a long way forward,” Laveille adds.<hr><h2 id="isPasted">Complex technology infrastructure</h2>“The Swiss Cat+ hub provides us with complex research infrastructure that we wouldn’t be able to operate ourselves with the groups in our laboratories,” explains Professor Christophe Copéret from the Department of Chemistry and Applied Biosciences at ETH Zurich. Research at universities is heavily dependent on doctoral students, but they stay only for a few years. Every time a doctoral student leaves, much of the expertise they have built up is lost. In contrast, Swiss Cat+ is a technology platform designed to work with permanently employed experts who are able to continuously develop their expertise and use the latest technologies to refine the infrastructure.Initiated in 2019 by Copéret and Nicolai Kramer, a professor at EPFL, the <a href="https://swisscatplus.ethz.ch/" target="_blank">Swiss Cat+ hub</a> now provides researchers from universities and industry with state-of-the-art infrastructure at two locations in Zurich and Lausanne. These make it possible to design catalysts with the help of AI data analysis tools, then produce them immediately in automated high-throughput laboratories and test their effectiveness. Dozens of ETH projects are already using the two platforms.<hr><h2 id="isPasted">References</h2>Ramirez A, Lam E, Pacheco Gutierrez D, Hou Y, Tribukait H, Roch LM, Copéret C, Laveille P: Accelerated Exploration of Heterogenous CO2 Hydrogenation Catalyts by Bayesian-optimized High-throughput and Automated Experimentation. Chem Catalysis, 18. Januar 2024, doi: <a href="https://doi.org/10.1016/j.checat.2023.100888" target="_blank">external page10.1016/j.checat.2023.100888</a>Laveille P, Miéville P, Chatterjee S, Clerc E, Cousty JC, de Nanteuil F, Lam E, Mariano E, Ramirez A, Randrianarisoa U, Villat K, Copéret C, Cramer N: Swiss Cat+, a Data-driven Infrastructure for Accelerated Catalysts Discovery and Optimization. Chimia 2023, 77: 154, doi: <a href="https://doi.org/10.2533/chimia.2023.154" target="_blank">external page10.2533/chimia.2023.154</a>

This robotic arm transfers glass vials into a centrifuge. It is part of a robot unit that produces catalysts completely autonomously according to the specifications of an AI model. (Photograph: ETH Zurich / Michel Büchel)

Artificial intelligence and automated laboratory infrastructure are massively accelerating the development of new chemical catalysts. With these tools, researchers at ETH Zurich are developing catalysts for efficiently and cost-​effectively synthesising the energy source methanol from CO2.

A sustainable fuel and chemical from the robotic lab

<section id="isPasted">There is a global consensus that humankind needs to move away from fuels produced from fossil feedstocks to curb the effects of climate change. While smaller vehicles turn to e-mobility, unfortunately, heavy-duty transport systems such as trucks, ships, and airplanes will rely on traditional liquid hydrocarbon fuels for the foreseeable future. As an alternative to fossil oils, these renewable fuels can be produced from plant-based lignin, but yields are limited by the current processing approaches, hampering the adoption of these alternative plant-based fuels. In a new study led by Emiel Hensen’s research group at TU/e, a novel catalytic approach has been developed that can significantly improve yields from lignin by cracking hard-to-break carbon-carbon bonds.</section><section tabindex="-1">At COP28 – the 2023 United Nations Climate Change Conference held in Dubai in December 2023 – <a href="https://unfccc.int/sites/default/files/resource/cma2023_L17_adv.pdf" target="_blank" rel="noreferrer" data-lf-fd-inspected-kn9eq4roawkarlvp="true">an agreement</a> was reached calling on all countries to help “transition away from fossil fuels in energy systems in a just, orderly and equitable manner”.&nbsp;This statement could be revised slightly to account for the technologies that we need in the future, according to <a href="https://www.tue.nl/en/research/researchers/emiel-hensen" target="_blank">Emiel Hensen</a>, professor in the Department of Chemical Engineering and Chemistry.<h3 id="isPasted">Heavy-duty transportation</h3><section tabindex="-1" id="isPasted"><blockquote>We need to move away from fossil feedstocks such as oil to produce hydrocarbon fuels.</blockquote>“To be precise, we need to move away from fossil feedstocks such as oil to produce hydrocarbon fuels,” says Hensen. “And that’s because we are going to need hydrocarbon fuels for decades to come, whether we like it or not.”E-mobility technologies may be revolutionizing the family car, but largescale heavy-duty transportation such as ships and airplanes will continue to rely on hydrocarbon fuels for some time. “It’s an inescapable fact: we are going to need hydrocarbon fuels to enable the energy transition for some time to come. But we don’t need to make them from traditional crude oil. Instead, we can make them from renewable sources, such as lignin from plant biomass.”<h3>Does lignin pose problems?</h3>Lignin is one of the major components in plant biomass, and it’s this component that Hensen and others want to use to produce valuable fuels and chemicals. Currently, though there’s a catch.“In biomass, you’ll find sugars and lignin. Sugars can be converted into ethanol, while chemicals and fuels can in principle be made from lignin. The catch is having an effective process that can do the latter,” says Hensen.</section><section tabindex="-1">Lignin is a polymer of so-called aromatic compounds (a planar ring of atoms stabilized by the interaction of bonds in the ring) that is difficult to disentangle. In terms of bonds, lignin is made up of easy-to-break and weak carbon-oxygen bonds and much stronger carbon-carbon bonds.“Catalytic methods break the weak carbon-oxygen bonds with ease, but leave the carbon-carbon bonds untouched, thus limiting the yield of useful products from lignin,” says Hensen.So, in a study just published in the new journal Nature Chemical Engineering, which is featured on the inaugural cover, Hensen along with several TU/e colleagues working in collaboration with partners in the Netherlands, China, and Switzerland have cracked the carbon-carbon cleavage challenge using a new catalytic technology.<h3>The road to cracking carbon-carbon bonds</h3>So, how does the catalytic technology work? As Hensen explains, it requires a catalyst that can speed up two types of reactions at the same time.“We found that a bifunctional catalyst that combines an activation step of the ring structures with a cracking step can selectively cleave carbon-carbon bonds,” notes Hensen.The strong carbon-carbon bonds in the lignin are pre-activated on metal nanoparticles. This pre-activation step weakens the carbon-carbon bonds, which can then be cracked on acid sites in microporous zeolites. The researchers found that bringing the metal and acid sites close together resulted in the highest yield of monomer products that can be used as multifunctional building blocks. These are required to make (synthesize) different types of fuels or chemicals.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1705413380610-csm_Hensen+5L+CSTR+reactor+Vertoro_fa489e4c0d.jpg" style="width: 300px;" class="fr-fic fr-dib">Vertoro's pilot plant. Foto: Vertoro“Thanks to our innovation, we have moved from carbon-oxygen bond cleaving to a technology where carbon-carbon bond cleaving can become the norm,” says Hensen.While this work is hardcore fundamental science and was predominantly completed in Hensen’s group at TU/e, there was key input from around the world.“From the TU/e side, Zhicheng Luo and Alexandra Radu carried out most of the work, with the idea coming from Luo who found the benefit of bifunctional metal nanoparticle/zeolite crystals for breaking carbon-carbon bonds,” notes Hensen.Luo’s observation was just one part of the puzzle. The quantum-chemical calculations by Chong Liu, who is a former PhD researcher in Hensen’s group and is now based at the Fujian Institute of Research on the Structure of Matter in Fuzhou in China, were crucial in terms of guiding the science. Added to that, the spinoff companies&nbsp;<a href="https://www.tue.nl/nieuws-en-evenementen/nieuwsoverzicht/19-09-2023-nieuw-model-voor-de-valorisatie-van-lignine-voor-biobased-toepassingen" target="_blank">Vertoro</a> from the Netherlands and Bloom from Switzerland helped in evaluating the approach by applying it to real lignin feedstocks.<blockquote>Thanks to our innovation, we have moved from carbon-oxygen bond cleaving to a technology where carbon-carbon bond cleaving can become the norm.</blockquote>Finally, an additional collaboration with Southeast University in Nanjing, China – the current host university of Zhicheng Luo – helped with the techno-economic analysis, showcasing the impact of the carbon-carbon bond cleaving.“The solution we have devised enables the production of biofuels from lignin in substantially higher yields than realized so far. This can help makes lignin-based renewable fuel commercially viable,” says Hensen.<h3 id="isPasted">The sky’s the limit!</h3>To test the effectiveness of the approach further, the new catalytic technology developed has not only been demonstrated with model components present in lignin but also with real lignin feedstock obtained from leading technology developers such as Bloom and Vertoro. “This means that the technology can be integrated into the industrial processes being realized at these spinoffs,” says Hensen.Thus far, Hensen and his collaborators have conducted experiments in batch reactors. “The next natural step is to evaluate the stability of the catalysts in continuous processes that are the norm in the chemical industry.”An additional complication for the researchers is the wide variability in terms of the&nbsp;<a href="https://www.tue.nl/en/news-and-events/news-overview/19-09-2023-new-model-to-help-valorize-lignin-for-bio-based-applications" target="_blank">chemical composition of lignin</a>. “Such variability means that it is imperative to evaluate how impurities in regular biomass lignin samples affect yield,” notes Hensen.To use the lignin-derived parts to make sustainable aviation fuels for the aviation industry – which is one industry that needs to change how it accesses hydrocarbon fuels, the researchers will need to make the process ‘milder’ so that slightly heavier compounds could be obtained. “A milder process needs a lower reaction temperature and pressure. So, we are tailoring the catalyst to obtain molecules with two ring structures with high selectivity, which could immediately be blended with aviation fuels,” says Hensen.Blending would allow the fuels to be used in the current generation of airplanes engines too. In addition, these engines can be tailored to operate on lignin-only fuels, which could help transition entire transportation sectors to use sustainable fuel options only.<hr><h3 id="isPasted">Further information</h3>'<a href="https://www.nature.com/articles/s44286-023-00006-0" target="_blank" rel="noreferrer">Carbon-carbon bond cleavage for a lignin refinery</a>', Luo&nbsp;et. al, Nature Chemical Engineering, (2024).</section></section>

A TU/e-led project using advanced catalytic methods to cleave carbon-carbon bonds in plant-based lignin is featured on the cover of the first-ever issue of Nature Chemical Engineering.

Cracking carbon-carbon bonds in lignin to make sustainable aviation fuels

<h2 dir="ltr" id="isPasted">FREE REPORT:&nbsp;Reducing Human Driver Error and Setting Realistic Expectations with Advanced Driver Assistance Systems</h2>Thousands die or are injured each year in automobile crashes. Bringing automated driving systems technologies into the advanced driver assist systems (ADAS) and connected vehicle space will help humans drive more safely and better prepare us for automated vehicles (AVs).Learn more about ADAS and ADS implementation with the goal of reaching zero deaths and serious injuries by downloading this FREE report from SAE International (valued at $50).&nbsp;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzAyMjkzOTY4NzIxLXNhZSBmcmVlIHJlcG9ydC5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 300px;" class="fr-fic fr-dib"><h2 dir="ltr"><iframe width="540" height="740" src="https://c8056756.sibforms.com/serve/MUIFAIm7QnvQQ9ZyzkX--H5jNS-TSb9GWr5SQBXi_SUjRPpt67CBveq_yevZYMSeiJ-O1dwYw05f2kl-Q7sfNDRem1Y-03GXYZV4qkTbJeR_K_VpJzgMk_8Ry8fjyfgJ7fAMrCmcRHc1KXsSTuhIU5p5pBa3F1-TGDgOdQgcF-pU8cSTrl8JF2j2b9gl6-5e66Ro-rltcIrGxsRG" frameborder="0" scrolling="auto" allowfullscreen="" style="display: block;margin-left: auto;margin-right: auto;max-width: 100%;" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe> </h2><h2 dir="ltr">Circular thinking is critical to companies’ sustainability efforts</h2>Sustainability extends beyond just decarbonization. &nbsp;A term popping up more and more in executive and engineering-focused presentations is “circular economy,” referring to a closed-loop production cycle that seeks to minimize resource inputs and reduce or eliminate waste and emissions.Attendees at the recent SAE COMVEC 2023 heard from Rob Zemenchik, CNH Industrial’s Sr. Manager for Product Sustainability, explaining how the company specifically seeks projects that deliver on circularity in the product lifecycle. CNH Industrial’s roadmap to hit its 2030 and 2050 climate targets includes more than 150 specific projects. One of the “early success stories” is its work with British company Bennaman on an on-farm liquid fugitive biomethane production process.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzAyMjc5MzU5NTU2LXNhZS1jb212ZWNfZHRuYS1yZWZ1ZWxpbmctaW5mcmFzdHJ1Y3R1cmVfZ2FsbGVyeS5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 766px;" class="fr-fic fr-dib">Daimler Truck North America and DTE Energy are partnering on a real-world prototype program in Michigan called the Mobility Charging Hub, which will test new technologies, digital services and business models designed to modernize truck stops and accelerate deployment of commercial EVs at scale.“Biodigestion is not new, but the cost was always too high. You had physical structures that were very capital intensive,” he said. Bennaman developed a “low-cost” lagoon cover that captures fugitive methane from livestock manure and converts it to automotive-grade CNG and LNG (compressed and liquefied natural gas) that the OEM claims is a “better-than-zero-carbon” biofuel.Methane has a global warming potential of more than 80 times that of CO2 over a 20-year period, according to the United Nations Economic Commission for Europe (UNECE). “Cows, which are often indicted as culprits in global warming, can now be part of the solution,” Zemenchik asserted. “One of the successes we’ve seen so far [in this project] is that we can now do this with less than a five-year payback in a system that lasts up to 20 years.”<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzAyMjk0MTkxODExLWJpZnVlbCAyLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 300px;" class="fr-fic fr-dib">Part of the biofuel production facility. Image credit: BennamannSpeakers on the “Smart Engineering for Sustainability” executive roundtable at COMVEC addressed the question posed by SAE Media about how their companies prioritize their technology portfolios and decide which projects to pursue. “We will touch everything from powertrains to hydraulics,” Zemenchik said. “It’s incremental – it’s a percent here, two percent there. To decarbonize a fleet, we have to do the deep dive into all of those products.” He added that being open to collaborative operations with “interesting, non-traditional players” can help with gains, instead of relying solely on in-house R&amp;D.Engineers need to be economists and perform what-if scenarios for strategic planning, according to Tim Frazier, VP of Research and Technology at Cummins Inc. “As economists you have to start thinking about what are the minimum set of building blocks that we need to assemble resilient solutions for our customer base. It doesn’t mean we’re going to take them all into production, but we’re building technology capability [for when] the future becomes more clear.”Rakesh Aneja, head of eMobility for Daimler Truck North America (DTNA), replied: “The engineer in me wants to do everything. The reality is that [we have] finite resources, both financial and even more importantly, people.” Regulations and customer demand are two factors to consider, as is balancing between near- and long-term solutions. Hydrogen technology – both fuel cells and combustion engines – will play a complementary role, he said, but in the U.S. is at least a “couple years” behind the battery-electric ecosystem.A “trifecta” of conditions is required for successful decarbonization, Aneja said: viable product solutions, total cost of ownership (TCO) parity, which is “not where it needs to be” but is improving, and dependable charging/refueling infrastructure, which is lagging. “We have several battery-electric vehicles in production today. The initial acquisition price of those vehicles is two to three times the cost of a comparable diesel vehicle,” he said, noting that localization and industrialization of <a href="http://www.sae.org/news/2023/09/lfp-battery-cell-production-for-electric-commercial-vehicles" target="_blank">battery production</a> will help bring costs down.Don Hillebrand, division director at Argonne National Laboratory, referenced a recent meeting he attended in which several people from both the utility and OEM sides said that the infrastructure is at least five years behind where electric vehicles are. “And that’s probably a true statement,” he said. “It’s building up very quickly, but infrastructure [still] moves slower than the needs of our vehicle fleets.”Aneja agreed, saying that some of the best-case scenarios for infrastructure installation are 18-24 months. “In many cases, infrastructure timelines are much longer – two or three years, even longer,” he said. “That continues to be a challenge, and a lot needs to be done from a proactive perspective to meet our emissions goals.”But why wait? posited Cummins’ Frazier. “Rather than waiting for a few specific answers to be right in the future against all the limitations and infrastructure challenges that are up against them, [we could] employ a broader matrix of solutions to go further, faster,” he said. “If we leverage low-carbon fuels, liquid fuels, hydrogen and renewable grids, we can take about 1.4 gigatons of CO2 out of the environment, ahead of waiting for [widespread] grid infrastructure. That’s the equivalent of taking every truck off the street for three years. Not a bad goal.”

The New Holland T7 Methane Power LNG tractor can run on “better-than-zero-carbon” biofuel – liquefied fugitive methane captured and converted from slurry lagoons that hold livestock manure. (CNH Industrial)

How can circular economy principles be applied to the automotive industry?

Circular economy principles for a sustainable automotive future

MIT researchers and colleagues have demonstrated a way to precisely control the size, composition, and other properties of nanoparticles key to the reactions involved in a variety of clean energy and environmental technologies. They did so by leveraging ion irradiation, a technique in which beams of charged particles bombard a material.They went on to show that nanoparticles created this way have superior performance over their conventionally made counterparts.“The materials we have worked on could advance several technologies, from fuel cells to generate CO2-free electricity to the production of clean hydrogen feedstocks for the chemical industry [through electrolysis cells],” says Bilge Yildiz, leader of the work and a professor in MIT’s departments of Nuclear Science and Engineering and Materials Science and Engineering.<h2>Critical catalyst</h2>Fuel and electrolysis cells both involve electrochemical reactions through three principal parts: two electrodes (a cathode and anode) separated by an electrolyte. The difference between the two cells is that the reactions involved run in reverse.The electrodes are coated with catalysts, or materials that make the reactions involved go faster. But a critical catalyst made of metal-oxide materials has been limited by challenges including low durability. “The metal catalyst particles coarsen at high temperatures, and you lose surface area and activity as a result,” says Yildiz, who is also affiliated with the Materials Research Laboratory and is an author of&nbsp;<a href="https://pubs.rsc.org/en/content/articlelanding/2023/EE/D3EE02448B" target="_blank">an open-access paper on the work</a> published in the journal&nbsp;Energy &amp; Environmental Science.Enter metal exsolution, which involves precipitating metal nanoparticles out of a host oxide onto the surface of the electrode. The particles embed themselves into the electrode, “and that anchoring makes them more stable,” says Yildiz. As a result, exsolution has “led to remarkable progress in clean energy conversion and energy-efficient computing devices,” the researchers write in their paper.However, controlling the precise properties of the resulting nanoparticles has been difficult. “We know that exsolution can give us stable and active nanoparticles, but the challenging part is really to control it. The novelty of this work is that we’ve found a tool — ion irradiation — that can give us that control,” says Jiayue Wang PhD ’22, first author of the paper. Wang, who conducted the work while earning his PhD in the MIT Department of Nuclear Science and Engineering, is now a postdoc at Stanford University.Sossina Haile ’86, PhD ’92, the Walter P. Murphy Professor of Materials Science and Engineering at Northwestern University, who was not involved in the current work, says:“Metallic nanoparticles serve as catalysts in a whole host of reactions, including the important reaction of splitting water to generate hydrogen for energy storage. In this work, Yildiz and colleagues have created an ingenious method for controlling the way that nanoparticles form.”Haile continues, “the community has shown that exsolution results in structurally stable nanoparticles, but the process is not easy to control, so one doesn’t necessarily get the optimal number and size of particles. Using ion irradiation, this group was able to precisely control the features of the nanoparticles, resulting in excellent catalytic activity for water splitting.”<h2>What they did</h2>The researchers found that aiming a beam of ions at the electrode while simultaneously exsolving metal nanoparticles onto the electrode’s surface allowed them to control several properties of the resulting nanoparticles.“Through ion-matter interactions, we have successfully engineered the size, composition, density, and location of the exsolved nanoparticles,” the team writes in&nbsp;Energy &amp; Environmental Science.For example, they could make the particles much smaller — down to 2 billionths of a meter in diameter — than those made using conventional thermal exsolution methods alone. Further, they were able to change the composition of the nanoparticles by irradiating with specific elements. They demonstrated this with a beam of nickel ions that implanted nickel into the exsolved metal nanoparticle. As a result, they demonstrated a direct and convenient way to engineer the composition of exsolved nanoparticles.“We want to have multi-element nanoparticles, or alloys, because they usually have higher catalytic activity,” Yildiz says. “With our approach, the exsolution target does not have to be dependent on the substrate oxide itself.” Irradiation opens the door to many more compositions. “We can pretty much choose any oxide and any ion that we can irradiate with and exsolve that,” says Yildiz.The team also found that ion irradiation forms defects in the electrode itself. And these defects provide additional nucleation sites, or places for the exsolved nanoparticles to grow from, increasing the density of the resulting nanoparticles.Irradiation could also allow extreme spatial control over the nanoparticles. “Because you can focus the ion beam, you can imagine that you could ‘write’ with it to form specific nanostructures,” says Wang. “We did a preliminary demonstration [of that], but we believe it has potential to realize well-controlled micro- and nano-structures.”The team also showed that the nanoparticles they created with ion irradiation had superior catalytic activity over those created by conventional thermal exsolution alone.Additional MIT authors of the paper are Kevin B. Woller, a principal research scientist at the Plasma Science and Fusion Center (PSFC), home to the equipment used for ion irradiation; Abinash Kumar PhD ’22, who received his PhD from the Department of Materials Science and Engineering (DMSE) and is now at Oak Ridge National Laboratory; and James M. LeBeau, an associate professor in DMSE. Other authors are Zhan Zhang and Hua Zhou of Argonne National Laboratory, and Iradwikanari Waluyo and Adrian Hunt of Brookhaven National Laboratory.<hr>This work was funded by the OxEon Corp. and MIT’s PSFC. The research also used resources supported by the U.S. Department of Energy Office of Science, MIT’s Materials Research Laboratory, and MIT.nano. The work was performed, in part, at Harvard University through a network funded by the National Science Foundation.

Artist’s representation of nanoparticles with different compositions created by combining two techniques: metal exsolution and ion irradiation. The different colors represent different elements, such as nickel, that can be implanted into an exsolved metal particle to tailor the particle’s compositions and reactivity. Image: Jiayue Wang

The work demonstrates control over key properties leading to better performance.

Team engineers nanoparticles using ion irradiation to advance clean energy and fuel conversion

In this episode, we dive into how MIT researchers have found a new way of efficiently leveraging the abundant carbon dioxide in the atmosphere to create clean, stable fuel capable of addressing Hydrogen’s shortcomings while still offering its core benefits!

Podcast: Converting CO2 To Clean Fuel

Ammonia, a main component of many fertilizers, could play a key role in a carbon-free fuel system as a convenient way to transport and store clean hydrogen. The chemical, made of hydrogen and nitrogen (NH3), can also itself be burned as a zero-carbon fuel. However, new research led by Princeton University illustrates that even though it may not be a source of carbon pollution, ammonia’s widespread use in the energy sector could pose a grave risk to the nitrogen cycle and climate without proper engineering precautions.Publishing&nbsp;<a href="https://www.pnas.org/doi/10.1073/pnas.2311728120" target="_blank">their findings</a> November 6 in&nbsp;PNAS, the interdisciplinary team of 12 researchers found that a well-engineered ammonia economy could help the world achieve its decarbonization goals and secure a sustainable energy future. A mismanaged ammonia economy, on the other hand, could ramp up emissions of nitrous oxide (N2O), a long-lived greenhouse gas around 300 times more potent than CO2&nbsp;and a major contributor to the thinning of the stratospheric ozone layer. It could lead to substantial emissions of nitrogen oxides (NOx), a class of pollutants that contribute to the formation of smog and acid rain. And it could directly leak fugitive ammonia emissions into the environment, also forming air pollutants, impacting water quality, and stressing ecosystems by disturbing the global nitrogen cycle.Fortunately, the researchers found that the potential negative impacts of an ammonia economy can be minimized with proactive engineering practices. They argued that now is the time to start seriously preparing for an ammonia economy, tackling the potential sticking points of ammonia fuel before its widespread deployment.“We know an ammonia economy of some scale is likely coming,” said research leader&nbsp;<a href="https://engineering.princeton.edu/faculty/amilcare-porporato" target="_blank">Amilcare Porporato</a>, the Thomas J. Wu ’94 Professor of Civil and Environmental Engineering and the&nbsp;<a href="https://environment.princeton.edu/" target="_blank">High Meadows Environmental Institute</a>. “And if we are proactive and future-facing in our approach, an ammonia economy could be a great thing. But we cannot afford to take the risks of ammonia lightly. We cannot afford to be sloppy.”<h2>Translating ammonia from agriculture to energy</h2>As interest in hydrogen as a zero-carbon fuel has grown, so too has an inconvenient reality: it is notoriously difficult to store and transport over long distances. The tiny molecule must be stored at either temperatures below -253 degrees Celsius or at pressures as high as 700 times atmospheric pressure, conditions that are infeasible for widespread transport and prone to leakage.Ammonia, on the other hand, is much easier to liquify, transport, and store, capable of being moved around similarly to tanks of propane.Moreover, an established process for converting hydrogen into ammonia has existed since the early 20th century. Known as the Haber-Bosch process, the reaction combines atmospheric nitrogen with hydrogen to form ammonia. While the process was originally developed as a cost-effective way to turn atmospheric nitrogen into ammonia for use in fertilizers, cleaning products, and even explosives, the energy sector has looked to the Haber-Bosch process as a way to store and transport hydrogen fuel in the form of ammonia.Ammonia synthesis is inherently energy-intensive, and fossil fuels without CO2 capture are currently used to meet almost all of its feedstock and energy demands. But as the researchers pointed out in their article, if new, electricity-driven processes that are currently under development can replace conventional fossil-fuel-derived ammonia synthesis, then the Haber-Bosch process — or a different process altogether — could be widely used to convert clean hydrogen into ammonia, which can itself be burned as a zero-carbon fuel.“Ammonia is an easy way to transport hydrogen over long distances, and its widespread use in agriculture means there is already an established infrastructure for producing and moving ammonia,” said&nbsp;<a href="https://environment.princeton.edu/people/matteo-bertagni/" target="_blank">Matteo Bertagni</a>, postdoctoral researcher at the High Meadows Environmental Institute working on the&nbsp;<a href="https://cmi.princeton.edu/" target="_blank">Carbon Mitigation Initiative</a>. “You could therefore create hydrogen in a resource-rich area, transform it into ammonia, and then transport it anywhere it’s needed around the globe.”Ammonia’s transportability is especially attractive to industries reliant on long-distance transportation, such as maritime shipping, and countries with limited available space for renewable resources. Japan, for example, already has a national energy strategy in place that incorporates the use of ammonia as a clean fuel. Straightforward storage requirements mean that ammonia might also find use as a vessel for long-term energy storage, complementary to or even replacing batteries.“At first glance, ammonia seems like an ideal cure for the problem of decarbonization,” Porporato said. “But almost every medicine comes with a set of potential side effects.”<h2>‘Look before we leap’</h2>In theory, burning ammonia should yield only harmless nitrogen gas (N2) and water as products. But in practice,&nbsp;<a href="https://engineering.princeton.edu/faculty/michael-mueller" target="_blank">Michael E. Mueller</a>, associate chair and professor of mechanical and aerospace engineering, stated that ammonia combustion can release harmful NOx­&nbsp;and N2O pollutants.Most N2O emissions from ammonia combustion are the result of disruptions to the combustion process. “N2O is essentially an intermediate species in the combustion process,” Mueller said. “If the combustion process is allowed to finish, then there will be essentially no N2O emissions.”Yet Mueller said that under certain conditions, such as when a turbine is ramping up or down or if the hot combustion gases impinge upon cold walls, the ammonia combustion process can become disrupted and N2O emissions can quickly accumulate.For instance, the researchers found that if ammonia fuel achieves a market penetration equal to around 5% of the current global primary energy demand (which would require 1.6 billion metric tons of ammonia production, or ten times current production levels), and if 1% of the nitrogen in that ammonia is lost as N2O, then ammonia combustion could produce greenhouse gas emissions equivalent to 15% of today’s emissions from fossil fuels. The greenhouse gas intensity of such a loss rate would mean that burning ammonia fuel would be more polluting than coal.Like ammonia’s N2O emissions,&nbsp;<a href="https://mae.princeton.edu/people/faculty/socolow" target="_blank">Robert Socolow</a>, a professor of mechanical and aerospace engineering, emeritus, and senior scholar at Princeton, said that widespread usage of ammonia in the energy sector will add to all the other impacts that fertilizer has already had on the global nitrogen cycle.In a&nbsp;<a href="https://www.pnas.org/doi/abs/10.1073/pnas.96.11.6001" target="_blank">seminal paper</a> published in 1999, Socolow discussed the environmental impacts of the food system’s widespread use of nitrogen-enriched fertilizers to promote crop growth, writing that, “Excess fixed nitrogen, in various guises, augments the greenhouse effect…contaminates drinking water, acidifies rain…and stresses ecosystems.”As the energy sector looks toward ammonia as a fuel, Socolow said that it can learn from agriculture’s use of ammonia as a fertilizer. He urged those in the energy sector to consult the decades of work from ecologists and agricultural scientists to understand the role of excess nitrogen in disturbing natural systems.“Ammonia fuel can be done, but it cannot be done in any way we wish,” said Socolow, whose 2004 paper with&nbsp;<a href="https://eeb.princeton.edu/people/stephen-pacala" target="_blank">Stephen Pacala</a>, the Frederick D. Petrie Professor in Ecology and Evolutionary Biology, emeritus, on&nbsp;<a href="https://www.science.org/doi/abs/10.1126/science.1100103" target="_blank">stabilization wedges</a> has become a foundation of modern climate policy. “It’s important that we look before we leap.”<h2>A roadmap for a sustainable ammonia economy</h2>While the environmental consequences of an ammonia economy gone wrong are serious, the researchers emphasized that the potential stumbling blocks they identified are solvable through proactive engineering.“I interpret this paper as a handbook for engineers,” Mueller said. “By identifying the worst-case scenario for an ammonia economy, we’re really identifying what we need to be aware of as we develop, design, and optimize new ammonia-based energy systems.”For instance, Mueller said there are alternative combustion strategies that could help to minimize unwanted NOx and N2O emissions. While each strategy has its own set of pros and cons, he said that taking the time now to evaluate candidate systems with an eye toward mitigating emissions will ensure that combustion systems are poised to operate optimally for ammonia fuel.Another option for accessing the energy in ammonia involves partially or fully splitting ammonia back into hydrogen and atmospheric nitrogen through a process known as cracking. Ammonia cracking, a line of research being actively pursued by&nbsp;<a href="https://engineering.princeton.edu/faculty/emily-carter" target="_blank">Emily A. Carter</a>, could help to make the fuel composition more favorable for combustion or even bypass the environmental concerns of ammonia burning by regenerating hydrogen fuel at the point of use. Carter is the Gerhard R. Andlinger Professor of Energy and the Environment and senior strategic advisor and associate laboratory director for applied materials and sustainability sciences at the&nbsp;<a href="https://www.pppl.gov/" target="_blank">Princeton Plasma Physics Laboratory</a> (PPPL).Furthermore, several technologies already exist at the industrial scale to convert unwanted NOx emissions from combustion back into N2 through a process known as selective catalytic reduction. These technologies could be straightforward to transfer to ammonia-based fuel applications. And as a convenient bonus, many of them rely on ammonia as a feedstock to remove NOx — something that there would already be plenty of in an ammonia-based system.Beyond the engineering practices that could be developed to minimize the environmental impacts of an ammonia economy, Porporato said future work will also look beyond engineering approaches to identify policies and regulatory strategies that would ensure the best-case scenario for ammonia fuel.“Imagine the problems we could have avoided if we knew the risks and environmental impacts of burning fossil fuels before the Industrial Revolution began,” Porporato said. “With the ammonia economy, we have the chance to learn from our carbon-emitting past. We have the opportunity to solve the challenges we’ve identified before they become an issue in the real world.”<hr>The paper, “<a href="https://www.pnas.org/doi/10.1073/pnas.2311728120" target="_blank">Minimizing the Impacts of the Ammonia Economy on the Nitrogen Cycle and Climate</a>,” was published November 6 in PNAS. In addition to Porporato, Bertagni, Mueller, Socolow, and Carter, coauthors include J. Mark P. Martirez of the Princeton Plasma Physics Laboratory (PPPL); Chris Greig, Yiguang Ju, Sankaran Sundaresan, Mark Zondlo, and Rui Wang of Princeton University; and Tim Lieuwen of the Georgia Institute of Technology. The research was supported by the U.S. Department of Energy, the National Science Foundation, the BP-funded Carbon Mitigation Initiative at Princeton University, and the Moore Foundation.

While interest in the use of ammonia as a hydrogen carrier and zero-carbon fuel grows, a Princeton-led team of researchers found that a mismanaged ammonia economy could have unwanted environmental consequences. (adobe.stock.com)

Ammonia, a main component of many fertilizers, could play a key role in a carbon-free fuel system as a convenient way to transport and store clean hydrogen. The chemical, made of hydrogen and nitrogen (NH3), can also itself be burned as a zero-carbon fuel.

Ammonia fuel offers great benefits but demands careful action

In this episode, we discuss a novel approach from ETH Zurich to remove a design bottleneck from solar reactors that enables power generation output that is 2X the current state of the art!

Podcast: Solar Fuel Reactor Generates Energy Out of Thin Air

This article was discussed in our <a href="https://www.wevolver.com/profile/the.next.byte" rel="noopener noreferrer" target="_blank">Next Byte podcast</a>.&nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/1b7aa39d-b7fc-4b88-8961-8bb4db9d0f41?dark=false" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe>The full article will continue below.<hr>The search is on worldwide to find ways to extract carbon dioxide from the air or from power plant exhaust and then make it into something useful. One of the more promising ideas is to make it into a stable fuel that can replace fossil fuels in some applications. But most such conversion processes have had problems with low carbon efficiency, or they produce fuels that can be hard to handle, toxic, or flammable.Now, researchers at MIT and Harvard University have developed an efficient process that can convert carbon dioxide into formate, a liquid or solid material that can be used like hydrogen or methanol to power a fuel cell and generate electricity. Potassium or sodium formate, already produced at industrial scales and commonly used as a de-icer for roads and sidewalks, is nontoxic, nonflammable, easy to store and transport, and can remain stable in ordinary steel tanks to be used months, or even years, after its production.The new process, developed by MIT doctoral students Zhen Zhang, Zhichu Ren, and Alexander H. Quinn; Harvard University doctoral student Dawei Xi; and MIT Professor Ju Li, is described this week in an <a href="https://www.cell.com/cell-reports-physical-science/fulltext/S2666-3864(23)00485-X" target="_blank">open-access paper in Cell Reports Physical Science</a>. The whole process — including capture and electrochemical conversion of the gas to a solid formate powder, which is then used in a fuel cell to produce electricity — was demonstrated at a small, laboratory scale. However, the researchers expect it to be scalable so that it could provide emissions-free heat and power to individual homes and even be used in industrial or grid-scale applications.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk4NzM2MzM3MjQ3LU1JVC1GdWVsZnJvbS0wMS1wcmVzcy5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 766px;" class="fr-fic fr-dib">A schematic shows the formate process. The top left shows a household powered by the direct formate fuel cell, with formate fuel stored in the underground tank. In the middle, the fuel cell that harnesses formate to supply electricity is shown. On the lower right is the electrolyzer that converts bicarbonate into formate. Image: Shuhan Miao, Harvard Graduate School of DesignOther approaches to converting carbon dioxide into fuel, Li explains, usually involve a two-stage process: First the gas is chemically captured and turned into a solid form as calcium carbonate, then later that material is heated to drive off the carbon dioxide and convert it to a fuel feedstock such as carbon monoxide. That second step has very low efficiency, typically converting less than 20 percent of the gaseous carbon dioxide into the desired product, Li says.By contrast, the new process achieves a conversion of well over 90 percent and eliminates the need for the inefficient heating step by first converting the carbon dioxide into an intermediate form, liquid metal bicarbonate. That liquid is then electrochemically converted into liquid potassium or sodium formate in an electrolyzer that uses low-carbon electricity, e.g. nuclear, wind, or solar power. The highly concentrated liquid potassium or sodium formate solution produced can then be dried, for example by solar evaporation, to produce a solid powder that is highly stable and can be stored in ordinary steel tanks for up to years or even decades, Li says.Several steps of optimization developed by the team made all the difference in changing an inefficient chemical-conversion process into a practical solution, says Li, who holds joint appointments in the departments of Nuclear Science and Engineering and of Materials Science and Engineering.The process of carbon capture and conversion involves first an alkaline solution-based capture that concentrates carbon dioxide, either from concentrated streams such as from power plant emissions or from very low-concentration sources, even open air, into the form of a liquid metal-bicarbonate solution. Then, through the use of a cation-exchange membrane electrolyzer, this bicarbonate is electrochemically converted into solid formate crystals with a carbon efficiency of greater than 96 percent, as confirmed in the team’s lab-scale experiments.These crystals have an indefinite shelf life, remaining so stable that they could be stored for years, or even decades, with little or no loss. By comparison, even the best available practical hydrogen storage tanks allow the gas to leak out at a rate of about 1 percent per day, precluding any uses that would require year-long storage, Li says. Methanol, another widely explored alternative for converting carbon dioxide into a fuel usable in fuel cells, is a toxic substance that cannot easily be adapted to use in situations where leakage could pose a health hazard. Formate, on the other hand, is widely used and considered benign, according to national safety standards.Several improvements account for the greatly improved efficiency of this process. First, a careful design of the membrane materials and their configuration overcomes a problem that previous attempts at such a system have encountered, where a buildup of certain chemical byproducts changes the pH, causing the system to steadily lose efficiency over time. “Traditionally, it is difficult to achieve long-term, stable, continuous conversion of the feedstocks,” Zhang says. “The key to our system is to achieve a pH balance for steady-state conversion.”To achieve that, the researchers carried out thermodynamic modeling to design the new process so that it is chemically balanced and the pH remains at a steady state with no shift in acidity over time. It can therefore continue operating efficiently over long periods. In their tests, the system ran for over 200 hours with no significant decrease in output. The whole process can be done at ambient temperatures and relatively low pressures (about five times atmospheric pressure).Another issue was that unwanted side reactions produced other chemical products that were not useful, but the team figured out a way to prevent these side reactions by the introduction of an extra “buffer” layer of bicarbonate-enriched fiberglass wool that blocked these reactions.The team also built a fuel cell specifically optimized for the use of this formate fuel to produce electricity. The stored formate particles are simply dissolved in water and pumped into the fuel cell as needed. Although the solid fuel is much heavier than pure hydrogen, when the weight and volume of the high-pressure gas tanks needed to store hydrogen is considered, the end result is an electricity output near parity for a given storage volume, Li says.The formate fuel can potentially be adapted for anything from home-sized units to large scale industrial uses or grid-scale storage systems, the researchers say. Initial household applications might involve an electrolyzer unit about the size of a refrigerator to capture and convert the carbon dioxide into formate, which could be stored in an underground or rooftop tank. Then, when needed, the powdered solid would be mixed with water and fed into a fuel cell to provide power and heat. “This is for community or household demonstrations,” Zhang says, “but we believe that also in the future it may be good for factories or the grid.”“The formate economy is an intriguing concept because metal formate salts are very benign and stable, and a compelling energy carrier,” says Ted Sargent, a professor of chemistry and of electrical and computer engineering at Northwestern University, who was not associated with this work. “The authors have demonstrated enhanced efficiency in liquid-to-liquid conversion from bicarbonate feedstock to formate, and have demonstrated these fuels can be used later to produce electricity,” he says.

An electrolzyer configuration with a bicarbonate cathode, intermediate buffer layer, cation exchange membrane and a water anode. Image: Shuhan Miao, Harvard Graduate School of Design

The approach directly converts the greenhouse gas into formate, a solid fuel that can be stored indefinitely and could be used to heat homes or power industries.

Engineers develop an efficient process to make fuel from carbon dioxide

This article originally appeared in <a href="https://www.dlr.de/en/latest/news/2023/04/boeing-nasa-united-airlines-and-dlr-to-test-saf-benefits-with-air-to-air-flights" target="_blank" rel="noopener noreferrer">DLR</a> and has been republished with permission.<hr>In a collaboration to strengthen sustainability in aviation, Boeing [NYSE: BA] is partnering with NASA and United Airlines for in-flight testing to measure how sustainable aviation fuel (SAF) affects contrails and non-carbon emissions, in addition to reducing the fuel's life cycle climate impact.Boeing's second <a href="https://investors.boeing.com/investors/news/press-release-details/2023/Boeing-Expands-ecoDemonstrator-Flight-Testing-with-Explorer-Airplanes-Announces-2023-Plan/default.aspx" target="_blank" rel="noopener noreferrer">ecoDemonstrator Explorer</a>, a 737-10 destined for United Airlines, will fly with 100% SAF and conventional jet fuel in separate tanks and alternate fuels during testing. NASA's DC-8 Airborne Science Lab will fly behind the commercial jet and measure emissions produced by each type of fuel and contrail ice particles. NASA satellites will capture images of contrail formation as part of the testing.The researchers aim to understand how advanced fuels, engine combustor designs and other technologies may reduce atmospheric warming. For example, tests will assess how SAF affects the characteristics of contrails, the persistent condensation trails produced when airplanes fly through cold, humid air. While their full impact is not yet understood, <a href="https://www.dlr.de/en/latest/news/2020/03/20200903_global-air-transport-contributes-3-5-percent-to-global-warming" target="_blank">some research has suggested certain contrails can trap heat in the atmosphere</a>.World Energy is supplying SAF for the tests from its Paramount, Calif., facility. Additional support includes:<ul><li>U.S. Federal Aviation Administration (FAA) is providing funding through the ASCENT Center of Excellence</li><li>GE Aerospace is providing technical expertise and project funding</li><li>German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt or DLR) is providing experts and instrumentation</li></ul><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1697556949654-image-2000-c615e0211234b4ee06b06a3e82d811b0.jpeg" style="width: 766px;" class="fr-fic fr-dib">During flight tests, NASA's DC-8 Airborne Science Lab will fly behind the Boeing ecoDemonstrator Explorer to measure emissions and ice particles in contrails. Credit: DLR/NASA/FrizThe project is the latest phase in a multi-year partnership between Boeing and NASA to analyze how SAF can reduce emissions and enable other environmental benefits. Compared to conventional jet fuel, SAF – made from a range of sustainably produced feedstocks – can reduce emissions by up to 85% over the fuel's life cycle and offers the greatest potential to reduce aviation CO2 over the next 30 years. SAF also produces less soot which can improve air quality near airports."We are honored to collaborate with NASA, United Airlines, and other valued partners on research that will strengthen the industry's understanding of the benefits of SAF beyond reducing carbon emissions," said Boeing Chief Sustainability Officer Chris Raymond. "We've solved hard problems before, and if we continue to take meaningful actions, I'm confident we'll achieve a more sustainable aerospace future, together.""Flight testing is complex and resource-intensive, yet it's the gold standard for understanding how sustainable aerospace innovations affect changes in contrails and climate," says Rich Wahls, NASA mission integration manager for the Sustainable Flight National Partnership. "This is why we're bringing NASA's DC-8 to bear on this collaboration, where the valuable flight data will improve our predictive models.""There's no question that contrail formations contribute to global warming, but we don't know the extent of their impact or the benefit of using SAF to combat these formations," said United Chief Sustainability Officer Lauren Riley. "This collaboration between Boeing, NASA and United has the potential to not only help us better understand contrails but to provide the full scope of what our transition to SAF can provide beyond greenhouse-gas reductions.""We at GE Aerospace proudly support this groundbreaking research collaboration that will deepen our scientific understanding of the impact of SAF on emissions for a more sustainable future of flight," said GE Aerospace Vice President of Engineering Mohamed Ali."To achieve climate-compatible aviation, we need close international cooperation. The German Aerospace Center has decades of experience in research on the climate impact of the entire aviation system by advancing measurement technology and simulations," says Markus Fischer, DLR Divisional Board Member for Aeronautics. "The continuation of transatlantic cooperation now finds a new summit and underlines the international commitment to reduce the climate impact from aviation's CO2 and non-CO2 effects."The Boeing <a href="https://www.boeing.com/principles/environment/ecodemonstrator" target="_blank" rel="noopener noreferrer">ecoDemonstrator</a> program was expanded this year to include <a href="https://investors.boeing.com/investors/news/press-release-details/2023/Boeing-Expands-ecoDemonstrator-Flight-Testing-with-Explorer-Airplanes-Announces-2023-Plan/default.aspx?_gl=1*hdip01*_ga*MTE5NTM3MTU0OS4xNjUyMzAyNTQ3*_ga_3N2PEGZ4HD*MTY5MjA0ODc2MC4yMTguMS4xNjkyMDQ4Nzg0LjAuMC4w" target="_blank" rel="noopener noreferrer">Explorer</a> airplanes focused on short-term, specific test projects. Boeing and NASA conducted SAF emissions ground testing on an Alaska Airlines 737-9 in <a href="https://aviationweek.com/special-topics/sustainability/nasa-boeing-probe-saf-emissions-777-ecodemonstrator" target="_blank" rel="noopener noreferrer">2021</a> and ecoDemonstrator 777-200ER and 787-10 flight-test jets in <a href="https://onfirstup.com/boeing/BNN/articles/boeing-nasa-measure-sustainable-aviation-fuel-emissions-1?bypass_deeplink=true" target="_blank" rel="noopener noreferrer">2022</a>. Boeing has committed to deliver commercial airplanes compatible with 100% SAF by 2030. The 737-10 is the largest airplane in Boeing's single-aisle 737 MAX family, which reduces fuel use and emissions by 20% compared to airplanes it replaces.<h2>Previous DLR flight tests with sustainable fuels</h2>In 2015, DLR conducted the <a href="https://www.dlr.de/en/latest/news/2015/20151009_a-journey-through-an-exhaust-plume-dlr-flight-tests-for-alternative-fuels_15388" target="_blank">ECLIF1 campaign</a>, which examined alternative fuels using two research aircraft, the Falcon 20E and A320 ATRA. These flight tests were continued in 2018 with the <a href="https://www.dlr.de/en/latest/news/2018/1/20180124_dlr-nasa-research-flights-over-northern-germany_25776" target="_blank">ECLIF2 campaign</a>, in which the <a href="https://www.dlr.de/en/research-and-transfer/research-infrastructure/research-aircraft-fleet/airbus-a320-232-d-atra" target="_blank">A320 ATRA</a> flew with a mixture of kerosene and up to 50 percent Hydroprocessed Esters and Fatty Acids (HEFA). This research demonstrated the beneficial emissions performance of fuel blends with up to 50 percent sustainable aviation fuel (SAF). During the <a href="https://www.dlr.de/en/latest/news/2021/02/20210617_significantly-lower-climate-impact-when-using-sustainable-fuels" target="_blank">joint DLR-NASA flight tests in 2018</a>, the <a href="https://www.dlr.de/en/pa" target="_blank">DLR Institute for Atmospheric Physics</a> was able to clearly demonstrate that the fewer soot particles in the exhaust produced by sustainable fuels result in fewer ice crystals in contrails and thus a lower climate impact.

Boeing is working with NASA, DLR and United Airlines to test how sustainable aviation fuel (SAF) affects contrails and non-carbon-dioxide emissions and reduces the fuel's impact on the climate throughout its lifecycle. Boeing's second ecoDemonstrator Explorer, shown here, a 737-10 built for United Airlines, will fly on 100 percent SAF and conventional jet fuel in separate tanks and alternate fuels during the tests. Credit: Boeing

In a collaboration to strengthen sustainability in aviation, Boeing [NYSE: BA] is partnering with NASA and United Airlines for in-flight testing to measure how sustainable aviation fuel (SAF) affects contrails and non-carbon emissions, in addition to reducing the fuel's life cycle climate impact.

Boeing, NASA, United Airlines and DLR to test SAF benefits with air-to-air flights

In this episode, we discuss how Penn state researchers accidentally discovered that heat treatment of paper bags could make them stronger - especially when wet - thereby increasing their reusability significantly.

Podcast: Burning Paper Bags For Sustainability

This article was discussed in our&nbsp;<a data-saferedirecturl="https://www.google.com/url?q=https://www.wevolver.com/profile/the.next.byte&source=gmail&ust=1672821999265000&usg=AOvVaw3lLKdHdEN0YvCEsaHI7hx9" href="https://www.wevolver.com/profile/the.next.byte" rel="noopener noreferrer" target="_blank">Next Byte podcast</a>.&nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/63f10d22-cd2f-4c1e-8609-6ae7d0af5a2e?dark=false" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe> The full article will continue below.<hr>The study suggests a process for creating paper bags durable enough to be used multiple times and then broken down chemically by an alkaline treatment to be used as a source for biofuel production, according to researcher <a href="https://abe.psu.edu/directory/dec109" target="_blank">Daniel Ciolkosz</a>, associate research professor of agricultural and biological engineering.&ldquo;When the primary use of these paper products ends, using them for secondary purposes makes them more sustainable,&rdquo; he said. &ldquo;Recycling and reducing paper waste also helps in reducing total solid waste destined for landfills. This is a concept we think society should consider.&rdquo;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjgxMjUzMTMxOTI4LXBhcGVyLWJhZy1wZXhlbHMtbGlzYS1mb3Rpb3MuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 766px;" class="fr-fic fr-dib">Paper bags are a popular alternative to plastic bags to reduce the environmental impacts caused by using plastics, but paper bags have short lifespans due to their low durability, particularly when wet. Credit:&nbsp;Lisa Fotios/Pexals.&nbsp;All Rights Reserved.&nbsp;Lead researcher <a href="https://abe.psu.edu/directory/jxt380" target="_blank">Jaya Tripathi</a>, who will graduate from Penn State this spring with a doctoral degree in biorenewable systems and has accepted a position at the Joint BioEnergy Institute in California, devised an innovative process in which cellulose in paper is torrefied, or roasted in an oxygen-deprived environment, to greatly increase its tensile strength when wet.Paper bags are a popular alternative to plastic bags to reduce the environmental impacts caused by using plastics, she explained, but paper bags have short lifespans due to their low durability, particularly when wet. And a paper bag must be reused several times to reduce its global-warming potential to below that of the conventional high-density polyethylene bag, Tripathi added.&ldquo;Reuse is mainly governed by bag strength, and it is unlikely that a typical paper bag can be reused the required number of times due to its low durability upon wetting,&rdquo; she said. &ldquo;Using expensive chemical processes to enhance wet strength diminishes paper&#39;s ecofriendly and cost-efficient features for commercial application, so there is a need to explore non-chemical techniques to increase the wet strength of paper bags. Torrefaction could be the answer.&rdquo;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjgxMjUzMTU3NTU0LWJhZy12ZWdnaWVzLW1hcmNvLXZlcmNoLWZsaWNrci1maXhlZC5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 766px;" class="fr-fic fr-dib">By switching to stronger, reusable paper shopping bags, a large volume of plastic waste could be eliminated, the researchers suggest..&nbsp;Credit:&nbsp;Marco Verch/Flickr.&nbsp;All Rights Reserved.&nbsp;Because torrefaction decreased the glucose yield in the paper, she then treated the paper with a solution of sodium hydroxide, also known as lye or caustic soda, that increased its glucose yield, making it a better source for biofuel production.In&nbsp;<a href="https://www.sciencedirect.com/science/article/abs/pii/S0921344923000198" target="_blank">findings recently published in Resources, Conservation and Recycling</a>, using filter paper as the medium, the researchers reported that the wet-tensile strength of the paper increased by 1,533%, 2,233%, 1,567% and 557% after torrefaction for 40 minutes at 392 degrees Fahrenheit, 428 F, 464 F and 500 F, respectively.Glucose yield decreased with increased torrefaction severity, but after treating torrefied paper samples with an alkaline sodium hydroxide solution, glucose yield increased, the researchers noted. For instance, the glucose yield of raw filter paper was 955 mg/g of substrate, whereas it was 690 mg/g of substrate for the same paper sample torrefied at 392 F. The glucose yield increased to 808 and 933 mg/g of substrate with 1% and 10% alkaline treatment, respectively.The need for a concept like the one demonstrated by the researchers to replace plastic bags is obvious, Tripathi pointed out. According to the U.N. Environment Programme,&nbsp;<a href="https://www.unep.org/interactives/beat-plastic-pollution/" target="_blank">5 trillion plastic bags are produced worldwide annually</a>. It can take up to 1,000 years for these bags to disintegrate completely. Americans throw away 100 billion bags annually &mdash; the equivalent to dumping nearly 12 million barrels of crude oil.&ldquo;By switching to stronger, reusable paper shopping bags, we could eliminate much of that waste,&rdquo; Tripathi said. &ldquo;The implications of a technology like the one we demonstrated in this research &mdash; if it can be perfected &mdash; including using the worn-out bags as a substrate for biofuel production, would be huge.&rdquo;Like many scientific discoveries, Tripathi learned about the synergy of torrefaction and alkaline treatment for increased paper capabilities by accident.&ldquo;I was looking into something else, studying how torrefaction impacts cellulose for glucose yield for use as a biofuel substrate,&rdquo; she said. &ldquo;But I noticed that the paper&rsquo;s strength was increasing as we torrefied the cellulose. That made me think that it probably would be good for packaging, an entirely different application.&rdquo;Contributing to the research was Daniel Sykes, teaching professor of chemistry.This research was supported by the U.S. Department of Agriculture&rsquo;s National Institute for Food and Agriculture.

As the world searches for ways to reduce the use of plastics such as single-use plastic bags, a novel study by Penn State researchers demonstrates a process to make paper bags stronger — especially when they get wet — to make them a more viable alternative.

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