Monday, May 23, 2022

Driving down the costs of hydrogen fuel: Prototype achieves 99% yield 8 times faster than conventional batch reactors

by Matt Shipman, North Carolina State University

New tech aims to drive down costs of hydrogen fuel — Credit: North Carolina State University

Researchers from North Carolina State University have developed a new technique for extracting hydrogen gas from liquid carriers that is faster, less expensive and more energy efficient than previous approaches.

"Hydrogen is widely viewed as a sustainable energy source for transportation, but there are some technical obstacles that need to be overcome before it can be viewed as a practical alternative to existing technologies," says Milad Abolhasani, corresponding author of a paper on the new technique and an associate professor of chemical and biomolecular engineering at NC State. "One of the big obstacles to the adoption of a hydrogen economy is the cost of storage and transportation."

Hydrogen fuel does not result in CO2 emissions. And hydrogen refueling stations could be located at existing gas stations, taking advantage of existing infrastructure. But transporting hydrogen gas is dangerous, so hydrogen needs to be transported via a liquid carrier. A key obstacle for this strategy is that extracting hydrogen from the liquid carrier at destination sites, such as fueling stations, is energy intensive and expensive.

"Previous research has shown that it is possible to use photocatalysts to release hydrogen gas from a liquid carrier using only sunlight," Abolhasani says. "However, existing techniques for doing this were laborious, time consuming and required a significant amount of rhodium—a metal that is very expensive."

"We've developed a technique that applies a reusable photocatalyst and sunlight to extract hydrogen gas from its liquid carrier more quickly and using less rhodium—making the entire process significantly less expensive," says Malek Ibrahim, first author of the paper and a former postdoctoral researcher at NC State. "What's more, the only byproducts are hydrogen gas and the liquid carrier itself, which can be reused repeatedly. It's very sustainable."

One key to the success of the new technique is that it is a continuous-flow reactor. The reactor resembles a thin, clear tube packed with sand. The "sand" consists of micron-scale grains of titanium oxide, many of which are coated with rhodium. The hydrogen-carrying liquid is pumped into one end of the tube. The rhodium-coated particles line the outer part of the tube, where sunlight can reach them. These particles are photoreactive catalysts that, in the presence of sunlight, react with the liquid carrier to release hydrogen molecules as a gas.

The researchers precisely engineered the system so that only the outer grains of titanium oxide are coated with rhodium, ensuring the system uses no more rhodium than is necessary.

"In a conventional batch reactor, 99% of the photocatalyst is titanium oxide and 1% is rhodium," Abolhasani says. "In our continuous flow reactor, we only need to use 0.025% rhodium, which makes a big difference in the final cost. A single gram of rhodium costs more than $500."

In their prototype reactor, the researchers were able to achieve a 99% yield—meaning that 99% of the hydrogen molecules were released from the liquid carrier—in three hours.

"That's eight times faster than conventional batch reactors, which take 24 hours to reach 99% yield," Ibrahim says. "And the system should be easy to scale up or scale out to allow for catalyst reuse on commercial scale—you can simply make the tube longer or merge multiple tubes running in parallel."

The flow system can run continuously for up to 72 hours before its efficiency decreases. At this point, the catalyst can be "regenerated" without removing it from the reactor—it's a simple cleaning process that takes about six hours. The system can then be restarted and run at full efficiency for another 72 hours.

NC State has filed a provisional patent for the technology.

The research was published in the journal ChemSusChem.

Researchers devise cheaper, faster way to continuously produce amines

More information: Malek Y. S. Ibrahim et al, Continuous Room‐Temperature Hydrogen Release from Liquid Organic Carriers in a Photocatalytic Packed‐Bed Flow Reactor, ChemSusChem (2022). DOI: 10.1002/cssc.202200733

Provided by North Carolina State University

Hydrogen production method opens up clean energy possibilities

Peer-Reviewed Publication

WASHINGTON STATE UNIVERSITY

Compressed Hydrogen — IMAGE: POSTDOCTORAL RESEARCHER JAMIE KEE AND PROFESSOR SU HA AND THE NOVEL REACTOR THEY DEVELOPED TO PRODUCE PURE COMPRESSED HYDROGEN. view more
CREDIT: WSU PHOTO SERVICES

PULLMAN, Wash. – A new energy-efficient way to produce hydrogen gas from ethanol and water has the potential to make clean hydrogen fuel a more viable alternative for gasoline to power cars.

Washington State University researchers used the ethanol and water mixture and a small amount of electricity in a novel conversion system to produce pure compressed hydrogen. The innovation means that hydrogen could be made on-site at fueling stations, so only the ethanol solution would have to be transported. It is a major step in eliminating the need to transport high-pressure hydrogen gas, which has been a major stumbling block for its use as a clean energy fuel.

“This is a new way of thinking about how to produce hydrogen gas,” said Su Ha, professor in the Gene and Linda Voiland School of Chemical Engineering and Bioengineering and corresponding author on the paper published in the journal, Applied Catalysis A. “If there are enough resources, I think it has a really good chance of making a big impact on the hydrogen economy in the near future.”

Using hydrogen as a fuel for cars is a promising but unrealized clean energy. Like an electric-powered car, a hydrogen fuel-cell powered car doesn’t emit any harmful carbon dioxide. Unlike an electric car, it can be filled up with hydrogen gas in minutes at hydrogen fueling stations.

Despite the promise of hydrogen technology, however, storing and transporting high-pressure hydrogen gas in fuel tanks creates significant economic and safety challenges. Because of the challenges, there is little hydrogen gas infrastructure in the U.S., and the technology’s market penetration is very low.

In their work, the WSU researchers created a conversion system with an anode and a cathode. When they put a small amount of electricity into the ethanol and water mixture with a catalyst, they were able to electrochemically produce pure compressed hydrogen. Carbon dioxide from the reaction is captured in a liquid form.

Instead of having to transport hazardous hydrogen gas, the conversion method would mean that the existing infrastructure for transporting ethanol could be used and that the compressed hydrogen gas could be easily and safely created on-demand at gas stations.

“We’re already using ethanol-containing gasoline at every gas station,” said Ha. “You can imagine that an ethanol water mixture can be easily delivered to a local gas station using our existing infrastructure, and then using our technology, you can produce hydrogen that is ready to pump into a hydrogen fuel cell car. We don’t need to worry about hydrogen storage or transportation at all.”

The electrochemical system the team developed uses less than half the electricity of pure water splitting, another method that researchers have studied for de-carbonized hydrogen production. Instead of working hard to compress the hydrogen gas later in the process, the researchers used less energy by instead compressing the liquid ethanol mixture, thereby directly producing an already compressed hydrogen gas.

“The presence of the ethanol in water changes the chemistry,” said graduate student Wei-Jyun Wang, a co-lead author on the paper. “We can actually do our reaction at a much lower electrical voltage than is typically needed for pure water electrolysis.”

Their system also doesn’t require an expensive membrane that other water splitting methods do. The resulting hydrogen from the electrochemical reaction is then ready for use.

“A process that offers a low-electrical energy cost alternative to water electrolysis and can effectively capture carbon dioxide while producing compressed hydrogen could have a significant impact on the hydrogen economy,” said Jamie Kee, a Voiland School postdoctoral researcher and one of lead authors on the paper. “It’s really exciting because there are a whole lot of aspects that play into improving the production methods of hydrogen.”

The researchers are working to scale up the technology and operate it in a continuous manner. They also are working to make use of the carbon dioxide captured in the liquid.

The work was funded by the Gas Technology Institute and the US Department of Energy’s RAPID Manufacturing Institute.

JOURNAL

Applied Catalysis

DOI

10.1016/j.apcata.2022.118647

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Caustic Aqueous Phase Electrochemical Reforming (CAPER) of Ethanol for Process Intensified Compressed Hydrogen Production

ARTICLE PUBLICATION DATE

10-May-2022

New life cycle assessment study shows useful life of tech-critical metals to be short

by University of Bayreuth

Worldwide, almost all technology-intensive industries depend on readily available metallic raw materials. Consequently, precise and reliable information is needed on how long these raw materials remain in the economic cycle. To obtain the necessary data, a research team from the universities of Bayreuth, Augsburg and Bordeaux has now developed a new modeling method and applied it to 61 metals. The study, published in Nature Sustainability, shows that the metals needed for specific high-tech applications, which in many cases are scarce around the world, are in use for only a decade on average.

The useful life of a metal comprises the entire period that begins with mining and ends when it dissipates—i.e., is finely dispersed—in the environment, and is no longer available for economic use. Iron and steel alloy metals have the longest useful life, averaging 150 years. The researchers see the reason for this primarily in the high efficiency of the industrial processes in which these metals are processed, as well as in high recycling rates. The lifespan of non-ferrous metals such as aluminum and copper and precious metals such as gold and silver is significantly shorter, but it is still over 50 years. By contrast, the technology-specific and in some cases critical—i.e. hardly available—metals only remain in the economic cycle for about twelve years. Cobalt and indium are examples of this large group of raw materials. For all these calculations, data from the Bureau de Recherches Géologiques et Minières (BRGM), a geoscientific institute based in Paris and Orléans, was used.

One thing all of the 61 metals studied have in common is that the quantities lost to the economic cycle over time must be constantly compensated for by new mining. The greater the losses, the more resources are irretrievably lost, and the more damaging the consequences are for the climate and the environment.

"It is in the urgent interest of the world's population to extend the useful life of metals and to strive for economic cycles that are as closed as possible to prevent these huge losses. However, these goals can only be achieved if the useful life of every raw material relevant to our technology can be extended and calculated with greater statistical accuracy," says Prof. Dr. Christoph Helbig, Chair of the newly established Ecological Resource Technology research group at the University of Bayreuth. The aim of his research is to increase the useful life of metallic resources, and in this way contribute to environmentally and climate-friendly industries.

The calculations now published in Nature Sustainability are based on a new modeling method developed by the authors, with which the useful life of metals can be calculated far more reliably than with the usual measurements based on recycling rates. The special feature of this statistical method is that it can be applied equally to almost all metals of the periodic table. This is a decisive prerequisite for the data obtained to be comparable. Only in this way can they form a reliable basis for life cycle assessments that provide information on the extent to which valuable raw materials are being used efficiently or wasted. Life cycle assessments in the area of abiotic raw materials look set to be considerably more meaningful thanks to the research results achieved by the study.

Prof. Dr. Christoph Helbig started work on the new study while still at the University of Augsburg and brought the topic to Bayreuth: "I am very much looking forward to continuing and developing the existing cooperation with working groups in Bordeaux and Augsburg at the University of Bayreuth," says Helbig. The University of Bordeaux is one of the partner institutions of the Gateway Office which the University of Bayreuth set up two years ago to further expand its international networking in research and teaching.New technology dramatically increases the recovery rate of precious metals

information: Alexandre Charpentier Poncelet et al, Losses and lifetimes of metals in the economy, Nature Sustainability (2022). DOI: 10.1038/s41893-022-00895-

Journal information: Nature Sustainability

Provided by University of Bayreuth

Ancient crocodile found in Peru sheds new light on their origin

A team of researchers at Universidad Peruana Cayetano Heredia, working with colleagues from the U.S. and France, has uncovered a prehistoric crocodile fossil in Peru. In their paper published in Proceedings of the Royal Society B, the group describes their find, what they have learned about it and what it shows about the evolution of marine crocodiles.

Though there are two species of modern crocodiles that live in the ocean, they are predominantly freshwater dwelling creatures. This feature, the researchers with this new effort note, makes it difficult to understand the evolution of the creatures from crocs that predominantly lived in the sea in the past. Also, prior research has suggested that crocodiles have been living in southeastern parts of the Pacific Ocean for approximately 14 million years. In this new effort, the researchers have been looking for evidence of early crocodiles in western parts of South America, most specifically, Peru. And as part of that effort, they have uncovered the partial remains of an ancient crocodile.

The crocodile fossil (a skull and jaw) was uncovered in East Pisco Basin, (in the Sacaco desert) in Peru in 2020. Since that time, the researchers have been studying its attributes and characteristics and have been seeking to find its place in the evolutionary history of crocodiles. Their testing has shown that the fossil is from approximately 7 million years ago. They have named it Sacacosuchus cordovai and have concluded that when alive, it would have been approximately four meters long.

The Sacaco site has been under study for a number of years: Prior fossil discoveries have shown that millions of years ago, the entire area was under the sea. Finding the crocodile fossil in the area suggests it was a saltwater creature, a finding that helps trace the evolution of crocodiles in South America.

The researchers suggest crocodiles made their way to South America by crossing the Atlantic Ocean. From there, some may have followed the coastline to arrive at what is now Peru. They further suggest that such marine crocodiles would have all had long thin faces and that there were two main types: one that lived almost exclusively on fish, and another that had a more varied diet.Four endangered American crocodiles are born in Peru

More information: Rodolfo Salas-Gismondi et al, Miocene fossils from the southeastern Pacific shed light on the last radiation of marine crocodylians, Proceedings of the Royal Society B: Biological Sciences (2022). DOI: 10.1098/rspb.2022.0380

Journal information: Proceedings of the Royal Society B

New study explains how to broaden strategy to avert catastrophic climate change

by University of California - San Diego

Slashing emissions of carbon dioxide, by itself, cannot prevent catastrophic global warming. But a new study concludes that a strategy that simultaneously reduces emissions of other largely neglected climate pollutants would cut the rate of global warming in half and give the world a fighting chance to keep the climate safe for humanity.

Published this week by the Proceedings of the National Academy of Sciences, the study is the first to analyze the importance of cutting non-carbon dioxide climate pollutants vis-à-vis merely reducing fossil fuel emissions, in both the near-term and mid-term to 2050. It confirms increasing fears that the present almost exclusive focus on carbon dioxide cannot by itself prevent global temperatures from exceeding 1.5 degrees Celsius above pre-industrial levels, the internationally accepted guardrail beyond which the world's climate is expected to pass irreversible tipping points.

Indeed, such decarbonization alone would be unlikely to stop temperatures from exceeding even the much more hazardous 2 degrees Celsius limit.

The study—by scientists at Georgetown University, Texas A&M University, Scripps Institution of Oceanography at UC San Diego, and others—concludes that adopting a dual strategy that simultaneously reduces emissions of both carbon dioxide and the other climate pollutants would cut the rate of warming in half by 2050, making it much more likely to stay within these limits.

The non-carbon dioxide pollutants include methane, hydrofluorocarbon refrigerants, black carbon soot, ground-level ozone smog, as well as nitrous oxide. The study calculates that together these pollutants currently contribute almost as much to global warming as carbon dioxide. Since most of them last only a short time in the atmosphere, cutting them slows warming faster than any other mitigation strategy.

Until now, however, the importance of these non-carbon dioxide pollutants has been underappreciated by scientists and policymakers alike, and largely neglected in efforts to combat climate change.

Recent reports by the Intergovernmental Panel on Climate Change conclude that cutting fossil fuel emissions—the main source of carbon dioxide—by decarbonizing the energy system and shifting to clean energy, in isolation, actually makes global warming worse in the short term. This is because burning fossil fuels also emits sulfate aerosols, which act to cool the climate, and these are reduced along with the carbon dioxide when switching to clean energy. These cooling sulfates fall out of the atmosphere fast, within days to weeks, while much of carbon dioxide lasts hundreds of years, thus leading to overall warming for the first decade or two.

The new study accounts for this effect and concludes that focusing exclusively on reducing fossil fuel emissions could result in "weak, near-term warming" which could potentially cause temperatures to exceed the 1.5 degrees Celsius level by 2035 and the 2 degrees Celsius level by 2050.

In contrast, the dual strategy that simultaneously reduces the non-carbon dioxide pollutants, especially the short-lived pollutants, would enable the world to stay well below the 2 degrees Celsius limit, and significantly improve the chance of remaining below the 1.5 degrees Celsius guardrail.

Indeed, a key insight from the study is the need for climate policies to address all of the pollutants that are emitted from fossil fuel sources such as coal power plants and diesel engines rather than considering just carbon dioxide or methane individually, as is common.

Continuing to slash fossil fuel carbon dioxide emissions remains vital, the study emphasizes, since that will determine the fate of the climate in the longer term beyond 2050. Phasing out fossil fuels also is essential because they produce air pollution that kills over eight million people every year and causes billions of dollars of damage to crops.

Tackling both carbon dioxide and the short-lived pollutants at the same time offers the best and the only hope of humanity making it to 2050 without triggering irreversible and potentially catastrophic climate change.Increase in atmospheric methane set new record in 2021: NOAA

More information: Gabrielle B. Dreyfus et al, Mitigating Climate Disruption in Time: A self-consistent approach for avoiding both near-term and long-term global warming, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2123536119

Journal information: Proceedings of the National Academy of Sciences

Provided by University of California - San Diego

Interprofessional collaboration leads to significant and sustained reduction in hospital-onset c. difficile infections

Community hospital reduced infections by 63% after one year and 77% after three years

Peer-Reviewed Publication

ASSOCIATION FOR PROFESSIONALS IN INFECTION CONTROL

Arlington, Va., May 12, 2022 – A new study published today in the American Journal of Infection Control (AJIC), suggests that health care facilities can significantly reduce the incidence of hospital-onset Clostridioides difficile infection (HO-CDI) by establishing interprofessional teams to implement selected, evidence-based infection-prevention interventions.

“Our project showed that interprofessional collaboration and continuous improvement can profoundly impact HO-CDI incidence, and sustain reductions over years,” said Cherith Walter, MSN, RN, Emory St. Joseph’s Hospital, and first author on the published study. “We hope our findings will help other healthcare teams struggling with this incredibly challenging healthcare-associated infection to improve patient safety and reduce associated costs.”

According to the Centers for Disease Control and Prevention, an estimated 500,000 cases of CDI occur in the United States annually[1], making it one of the most prevalent healthcare-associated infections (HAI) in the country. Due to the cost of caring for patients with HO-CDI, as well as financial penalties levied under the Centers for Medicare and Medical Services’ (CMS) hospital-acquired condition reduction program, these infections have increased the financial burden on the healthcare system.

To address the HO-CDI incidence at their 410-bed community hospital, which was consistently above the national CMS benchmark, Walter and colleagues created an interprofessional team comprising a clinical nurse specialist, a physician champion, a hospital epidemiologist, an infection preventionist, a clinical microbiologist, unit nurse champions, an antimicrobial stewardship pharmacist, and an environmental services representative. The team reviewed HO-CDI events at their facility between 2014 and 2016 to determine causative factors, and then identified appropriate, evidence-based infection prevention interventions. The selected interventions comprised diagnostic stewardship, including the development of a Diarrhea Decision Tree (DDT) testing algorithm with a nurse-driven ordering protocol; enhanced environmental cleaning; antimicrobial stewardship, including a system-wide Electronic Medical Record intervention to reduce fluoroquinolone use; and education and accountability, the latter of which focused on encouraging compliance with the DDT algorithm.

After the first year, the project leads recorded a 63% decrease in HO-CDIs as compared to the two years prior (4.72 per 10,000 patient days vs. 12 per 10,000 patient days). This number improved further to 2.8 per 10,000 days three years after implementation of the selected interventions (a 77% decrease from baseline). The team also saw a decrease in their facility’s standardized HO-CDI infection ratio (the total number of infections divided by the National Health Safety Network’s risk-adjusted predicted number of infections), from 1.11 in 2015 to 0.43 in 2020 – significantly lower than the national benchmark.

Interventions also improved CDI testing practices, increasing testing for appropriate patients within the first three days of hospital admission from 54% in 2014 to 81.1% in late 2019, to support prompt treatment of infected patients. This practice also helped identify and differentiate cases of community-acquired CDI (CA-CDI) from HO-CDI, reducing the financial impact of HO-CDIs on the facility after 2016. Finally, by empowering nurses to hold providers accountable for judicious test ordering and creating a system of ‘accountability notices’ alerting nurses and providers to DDT algorithm deviations, the team successfully increased compliance with the algorithm, from 50% in mid-2018 to 80% in mid-2020.

“These study findings are exciting, because they suggest that professional collaboration to consistently apply known, evidence-based practices can significantly reduce the incidence of HO-CDI, an intractable and costly HAI,” said Linda Dickey, RN, MPH, CIC, FAPIC, and 2022 APIC president. “They are also the first findings demonstrating the impact of education and accountability interventions in reducing HO-CDI incidence and improving compliance with standards of practice.”

About APIC

Founded in 1972, the Association for Professionals in Infection Control and Epidemiology (APIC) is the leading association for infection preventionists and epidemiologists. With more than 15,000 members, APIC advances the science and practice of infection prevention and control. APIC carries out its mission through research, advocacy, and patient safety; education, credentialing, and certification; and fostering development of the infection prevention and control workforce of the future. Together with our members and partners, we are working toward a safer world through the prevention of infection. Join us and learn more at apic.org.

About AJIC

As the official peer-reviewed journal of APIC, The American Journal of Infection Control (AJIC) is the foremost resource on infection control, epidemiology, infectious diseases, quality management, occupational health, and disease prevention. Published by Elsevier, AJIC also publishes infection control guidelines from APIC and the CDC. AJIC is included in Index Medicus and CINAHL. Visit AJIC at ajicjournal.org.

NOTES FOR EDITORS

“An Interprofessional Approach to Reducing Hospital-Onset Clostridioides difficile Infections,” by Cherith Walter, MSN, RN; Tanushree Soni, PhD, MPH; Melanie Alice Gavin, MPH; Julianne Kubes, MPH; and Kristen Paciullo, PharmD, was published online in AJIC on May 12, 2022. The article may be found online at: https://doi.org/10.1016/j.ajic.2022.02.017

AUTHORS

Cherith Walter, MSN, RN, APRN, AGPCNP-BC, AGCNS-BC (corresponding author: cherith.walter@emoryhealthcare.org)

Emory Saint Joseph’s Hospital, Atlanta, GA, USA

Tanushree Soni, PhD, MPH, CIC

Emory Saint Joseph’s Hospital, Atlanta, GA, USA

Melanie Alice Gavin, MPH, CIC, M (ASCP)

Emory Saint Joseph’s Hospital, Atlanta, GA, USA

Julianne Kubes, MPH

Emory Healthcare, Atlanta, GA, USA

Kristen Paciullo, PharmD, BCIDP

Emory Saint Joseph’s Hospital, Atlanta, GA, USA

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[1] Guery B, Galperine T, Barbut F. Clostridioides difficile: diagnosis and treatments. BMJ. 2019 Aug 20;366:l4609.