Tag: Carbon Emissions

Best case scenario for climate change is now 1.6°C of warming

[ad_1]

The sun is setting on 1.5°C

Taro Hama @ e-kamakura/Getty Images

Humanity’s goal of limiting global warming to 1.5°C above pre-industrial levels, which has been totemic in climate policy for the past decade, is now almost certainly now out of reach. Limiting warming to 1.6°C has become the best-case scenario for climate action, with the hope of bringing temperatures back to 1.5°C later in the century using technology to remove carbon dioxide from the atmosphere.

“1.5°C without overshoot is not attainable,” says Christoph Bertram at the Potsdam Institute for Climate Research in Germany. “You definitely…

[ad_2]

Source link

August 19, 2024
New Way To Recycle Steel Developed

[ad_1]

New steel recycling technology from the University of Toronto could revolutionize the industry by removing impurities electrochemically, fostering higher-grade production and aiding in global sustainability efforts.

Engineering professor Gisele Azimi and her research team at the University of Toronto have developed a novel electrochemical method to extract contaminants like copper from steel scrap.

Researchers at the University of Toronto’s engineering department have developed a novel steel recycling technique that could help decarbonize various manufacturing sectors and promote a circular steel economy. The approach is detailed in a recent study published in Resources, Conservation & Recycling, and was co-authored by Jaesuk (Jay) Paeng, William Judge, and Professor Gisele Azimi.

It introduces an innovative oxysulfide electrolyte for electrorefining, an alternative way of removing copper and carbon impurities from molten steel. The process also generates liquid iron and sulfur as by-products.

“Our study is the first reported instance of electrochemically removing copper from steel and reducing impurities to below alloy level,” says Azimi, who holds the Canada Research Chair in Urban Mining Innovations.

Challenges in Current Steel Production

Currently, only 25% of steel produced comes from recycled material. But the global demand for a greener steel is projected to grow over the next two decades as governments around the world endeavor to achieve net-zero emission goals.

Steel is created by reacting iron ore with coke — a prepared form of coal — as the source of carbon and blowing oxygen through the metal produced. Current standard processes generate nearly two tonnes of carbon dioxide per tonne of steel produced, making steel production one of the highest contributors to carbon emissions in the manufacturing sector.

From left to right: University of Toronto PhD candidate Jaesuk (Jay) Paeng stands next to Professor Gisele Azimi and holds the team’s newly designed electrochemical cell that can withstand temperatures up to 1600 degrees Celsius while electrochemically removing contaminants from steel using slag-based electrolyte. Credit: Safa Jinje / University of Toronto Engineering

Traditional steel recycling methods use an electric arc furnace to melt down scrap metal. Since it is difficult to physically separate copper material from scrap before melting, the element is also present in the recycled steel products.

“The main problem with secondary steel production is that the scrap being recycled may be contaminated with other elements, including copper,” says Azimi. “The concentration of copper adds up as you add more scrap metals to be recycled, and when it goes above 0.1 weight percentage (wt%) in the final steel product, it will be detrimental to the properties of steel.”

Advantages of the New Method

Copper cannot be removed from molten steel scrap using the traditional electric arc furnace steelmaking practice, so this limits the secondary steel market to producing lower-quality steel product, such as reinforcing bars used in the construction industry.

“Our method can expand the secondary steel market into different industries,” says Paeng. “It has the potential to be used to create higher-grade products such as galvanized cold rolled coil used in the automotive sector, or steel sheets for deep drawing, used in the transport sector.”

To remove copper from iron to below 0.1 wt%, the team had to first design an electrochemical cell that could withstand temperatures up to 1600 degrees Celsius.

Inside the cell, electricity flows between the negative electrode (cathode) and the positive electrode (anode) through a novel oxysulfide electrolyte designed from slag — a waste derived from steelmaking that often ends up in cement or landfills.

“We put our contaminated iron that has the copper impurity as the anode of the electrochemical cell,” says Azimi. “We then apply an electromotive force, which is the voltage, with a power supply and we force the copper to react with the electrolyte.”

“The electrolyte targets the removal of copper from the iron when we apply electricity to the cell,” adds Paeng.

“When we apply electricity on the one side of the cell, we force the copper to react with the electrolyte and come out from iron. At the other end of the cell, we simultaneously produce new iron.”

Azimi’s lab collaborated with Tenova Goodfellow Inc., a global supplier of advanced technologies, products, and services for metal and mining industries. Looking forward, the team wants to enable the electro-refining process to remove other contaminants from steel, including tin.

“Iron and steel are the most widely used metals in the industry, and I think the production rate is as high as 1.9 billion tonnes per year,” says Azimi. “Our method has great potential to offer the steelmaking industry a practical and easily implementable way to recycle steel to produce more of the demand for high-grade steel globally.”

Reference: “Electrorefining for copper tramp element removal from molten iron for green steelmaking” by Jaesuk Paeng, William D. Judge and Gisele Azimi, 22 April 2024, Resources, Conservation and Recycling.
DOI: 10.1016/j.resconrec.2024.107654

[ad_2]

Source link

June 22, 2024
A Sustainable Solution to Fighting Global Warming – New Catalyst Efficiently Converts CO2 to Natural Gas

[ad_1]

Researchers have developed a high-efficiency photocatalyst converting CO2 into methane using cadmium selenide and amorphous titanium dioxide, achieving 99.3% methane conversion with improved regeneration. Future work will focus on enhancing its energy efficiency and stability for commercial use.

A research team at DGIST has developed an advanced photocatalyst that efficiently converts CO2 into methane, potentially offering a sustainable solution to combat global warming.

Professor In Soo-il and his team from the Department of Energy Science & Engineering at DGIST have successfully developed a highly efficient photocatalyst. This innovation is capable of converting carbon dioxide (CO2), a significant factor in climate change, into methane (CH4), commonly known as natural gas.

Global warming causes abnormal climates around the world, threatening the survival of the human race. Reducing greenhouse gases is crucial to solving the increasingly concerning problem of global warming, which requires converting atmospheric carbon dioxide into other substances. Photocatalytic technology is an environmentally friendly solution that converts carbon dioxide into useful substances such as natural gas using only solar energy and water. The natural gas produced can be used in our daily lives as a fuel for heating and cooling systems and vehicles.

Enhancements in Photocatalytic Materials

The research team combined cadmium selenide, which absorbs visible and infrared light, with titanium dioxide—a metal oxide and well-known photocatalytic material—to convert carbon dioxide into natural gas with high efficiency.

Previously, crystalline titanium dioxide, which has a periodic lattice structure, was analyzed as a photocatalytic material. However, the formation of active sites for the trivalent cations of titanium (Ti³⁺) was limited owing to the regular arrangement of the particles. To overcome this problem, Professor In’s team improved the catalytic reaction using amorphous titanium dioxide, which can form more active sites for Ti³⁺ through irregular particle arrangements that lack the periodicity of the lattice structure.

In addition to improved catalysis, the charge-transfer process is stable, ensuring a sufficient supply of electrons to participate in the reaction. This facilitates the conversion of carbon dioxide into carbon compounds, particularly methane fuel. Furthermore, unlike conventional photocatalysts that require high temperatures for regeneration, amorphous catalysts can be regenerated within one minute when oxygen is supplied to the reactor without heating.

High Efficiency and Future Research Directions

The research team’s newly developed amorphous titanium dioxide–cadmium selenide photocatalyst (TiO₂-CdSe) maintained a methane-conversion performance of 99.3% for the first 6 hours after 18 hours of photoreaction, making it 4.22 times more regenerative than the crystalline photocatalyst (C-TiO₂-CdSe) having the same composition.

“This study is significant in that we have developed a catalyst with regenerative active sites and identified the mechanism by which carbon dioxide is converted into methane using an amorphous catalyst through computational chemistry research,” said DGIST Professor In. “We will conduct follow-up research to improve the energy loss of the amorphous photocatalyst and enhance its long-term stability for future commercialization of the technology,” he added.

Reference: “Unravelling the effect of Ti3+/Ti4+ active sites dynamic on reaction pathways in direct gas-solid-phase CO2 photoreduction” by Niket S. Powar, Sanghoon Kim, Junho Lee, Eunhee Gong, Chaitanya B. Hiragond, Dongyun Kim, Tierui Zhang, Minho Kim and Su-Il In, 26 March 2024, Applied Catalysis B: Environment and Energy.
DOI: 10.1016/j.apcatb.2024.124006

This study was supported by the Medium-sized Research Program and the South Korea-China Cooperation Program of the Ministry of Science and ICT.

[ad_2]

Source link

June 10, 2024
Breakthrough in CO2 Conversion: Cost-Effective Methods Discovered

[ad_1]

Doshisha University researchers developed a cost-effective electrochemical method to convert CO2 into hydrocarbons, achieving unprecedented efficiency by optimizing the electrolyte composition and revealing crucial molecular interaction mechanisms.

Researchers found that using ionic liquids as electrolytes with metal hydroxides enhances the electrochemical transformation of CO2 into hydrocarbons.

Electrochemical conversion of CO₂ into fuel and chemicals, powered by electricity, offers a viable method for reducing emissions. This technique enables the transformation of carbon captured from industrial outputs and the atmosphere into valuable resources traditionally derived from fossil fuels.

To advance ongoing research on efficient electrochemical conversion, scientists from Doshisha University have introduced a cost-effective method to produce valuable hydrocarbons from CO₂. The study was made available online on 17 May 2024 and will be formally published in the journal Electrochimica Acta on 20 July 2024. The research team, led by Professor Takuya Goto and including Ms. Saya Nozaki from the Graduate School of Science and Engineering and Dr. Yuta Suzuki from the Harris Science Research Institute, produced ethylene and propane on a basic silver (Ag) electrode by utilizing an ionic liquid containing metal hydroxides as the electrolyte.

“Most studies on CO₂electrolysis with room-temperature liquid electrolyte have focused on the electrode’s catalytic properties. In this groundbreaking study, we focused on the electrolyte and succeeded in producing valuable hydrocarbon gas even on a simple metal electrode,” says Prof. Goto.

Ionic liquids offer unique advantages for the electrochemical reduction of CO₂. They operate over a wide range of voltages without decomposing, are non-flammable, and have high boiling points. This stability enables the electrolyte to withstand the high temperatures generated during exothermic CO₂ reduction.

Advantages of DEME-BF4 Electrolyte

In their study, researchers investigated the electrochemical conversion of CO₂ and water with N, N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium tetrafluoroborate (DEME-BF₄) as the electrolyte. The DEME-BF₄ electrolyte provides optimal conditions for maximizing CO₂reduction. DEME⁺ ions enhance the solubility of CO₂, allowing a greater number of CO₂molecules to participate in the reaction. Moreover, due to its hydrophilic nature, the hydrogen ions required for reducing CO₂ to hydrocarbons can be easily supplied by mixing the electrolyte with water.

The production of hydrocarbons occurs through two intermediates formed on the surface of the silver electrode to produce useful hydrocarbons like ethylene, ethane, propylene, and propane. Credit: Takuya Goto from Doshisha University

The researchers determined that the electrochemical conversion of CO₂ to hydrocarbons could be increased with the addition of aqueous solutions containing metal hydroxides like calcium hydroxide (Ca(OH)₂), sodium hydroxide (NaOH), and cesium hydroxide (CsOH) to the electrolyte. The hydroxides in the ionic liquid can react with CO₂ to form bicarbonates (HCO₃⁻) and carbonates (CO₃²⁻), further enhancing the availability of CO₂ to participate in electrochemical reactions.

Achieving High Conversion Efficiencies

Under room temperature electrolysis (298 K or 25°C) in a CO₂ atmosphere, the researchers successfully reduced CO₂ to ethylene (C₂H₄), ethane (C₂H₆), propylene (C₃H₆), and propane (C₃H₈). They achieved the highest current efficiencies for each product using DEME-BF₄ electrolyte mixed with water and containing Ca(OH)₂, with efficiencies reaching up to 11.3% for propane and 6.49% for ethylene. This efficiency surpassed those obtained with other metal hydroxides by over 1000 times.

The reason for this high efficiency was explained using Raman spectroscopy and density functional theory (DFT) calculations. These analyses revealed that bicarbonate ions, formed when CO₂ interacts with OH^–ions in the electrolyte, interact with DEME⁺ and BF₄^– ions of the electrolyte to form a stable structure [DEME⁺-BF₄⁻-HCO₃⁻-Ca²⁺].

CO₂ and HCO₃^– species then adsorb onto the electrode surface forming adsorbed species CO⁻ _ads. The adsorbed CO^– ions then strongly interact with Ca²⁺ ions present in the electrolyte, forming two distinct intermediate structures: One structure A, consisting of a Ca²⁺ ion coordinated with two CO⁻ ions adsorbed on three Ag atoms, and the other Structure B, where the Ca²⁺ ion is coordinated with two CO⁻ ions adsorbed on two Ag atoms. This interaction with Ca²⁺ ions is crucial as it increases the stability of the adsorbed species, making the subsequent electrochemical reactions possible.

Among these structures, researchers suggest that structure B is more stable and is the preferred pathway for ethylene, while structure A leads to the production of propane. “We showed that tailoring the electrolyte can lead to molecular-level changes in the phase transformation of CO₂ in bulk solution and at the electrode/ionic liquid electrolyte interface and proposed a process that enables the synthesis of unique hydrocarbons such as C₃,” says Prof. Goto.

These findings shed light on the processes involved in the conversion of CO₂ at the interface between ionic liquid-based electrolytes and metal electrodes, such as the role of calcium ions. Such insights can help in the development of electrolytes for the efficient production of useful hydrocarbons from CO₂. “The physicochemical knowledge of this new route from CO₂ decomposition to synthesizing useful hydrocarbons, as revealed in this study, will be instrumental in advancing CO₂ utilization technology and contributing to academic progress in materials science.” concludes Prof. Goto.

Reference: “Electrochemical synthesis of C2 and C3 hydrocarbons from CO2 on an Ag electrode in DEME-BF4 containing H2O and metal hydroxides” by Saya Nozaki, Yuta Suzuki and Takuya Goto, 17 May 2024, Electrochimica Acta.
DOI: 10.1016/j.electacta.2024.144431

The study was funded by the Japan Society for the Promotion of Science and the Iron and Steel Institute of Japan.

[ad_2]

Source link

June 9, 2024
The World’s Largest Fungus Collection May Unlock the Mysteries of Carbon Capture

[ad_1]

Martinez-Suz’s research focuses on mycorrhizal fungi—a large group of fungi that coexist with plant root systems. The mycorrhizal fungi form networks that can go around and sometimes inside plant roots, transferring nutrients and water to the plants in exchange for carbon. Around 90 percent of plant species are known to make these symbiotic trade networks with different species of fungi. “These plants are covered by these fungi. It’s incredible. They are small but they are everywhere,” says Martinez-Suz.

This has serious implications for tree-planting schemes. Planting new forests is a major hope for carbon sequestration, but there is increasing evidence that the mycorrhizal networks might be crucial to the success of these attempts. One replanting study found that a forest of birch and pine trees planted onto heath moorland in northern Scotland did not increase soil carbon stocks even after nearly 40 years in the ground. The researchers who carried out the study think that it might be because the influx of new trees upset the delicate moorland mycorrhizal networks already present.

“Replacing the complete set of fungi with other fungi has implications for long-term carbon sequestration in soil and biodiversity,” says Martinez-Suz. Her current project involves comparing samples from forests in low-pollution sites like northern Finland with those in heavily polluted regions like Belgium and the Netherlands. The fungi in polluted regions are less diverse, she says, and this might have a knock-on effect on how well those forests store carbon.

The major culprit here is nitrogen pollution, which enters soils through burning fossil fuels for electricity and transport, and through agriculture. An excess of nitrogen changes the composition of soil fungi, so that the fungi that are the best at retaining nutrients and pumping carbon into the soil decrease.

But there is some hope that forests can turn things around. One study in the Netherlands found that when nitrogen pollution reduced, beneficial fungi species started to return to the forests. The danger, Martinez-Suz says, is that if ecosystems are pushed too far then there might not be any fungal spores remaining to boost populations.

If we’re to better understand how these fungi influence critical ecosystems, then we need to get to grips with all of these species. Mycologists think that nearly 90 percent of the world’s fungi species are still to be discovered, and the archivists at Kew are only halfway through the long process of digitizing their collection so that researchers can easily know where and when a species was found.

Around 5,000 extra specimens enter the fungarium each year, and the shelves are crammed with samples waiting to be dehydrated and stored. Many of them, Davies says, are sent by amateur mycologists who are fascinated by the world of fungi. “People in academic institutions like this will send them stuff to work on and do identifications, because they are world experts even though they have no formal training. They’re just really obsessive. It’s so cool.”

This article appears in the July/August 2024 issue of WIRED UK magazine.

[ad_2]

Source link

June 7, 2024
Zero-carbon cement process could slash emissions from construction
[ad_1]
Cement being produced in an electric arc furnace at the Materials Processing Institute, UK, for the first time

Materials Processing Institute

A new technique can produce cement using waste from demolished buildings, which researchers say could save billions of tonnes of carbon by 2050.

“We have definitely proved that cement can be recycled into cement,” says Julian Allwood at the University of Cambridge. “We are on course for making cement with zero emissions, which is amazing.”

Producing cement is highly polluting – responsible for 7.5 per cent of total greenhouse gas emissions – but until now there was no known way to produce it at scale without impacts on the climate.

Making cement requires “clinker”, which is made by heating a mix of raw materials, including limestone and clay, to 1450°C (2650°F). Both the heat requirements and the chemical reactions involved in making clinker result in carbon emissions, and clinker production accounts for 90 per cent of cement’s total carbon footprint.

Allwood and his colleagues have developed an alternative process to make clinker, which involves reusing cement paste from demolished buildings. This paste has an identical chemical composition to lime flux, a substance used to remove impurities from recycled steel.

As the steel melts, the flux made from old cement forms a slag that floats on the top of the recycled steel. Once ground into a powder, the slag is identical to clinker. It can then be used to make Portland cement, the most common form of cement.

If the recycled steel and cement are produced using an electric furnace, powered by renewable or nuclear energy, the process is almost entirely free of emissions. “The idea is really simple,” says Allwood.

Laboratory trials have proved the process works. It offers a “drop in” solution that could be used with conventional equipment, and a global switch to this process could save up to 3 gigatonnes of carbon dioxide a year, the team calculates.

The research team is now working on industrial trials via a spin-out company, Cambridge Electric Cement, with partners such as construction firms Balfour Beatty and Tarmac. “Within the next few weeks, we are starting a set of trials which will be producing batches of 30 tonnes per hour,” says Allwood.

Scaling up the new cement-making process depends in part on the growth of recycled steel-making, which currently accounts for about 40 per cent of global steel production. Allwood says production rates will at least double over the next 30 years, and most likely treble, as the industry decarbonises.

Yet some challenges lie ahead. The recycled cement process requires furnace temperatures of 1600 to 1750°C (2900 to 3200°F), slightly hotter than traditional cement production. This will increase power costs, says Leon Black at the University of Leeds, UK.

Other hurdles include establishing supply chains for waste cement, attracting the necessary capital investment and convincing a notoriously cautious industry to adopt a new process on a large scale.

“They have overcome one barrier in as much as they have made a material that has the same composition as Portland cement,” says Black. “The devil is in the details: the energy requirements, the logistics, the scaling up.”
Topics:

carbon emissions/

recycling
[ad_2]

Source link
May 22, 2024
Will we get to net zero fast enough, and how will the climate respond?

[ad_1]

A decade ago, the term “net zero” was arcane jargon. Today, it is the key goal of the fight against climate change and a familiar talking point across the world.

The concept is straightforward. In the words of the Intergovernmental Panel on Climate Change (IPCC): “Net zero carbon dioxide (CO₂) emissions are achieved when anthropogenic CO2 emissions are balanced globally by anthropogenic CO₂ removals over a specified period.”

It is also easy to trace the concept’s rise to prominence. Once the need for net-zero emissions to halt rising temperatures was established, it made its policy debut in the 2015 Paris Agreement. It then exploded into public consciousness following a 2018 IPCC report explicitly stating that the world must reach net zero by 2050 to avoid the worst effects of global warming.

The UK soon became the first major economy to come up with a net-zero emissions pledge. Now, most countries, including China, the US and India – the three largest emitters – have made such pledges of some sort.

What is less clear, however, is whether all these targets are strong enough to get us to net zero fast enough – and what happens to the climate once we do reach our goal.

Many net-zero pledges are “poor”, according to the Climate Action Tracker project. Often countries’ plans lack achievable interim steps or leave out important sectors of the economy. That suggests most deadlines will be missed. But reaching net zero 50 years from now, for instance, isn’t enough, says Amanda Levin at the Natural Resources…

[ad_2]

Source link

May 22, 2024
New Research Links Structure to Reaction Performance

[ad_1]

A team of researchers has developed a new research paradigm which simplifies the understanding of how catalyst structures affect their reactions. The study focused on the electrochemical CO2 reduction reaction using Tin-Oxide-based catalysts, revealing crucial insights into the active surface species and their performance. This breakthrough allows for the tailored design of efficient catalysts and paves the way for further exploration of electrocatalytic reactions, aiming to enhance the development of scalable and high-performance electrocatalysts.

In a significant advance in the fight against climate change and the shift towards sustainability, a team of researchers has introduced a new research framework that simplifies understanding how catalyst structures influence their reactions.

Details of the researchers’ breakthrough were published in the journal Angewandte Chemie.

Understanding how a catalyst’s surface affects its activity can aid the design of efficient catalyst structures for specific reactivity requirements. However, grasping the mechanisms behind this relationship is no straightforward task given the complicated interface microenvironment of electrocatalysts.

“To decipher this, we honed in on the electrochemical CO2 reduction reaction (CO2RR) in Tin-Oxide-based (Sn-O) catalysts,” points out Hao Li, associate professor at Tohoku University’s Advanced Institute for Materials Research (WPI-AIMR) and corresponding author of the paper. “In doing so, we not only uncovered the active surface species of SnO2-based catalysts during CO2RR but also established a clear correlation between surface speciation and CO2RR performance.”

The standard research paradigm uncovers the structure-property-activity relationships for the electrochemical CO2 reduction reaction (CO2RR) over SnO2. This picture illustrates the surface reconstruction induced by oxygen vacancies (1/1 ML coverage) and surface-active species (Sn layer) accountable for selective HCOOH production. Credit: Hao Li et al.

Promising Method for CO2 Reduction

CO2RR is recognized as a promising method for reducing CO2 emissions and producing high-value fuels, with formic acid (HCOOH) being a noteworthy product because of its various applications in industries such as pharmaceuticals, metallurgy, and environmental remediation.

The proposed method helped identify the genuine surface states of SnO2 responsible for its performance in CO2 reduction reactions under specific electrocatalytic conditions. Moreover, the team corroborated their findings through experiments using various SnO2 shapes and advanced characterization techniques.

Li and his colleagues developed their methodology by combining theoretical studies with experimental electrochemical techniques.

“We bridged the gap between the theoretical and experimental, offering a comprehensive understanding of catalyst behavior under real-world conditions in the process,” adds Li.

The research team is now focused on applying this methodology to a variety of electrochemical reactions. In doing those, they hope to uncover more about unique structure-activity correlations, accelerating the design of high-performance and scalable electrocatalysts.

Reference: “Deciphering Structure-Activity Relationship Towards CO2 Electroreduction over SnO2 by A Standard Research Paradigm” by Zhongyuan Guo, Yihong Yu, Congcong Li, Egon Campos dos Santos, Tianyi Wang, Huihui Li, Jiang Xu, Chuangwei Liu and Hao Li, 29 January 2024, Angewandte Chemie International Edition.
DOI: 10.1002/anie.202319913

[ad_2]

Source link

May 7, 2024
Is climate change accelerating after a record year of heat?

[ad_1]

The record-breaking heat of 2023 has seen a rare disagreement break out between climate scientists, with some saying it shows Earth may have entered a new period of warming

[ad_2]

Source link

May 2, 2024
Our plans to tackle climate change with carbon storage don't add up

[ad_1]

Modelling that shows how the world can remain below 1.5°C of warming assumes we can store vast amounts of carbon dioxide underground, but a new analysis reveals that achieving this is extremely unlikely

[ad_2]

Source link

April 16, 2024