How to Convert Carbon Dioxide (CO2) into Fuels

If the CO2 content of the atmosphere is not to increase any further, carbon dioxide must be converted into something else. However, as CO2 is a very stable molecule, this can only be done with the help of special catalysts. The main problem with such catalysts has so far been their lack of stability: after a certain time, many materials lose their catalytic properties.

At TU Wien (Austria), research is being conducted on a special class of minerals – the perovskites, which have so far been used for solar cells, as anode materials or electronic components rather than for their catalytic properties. Now scientists at TU Wien have succeeded in producing a special perovskite that is excellently suited as a catalyst for converting CO2 into other useful substances, such as synthetic fuels. The new perovskite catalyst is very stable and also relatively cheap, so it would be suitable for industrial use.

We are interested in the so-called reverse water-gas shift reaction,” says Prof. Christoph Rameshan from the Institute of Materials Chemistry at TU Wien. “In this process, carbon dioxide and hydrogen are converted into water and carbon monoxide. You can then process the carbon monoxide further, for example into methanol, other chemical base materials or even into fuel.”

This reaction is not new, but it has not really been implemented on an industrial scale for CO2 utilisation. It takes place at high temperatures, which contributes to the fact that catalysts quickly break down. This is a particular problem when it comes to expensive materials, such as those containing rare metals.

Christoph Rameshan and his team investigated how to tailor a material from the class of perovskites specifically for this reaction, and he was successful: “We tried out a few things and finally came up with a perovskite made of cobalt, iron, calcium and neodymium that has excellent properties,” says Rameshan.

Because of its crystal structure, the perovskite allows certain atoms to migrate through it. For example, during catalysis, cobalt atoms from the inside of the material travel towards the surface and form tiny nanoparticles there, which are then particularly chemically active. At the same time, so-called oxygen vacancies form – positions in the crystal where an oxygen atom should actually sit. It is precisely at these vacant positions that CO2 molecules can dock particularly well, in order to then be dissociated into oxygen and carbon monoxide.

We were able to show that our perovskite is significantly more stable than other catalysts,” says Christoph Rameshan. “It also has the advantage that it can be regenerated: If its catalytic activity does wane after a certain time, you can simply restore it to its original state with the help of oxygen and continue to use it.

Initial assessments show that the catalyst is also economically promising. “It is more expensive than other catalysts, but only by about a factor of three, and it is much more durable,” says Rameshan. “We would now like to try to replace the neodymium with something else, which could reduce the cost even further.“Theoretically, you could use such technologies to get CO2 out of the atmosphere – but to do that you would first have to concentrate the carbon dioxide, and that requires a considerable amount of energy. It is therefore more efficient to first convert CO2 where it is produced in large quantities, such as in industrial plants. “You could simply add an additional reactor to existing plants that currently emit a lot of CO2, in which the CO2 is first converted into CO and then processed further,” says Christoph Rameshan. Instead of harming the climate, such an industrial plant would then generate additional benefits.

Source: https://www.tuwien.at/

Graphene Smart Textiles Lower Body Temperature During Heatwave

New research on the two-dimensional (2D) material graphene has allowed researchers to create smart adaptive clothing which can lower the body temperature of the wearer in hot climates.

A team of scientists from The University of Manchester’s National Graphene Institute have created a prototype garment to demonstrate dynamic thermal radiation control within a piece of clothing by utilising the remarkable thermal properties and flexibility of graphene. The development also opens the door to new applications such as, interactive infrared displays and covert infrared communication on textiles.

The human body radiates energy in the form of electromagnetic waves in the infrared spectrum (known as blackbody radiation). In a hot climate it is desirable to make use the full extent of the infrared radiation to lower the body temperature which can be achieved by using infrared-transparent textiles. As for the opposite case, infrared-blocking covers are ideal to minimise the energy loss from the body. Emergency blankets are a common example used to deal with treating extreme cases of body temperature fluctuation.

The collaborative team of scientists demonstrated the dynamic transition between two opposite states by electrically tuning the infrared emissivity (the ability to radiate energy) of graphene layers integrated onto textiles.

The new research published today in journal Nano Letters, demonstrates that the smart optical textile technology can change its thermal visibility.

Ability to control the thermal radiation is a key necessity for several critical applications such as temperature management of the body in excessive temperature climates. Thermal blankets are a common example used for this purpose. However, maintaining these functionalities as the surroundings heats up or cools down has been an outstanding challenge”, explained Professor Coskun Kocabas, who led the research.

The successful demonstration of the modulation of optical properties on different forms of textile can leverage the ubiquitous use of fibrous architectures and enable new technologies operating in the infrared and other regions of the electromagnetic spectrum for applications including textile displays, communication, adaptive space suits, and fashion“, he added.

Source: https://www.manchester.ac.uk/

One Trillion Trees

The World Economic Forum has launched a global initiative to grow, restore and conserve 1 trillion trees around the world – in a bid to restore biodiversity and help fight climate changeThe 1t.org project aims to unite governments, non-governmental organisations, businesses and individuals in a “mass-scale nature restoration“. The initiative received the support of US President Donald Trump. While a sceptic on climate change, Trump said he wanted to show “strong leadership in restoring, growing and better managing our trees and our forests“.

Klaus Schwab, Founder and Executive Chairman of the World Economic Forum, said: “The next decade must see unprecedented levels of collaboration if we are to meet global climate, biodiversity and Sustainable Development Goals. 1t.org presents an important example of how stakeholders from all walks of life and all ages can work together to achieve a single, globally significant goal.”

Around 0.9 billion hectares of land worldwide would be suitable for reforestation, which could ultimately capture two thirds of human-made carbon emissions. The Crowther Lab of ETH Zurich has published a study in the journal Science that shows this would be the most effective method to combat climate changeThe Crowther Lab at ETH Zurich investigates nature-based solutions to climate change. In their latest study the researchers showed for the first time where in the world new trees could grow and how much carbon they would store.

Reforestation would be the most effective method to combat climate change

One aspect was of particular importance to us as we did the calculations: we excluded cities or agricultural areas from the total restoration potential as these areas are needed for human life,” explains study lead author and postdoc at the Crowther Lab Jean-François Bastin.

The researchers calculated that under the current climate conditions, Earth’s land could support 4.4 billion hectares of continuous tree cover. That is 1.6 billion more than the currently existing 2.8 billion hectares. Of these 1.6 billion hectares, 0.9 billion hectares fulfill the criterion of not being used by humans. This means that there is currently an area of the size of the US available for tree restoration. Once mature, these new forests could store 205 billion tonnes of carbon: about two thirds of the 300 billion tonnes of carbon that has been released into the atmosphere as a result of human activity since the Industrial Revolution.

According to Prof. Thomas Crowther, co-author of the study and founder of the Crowther Lab at ETH Zurich: “We all knew that restoring forests could play a part in tackling climate change, but we didn’t really know how big the impact would be. Our study shows clearly that forest restoration is the best climate change solution available today. But we must act quickly, as new forests will take decades to mature and achieve their full potential as a source of natural carbon storage.”

The study also shows which parts of the world are most suited to forest restoration. The greatest potential can be found in just six countries: Russia (151 million hectares); the US (103 million hectares); Canada (78.4 million hectares); Australia (58 million hectares); Brazil (49.7 million hectares); and China (40.2 million hectares).

Many current climate models are wrong in expecting climate change to increase global tree cover, the study warns. It finds that there is likely to be an increase in the area of northern boreal forests in regions such as Siberia, but tree cover there averages only 30 to 40 percent. These gains would be outweighed by the losses suffered in dense tropical forests, which typically have 90 to 100 percent tree cover.

A tool on the Crowther Lab website< enables users to look at any point on the globe, and find out how many trees could grow there and how much carbon they would store. It also offers lists of forest restoration organisations. The Crowther Lab will also be present at this year’s Scientifica to show the new tool to visitors.

The Crowther Lab uses nature as a solution to:

1) better allocate resources – identifying those regions which, if restored appropriately, could have the biggest climate impact;

2) set realistic goals – with measurable targets to maximise the impact of restoration projects;

3) monitor progress – to evaluate whether targets are being achieved over time, and take corrective action if necessary.

Source: https://www.weforum.org/
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https://ethz.ch/

Cut emissions to avert catastrophic sea-level rise

Scientists behind a landmark study of the links between oceans, glaciers, ice caps and the climate delivered a stark warning to the world: slash emissions or watch cities vanish under rising seas, rivers run dry and marine life collapse. Days after millions of young people demanded an end to the fossil-fuel era in protests around the globe, a new report by a U.N.-backed panel of experts found that radical action may yet avert some of the worst possible outcomes of global warming. But the study was clear that allowing carbon emissions to continue rising would upset the balance of the geophysical systems governing oceans and the frozen regions of the Earth so profoundly that nobody would escape untouched.

We are in a race between two factors, one is the capacity of humans and ecosystems to adapt, the other is the speed of impact of climate change. This report…indicates we may be losing in this race. We need to take immediate and drastic action to cut emissions right now,” IPCC Chair Hoesung Lee said at the presentation of the report in Monaco.

Finalised in a marathon 27-hour session of talks in Monaco between authors and representatives of governments, the report was the culmination of two years’ efforts by the U.N.-backed Intergovernmental Panel on Climate Change (IPCC). Compiled by more than 100 authors who crunched 7,000 academic papers, the study documents the implications of warm, fast-melting ice sheets in Greenland and Antarctica and shrinking glaciers for more than 1.3 billion people living in low-lying or high-mountain regions.

The report projects that sea levels could rise by one meter (3.3 feet) by 2100 — ten times the rate in the 20th century — if emissions keep climbing. The rise could exceed five meters by 2300. In the Himalayas, glaciers feeding ten rivers, including the Ganges and Yangtze, could shrink dramatically if emissions do not fall, hitting water supplies across a swathe of Asia. Thawing permafrost in places like Alaska and Siberia could release vast quantities of greenhouse gases, potentially unleashing feedback loops driving faster warming.

Could Spruce Forests Offset Global Warming?

Researchers from the University of Lund in Sweden,  are measuring terpene particles emitted by spruce/fir forests, which are believed to have a cooling effect on the climate. They believe that planting more of this type of forest could help offset global warmingPlanting spruce forests could increase the carbon uptake. They would release aerosol particles which have a cooling effect on the earth.

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We saw that in the 1990s there was a big eruption of a volcano called Mount Pinatubo. It released an enormous amount of atmospheric particles into the air. Then the global climate was cooled for two years. And that’s how the atmospheric particles are acting on the climate. That’s one example of how the terpenes can cool the climate via atmospheric particles,” says Adam Kristensson, Nuclear physicist at the Lund University. Various of air samples  are being tested through solution reacting with carbon to find out if carbon comes from natural sources or fossil fuel burning.

Source: https://www.reuters.com/