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Better wood for storing carbon

August 29, 2024 By EarthWise Leave a Comment

Scientists have discovered a new type of wood that is highly efficient at storing carbon. A comprehensive survey of the microscopic structure of the wood from many species of trees revealed that there is a type of wood that is neither softwood, such as pine and conifers, or hardwood, such as oak, ash, and birch.

The scientists from Cambridge University and Jagiellonian University in Poland analyzed some of the world’s most iconic trees using electron microscopy to survey their microscopic structure.

They found that tulip trees, which are related to magnolias and can grow over 100 feet tall, have a unique type of wood. The trees, which diverged from magnolias far back to a time when atmospheric CO2 concentrations were low, grow very tall and very quickly. These features were an adaptation to those conditions and result in the ability to store larger concentrations of carbon to compensate based on their microstructure. The elementary units of wood are known as macrofibrils, and tulip trees have much larger macrofibrils than hardwoods but smaller than those of softwoods. This unusual intermediate structure makes the trees highly effective at carbon storage.

Based on the research, it may be the case that tulip trees will end up being useful for carbon capture plantations – tree plantings specifically for the purpose of mitigating the effects of climate change. Some east Asian countries are already using various tulip tree species in plantations for locking in carbon. This was based on their large size and rapid growth, but it turns out that their novel wood structure may be the most compelling reason to use them.

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Scientists discover entirely new wood type that could be highly efficient at carbon storage

Photo, posted March 3, 2021, courtesy of Thomas Quine via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Recycling cement

June 21, 2024 By EarthWise Leave a Comment

Concrete is the second-most-used material on the planet. Only water is used more. Producing concrete is responsible for 7.5% of human-produced carbon dioxide emissions. So, finding a cost-effective way to reduce these emissions is a major challenge in the face of ever-growing global demand for concrete.

Researchers at Cambridge University have found that used cement is an effective substitute for lime flux, which is an essential material used in steel recycling that results in a waste product called slag. When lime is replaced with used cement, the end product instead is recycled cement that can be used to make new concrete.

The process does not add any significant costs to concrete or steel production and significantly reduces the emissions associated with both.

Concrete is made from sand, gravel, water, and cement. Cement is made by a process called clinkering, in which limestone and other materials are heated to 2,600 degrees Fahrenheit. The process converts the materials into cement but releases large amounts of CO2 as limestone decarbonates into lime.

Cambridge researchers found that using cement clinker and iron oxide instead of lime works well in steel recycling. Crushing old concrete and taking out the sand and stone results in a cement that is reactivated by the recycling furnace to produce a material with excellent properties.

Recent tests by the Materials Processing Institute showed that recycled cement can be produced at scale in an electric arc furnace. Ultimately, this method could produce zero emission cement if the electricity for the furnace comes from renewable sources.

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Cement recycling method could help solve one of the world’s biggest climate challenges

Photo, posted July 18, 2011, courtesy of Kenta Mabuchi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Major Funding For Novel Energy Storage | Earth Wise

October 21, 2021 By EarthWise Leave a Comment

The accelerating adoption of wind and solar energy is driving a growing interest in energy storage technologies. An electric grid dominated by intermittent power sources will need large-scale energy storage. Grid-scale energy storage is expected to increase at least 10 times over the next decade and this will require nearly $300 billion in investments over that time period.

Much of the effort in energy storage has focused on battery storage. But there are other storage technologies that are attracting attention and investment.

Energy Vault is a Swiss-based company specializing in gravity and kinetic energy-based energy storage. Their technology uses a multi-headed crane to store energy generated by renewable sources by stacking heavy blocks made of composite material into a tower, capturing potential energy from the elevation gain of the blocks. To produce electricity, the crane lowers the blocks to the ground, driving generators in the process. The company has just raised $100 million in funding from investors.

Malta, Inc. is an energy storage company based in Cambridge, Massachusetts that is developing an electro-thermal energy storage system. Energy generated from renewable (or other) sources drives a heat pump to create thermal energy producing both hot and cold reservoirs. The heat is then stored in molten salt while the cold is stored in a chilled liquid. To generate electricity, the temperature difference between the two reservoirs is used to drive a heat engine. Malta has recently raised $60 million in new funding including significant support from Chevron Energy Ventures.

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Energy Vault Raises $100 Million In Series C Funding

Chevron backs long-duration thermal energy storage developer Malta

Photo, posted October 16, 2019, courtesy of Jonathan Cutrer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Protecting Nature Is Valuable | Earth Wise

April 15, 2021 By EarthWise Leave a Comment

A study by the University of Vermont, the University of Cambridge, and several other institutions compared the value of protecting nature at particular locations with that of exploiting it. The study concluded that the economic benefits of conserving or restoring natural sites outweigh the profit potential of converting them for intensive human use.

The study analyzed dozens of sites across the globe – from Kenya to Fiji and China to the UK across six continents. It was published in the journal Nature Sustainability.

The analysis utilized a methodology devised ten years ago called TESSA (the Toolkit for Ecosystem Service Site-based Assessment) which enables users to measure, and in many cases, assign monetary values to services provided by sites – clean water, nature-based recreation, crop pollination, and so on. This is then compared with the economic benefits that can be derived by converting the site for farming, logging, or other human uses.

A major economic benefit of natural sites comes from their ability to sequester carbon and thereby help regulate the quantity of greenhouse gases in the atmosphere. If one assigns a value to global society of $31 a ton of carbon removed, over 70% of the sites surveyed had a greater value to society when kept natural rather than being converted. Many scientists actually consider this carbon price to be conservative. Nevertheless, if carbon is assigned the paltry cost of $5 a ton, 60% of the sites are still more valuable in their natural state.

Beyond these economic calculations, there is the pressing issue that current rates of habitat conversion are driving a species extinction crisis unprecedented in human history. But even if one is only interested in dollars and cents, conserving and restoring nature is now very often the best bet for human prosperity.

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Economic Benefits of Protecting Nature Exceed Value of Exploiting it, Global Study Finds

Photo, posted June 7, 2017, courtesy of Mouli Choudari via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Clean Gas From An Artificial Leaf

November 27, 2019 By EarthWise Leave a Comment

Photosynthesis is the process used by plants, algae and certain bacteria to harness energy from sunlight and turn it into chemical energy. It is often described as the green engine of life on earth.

For quite some time, there have been extensive research efforts around the world in the area of artificial photosynthesis. The goal is to somehow mimic the behavior of plants in order to generate clean-burning fuels using nothing more than sunlight and the carbon dioxide in the air.

Researchers at the University of Cambridge have recently demonstrated a so-called artificial leaf that can directly produce syngas using sunlight. Syngas is a fuel gas mixture consisting primarily of hydrogen and carbon monoxide. Most people haven’t heard of syngas, but many products are created using it. Being able to produce it sustainably would be a critical step to a far greener chemical and fuel industry.

The artificial leaf contains two light absorbers, similar to the molecules in plants that harvest sunlight, which are combined with a catalyst made from the naturally abundant element cobalt. When the device is immersed in water, one light absorber uses the catalyst to produce oxygen. The other carries out the chemical reaction that reduces carbon dioxide and water into carbon monoxide and hydrogen. The result is the syngas mixture.

It turns out that even a rainy or overcast day provides enough light to drive the process.

Previous artificial leaf devices have mostly just produced hydrogen. The Cambridge device produces syngas thanks to the novel combination of materials and catalysts it uses.

The researchers are now focused on finding ways to use the technology to produce a sustainable gasoline substitute.

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‘Artificial leaf’ successfully produces clean gas

Photo, posted August 15, 2014, courtesy of Mike Mozart via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.