capturing

Tracking atmospheric mercury

May 13, 2025 By EarthWise Leave a Comment

Atmospheric mercury is a toxic pollutant released into the air from natural sources—such as volcanoes and wildfires—and from human activities like coal burning and gold mining. Once in the atmosphere, mercury can travel long distances before settling onto land or into water, transforming into toxic forms that threaten ecosystems and human health.

But tracking atmospheric mercury is a costly and challenging endeavor, requiring specialized equipment and trained personnel. Active monitors, which pump air to collect mercury, are expensive and need electricity, while passive samplers, using activated charcoal for remote areas, cost up to $100 each.

Researchers from Cornell University have found a cheap method for tracking toxic atmospheric mercury near gold mining sites throughout the Global South: wild fig trees. In the study, which was conducted in the Peruvian Amazon and recently published in the journal Frontiers in Environmental Science, the research team found that the rings in wild fig trees can serve as natural archives of atmospheric mercury, capturing and preserving historical pollution levels over time.

The technique itself is not actually new. Previous studies have used tree rings to track mercury pollution from coal combustion, particularly in Canada. But the research team wanted to test this method in regions of the Global South, where mercury emissions from gold mining are widespread.

According to the research team, wild fig trees might soon serve as an important biomonitoring tool, helping scientists better understand how mercury disperses across landscapes and through time.

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Tree rings track atmospheric mercury cheaply

Photo, posted November 13, 2012, courtesy of Steve Kessler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Capturing hot carbon dioxide

December 13, 2024 By EarthWise Leave a Comment

Decarbonizing industries like steel and cement is a difficult challenge. Both involve emitting large amounts of carbon dioxide both from burning fossil fuels and from intrinsic chemical reactions taking place. A potential solution is to capture the carbon dioxide emissions and either use them or store them away. But this sort of carbon capture is not easy and can be quite expensive.

The most common method for capturing carbon dioxide emissions from industrial plants uses chemicals called liquid amines which absorb the gas. But the chemical reaction by which this occurs only works well at temperatures between 100 and 140 degrees Fahrenheit. Cement manufacturing and steelmaking plants produce exhaust that exceeds 400 degrees and other industrial processes produce exhaust as hot as 930 degrees.

Costly infrastructure is necessary to cool down these exhaust streams so that amine-based carbon capture technology can work.

Chemists at the University of California, Berkeley, have developed a porous material – a type of metal-organic framework – that can act like a sponge to capture CO2 at temperatures close to those of many industrial exhaust streams. The molecular metal hydride structures have demonstrated rapid, reversible, high-capacity capture of carbon dioxide that can be accomplished at high temperatures.

Removing carbon dioxide from industrial and power plant emissions is a key strategy for reducing greenhouse gases that are warming the Earth and altering the global climate. The captured CO2 can be used to produce value-added chemicals or can be stored underground or chemically-reacted into stable substances.

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Breakthrough in capturing ‘hot’ CO2 from industrial exhaust

Photo, posted March 3, 2010, courtesy of Eli Duke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

An electric reactor for industry

September 17, 2024 By EarthWise Leave a Comment

The industrial sector accounts for nearly a third of greenhouse gas emissions in the US, which is more than the annual emissions from cars, trucks, and airplanes combined. These emissions primarily come from burning fossil fuels to produce goods from raw materials as well as from the chemical reactions associated with production. Many industrial processes require very high temperatures that are not easily achieved other than by burning fossil fuels.

Researchers at Stanford University have developed and demonstrated a new kind of thermochemical reactor that can generate the huge amounts of heat required for many industrial processes that runs on electricity rather than the burning of fossil fuels. The researchers claim that the design is also smaller, cheaper, and more efficient than the fossil fuel technology it would replace.

Standard industrial thermochemical reactors burn fossil fuel to heat a fluid that is piped into the reactor, much like the way home radiators work, albeit at far higher temperatures. The new reactor uses magnetic induction, similar to the way that induction cooktops work. Heat is transferred by inducing a current into materials that heat up as the current flows.

A proof-of-concept demonstration powered a chemical reaction called the reverse water gas shift reaction and resulted in more than 85% efficiency. The reaction in question converts carbon dioxide into a valuable gas that can be used to create sustainable fuels.

The Stanford researchers are working to scale up their new reactor technology and expand its potential applications. They are working on designs for reactors for capturing carbon dioxide and for manufacturing cement.

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Electric reactor could cut industrial emissions

Photo, posted October 30, 2022, courtesy of Helmut via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Iceland power

March 15, 2024 By EarthWise Leave a Comment

Iceland burns very little fossil fuel to power its economy and heat its homes. About 85% of its energy comes from geothermal power and hydropower. Its unique geology provides it with the highest percentage of renewable energy in the world. The fossil fuel that Iceland does burn is primarily used to power cars and trucks as well as boats in its fishing fleet. And Iceland is rapidly embracing the use of electric vehicles.

Iceland can make far more electricity than its 373,000 people can use. The majority of its electricity is essentially exported as bars of aluminum. Iceland is one of the world’s largest refiners of aluminum. The aluminum ore comes from other countries but gets shipped to Iceland where electricity is cheap. Refining aluminum is so energy-intensive that some say that aluminum is basically just pure electricity in solid metal form.

Electricity-rich Iceland is finding other ways to make use of its resources. There is a proposed project called Icelink, which is an electricity interconnector between Iceland and Great Britain. The high-voltage direct current link would run between 620 and 750 miles and would be the longest sub-sea power interconnector in the world. It is controversial in Iceland and it may or may not happen.

Another technology that is establishing an early foothold in Iceland is carbon capture. An Icelandic company called Carbix is doing leading work on taking captured carbon dioxide and sequestering it underground. Capturing and storing carbon dioxide is energy-intensive and the promise of cheap, clean geothermal power makes Iceland an attractive place to do it.

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Iceland Is Living in our Future

Photo, posted July 2, 2012, courtesy of Emily Qualey / PopTech via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Protecting wine grapes from wildfire smoke

February 27, 2024 By EarthWise Leave a Comment

In recent years, wildfires have become a major threat to the wine industry because of the effects of smoke on wine grapes. Smoke taint from the California fires of September 2020 significantly impacted the quality of wine grapes. In total, smoke taint cost the wine industry in Western states more than $3 billion in losses from the hundreds of thousands of tons of wine grapes that could not be harvested because of the off flavors imparted by the smoke. The California wine industry alone is a $43 billion a year business and the state’s frequent wildfires are a major threat to it.

Researchers at Oregon State University have developed techniques for eliminating the effects of three volatile chemical compounds that contribute to smoke taint in grapes. The compounds are guaicol, syringol, and meta-cresol.

The researchers developed cellulose nanofiber-based coatings that can be applied to grapes in the vineyard. The coatings can block guaicol and syringol and capture meta-cresol.

Blocking is ideal because the coating doesn’t absorb the wildfire smoke compounds. Therefore, it doesn’t have to be washed off. Capturing means the coating absorbs the compounds and would need to be washed off. Ideally, a coating that doesn’t need to be washed off would save time, money, and water.

Two years of studies at Oregon State found that the coatings do not impact the growth and quality of wine grapes. In an era when wildfires are increasingly common and extensive, growers need something they can spray on their vines to protect their grapes. If the Oregon State technology can be commercialized, it would be a game-changer for the Western U.S. wine industry.

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Spray coating for grapes shows promise in battle between wildfire smoke and wine

Photo, posted October 3, 2006, courtesy of Naotake Murayama via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Harvesting Fresh Water From Ocean Air | Earth Wise

January 19, 2023 By EarthWise Leave a Comment

Roughly three-quarters of the world population has access to a safely managed water source. That means that one-in-four people do not have access to safe drinking water. Even in the wealthy United States, persistent drought in the west is creating problems in places like Phoenix, Arizona.

Water is plentiful on Earth but more than 99% of it is unusable by humans and many other living things because it is saline, frozen, or inaccessible. Only about 0.3% of our fresh water is found in the surface water of lakes, rivers, and swamps.

There is an almost limitless supply of fresh water in the form of water vapor above the oceans, but this source is untapped. Researchers at the University of Illinois have been evaluating the feasibility of a hypothetical structure capable of capturing water vapor from above the ocean and condensing it into fresh water.

Existing ways to obtain fresh water like wastewater recycling, cloud seeding, and desalination have met only limited success and present various problems with regard to cost, environmental impact, and scalability.

The researchers have proposed hypothetical large offshore structures measuring 700 feet by 300 feet to capture water vapor that is continually evaporating from the ocean in subtropical regions. Their modeling concluded that such structures could provide fresh water for large population centers in the subtropics. Furthermore, climate projections show that the amount of water vapor over the oceans will only increase over time, providing even more fresh water supply.

This is only a theoretical study at this point, but the researchers believe it opens the door for novel infrastructure investments that could address global water scarcity.

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Researchers propose new structures to harvest untapped source of fresh water

Photo, posted June 28, 2009, courtesy of Nicolas Raymond via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Carbon Capture: Solution Or Band-Aid? | Earth Wise

July 13, 2022 By EarthWise Leave a Comment

The idea of capturing the CO2 emissions from industry and locking them up is nothing new. It’s been going on for decades in some places. Norway’s state-owned oil company Equinor has been holing away a million tons of CO2 a year for a long time. But overall, CCS – carbon capture and storage – has had very limited use. As of last year, there were only about 30 large-scale projects in operation around the world, capturing only 0.1% of global emissions.

There is now growing interest in CCS and many new projects are underway. A combination of rising carbon prices in Europe, tax breaks for CCS in the US, national net-zero targets, and the increasing need to ramp down global emissions are all driving rising CCS activities.

While recent reports from the Intergovernmental Panel on Climate change still claim that it is possible to remain below 2 degrees Celsius of warming without using carbon capture, there is growing belief that it may be necessary given the present pace of the transition away from fossil fuels.

Two industries that together produce about 14% of global CO2 emissions are cement and steel. These are both industries for which it is difficult to eliminate emissions regardless of the energy sources used. CCS may be the best approach to reducing their emissions.

But there is considerable pushback against CCS. The concern is that CCS is primarily a way to delay decarbonization. It encourages various industries to continue to use fossil fuels instead of shifting away from them. Nonetheless, CCS no doubt has its place as part of the solution to climate change.

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Solution or Band-Aid? Carbon Capture Projects Are Moving Ahead

Photo, posted June 5, 2022, courtesy of Mark Dixon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Storing Sunshine To Make Electricity On Demand | Earth Wise

June 1, 2022 By EarthWise Leave a Comment

Researchers at Chalmers University in Sweden have developed an entirely new way of capturing and storing energy from sunlight. The system is called the Molecular Thermal Energy Storage System or MOST. It is based on a specially designed molecule that changes shape when it is exposed to sunshine.

The molecule is composed of carbon, hydrogen, and nitrogen. When sunlight hits it, it changes into an energy-rich isomer – a molecule made up of the same atoms but arranged together in a different way. That isomer is stable and can be stored for many years. When a specially designed catalyst is applied, the stored energy is released in the form of heat and the molecule returns to its original form and can be reused.

The Chalmers researchers sent some of the energy-laden isomer to researchers in China who used it to operate a micron-thin thermoelectric generator, which used the heat released by the isomer material to generate electricity. The generator is an ultra-thin chip that could be integrated into electronics such as headphones, smart watches, and telephones. It is currently only at the proof-of-concept stage, but the results are quite promising. The integration with the MOST technology provides a way that solar energy can generate electricity regardless of weather, time of day, season, or geographical location. The results of the study were recently published in the journal Cell Reports Physical Science.

In effect, for this demonstration, Swedish sunshine was sent to the other side of the world and converted into electricity in China. The ultimate goal of this research is to create self-charging electronics that uses stored solar energy on demand.

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Converting solar energy to electricity on demand

Photo, posted March 11, 2013, courtesy of Steve Slater via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.