techniques

Plastic From Sunlight | Earth Wise

March 13, 2023 By EarthWise Leave a Comment

Photosynthesis is the process that plants use to turn water, carbon dioxide, and energy from sunlight into plant biomass. It provides humans and much of animal life with food. Photosynthesis is also nature’s way of reducing the amount of carbon dioxide in the atmosphere. The CO2 is not directly stored in plants but rather is combined into organic compounds.

Researchers across the globe are trying to find effective ways to mimic photosynthesis. One version of artificial photosynthesis seeks to take carbon dioxide and combine it into organic compounds that can be used as raw materials for various kinds of manufacturing.

A research team in Japan has found a way to synthesize fumaric acid from carbon dioxide using sunlight to power the process. Fumaric acid is a chemical typically synthesized from petroleum and is used as a raw material for making biodegradable plastics such as polybutylene succinate.

Much of artificial photosynthesis research is aimed at using solar energy to convert carbon dioxide directly into a fuel rather than a raw material. Such solar fuels can be produced by a variety of means including thermochemical (using the sun’s heat to drive chemical reactions), photochemical (using the sun’s light to drive chemical reactions), and electrochemical (using solar-generated electricity to drive chemical reactions.) These approaches generally involve the use of specialized catalysts to drive the desired chemical reactions.

One way or another, what techniques for artificial photosynthesis have in common is trying to imitate what plant life on Earth has been doing for millions of years.

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Artificial photosynthesis uses sunlight to make biodegradable plastic

Photo, posted June 14, 2017, courtesy of Alex Holyake via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Windows To Cool Buildings | Earth Wise

December 15, 2022 By EarthWise Leave a Comment

About 15% of global energy consumption is for cooling buildings. Because of this, there is an ever- growing need for technologies that can more efficiently cool buildings. Researchers at Notre Dame University have used advanced computing technology and artificial intelligence to design a transparent window coating that is able to lower the temperature inside buildings without using any energy.

The idea is to create a coating that blocks the sun’s ultraviolet and near-infrared light, which are parts of the solar spectrum that otherwise pass through glass and help to heat an enclosed room. Cooling needs can be reduced further if the coating can radiate heat from the surface of the window so it can pass through the atmosphere into space. Designing a coating that does both of those things simultaneously while transmitting visible light is difficult. Coatings should not interfere with the view out the window.

The Notre Dame researchers used advanced computer modeling to create a so-called transparent radiative cooler that meets these goals. The coating consists of alternating layers of common materials like silicon dioxide, silicon nitride, and aluminum oxide or titanium dioxide on top of a glass base and topped with a film of polydimethylsiloxane. The computing method was able to optimize this structure far faster and better than conventional design techniques.

The researchers say that in hot, dry cities, the coating could potentially reduce cooling energy consumption by 31% compared with conventional windows. The same materials could be used in other applications, such as car and truck windows. In addition, the quantum computing-enabled optimization method used for this work could be used to design other composite materials.

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Clear window coating could cool buildings without using energy

Photo, posted September 6, 2015, courtesy of Robert Otmn via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cleaning Up Urban Rivers With Nature’s Tools | Earth Wise

October 7, 2022 By EarthWise Leave a Comment

Fifty years after the passage of the Clean Water Act, urban waterways across the United States are continuing their comeback and are showing increasing signs of life. A strategy that is being adopted in many places is to use natural restoration techniques focused on bolstering plants and wildlife to improve water quality.

A nonprofit called the Upstream Alliance has focused on public access, clean water, and coastal resilience in the Delaware, Hudson, and Chesapeake watersheds. Working with the Center for Aquatic Sciences and with support from the EPA and the National Fish and Wildlife Foundation, the alliance has been repopulating areas of an estuary of the Delaware River near Camden, New Jersey with wild celery grass, which is a plant vital to freshwater ecosystems.

In many places, scientists, nonprofits, academic institutions, and state agencies are focusing on organisms like bivalves (typically oysters and mussels) along with aquatic plants to help nature restore fragile ecosystems, improve water quality, and increase resilience.

Bivalves and aquatic vegetation improve water clarity by grounding suspended particles, which allows more light to penetrate. These organisms also cycle nutrients both by absorbing them as food and by making them more available to other organisms.

Underwater restoration projects have been underway in New York Harbor for more than a decade, where the Billion Oyster Project has engaged 10,000 volunteers and 6,000 students.

The hope is that bringing back bivalves and aquatic plants can create a lasting foundation for entire ecosystems. It is restoring nature’s ability to keep itself clean.

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How Using Nature’s Tools Is Helping to Clean Up Urban Rivers

Photo, posted December 19, 2019, courtesy of Scott via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Cheap Material For Carbon Capture | Earth Wise

September 12, 2022 By EarthWise Leave a Comment

The recently passed Inflation Reduction Act includes significant support for carbon capture technologies. Eliminating fossil fuel burning is essential for halting climate change, but in the interim, methods for capturing emissions of carbon dioxide and either storing it or turning it into usable products are increasingly necessary.

There are a variety of techniques being developed for carbon capture but at this point, none of them are commercially viable. The best technique in use today involves piping flue gases through chemicals called liquid amines, which bind CO2. The process requires large amounts of energy to release the bound carbon dioxide so it can be concentrated and stored. As a result, it is complicated and expensive.

Researchers at UC Berkeley, Stanford, and Texas A&M University have developed a carbon capture method using melamine, which is an inexpensive polymer used to make Formica, as well as low-cost dinnerware, industrial coatings, and other plastics. Porous melamine itself adsorbs CO2 to a limited extent. But the researchers discovered that adsorption could be much improved by adding the chemical DETA (diethylenetriamine) to bind the CO2. In addition, adding cyanuric acid increased the melamine pore size and radically improved CO2 capture efficiency even more.

The result is a material that is more efficient even than exotic carbon capture materials like metalorganic frameworks and is much cheaper and easier to make. The researchers aim to design equipment that can used in industrial facilities, attached to buildings and other structures, or even to the tailpipes of gas-powered vehicles.

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A simple, cheap material for carbon capture, perhaps from tailpipes

Photo, posted June 10, 2006, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Harvesting Water From Air | Earth Wise

May 17, 2021 By EarthWise Leave a Comment

Developing new technologies that harvest water from the air is a growing field of research driven by the fact that more and more people live in areas where fresh water is in short supply. Estimates are that roughly half the world’s population lives in regions with severe freshwater shortages for at least one month each year.

We have previously discussed some of the novel approaches that researchers are taking to enhance water harvesting. The work at UC Berkeley using metalorganic frameworks is a notable example.

One of the key problems in harvesting water from air is that many droplets that condense from water vapor in the air are too small to be collected and when they cover a surface, they can actually impede further condensation.

University of Texas at Dallas researchers have developed a novel surface that encourages tiny water droplets to move spontaneously into larger droplets. The droplets actually self-climb along an oil, ramp-shaped meniscus. The meniscus acts like a bridge along which microdroplets spontaneously climb upward and coalesce with larger water droplets. They call this the coarsening droplet phenomenon. It is enabled by a liquid lubricant with a unique hydrophilic nature. They actually discovered the lubricant’s special properties by accident when in a lubricant test they observed smaller water droplets propel themselves into larger droplets.

Based on experimental data, the coarsening surface enhances the water harvesting rate 200% higher than other techniques. The team continues to work on ways to use the new lubricant to make sustainable water harvesting systems that are mobile, smaller in size, lower in weight, and less expensive. If they are successful, they will essentially be able to harvest water anywhere that has air.

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New Physical Phenomenon Aids Harvest of Water from Air

Photo, posted April 26, 2014, courtesy of Toukou Sousui via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Increasing Palm Oil Production Without Harming The Environment | Earth Wise

May 5, 2021 By EarthWise Leave a Comment

Palm oil is the most important source of vegetable oil in the world. The oil itself and ingredients based on it are found in approximately 50% of the products on supermarket shelves, including both food and non-food items. Many of the mysterious chemicals that show up on ingredient lists such as sodium lauryl sulfate are actually derived from palm oil.

Dozens of countries produce palm oil, but about 2/3 of the world’s supply comes from Indonesia and the demand for its oil keeps growing. To keep up with that demand, Indonesia continues to convert valuable ecosystems that contribute greatly to biodiversity to palm production.

A four-year research project at the University of Nebraska- Lincoln has found that keeping up with palm oil demand may not necessarily mean converting valuable, fragile ecosystems into agricultural land. According to the study published in Nature Sustainability, palm oil yields on existing farms and plantations could be greatly increased with improved management practices.

The researchers identified key practices that could lead to larger yield. These include improved harvest methods, better weed control, improved pruning, and better plant nutrition. With such practices, Indonesia could produce 68% more palm oil on existing plantation areas.

The results were surprising to the researchers and are significant from both environmental and economic standpoints. In particular, it could have a great impact on the millions of individual farmers who draw their livelihood from small palm farms often containing just a few acres. In Indonesia, about 42% of land used for palm oil production is owned by smallholder farms.

The researchers are now working with various stakeholders in Indonesia to put these management techniques into practice.

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Husker research shows palm oil production can grow while protecting ecosystems

Photo, posted August 15, 2006, courtesy of Lian Pin Koh via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Geothermal Power In The Energy Transition | Earth Wise

February 22, 2021 By EarthWise Leave a Comment

The heat beneath the earth represents a vast repository of energy that in principle could provide for a significant part of our needs. In some places, geothermal energy is easy to get to and is already being exploited. California and Nevada operate dozens of geothermal electric generating plants. Boise Idaho heats 92 of its biggest buildings with the river of hot water that flows 3,000 feet below the city. In total, the U.S. produces enough geothermal electricity to power more than a million homes.

But all these examples make use of relatively rare local features that are not available to the great majority of locations. As a result, geothermal energy has generally not been viewed as being able to play a major role in the alternative energy transition.

A number of experts around the world disagree with this assessment. To a fair extent due to the deep-drilling techniques and knowledge about underground formations developed by the oil and gas industry during the fracking boom, there is growing interest in a type of geothermal energy called deep geothermal that accesses hot temperatures in the earth’s mantle as far down as two or three miles.

Deep geothermal can either access extremely hot water that exists down at those depths or water can be injected into hot rock down there, which is a technology known as enhanced geothermal systems.

There is enormous untapped potential for geothermal energy. A 2019 report by the U.S. Department of Energy says that by 2050, geothermal could provide 8.5% of the United States’ electricity as well as direct heat. Geothermal could be an important part of the so-called all-of-the-above future energy strategy.

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Can Geothermal Power Play a Key Role in the Energy Transition?

Photo, posted August 2, 2008, courtesy of ThinkGeoEnergy via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Metal From Plants | Earth Wise

March 31, 2020 By EarthWise 2 Comments

Large amounts of metal in soil are generally bad for plants. But there are about 700 species of plants that thrive in metal-rich soils. These plants don’t just tolerate minerals from soil in their bodies but actually seem to hoard them to ridiculous levels.

In areas where soils are naturally rich in nickel, typically in the tropics and Mediterranean basin, plants have either died off or have adapted to become nickel loving. Slicing open a tree with this adaptation produces a neon blue-green sap that is actually one-quarter nickel, which is far more concentrated than the ore that typically feeds commercial nickel smelters.

A group of researchers from the University of Melbourne and other institutions is investigating whether this phenomenon is not just interesting but might also be of real commercial value. They established a plot of land in a rural village in Borneo and have been harvesting growth from nickel-hyper accumulating plants. Every six to twelve months, a farmer shaves off one foot of growth from these plants and either burns or squeezes the metal out. After a short purification, they end up with about 500 pounds of nickel citrate, potentially worth thousands of dollars on international markets.

Phytomining – extracting minerals from hyper-accumulating plants – cannot fully replace traditional mining techniques. But the technology could enable areas with toxic soils to be made productive and might allow mining companies to use plants to clean up their former mines and waste while actually collecting some revenue.

There are other plants that suck up cobalt, zinc, and similarly crucial metals. With growing demand for metals, perhaps it is time to harvest them on the farm.

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