Earth Wise

A look at our changing environment.

You are here: Home / Archives for methods

methods

Sun powered carbon capture

By Leave a Comment

As the world struggles to implement technologies and find the political will to reduce carbon emissions, there are also ongoing efforts to find ways to capture carbon from emitting sources and from the atmosphere itself.  After capturing carbon dioxide, there is then the need to safely store it or make use of it.

Current methods for capturing and then releasing carbon dioxide are expensive and energy intensive.  In fact, some methods even require the use of fossil fuels.  Recently, researchers at Cornell University have developed a method for capturing carbon dioxide that is powered by sunlight.

The Cornell method mimics the mechanisms that plants use to store carbon which involves using sunlight to make a reactive enol molecule that grabs carbon dioxide.  

Existing chemical-based carbon capture techniques make use of amines, which are organic ammonia-derived compounds that react selectively with carbon dioxide.  But amines are not stable in the presence of oxygen and don’t last, which necessitates the energy-intensive production of more and more amines.

The Cornell method uses the same method that the plant enzyme RuBisCo uses in photosynthesis.  It is based on an inexpensive sorbent material that is capable of a high rate of carbon capture.

The researchers tested the system using flue samples from Cornell’s Combined Heat and Power Building, an on-campus power plant that burns natural gas.  The system was successful in isolating carbon dioxide.

Ultimately, they would like to stage the reaction on what looks like a solar panel, but one that would capture carbon instead of generating electricity.

**********

Web Links

In a first, system uses sunlight to power carbon capture

Photo, posted August 8, 2015, courtesy of Holly Victoria Norval via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Fighting fires with man-made wind

By Leave a Comment

Researchers at Ohio State University have developed a new portable tool that may help firefighters battle blazes more efficiently and with less risk.

Traditional firefighting methods include chemical foams – which are toxic – and the use of hydrants, which can strain water resources.  The recent fires in Southern California demonstrated the need for efficient fire suppression methods.  The new device works to suppress flames using conductive aerosols, which are small particles that can direct electricity.

The device uses vortex rings – small donut-shaped bands of air – that transform the aerosol particles into short pulses of wind that convert nearby oxygen into ozone.  This accelerated airflow generates rapid turbulence, which disrupts the natural combustion process and quickly extinguishes the target fire.

The device resembles a small bucket, attached to an arm brace.  Firefighters would aim the bucket toward the fire, and it would use bursts of compressed air to deliver aerosols in an electric arc to fight the fire.

Testing identified a coarse copper solution for the vortex ring material and simulations showed that the device would succeed in suppressing fires.  They then worked on optimizing the power and range of the device.

Depending on the size of the fire and number of firefighters, it is likely that several of the devices would be required in a real emergency.  According to the developers, the design of the vortex launcher is actually very simple and is very scalable.  The device is maneuverable in tight spaces and could be taken through doors and indoor environments.  Vortex rings can carry chemical payloads over longer distances than other methods, making firefighters safe by staying further from flames. 

**********

Web Links

New device uses electrically assisted wind to fight fires

Photo, posted November 12, 2024, courtesy of the USDA Forest Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wave energy in LA

By Leave a Comment

Ocean waves form as wind blows over the surface of open water.  Globally, waves contain tremendous amounts of energy.  Theoretically, the energy generating potential of waves off the coasts of the U.S. would meet more than 60% of the country’s electricity needs.  There are a variety of methods and technologies for tapping into this energy source, but none have reached the point of commercial adoption to date.  There are many problems that remain to be solved.

Eco Wave Power, a wave energy company, announced that it has received the necessary permit from the U.S. Army Corps of Engineers to operate the first onshore wave energy installation in the United States.  The installation will be at the Port of Los Angeles at the facilities of AltaSea, a public-private ocean institute that conducts research on food and energy supply, climate change, and ocean exploration.

The system will utilize eight of Eco Wave Power’s energy floaters that will be installed on the piles of an existing concrete wharf structure on Municipal Pier One.  The system will also include an energy conversion unit enclosed in two shipping containers and connected to the floaters.  The installation is expected to be completed by the end of the first quarter of this year.

Floaters draw energy from waves by using their rising and falling motion to generate electricity. The bobbing motion of the floaters compresses and decompresses hydraulic pistons.  These transmit hydraulic fluid into land-based accumulators that build up pressure.  The pressure rotates a hydraulic motor, which then operates a generator, producing electricity.

The project is a collaboration on the development of wave energy in the Port of Los Angeles between Eco Wave Power and Shell Marine Renewable Program.

**********

Web Links

Eco Wave Power secures final USACE permit for its first U.S. wave energy project

Photo courtesy of Eco Wave Power.

Earth Wise is a production of WAMC Northeast Public Radio

Curbing food waste

By Leave a Comment

According to the U.S. Department of Agriculture, as much as 40% of the food supply in the United States is wasted.  In fact, Americans generate more food waste than all but two countries.

To address this problem, the federal government announced a goal nearly a decade ago to cut food waste in half by 2030 compared to 2016 levels.  Doing so would bring food waste down to approximately 164 pounds per person annually.

However, according to a new study led by researchers from the University of California – Davis, since 2016, per capita food waste has actually increased instead of decreasing. 

The study, which was recently published in the journal Nature Food, looked at how state policies align with federal targets.  The research team found that state policies focus more on recycling methods, such as composting and anaerobic digestion, rather than on prevention and rescue strategies, like food donations or repurposing food for animal feed.

In 2021, the EPA revised its definition of food waste to no longer include recycling methods.  But when food is wasted, the resources used to grow the food, including energy, water, and fertilizer, are also wasted. 

In the study, the researchers analyzed state-level food waste reduction efforts across four areas: prevention, rescue, repurposing, and recycling.  They found that recycling policies offered the most potential for diversion. Despite this, most states still fell short of the federal goal of 164 pounds per person annually. 

According to the research team, more comprehensive policies to address food waste must be implemented as soon as possible.

**********

Web Links

States Struggle to Curb Food Waste Despite Policies

Photo, posted June 28, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Less coal for making steel

By Leave a Comment

Steel is primarily produced using one of two methods:  blast furnaces or electric arc furnaces.  The first blast furnaces were built in the 14th century.  Making steel in a blast furnace starts by melting the raw materials of iron ore, limestone, and coal at very high temperatures.  The resultant reactions ultimately lead to two products:  iron saturated with carbon and carbon dioxide.  A second furnace reacts the liquid iron with oxygen to remove the carbon and results in steel along with even more carbon dioxide.

Making steel using an electric arc furnace is considerably less emissions-intensive and more sustainable.  So-called circular steel making powered by electric arc furnaces uses electricity to melt scrap and other input materials and turn them into high-quality steel.  Of course, to really minimize the emissions associated with steelmaking, the arc furnaces need to get their power from renewable energy sources. 

The global steel industry is turning away from polluting coal-fired blast furnaces and towards electric arc furnaces, which now account for roughly half of all planned new steelmaking capacity. This represents real progress towards a green steel transition.

By the end of this decade, electric arc furnaces will account for more than a third of steelmaking.  However, there are still plenty of new coal-based steel furnaces being built.  So even as electric arc furnaces account for a greater share of steelmaking, these new coal furnaces will still drive emissions upward.   Environmental advocates argue that what the steel industry needs is to make clean development a true priority and back away from coal-based developments.

**********

Web Links

Steelmakers Increasingly Forgoing Coal, Building Electric

Photo, posted July 16, 2018, courtesy of Daniel Steelman via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wind farms and land use

By Leave a Comment

Wind power has become one of the most affordable ways to generate electricity as well as being renewable and not contributing to global warming.  But there has been the perception that wind farms require a lot of land compared with fossil fuel power plants. This issue of land use has made decision-makers reluctant to invest in wind energy in many instances.

A new study by McGill University in Montreal looked at this issue and has found that land use for wind power is far more efficient than previously thought.  The study combined data from geographic information systems with machine learning models to assess land usage associated with nearly 16,000 wind turbines in the western U.S.

The study assessed the land use of 320 wind farms.  They found that wind power infrastructure (mostly the turbines themselves and the roads that lead to them) typically only uses 5% of the land area of a wind farm.  If the wind farm is sited in locations with existing infrastructure, such as on agricultural land, then it can be as much as seven times more land-efficient – meaning the amount energy produced in a given area of land impacted by the infrastructure – than a wind farm that is developed on unused land.

Previous studies of wind farm land usage assumed that all of the land where the wind farm was located was devoted to energy generation.  In reality, most of land in question is often used for other purposes, such as agriculture.

The methods developed by the researchers are potentially useable for future assessments of various energy technologies in terms of their environmental sustainability.

**********

Web Links

Clearing the air: wind farms more land efficient than previously thought

Photo, posted September 29, 2009, courtesy of Tim Green via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wild pigs in the U.S.

By Leave a Comment

In the U.S., there are as many as nine million feral swine living in 38 states.  A conservative estimate indicates that they cause about $1.5 billion in property and agricultural damage each year in this country. 

Pigs were introduced to the United States centuries ago as a food source, but they quickly established wild populations. Feral domestic pigs bred with purebred Eurasian boar that were introduced for hunting, and these hybridized wild pigs spread across the landscape thanks to their prolific reproductive rates and willingness to eat just about anything.

When wild pigs forage, they upturn roots and soil with their snouts, damaging natural habitats and other animals. A 2021 study found that wild pigs are releasing over five million tons of carbon dioxide annually by uprooting carbon trapped in soil. 

As a result, many programs were implemented nationwide to try to reduce populations, usually through lethal methods. 

According to new research from the University of Georgia’s Savannah River Ecology Laboratory and Warnell School of Forestry and Natural Resources, recent conservation efforts have proven effective at controlling wild pig populations in the Southeastern U.S.  Within 24 months of the start of control efforts in the study area in South Carolina, the research team found a reduction of about 70% in relative abundance of pigs, and a corresponding decline in environmental rooting damage of about 99%.

Wild pigs are basically a human-caused problem, and controlling their populations will require continued cooperation and collaboration. 

**********

Web Links

Wild pig populations in U.S. can be managed

Wild Pigs And The Environment

Photo, posted January 28, 2013, courtesy of Don and Janet Beasley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Planting Rocks To Capture Carbon | Earth Wise

By Leave a Comment

Getting humanity to stop dumping carbon dioxide into the atmosphere continues to be very challenging regardless of how increasingly apparent the need to do so becomes.  For this reason, climate change mitigation strategies increasingly include interventions in the form of removing carbon dioxide that is already there.  There are a variety of ways to draw carbon dioxide out of the atmosphere, but they face a host of technological, economic, and even environmental difficulties.

A new study at Yale University evaluated a type of climate intervention called enhanced rock weathering.  Rock weathering is a natural chemical process by which certain minerals absorb carbon dioxide over time.  Enhanced rock weathering is simply speeding up weathering such so it can have beneficial results soon enough to make a difference.

The study explored the potential of applying crushed basalt, which is a fast-weathering rock that forms when lava cools, to agricultural fields around the world.  Basically, the idea is for farmers to mix the crushed rocks into their fields. There is no real downside to doing this.  In fact, adding crushed basalt to fields rejuvenates depleted soils and helps counter ocean acidification.

The study simulated the results of enhanced rock weathering on 1,000 agricultural sites around the world.  Over a 75-year period, these sites would remove 64 billion tons of carbon dioxide from the atmosphere.  This is roughly the amount climate scientists believe is needed to take out of the atmosphere. 

Enhanced rock weathering has been used on a small scale on farms around the world.  Perhaps it is time to ramp up its use.

**********

Web Links

‘Planting’ rocks in farms, along with emissions reductions, could help meet key IPCC carbon removal goal

Photo, posted January 14, 2023, courtesy of Ron Reiring via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastic Eating Fungus | Earth Wise

By Leave a Comment

More than five billion tons of plastic have accumulated on land and sea including the most remote regions of the planet as well as in the bodies of animals and humans.  There is a compelling need to recycle as much plastic as possible but doing so is a major challenge. Plastic comes in many varieties and breaking it down for reuse requires different methods for each.

Polypropylene is one of the biggest challenges for recycling.  It is a very common plastic used for all sorts of products including food containers, coat hangers, plastic wrap, toys, and much more. It accounts for roughly 28% of the world’s plastic waste, but only 1% of it is recycled.

Polypropylene is seldom recycled because it generally has a short life as a packaging material, and it often becomes contaminated by other materials and plastics.  Thus, it generally ends up in landfills.

Researchers at the University of Sydney in Australia have discovered that two common strains of fungi were able to successfully biodegrade polypropylene.  The fungi species – with unavoidable Latin names of Aspergillus terreus and Engyodontium album – are typically found in soil and plants.

The researchers found that the fungi were able to break down polypropylene after it had been pre-treated with either UV light or heat, by 21% over 30 days, and by 25-27% over 90 days.  This seems rather slow but compared with the nearly endless life of polypropylene in landfills, it is a major improvement.

The hope is that methods like this could ultimately reduce the amount of plastic polluting the environment by encouraging plastic to biodegrade naturally under the appropriate conditions.

**********

Web Links

Fungi makes meal of hard to recycle plastic

Photo, posted March 5, 2010, courtesy of Kevin Krejci via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Pulling Carbon Dioxide Out Of Seawater | Earth Wise

By Leave a Comment

The world’s largest sink for carbon dioxide from the atmosphere is the ocean.  The world’s oceans soak up 30-40% of all the gas produced by human activities.  Dissolving carbon dioxide in water produces carbonic acid.   This is the reason that oceans are becoming increasingly acidic, which is causing serious damage to ocean ecosystems.

There are many efforts underway aimed at directly removing carbon dioxide from the air as a way to mitigate the effects of ongoing emissions.  But another possibility is to remove CO2 directly from ocean water.  Existing methods for doing it involve the use of expensive membranes and complex chemicals. The economics of such methods are quite unfavorable.

Recently, a team of researchers at MIT has identified what they claim is a truly efficient and inexpensive removal mechanism. It involves a reversible process based on membrane-free electrochemical cells.  Electrodes in the cells release protons that are introduced to seawater which drive the release of carbon dioxide dissolved in the water. The carbon dioxide can be collected and the processed water ends up being alkaline.

Running this process at a site that is already collecting seawater – such as at a desalination plant – would be an effective way to collect carbon dioxide as well as help mitigate ocean acidification.

Once the carbon dioxide is removed from the water, it still needs to be disposed of, just as is the case for other carbon removal processes.  It could be turned into useful chemicals or it could be stored in underground caverns.  But this approach is fairly unique in that the carbon dioxide has already been captured by the ocean.  The issue remains what to do with it.

**********

Web Links

How to pull carbon dioxide out of seawater

Photo, posted January 19, 2016, courtesy of Judy Dean via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Harvesting Fresh Water From Ocean Air | Earth Wise

By 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.

**********

Web Links

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

Beavers As Climate Change Fighters | Earth Wise

By Leave a Comment

California is fighting the effects of climate change on multiple fronts.  The state has been grappling with relentless drought, record heat waves, and persistent wildfires.  The California Department of Fish and Wildlife is enlisting the help of beavers in its battle against climate change.

The state has created a beaver restoration unit charged with developing methods for nature-based restoration solutions involving beavers as well as artificial beaver dams. The agency plans to spend at least $3 million over the next two years to oversee a restoration program for the North American beaver.

A 2020 study showed that beaver-dammed corridors were relatively unharmed by wildfires compared with other areas that lacked beaver damming.  The study highlighted the differences between two adjacent corridors – one without a beaver population with a landscape scarred by a recent wildfire and another with beavers that remained a lush wetland after a fire.   The differences in burn severity, air temperature, humidity, and soil moisture between the beaver complex and the adjacent landscape were huge. 

From the 1920s through the 1950s, California actively exported beavers to other parts of the state and country so they could build dams in eroded areas where beaver dams could help evenly distribute water.  Now, the state wants to reintroduce beavers into watersheds where they once flourished.

The Department of Fish and Wildlife’s proposal to the California Legislature called beavers an important keystone species that can be used to combat climate change.   The state has spent enormous amounts of money on wildfire measures with minimal results.  Now they are going to see if beavers can make a difference.

**********

Web Links

California says the beaver can be superhero in fighting climate change

Photo, posted September 19, 2021, courtesy of Larry Lamsa via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Cheap Material For Carbon Capture | Earth Wise

By 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.

**********

Web Links

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.

Wastewater And Ammonia | Earth Wise

By Leave a Comment

Ammonia is the second most produced chemical in the world.  More than half of it is used in agriculture to produce various kinds of fertilizer, to produce cotton defoliants that make cotton easier to pick, and to make antifungal agents for fruits.  Globally, ammonia represents more than a $50 billion a year market.

Current methods to make ammonia require enormous amounts of heat – generated by burning fossil fuels – to break apart nitrogen molecules so that they can bind to hydrogen to form the compound. Ammonia production accounts for about 2% of worldwide fossil energy use and generates over 400 million tons of CO2 annually.

Engineers at the University of Illinois Chicago have created a solar-powered electrochemical reaction that uses wastewater to make ammonia and does it with a solar-to-fuel efficiency that is 10 times better than previous comparable technologies.

The process uses nitrate – which is one of the most common groundwater contaminates – to supply nitrogen and uses sunlight to power the reaction.  The system produces nearly 100% ammonia with almost no hydrogen side reactions.  No fossil fuels are needed, and no carbon dioxide or other greenhouse gases are produced.  The new method makes use of a cobalt catalyst that selectively converts nitrate molecules into ammonia.

Not only is the reaction itself carbon-neutral, which is good for the environment, but if it is scaled up for industrial use, it will consume wastewater, thereby actually being good for the environment.  The new process is the subject of a patent filing and the researchers are already collaborating with municipal corporations, wastewater treatment centers, and others in industry to further develop the system.

**********

Web Links

Combining sunlight and wastewater nitrate to make the world’s No. 2 chemical

Photo, posted August 29, 2018, courtesy of Montgomery County Planning Commission via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Floating Renewable Energy | Earth Wise

By Leave a Comment

A team of researchers at Texas A&M University believes that the next generation of offshore energy could come in the form of a synergistic combination of multiple renewable energy generators installed on a floating offshore platform.

Their concept for the ocean renewable energy station comprises wind, wave, ocean current, and solar energy elements that could generate electricity for anything from a coastal or island community to a research lab or military unit.  The station would be tethered to the sea bottom and could be used in locations where the water depth increases quickly, such as along the U.S. Pacific Coast or Hawaii.

Offshore wind is already commercially competitive, while wave-energy converters so far have been less cost-effective and only useful for specialized, smaller-scale applications.  The proposed ocean renewable energy station would make use of multiple different methods of electricity generation and incorporate innovative smart materials in the wave energy converters that respond to changes in wave height and frequency and allow for more consistent power production.

Denmark is already building a huge multi-source, multi-purpose ocean energy island.  This world’s first energy island will be 30 acres in area and serve as a hub for 200 giant offshore wind turbines generating 3 GW of electric power.  It is the largest construction project in Danish history, and will cost an estimate $34 billion.  As well as supplying other European countries with electricity, the goal is to use the new offshore island to produce green hydrogen from seawater, which can also be exported.  Large battery banks on the island will store surplus electricity for use in times of high demand.

**********

Web Links

Research Underway On Floating Renewable Energy Station

Photo, posted September 27, 2014, courtesy of Eric Gross via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recycling Solar Panels | Earth Wise

By Leave a Comment

It is inevitable that the things we make and use eventually outlive their useful lives and become waste that we have to deal with.  Solar panels, despite their impressively long lifetime, can’t escape this general principle.   As pioneering solar panels near the end of their 30-year electronic lives, they could well become the world’s next big wave of e-waste.

According to the International Renewable Energy Agency, nearly 90 million tons of solar panels will have reached their end of life by the year 2050, resulting in about 7 million tons of new solar e-waste per year.

Solar photovoltaic deployment has grown at unprecedented rates in recent years.  The total global installed capacity is about 600 GW today; projections are that there will be 1,600 GW by 2030 and 4,500 GW by 2050.

Solar panels contain valuable materials, including silver and high-purity silicon.  But current recycling procedures are not cost-effective.   Only about 10% of panels are currently recycled in the U.S.   The rest go to landfills or are shipped overseas to become another country’s problem.

Before solar waste becomes a major problem, the industry needs to better address the issue.  Strategies include improving the design of panels to align with recycling capabilities as well as developing new recycling methods that can more efficiently extract and purify the valuable materials in the panels.  Industry researchers are also looking into ways to repair and resell panels that are still in good condition and to repurpose old panels for less demanding functions like e-bike charging stations and housing complexes.

Like most things, solar panels do fail over time and with a rapidly growing number of them in the world, we need to figure out how to avoid them adding to the world’s problems.

**********

Web Links

Solar Panels Are Starting to Die. Will We be Able to Recycle the E-Waste?

Photo, posted January 6, 2006, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A High-Tech Fire Alarm | Earth Wise

By Leave a Comment

In recent years, wildfires have been a global problem, notably in California, Brazil, and Australia.  It has become increasingly important to be able to respond to new fires as soon and as quickly as possible.  Such response can make the task of extinguishing them easier, thereby reducing the amount of damage and the loss of property and life.

Traditional methods for detecting forest fires include satellite monitoring, ground patrols, and watch towers, all of which have high labor and financial costs but suffer from low efficiency.  Remote sensing technologies are becoming increasingly common but rely on batteries for power, requiring servicing in remote locations to replace depleted batteries.  Solar cells represent an alternative to batteries, but it is challenging to use them in forests because of shading and foliage coverage.

A team of researchers at Michigan State University has developed a remote forest fire detection and alarm system powered by nothing more than the movement of tree limbs in the wind.  The device is known as an MC-TENG, which is an acronym for multilayered cylindrical triboelectric nanogenerator.  The triboelectric effect is a phenomenon where certain materials become electrically charged when they separate from a second material with which they were previously in contact.  In the new device, two cylindrical sleeves fit within one another – one anchored and the other free to slide.  The device is tied to a tree branch and when the branch sporadically moves in the wind, electricity is generated and stored in a carbon-nanotube-based micro supercapacitor.  This powers a sensing system that can continuously monitor environmental conditions without requiring any maintenance.

A combination of carbon monoxide and temperature sensors provides a high-tech fire alarm that can operate continuously in the most remote forest.

**********

Web Links

Self-Powered Alarm Fights Forest Fires, Monitors Environment

Photo, posted August 3, 2012, courtesy of Lukas Schlagenhauf via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Building For Climate Change

By Leave a Comment

The manifestations of climate change are creating increasingly familiar images:  floodwaters rising up house windows, charred buildings in the wake of wildfires, and homes and businesses demolished by storm winds. As these sorts of calamities become ever more common, changes to how houses are built are going to be necessary.

How can homes become more resilient against severe and unpredictable weather?

Research at Carlton University’s Sprott School of Business looks at this issue.

As an example, houses can be framed and finished in certain ways that help protect them from wind and flooding.  But such methods are currently only happening in the custom-build fringes of the housing sector.  Widespread adoption will require, at the minimum, significant changes to building codes.

Revising building codes is not an easy matter.  The codes themselves are highly technical and complex, and beyond that, the process Is often politicized.

Even simple things like hurricane ties, which are small pieces of hardware that prevent a roof from lifting during a severe wind are not now included in building codes.  Insurance companies support their use as inexpensive protection for houses.  But even though the overall cost is relatively minor, the building industry pushes back at the additional expense.

The need to reduce carbon emissions has created a push for sustainable housing.  But the increasingly erratic weather means that houses also need resilience and adaptation.  These features will inevitably add costs and incorporating them into building codes requires producing convincing business cases.

The U.S. experienced 394 natural catastrophe events last year costing $225 billion in damage.  Finding ways to make homes and businesses more resilient is not just a good idea; it is essential.

**********

Web Links

How to Start Weather-Proofing Homes for Unpredictable Weather

Photo, posted June 12, 2008, courtesy of U.S. Geological Survey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Plant-Based Jet Fuels

By Leave a Comment

The global aviation industry uses a whole lot of fuel:  more than 5 million barrels a day.  It is an incredibly energy-intensive industry and almost all of its energy comes from petroleum-based fuels.

While other large energy sectors such as electric power, ground transportation and commercial buildings have well-defined pathways to adopting renewable energy sources, the aviation industry does not have such a straightforward way to make a transition to sustainability.  Electrifying planes using batteries or fuel cells is very challenging for a number of reasons, notably the weight restrictions on aircraft.  So liquid biofuels as replacements for petroleum-based fuels remain the most promising approach.

A new study at the Lawrence Berkeley National Laboratory concludes that sustainable plant-based biofuels could provide a competitive alternative to conventional petroleum fuels if current development and scale-up initiatives are successful.

Multidisciplinary teams based at the Department of Energy’s Joint BioEnergy Institute are focused on optimizing each stage of the bio-jet fuel production process.  This includes bioengineering ideal source plants and developing methods for efficiently isolating the carbohydrates in non-food biomass that bacteria can digest and bioconvert into fuel molecules.

The critical issue is cost.  The theoretical cost of bio-jet fuel has come down dramatically in recent years but is still around $16 a gallon.  The cost of standard jet fuel is about $2.50 a gallon.  So, the real challenge is bridging that gap.

Reducing the cost of the fuel could come both from the material and process improvements that are underway as well as by finding ways to turn the leftover lignin residuals from the bioconversion process into valuable chemicals. 

**********

Web Links

Bright Skies for Plant-Based Jet Fuels

Photo, posted March 28, 2009, courtesy of Yasuhiro Chatani via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rare Earths From Mining Waste

By Leave a Comment

The 17 rare earth elements have become important parts of much of modern technology.  Despite their name, most of these elements are relatively plentiful in the earth’s crust, but because of their geochemical properties they are typically dispersed and not often found concentrated in minerals.  As a result, economically exploitable ore deposits are uncommon.  There are no significant sources in the U.S.

Rare earths play important roles in high-performance magnets, electric motors in vehicles, wind turbines, microphones and speakers, and in portable electronics like cell phones.  As these applications become ever larger, the need for additional sources of rare earths increases.

Researchers at Idaho National Laboratory and Rutgers University have studied a method for extracting rare-earth elements from mining waste that could greatly increase the world’s supply of these valuable materials.

It turns out that large amounts of rare earths exist in phosphogypsum, a waste product from producing phosphoric acid from phosphate rock.  The U.S. alone mined 28 million tons of phosphate rock in 2017.  (Phosphoric acid is used in the production of fertilizers and other products).

The researchers estimate that more than a billion tons of phosphogypsum waste sits in piles at storage sites across the U.S. alone.   World-wide, about 100,000 tons of rare earth elements per year end up in phosphogypsum waste.  This compares to the total current world-wide production of rare earth oxides of 126,000 tons.

The researchers studied methods for extracting the elements from the waste. A method utilizing a common environmental bacterium showed great promise.

There are concerns about residual radioactivity and other environmental issues in dealing with the waste material, but the world’s supply of rare earth elements might become much greater based on this research.

**********

Web Links

Critical Materials: Researchers Eye Huge Supply of Rare-Earth Elements from Mining Waste

Photo, posted June 19, 2015, courtesy of David Stanley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

WAMC Northeast Public Radio

WAMC/Northeast Public Radio is a regional public radio network serving parts of seven northeastern states (more...)