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Hidden hydrogen

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The idea of using hydrogen as a fuel or an energy source has been around for a long time.  Hydrogen is the most common element in the universe, but most of it is locked up in various chemical compounds, such as water.  Hydrogen is a clean fuel; burning it or using it to generate electricity in a fuel cell produces no greenhouse gas emissions.  But more than 99% of the hydrogen that people current produce is obtained by methods that result in greenhouse gas emissions.

A new study by scientists at the University of Oxford, the University of Durham in the UK, and the University of Toronto looks at geological environments in which naturally occurring hydrogen could be hiding.  According to the study, over the last billion years, the Earth’s continental crust is likely to have produced enough hydrogen to satisfy the energy needs of modern society for 170,000 years.

Much of that hydrogen is likely to have been lost or is inaccessible; most of it is not economically feasible to extract.  But even the relatively small amount of hydrogen left could provide thousands of years of energy for us.  We just have to be able to find it.

The researchers have developed what they call an “exploration recipe” which identifies where natural hydrogen might be located as well as where it could be commercially feasible to extract.  These places with hydrogen have so-called reservoir rocks and geologic formations that prevent the gas from leaking into the atmosphere.

A few such places have already been identified such as one in Albania.  There are various candidates to explore, even including an area in Kansas.  The study’s authors have founded a company whose mission is to find these natural sources of hydrogen.

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Scientists Say Hidden Hydrogen Could Power the World for 170,000 Years

Photo, posted October 4, 2019, courtesy of Tony Sprezzatura via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Restoring oil well sites with moss

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Researchers at the University of Waterloo in Canada have developed a method for restoring peatlands at tens of thousands of oil and gas exploration sites in Western Canada. 

A well pad is a prepared area used for drilling oil or gas wells, encompassing the site where drilling equipment, wellheads, and related facilities are located.  Preparing well pads involves burying native peatland vegetation under clay or sand, thereby eliminating the ability of the peatland to sequester carbon as well reducing available habitat for wildlife.

Restoring well sites has typically involved planting trees or grasses to eventually establish forests or grasslands.  The Waterloo method returns a well pad to its condition before drilling occurred and is part of ongoing efforts to restore peatlands, which are known to be even more effective for sequestering carbon than tropical forests.

The Waterloo technique involves lowering the surface of a decommissioned well site and transplanting native mosses onto it to effectively recreate a peatland.    They tested the technique to scale at an entire well pad and found that it results in sufficient water for the growth of peatland moss across large portions of the study site.

The results suggest that re-establishment of peatland vegetation on lowered well pads is possible.  The researchers plan to continue monitoring the ecosystem in the study’s well pads to confirm that the transplanted mosses will be self-sustaining over the coming decades.  They will focus on increasing the amount of water that flows from surrounding natural peatlands into the converted well pads to further optimize soil moisture. 

This work could represent an important milestone in ecological restoration.

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Restoring oil wells back to nature with moss

Photo, posted November 6, 2014, courtesy of Chris Boyer / Kestrel Aerial Services via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Fighting honey fraud

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Honey fraud is a significant issue for the food industry.  What is honey fraud?  Typically, it involves mislabeling where honey was produced or what types of flowers the bees collected nectar from.  Honey made from a single type of flower is often more expensive because of the unique flavor it provides or from potential health benefits.  Sometimes even cheap alternatives like sugar syrups are labelled as honey.  It turns out that honey is one of the most fraud-prone commodities in global trade, with fraud estimated to occur in up to 10% of the honey traded internationally.  Honey from some countries, such as China and India, has had 30% or more of samples found to be fraudulent.

Researchers at McGill University in Montreal have developed an AI-powered method to verify the origin of honey thereby ensuring that what is on the label corresponds to what is in the jar.

The McGill method can determine what kind of flowers the bees visited to produce a particular sample of honey.  Previous honey authentication involved pollen analysis, which is ineffective for honey that was processed or filtered.  The new method uses high-resolution mass spectrometry which captures a unique chemical “fingerprint” from the honey.  Machine learning algorithms read the fingerprint to identify the honey’s origin.

The researchers tested their methodology on a variety of honey samples which they then compared with honey from known botanical sources.  Using previous methods for honey authentication can take days.  The McGill method takes only minutes and works regardless of how the honey was processed.

According to the researchers, people deserve to know that the honey they buy is what it claims to be, and honest honey producers deserve protection from fraudulent competitors.

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Fighting honey fraud with AI technology

Photo, posted May 6, 2012, courtesy of Emma Jane via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A new way to recycle plastic

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Researchers at Northwestern University have developed a new method for recycling plastic that is safer, cleaner, cheaper, and more sustainable than those currently in use.  The U.S. is the world’s largest plastic polluter per capita, and we only recycle 5% of our plastics.  There is a pressing need for better technologies for processing different types of plastic waste.

The Northwestern method is designed to break down polyethylene terephthalate or PET, which is the most common type of polyester plastic.  PET plastic is used in food packaging and beverage bottles and represents 12% of total plastics used globally.  It does not break down easily and is therefore a major contributor to plastic pollution.  It mostly either ends up in landfills or, over time, degrades into tiny microplastics or nanoplastics that end up almost everywhere. 

The non-toxic, environmentally friendly, solvent-free Northwestern process first uses an inexpensive molybdenum catalyst to break apart the bonds in PET.  Then the broken plastic is exposed to ambient air.  Just from the trace amounts of moisture in air, the broken-down PET is converted into monomers, which are the building blocks of plastic.  The monomers could then be recycled back into PET products or used to make other valuable materials.

The process is fast and effective and takes just a few hours.  The catalyst is durable and recyclable, meaning it can be used over and over again.  It only works on polyesters, which means it can be used for recycling mixed plastics without sorting them since it will select only the PET from its inputs.

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Plastic recycling gets a breath of fresh air

Photo, posted August 10, 2013, courtesy of Lisa Risager via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A new way to help purify water

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Engineers at the University of Michigan and Rice University have developed a new technology for removing boron from seawater, an important step in turning seawater into safe drinking water.

Boron is a natural component of seawater that remains a toxic contaminant in drinking water after conventional filters remove salts from seawater.  The boron levels in seawater are about twice as high as the World Health Organization’s most lenient limits for safe drinking water and 5 to 12 times higher than what many agricultural plants can tolerate.

Boron passes through the reverse osmosis membranes used in desalination plants in the form of boric acid.  To remove it, the desalination plants normally add a base to the treated water that causes the boric acid to become negatively charged.  An additional membrane then removes the charged boron, and an acid is then added to neutralize the water.  All of this is expensive and complicated.

The new technology uses electrodes that remove boron by trapping it inside pores studded with oxygen-containing structures that bind with boron but let other ions pass through.  Capturing boron with electrodes enables treatment plants to avoid the need for a second stage of reverse osmosis.

Global desalination capacity reached 95 million cubic meters a day in 2019.  The new membranes could save nearly $7 billion a year.  Such savings could make seawater a more accessible source of drinking water for a thirsty world.  Freshwater supplies are expected to meet only 40% of the world’s demand by 2030.

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New water purification technology helps turn seawater into drinking water without tons of chemicals

Photo, posted August 21, 2018, courtesy of Alachua County via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Hybrid beef rice

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There is growing interest in innovative and more environmentally friendly ways to provide protein in our diets.  We’ve heard a great deal about lab-grown or cultured meats and about protein derived from insects. Whether either of these things achieves mainstream acceptance remains to be seen.

Scientists at Yonsei University in South Korea have developed a method for creating cultured beef rice – truly a hybrid food.  The method, described in the journal Matter, results in a nutritious and flavorful food that could be more affordable and have a smaller carbon footprint than current protein sources.

The researchers took rice grains – which are porous and have organized structures – and seeded them with beef muscle and stem cells and allowed them to culture for 9 to 11 days.  The harvested final product is a cell-cultured beef rice.

The hybrid beef rice was steamed and subjected to various food industry analyses, including nutritional value, odor, and texture.  The hybrid rice has 8% more protein and 7% more fat than regular rice.  It was somewhat firmer and more brittle than ordinary rice.  Hybrid rice with higher muscle content had beef- and almond-related odor compounds, while those with higher fat content had compounds corresponding to cream, butter, and coconut oil.

The hybrid rice has low food safety risks and a relatively easy production process.  If commercialized, the hybrid rice would be far less expensive than beef.  The researchers are optimistic that it can be commercialized.  They are continuing to work on the processing, hoping to further boost the nutritional value.  Like other unconventional foods under development, the biggest question is ultimately whether people will want to eat it.

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By growing animal cells in rice grains, scientists dish up hybrid food

Photo, posted January 26, 2010, courtesy of CIAT / Neil Palmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cryopreserving Corals | Earth Wise

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Recent climate models estimate that if the effects of climate change are not mitigated soon enough, 95% of the world’s corals could die by the mid 2030s.  Given the current rate of greenhouse gas emissions, this is an increasingly likely outcome.  Coral reefs are estimated to have a $10 trillion economic value apart from their essential role in marine ecosystems.

Researchers at the University of Hawaii at Manoa have demonstrated a successful technique for cryopreserving entire coral fragments; in other words, preserving coral using cold temperatures and successfully reviving them.

Existing coral cryopreservation techniques rely on freezing sperm and larvae, which can only be collected during spawning events, which occur only a few days each year for coral species.  This makes it logistically very challenging for researchers and conservationists.

The Hawaiian researchers focused on a process called isochoric vitrification, which is a method of freezing with liquid nitrogen that prevents the formation of ice crystals.  They tested the technique with thumbnail-sized fragments of coral, freezing them in small aluminum chambers which restrict the growth of ice crystals that would otherwise damage delicate polyp tissues.  Once the chambers were warmed, the fragments were transferred to seawater and allowed to recover.  They found that the revived corals behaved the same as those that were never cooled.

The process holds great promise to conserve the biodiversity and genetic diversity of coral.  If the process can be scaled up, it may be possible to preserve as many species of coral as possible by 2030, when it may no longer be viable for them to survive in the warming and acidifying oceans.

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Cryopreservation breakthrough could save coral reefs

Photo, posted June 2, 2023, courtesy of USFWS – Pacific Region via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Harvesting Water From The Air | Earth Wise

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Engineers at MIT have created a superabsorbent material that can soak up significant amounts of moisture from the air, even in desert-like conditions.

The material is a transparent, rubbery substance made from hydrogel, which is a naturally absorbent material that is already widely used in disposable diapers.  The MIT researchers enhanced the absorbency of hydrogel by infusing it with lithium chloride, which is a type of salt that is a powerful desiccant.

They found that they could infuse hydrogel with more salt than was possible in previous studies.  Earlier studies soaked hydrogels in salty water and waited 24 to 48 hours for the salt to infuse into the gels.  Not much salt ended up in the gels and the material’s ability to absorb water vapor didn’t change much.  In contrast, the MIT researchers let the hydrogels soak up the salt for 30 days and found that far more salt was absorbed into the gel.  The result was that the salt-laden gel could then absorb and retain unprecedented amounts of moisture, even under very dry conditions.

Under very dry conditions of 30% relative humidity, the gels captured 1.79 grams of water per gram of material.  Deserts at night have those levels of relative humidity, so the material is capable of generating water in the desert.

The new material can be made quickly and at large scale.  It could be used as a passive water harvester, particularly in desert and drought-prone regions.  It could continuously absorb water vapor from the air which could then be condensed into drinking water.  The material could also be used in air conditioners as an energy-saving, dehumidifying element.

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This salty gel could harvest water from desert air

Photo, posted July 26, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Saving Our Soil | Earth Wise

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The majority of food we eat is grown in topsoil, that carbon-rich, black soil that nurtures everything from carrots to watermelons.  The fertility of this soil has developed over eons.    

But over the past 160 years, the Midwestern United States has lost 63.4 billion tons of topsoil due to farming practices.  In fact, Midwestern topsoil is eroding between 10 and 1,000 times faster than it did in the pre-agricultural era.  The rate of erosion is 25 times greater than the rate at which topsoil forms.

According to new research from the University of Massachusetts-Amherst, this rapid and unsustainable rate of topsoil erosion can be drastically reduced by utilizing an agricultural method already in practice: No-till farming.  This method, which is currently practiced on 40% of cropland acres in the Midwest, can extend our current level of soil fertility for the next several centuries.   

In the study, which was recently published in the journal Earth’s Future, the research team looked at the current business-as-usual method, under which approximately 40% of the midwestern U.S.’s acres are no-till farmed, all the way up to 100% adoption of no-till methods. 

If the U.S.’s current agricultural practices remain largely unchanged, approximately 9.6 billion tons of topsoil will be lost over the next century alone.  However, approximately 95% of the erosion in the business-as-usual scenario could be prevented by adopting 100% no-till farming practices. 

Saving our soil by improving our farming methods has implications for everything from food security to climate change mitigation. 

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Saving Our Soil: How to Extend U.S. Breadbasket Fertility for Centuries

Photo, posted January 19, 2022, courtesy of Terri Dux via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Large Lakes In Decline | Earth Wise

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Globally, freshwater lakes and reservoirs hold 87% of the planet’s liquid freshwater, making them a valuable resource for both people and wildlife.  Despite their value, the long-term trends and changes to water levels of lakes have been largely unknown – until now.

According to a new assessment recently published in the journal Science, more than half of the largest lakes around the world are losing water.  Using satellite observations and climate data, the research team created a technique to measure changes in water levels in nearly 2,000 of the world’s biggest lakes and reservoirs, representing 95% of the total lake water storage on Earth.

The results are staggering.  According to the findings, 53% of Earth’s largest lakes and reservoirs now store significantly less water than they did in 1992.  The total amount of water lost is estimated to be 144.5 cubic miles, which is equivalent to the volume of 17 Lake Meads (the largest reservoir in the U.S.). 

Unsurprisingly, climate warming and human consumption were the main drivers of water loss from lakes, whereas sedimentation — the buildup of debris — was the biggest driver of water loss in reservoirs.  Roughly one-quarter of the world’s population – two billion people – live in the basin of a drying lake, indicating the urgent need for sustainable water resources management.

But the news is not entirely bleak.  According to the research team, the new method of tracking lake water storage trends can give water managers and communities insight into how to better protect this critical resource. 

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Satellites reveal widespread decline in global lake water storage

Photo, posted February 10, 2010, courtesy of Ninara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Storing Carbon Dioxide In The Ocean | Earth Wise

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Reducing the amount of carbon dioxide entering the atmosphere means either shutting down emission sources (primarily curbing the use of fossil fuels) or capturing the CO2 as it is emitted.  Capturing carbon dioxide from smokestacks and other point sources with high concentrations is relatively efficient and can make economic sense.  Removing it from the air, which even at today’s dangerously high levels contains only 400 parts per million, is difficult and energy intensive.  And even when it is removed, it then must be stored somewhere.

Researchers at Lehigh University have developed a novel way to capture carbon dioxide from the air and store it in what is effectively the infinite sink of the ocean.  The approach uses an innovative copper-containing filter that essentially converts CO2 into sodium bicarbonate (better known as baking soda.)  The bicarbonate can be released harmlessly into the ocean.

This technique has produced a 300 percent increase in the amount of carbon dioxide captured compared with existing direct air capture methods.   It does not require any specific level of carbon dioxide to work.  The filter becomes saturated with the gas molecules as air is blown through it.  Once this occurs, seawater is passed through the filter and the CO2 is converted to dissolved bicarbonate.  Dumping it into the ocean has no adverse effect on the ocean.  It doesn’t change the salinity at all, and the stuff is slightly alkaline, which will help reduce ocean acidification.

Reusing the filter requires cleaning it with a sodium hydroxide solution, which can be created from seawater using electricity generated by waves, wind, or sun.

The filter, called DeCarbonHIX, is attracting interest from companies based in countries around the world.

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Path to net-zero carbon capture and storage may lead to ocean

Photo, posted March 10, 2007, courtesy of Gail via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Self-Deicing Roads | Earth Wise

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Driving on snowy or icy roads can be pretty dangerous.  That is why roads are salted or coated with sand to provide traction in icy weather.  But excessive use of these substances is bad for the environment and sometimes a storm will blow in before the roads can be coated.

In a paper published in the American Chemical Society Journal ACS Omega, researchers in China describe a method of adding microcapsules filled with a chloride-free salt mixture to the asphalt with which roads are paved.  The idea is to provide the road itself with long-term snow melting capabilities.

The researchers prepared a sodium-acetate salt and combined it with a surfactant, silicon dioxide, sodium bicarbonate, and blast furnace slag, which is a waste product from power plants.  The substances were reduced to a fine powder and then coated with a polymer solution to form tiny microcapsules.  The microcapsules were then used to replace some of the standard mineral filler in asphalt.

Lab experiments showed that the special additive lowered the freezing point of water on the asphalt to -6 degrees Fahrenheit.   The researchers estimated that a 2-inch-thick layer of the anti-icing asphalt would be effective at melting snow for seven or eight years.  A real-world pilot test of the coating on a highway offramp showed that it melted snow that fell on the road whereas an uncoated road required snow removal operations.

According to the researchers, given the cost of materials used for the coating and its potential useful lifetime, it could be a practical and economic enhancement for wintertime snow and ice removal.  Maybe we’ll someday have roads that can fairly often deice themselves. 

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Keeping drivers safe with a road that can melt snow, ice on its own

Photo, posted April 8, 2007, courtesy of the Oregon Department of Transportation via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Vaccine For Bees | Earth Wise

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The US has seen annual reductions in honey bee colonies since 2006.  According to the USDA, there are many factors that have contributed to the decline.  These include parasites, pests, insecticides, disease, and a phenomenon called Colony Collapse Disorder in which worker bees abandon a hive and leave behind the queen.

One of major threats to bee colonies is American foulbrood disease, which is a bacterial condition that attacks bee larvae.  It is highly contagious and has no cure.  Until now, the only treatment method required burning the colony of infected bees along with the hives and equipment and treating nearby bee colonies with antibiotics.

Recently, the USDA has approved a conditional license for the world’s first vaccine for honey bees.  The vaccine contains inactive bacteria of the type that causes American foulbrood disease.

The vaccine is incorporated into the royal jelly fed by worker bees to the queen bee.  The queen ingests the feed and keeps some of vaccine in her ovaries.  This gives bee larvae immunity to the disease as they hatch and thereby reduces death from the illness.

According to the California State Beekeepers Association, the new vaccine could be a major breakthrough for protecting bees.  Preventing the infection in hives could avoid costly, destructive measures and allow the beekeepers to focus on other important elements of keeping bees healthy.

Bees as pollinators play a critical role in many ecosystems.  For humankind, pollinators such as bees, birds, and bats are responsible for about a third of the world’s crop production.

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US approves world’s first vaccine for declining honey bees

Photo, posted June 6, 2022, courtesy of Bernd Thaller via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A New Method of Refrigeration | Earth Wise

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Salting roads before winter storms is a familiar sight in the Northeast.  The purpose is to change the temperature at which ice can form on the road.  The underlying concept has formed the basis of a new method of refrigeration that has been dubbed “ionocaloric cooling.”

It is described in a paper published in the journal Science by researchers at the Lawrence Berkeley National Laboratory.  The method takes advantage of how energy in the form of heat is either stored or released when a material changes phase – such as water changing from ice to liquid and vice versa.  Melting absorbs heat from the surroundings while freezing releases heat.  An ionocaloric refrigerator makes use of this phase and temperature change using an electrical current to add or remove ions provided from a chemical salt.

The potential is to make use of this refrigeration cycle instead of the vapor compression systems in present-day refrigerators, which make use of refrigerant gases that are greenhouse gases, many of which very powerful ones.  The goal is to come up with a system that makes things cold, works efficiently, is safe, and doesn’t harm the environment. 

There are a number of alternative refrigeration systems under development that make use of a variety of mechanisms including magnetism, pressure, physical stretching, and electric fields.  Ionocaloric cooling uses ions to drive solid-to-liquid phase changes.

Apart from some very promising theoretical calculations of the system’s potential, the researchers have also demonstrated the technique experimentally.  They have received a provisional patent for the technology and are continuing to work on prototypes to demonstrate its capabilities and amenability to scaling up.

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Berkeley Lab Scientists Develop a Cool New Method of Refrigeration

Photo, posted October 29, 2021, courtesy of Branden Frederick via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Windows To Cool Buildings | Earth Wise

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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

Mosquito Magnets | Earth Wise

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We’ve all probably had the experience of being in the great outdoors with other people and having some of them being nearly devoured by mosquitoes while others didn’t get bitten at all.  It seemed like some people are mosquito magnets while others just aren’t the insects’ cup of tea, so to speak.

There have been various theories proposed over the years including such things as it being a question of blood type, or it having to do with how close one’s blood vessels are to their skin surface.

A new study by the Howard Hughes Medical Institute and the Rockefeller University has uncovered what appears to be the real explanation.  According to the paper published in the journal Cell, certain body odors are the deciding factor.  Every person has a unique scent profile associated with different chemicals present on their skin.  The researchers found that people whose skin produces high levels of carboxylic acids are the most attractive to mosquitos.

The researchers collected scent samples from participants by having them wear silk stockings on their arms for six hours.  The nylons were then cut into pieces and the pieces exposed to mosquitos.  After several months of head-to-head battles between various nylon samples, the study clearly demonstrated that the samples from subjects with higher levels of carboxylic acids in the skin were far more attractive to mosquitos.

Humans produce the substance at much higher levels than other animals.  There is little one can do about their own levels.  Changing one’s diet or what soap they use doesn’t seem to make a difference. 

Perhaps researchers can come up with some method of breaking down carboxylic acids in the skin in the future.  Until such time, there are really people who are mosquito magnets.

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Some People Really Are Mosquito Magnets, and They’re Stuck That Way

Photo, posted September 4, 2014, courtesy of James Gathany / Centers for Disease Control via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Better Way To Recycle Plastics | Earth Wise

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The global accumulation of plastic waste is an ever-growing problem.  At least five billion tons of the stuff has accumulated on land and sea and is even showing up in the bodies of animals and humans.  Recycling plastic instead of making even more of it seems like an essential thing to do but it has proven to be extremely challenging.

The main problem is that plastics come in many different varieties and the ways of breaking them down into a form that can be reused are very specific to each type of plastic.  Sorting plastic waste by plastic type is extremely impractical at large scale.  Certainly, most consumers can’t do it themselves.  As a result, most plastic gathered in recycling programs ends up in landfills.

New research at MIT has developed a chemical process using a catalyst based on cobalt that is very effective at breaking down a variety of plastics, including polyethylene and polypropylene, which are the two most widely produced plastics.   The MIT process breaks plastics down into propane.  Propane can be used as a fuel or as a feedstock for making many different products, including new plastics.

Plastics are hard to recycle because their long-chain molecules are very stable and difficult to break apart.  Most chemical methods for breaking their chemical bonds produce a random mix of different molecules which would somehow have to be sorted out in order to be useful for anything.

The new process uses a catalyst called a zeolite that contains cobalt nanoparticles.  The catalyst selectively breaks down various plastic polymer molecules and turns more than 80% of them into propane.

The researchers are still studying the economics and logistics of the method, but it looks quite promising.

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New process could enable more efficient plastics recycling

Photo, posted April 25, 2016, courtesy of NOAA Coral Reef Ecosystem Program via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Better Way To Recycle Plastic | Earth Wise

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The current state of plastic recycling is not very effective.  Plastic recycling is only able to replace 15-20% of the fossil-fuel-derived raw material needed to produce society’s demand for plastic.

Researchers at Chalmers University in Sweden have now demonstrated how the carbon content in mixed waste could be used to replace all of the fossil raw materials in the production of new plastic.  In principle, their technology could completely eliminate the climate impact of plastic materials.

According to the researchers, there are enough carbon atoms in waste to meet the needs of all global plastic production.

The Chalmers process is based on thermochemical technology and involves heating waste to 1100-1500 degrees Fahrenheit.  The waste is thereby vaporized and when hydrogen is added, becomes a carbon-based substance that can replace the fossil-fuel building blocks of plastic.  The method does not require sorting the waste materials.  Different types of waste, such as old plastic products and even paper cups, with or without food residues, can be fed into the recycling reactors.  The researchers are now developing the techniques required to utilize their recycling technology in the same factories in which plastic products are currently being made from fossil oil or gas.

The principle of the process is inspired by the natural carbon cycle in which plants break down into carbon dioxide when they wither and die, and then photosynthesis uses carbon dioxide and solar energy to grow new plants.

Producing new plastics would no longer require petroleum or other fossil fuels as raw materials.  If the energy needed to drive the recycling reactors is taken from renewable sources, plastics could become the basis of a sustainable and circular economy.

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Pioneering recycling turns mixed waste into premium plastics with no climate impact

Photo, posted August 10, 2013, courtesy of Lisa Risager via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Removing Lead From Water With Beer Yeast | Earth Wise

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Lead and other heavy metals in water are a serious global problem that is worsening because of electronic waste and discharges from mining operations.  In the U.S., over 12,000 miles of waterways are impacted by mine-drainage water that is rich in heavy metals.

Lead in particular is highly toxic, especially to children.  The European Union established a standard for allowable lead in drinking water of only 5 parts per billion.  In the US, the EPA has declared that no level of lead at all is safe.

Researchers at MIT have recently discovered that inactive yeast can be effective as an inexpensive, abundant, and simple material for removing lead contamination from drinking water supplies.  The MIT study shows that the method works even at parts-per-billion levels of contamination.

The method is called biosorption, in which inactive biological material is used to remove heavy metals from water.  Previously, it has been studied at parts-per-million contaminant levels, but the MIT study shows that it works at much lower levels as well.

The team studied a type of yeast widely used in brewing.   The yeast cells used are inactive and desiccated and require no special care.  Such yeast is abundantly available as a waste product from beer brewing and various other fermentation-based industrial processes. 

The researchers estimate that to clean a water supply for a city the size of Boston would require about 20 tons of yeast a day, or 7,000 tons a year.  That seems like a lot, but one single brewery, the Boston Beer Company, generates 20,000 tons a year of surplus yeast that is no longer useful for fermentation.

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Could used beer yeast be the solution to heavy metal contamination in water?

Photo, posted September 5, 2017, courtesy of Allagash Brewing via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Better Way To Capture Carbon | Earth Wise

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The goal of carbon capture and storage technology is to remove carbon dioxide from the atmosphere and safely store it for the indefinite future.  There are existing industrial facilities that capture carbon dioxide from concentrated sources – like the emissions from power plants.  The technology currently captures and stores only about a tenth of a percent of global carbon emissions.

Most existing CCS technologies use chemical binders to trap carbon dioxide quickly and efficiently, but they are extraordinarily energy intensive as well as expensive.

Researchers at the University of Colorado Boulder have developed a new tool that could lead to more efficient and cheaper ways to capture carbon dioxide directly out of the air.  The tool predicts how strong the bond will be between carbon dioxide and a candidate molecule for trapping it – that is, a binder.  This new electrochemical diagnostic tool can be used to identify suitable molecular candidates for capturing carbon dioxide from everyday air.

Current carbon capture technologies are very expensive at the scale required to be able to turn the captured CO2 into useful substances, such as carbonates – which are an ingredient in cement – or formaldehyde or methanol, which can be used as fuels.  Making useful materials out of the captured CO2 is an important way to offset the cost of capturing it that merely storing it away does not permit.

The new electrochemical analytical tool developed by the Colorado researchers offers the potential for identifying binders that will be more efficient and less expensive, thereby making direct air carbon capture a realistic part of the efforts to address climate change.

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New method could lead to cheaper, more efficient ways to capture carbon

Photo, posted October 25, 2015, courtesy of Frans Berkelaar via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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