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Hydrogen And The Methane Problem | Earth Wise

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Theoretically, hydrogen could be the fuel of the future.  It is the most common element in the universe and its combustion produces no harmful emissions.  Most industrial hydrogen comes from a process called steam reforming that extracts it from natural gas – basically methane.  Carbon dioxide is a byproduct of the process.   But it is also possible to get hydrogen by breaking down water resulting only in oxygen as a byproduct.   There is a great deal of ongoing development of so-called green hydrogen.

New research from Princeton University and the National Oceanic and Atmospheric Administration has uncovered a potential problem associated with the use of hydrogen as a clean fuel. 

There is a molecule in the atmosphere called the hydroxyl radical.  It is known as “the detergent of the troposphere”.  It plays a critical role in eliminating greenhouse gases such as methane and ozone from the atmosphere.  It turns out that the hydroxyl radical also reacts with any hydrogen gas in the atmosphere and there is only so much hydroxyl to go around.  If large amounts of hydrogen were to enter the atmosphere, much of the hydroxyl radical would be used up reacting with it and there would be much less available to break down methane.  As a result, there would end up being more methane in the atmosphere, and methane is a powerful greenhouse gas.

The bottom line is that there would need to be proactive efforts to limit the amount of hydrogen getting into the atmosphere whether from producing it, transporting it, or anyplace else in the value chain.  Otherwise, the hydrogen economy would cancel out many of the climate benefits of eliminating fossil fuels.

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Switching to hydrogen fuel could prolong the methane problem

Photo, posted June 12, 2021, courtesy of Clean Air Task Force via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Storing Sunshine To Make Electricity On Demand | Earth Wise

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

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

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

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

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Converting solar energy to electricity on demand

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

Earth Wise is a production of WAMC Northeast Public Radio.

Plastic From Algae | Earth Wise

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Many researchers consider algae to be one of the best renewable resources for replacing fossil fuels and even as a food source.  The green microalgae Nannochloropsis salina is already a common source of omega-3 fatty acids that are sold as dietary supplements.  As a result, that algae strain is already grown on a large scale for the production of omega-3 products.

A group of researchers at UC San Diego has developed a way to make use of the waste stream from that production to create plastics and other useful products.  Currently, when the algae is processed to extract the omega-3 oil, leftover oils comprising more than 70% of the starting material are either thrown away or burned. 

The UCSD team has developed a process to purify and convert this waste stream into azelaic acid, which is a building block for flexible polyurethanes.   These materials have all kinds of commercial applications from flip-flops and running shoe soles to mattresses and yoga mats.

By analogy to the use of animals by native American tribes, the researchers wanted to “use the whole buffalo” in their solution for algae processing waste and therefore figured out how to convert heptanoic acid – another substance in the algae waste stream – into a food flavoring and fragrance.  The flavoring molecule is valued at over $500 per kilogram.

The work, published in the journal Green Chemistry, demonstrates that an algae-source waste stream has both the practical and economic potential to support production of polyurethanes.  The team is already working with shoe companies to commercialize the technology.  With mounting concern over petroleum-based plastic waste, renewable plastic made from algae is an attractive alternative.

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Researchers Turn Algae Leftovers into Renewable Products with Flare

Photo, posted November 8, 2006, courtesy of Adam Moore via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Keeping Plants Plump

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The leading cause of crop failures worldwide is drought.  Ironically, the very close runner-up is flooding.  Facing a changing and increasingly erratic climate, farmers need all the help they can get in protecting their crops.

Researchers at the University of California, Riverside, have created a chemical to help plants hold onto water, which could stem the tide of massive annual crop losses from drought.  Details of the team’s work is described in a paper published in Science.

The chemical is called Opabactin, but is also known as “OP.” OP is gamer slang for overpowered, referring to the best character or weapon in a game.

OP mimics abscisic acid, or ABA, which is the natural hormone produced by plants in response to drought stress.  ABA slows a plant’s growth, so it doesn’t consume more water than is available and doesn’t wilt.  OP is 10-times stronger than ABA, which makes it a super hormone.  It works fast.  Within hours, there is a measurable improvement in the amount of water plants release.  Because it works so quickly, OP could give farmers more flexibility in how they deal with drought.   Plants can’t predict the future, but if, for example, farmers think there is a reasonable chance of drought, they could make decisions such as to apply OP to improve crop yields.

The research team is now trying to find a second chemical tool.  Whereas OP slows down plant growth, the team wants to find a molecule that will accelerate it.  Such a molecule could be useful in controlled environments such as indoor greenhouses.  There are times when you want to speed up growth and times when you want to slow it down.

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Game changer: New chemical keeps plants plump

Photo, posted June 7, 2013, courtesy of Bayer CropScience UK via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hacking Photosynthesis

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There is an enzyme known as RuBisCo that is involved in carbon fixation, the process plants use to convert carbon dioxide into sugar molecules.  The RuBisCo molecule is inside the leaves of most plants and is probably the most abundant protein in the world.

RuBisCo picks up carbon dioxide from the air and uses energy from the sun to turn the carbon into sugar molecules.  This process of photosynthesis is pretty much the foundation of life on Earth.

Wonderful as it is, the process is not perfect.  RuBisCo is not very selective in grabbing molecules from the air.  It picks up oxygen as well as CO2 and it produces a toxic compound when it does that.

Plants operate a whole other complicated chemical process to deal with this toxic byproduct and uses up a lot of energy along the way, leaving less energy for making leaves or food that we can eat.

A research program at the University of Illinois called Realizing Increased Photosynthetic Efficiency (or RIPE) has been trying to correct this problem; they have been trying to hack photosynthesis.  And they may well have succeeded.

Using genetic modification on tobacco plants, they have shut down the existing detoxification process and set up a much more efficient new one.  The result is super plants that grow faster and up to 40% bigger.

The next step is to get it to work on plants that people actually rely upon for food, like tomatoes, soybeans and black-eyed peas (which are a staple food crop in sub-Saharan Africa where food is scarce.)

It will be years before we know if the process can really produce more food and be safe, but it may end up leading to a major increase in crop productivity.

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Scientists Have ‘Hacked Photosynthesis’ In Search Of More Productive Crops

Photo, posted June 10, 2013, courtesy of Boon Hong Seto via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Tires From Trees

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Car tires are generally considered environmentally unfriendly because they are predominantly made from fossil fuels.  Natural rubber is generally not used anymore; most tires are made from isoprene, which is chemically very like rubber but is produced by thermally breaking apart molecules in petroleum in a process called cracking.  The isoprene is separated out and purified and then reacted to form the artificial rubber that is the major component in car tires.  The tires eventually end up discarded in giant piles that represent one of our biggest waste disposal problems.

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