fuel cells

Hydrogen-powered aviation

December 16, 2024 By EarthWise Leave a Comment

The transportation sector is responsible for about a quarter of human-generated greenhouse gas emissions. Most of the energy used by transport systems comes from fossil fuels. The transition to electric vehicles – cars, trucks, and buses – is making a real difference. However, the emissions from the aviation industry have continued to grow faster than those of other forms of transportation. There have been increased efforts to develop hydrogen-powered aircraft, but the challenges are substantial.

Hydrogen can be used for aviation both as a directly combusted fuel, or to power electric fuel cells. Its advantages are that its use produces no carbon dioxide, and, in fact, hydrogen produces more energy per pound than jet fuel.

A study by researchers at MIT looked at the prospects for hydrogen use in aircraft and what needs to be done to make it practical. The biggest issue is that the extra bulk of a hydrogen fuel tank and fuel cells in a plane would have to be offset by weight reductions elsewhere, such as reducing payload (cargo or passengers). This would mean there would need to be more flights, thereby reducing the gains made. The researchers argued that improvements in fuel cell power and more weight efficient fuel systems could eliminate the need for additional flights.

The bigger challenge is the infrastructure for generating and distributing hydrogen. There needs to be green hydrogen – hydrogen produced without carbon emissions – and the infrastructure for getting it to planes where it is needed has to also not produce substantial emissions.

The study suggests that the rollout of hydrogen-based aviation should start at locations that have favorable conditions for hydrogen production.

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Fueling greener aviation with hydrogen

Photo, posted December 20, 2016, courtesy of Dylan Agbagni via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A better way to produce green hydrogen

September 9, 2024 By EarthWise Leave a Comment

Hydrogen has great potential as a fuel and an energy carrier for many applications. Burning it or consuming it in fuel cells does not produce carbon emissions. As a result, there has long been the vision for a future hydrogen economy. Whether the hydrogen economy would ever come about given how various other technologies have evolved over time is questionable. But regardless, hydrogen is valuable for many industrial and commercial applications including the manufacture of ammonia and the refining of metals.

Hydrogen is produced in industrial quantities from natural gas by a carbon-dioxide-producing process known as methane-steam reforming. To take its place as a green energy source, hydrogen needs to be produced by splitting water into its constituent oxygen and hydrogen components by the process of electrolysis.

The problem is economic. Methane-steam reforming produces hydrogen at a cost of about $1.50 per kilogram. Green hydrogen costs about $5 a kilogram.

Researchers at Oregon State University have developed a new photocatalyst that enables the high-speed, high-efficiency production of hydrogen. The material, called RTTA, is a metal organic framework containing ruthenium oxide and titanium oxide. Ruthenium oxide is expensive, but very little is needed. For industrial applications, if the catalyst shows good stability and reproducibility, the cost of the small amount of this exotic material becomes less important.

The photocatalyst, when exposed to sunlight, quickly and efficiently splits water yielding hydrogen. The Oregon State discovery has real potential.

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Oregon State University research uncovers better way to produce green hydrogen

Photo, posted July 7, 2023, courtesy of Bill Abbott via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electricity from chicken feathers

December 4, 2023 By EarthWise Leave a Comment

The food industry generates enormous amounts of waste and by-products. Each year, 40 million tons of chicken feathers are incinerated, causing adverse environmental effects. Not only does it release large amounts of carbon dioxide but also produces toxic gases such as sulfur dioxide.

Researchers at ETH Zurich in Switzerland and Nanyang Technological University in Singapore have developed a way to put chicken feathers to good use by using them to make fuel cells more cost-effective and sustainable.

Using a simple and environmentally friendly process, they extract the keratin from the feathers. Keratin is the protein that helps form hair, nails, the outer layer of skin, and feathers. The extracted keratin is then converted into ultra-fine fibers known as amyloid fibrils. The keratin fibrils are used in the membrane of a fuel cell.

Fuel cells generate clean energy from hydrogen and oxygen with only heat and water as byproducts. At the heart of every fuel cell is a semipermeable membrane that allows protons to pass through but blocks electrons, thereby producing an electric current. Fuel cells are the primary way hydrogen is used to directly generate electricity. Hydrogen cars run on fuel cells.

Conventional fuel cells typically use membranes made from highly toxic chemicals. The new ETH membranes essentially replace these toxic substances with biological keratin.

The researchers are investigating how stable and durable their keratin membrane is and to improve it if necessary. The team has already applied for a joint patent and is looking for partners and investors to further develop the technology and bring it to market.

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Generating clean electricity with chicken feathers

Photo, posted July 10, 2016, courtesy of Matthew Bellemare via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Energy From Fruit Waste | Earth Wise

June 20, 2023 By EarthWise Leave a Comment

In the Back to the Future films, Doc Brown ran his DeLorean time machine on food scraps. It was a fun bit of science fiction. But researchers at the University of British Columbia Okanagan in Canada are investigating the potential for using food waste to generate power.

Food waste is not a candidate to replace solar or wind power, but it could be a source of energy for powering fuel cells. As it is, food waste represents a sustainability challenge because of its detrimental impacts on the economy and the environment. Organic waste represents a significant fraction of the material in landfills and contributes to methane production, air pollution, and other harmful pollutants.

The UBC researchers focused on fruit waste, which is abundantly available in agricultural regions. They have devised microbial fuel cells that convert fruit waste into electrical energy using an anaerobic anode compartment. That is a chamber in which anaerobic microbes – ones that don’t need oxygen – utilize the organic matter to convert it into energy. The microbes consume the fruit waste and produce water while generating bioelectricity.

It is not like the Back to the Future time machine where you can just toss in scraps of whatever is on hand. Different types of fruits provide different results when used in the microbial fuel cell. The process works best when the food waste is separated and ground into small particles. There is a long way to go before the technology could produce bioenergy on a commercial scale, but there is considerable potential for doing something useful with something that is currently worthless.

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UBCO researchers aim to energize fruit waste

Photo, posted July 24, 2011, courtesy of Andrew Girdwood via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Minerals And Metals For A Low-Carbon Future | Earth Wise

February 14, 2020 By EarthWise Leave a Comment

For the past century, economies and geopolitics have largely been driven by our insatiable appetite for oil and fossil fuels in general. As we gradually make the transition to a low-carbon energy future, the focus on oil will shift to sustainable supplies of essential minerals and elements.

The use of solar panels, batteries, electric vehicle motors, wind turbines, and fuel cells is growing rapidly around the world. These technologies make use of cobalt, copper, lithium, cadmium, and various rare earth elements. The need for any one of these things may diminish if alternatives are found, but there will continue to be a growing reliance on multiple substances whose physical and chemical properties are essential to the function of modern devices and technologies.

In some cases, global supplies of particular minerals and elements are dominated by a particular country, are facing social and environmental conflicts, or face other market issues. Shortages of any of them could create economic problems and derail progress much as the oil-related energy crises of the past have.

The world faces challenges in managing the demand for low-carbon technology minerals as well as limiting the environmental and public health damage that might be associated with their extraction and processing. Expanded use of recycling and reuse of rare minerals will be essential.

As the relatively easy sources of these materials become exhausted, other resources will become more attractive. These include various valuable ecosystems, oceanic deposits, and even space-based reserves.

Ushering in the low-carbon future is not a simple matter and will require responsible actions by the world’s governments and industries. In undoing the damage from the oil age, we must avoid new damage from the low-carbon age.

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