liquid fuel

Liquid Fuel From Sunshine | Earth Wise

July 6, 2023 By EarthWise Leave a Comment

A key goal of artificial photosynthesis research is to be able to produce a useful liquid fuel using only carbon dioxide, water, and sunlight in a single step. Such a so-called solar fuel would produce net zero carbon emissions and would be completely renewable.

Bioethanol has long been touted as a green alternative to fossil fuels, since it is made from plants rather than petroleum. But producing it takes up agricultural land that could be used to grow food instead and there are emissions associated with many aspects of the process by which plant mass becomes fuel.

Researchers from the University of Cambridge in the UK have developed a so-called artificial leaf that produces ethanol or propanol – usable liquid fuels – in a single step. They developed a copper and palladium-based catalyst that allows the artificial leaf to directly produce multicarbon complex chemicals. Earlier versions of artificial leaves could make simple chemicals, such as syngas, which would then require additional processing to turn into high-density fuels.

The new device produces liquid fuel from carbon dioxide and water simply by shining sunlight on it.

At present, the artificial leaf is a proof-of-concept device that exhibits only modest efficiency. The researchers are working to optimize the device’s light absorbers so that they can better make use of sunlight and to optimize the catalyst so that it can convert more of the sunlight into fuel. In addition, the device needs to be scaled up so that it can produce large volumes of fuel.

All that being said, it is an important step towards people being able to do what plants have been doing for millions of years.

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Driving on sunshine: clean, usable liquid fuels made from solar power

Photo, posted March 23, 2015, courtesy of Astro via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Liquid Fuel From The Sun

February 21, 2019 By EarthWise Leave a Comment

Most forms of energy we use ultimately come from the sun in one way or another. Even fossil fuels are the end product of millions of years of plant life that captured solar energy. The advantage fossil fuels have over direct solar power is that they are, in fact, fuels and therefore can be stored for use when needed.

Scientists in Sweden have now developed a specialized fluid that absorbs some of the sun’s energy, holds it for months or even years, and then releases it when needed. This solar thermal fuel is like a rechargeable battery for heat rather than electricity.

The special fluid is pumped through transparent tubes where ultraviolet light from the sun excites its molecules into an energized state. A compound called norbornadiene is converted into quadricyclane. The quadricyclane is a quite stable substance until it is passed over a cobalt-based catalyst, which causes it to turn back into norbornadiene and release copious amounts of heat.

Such a solar thermal fuel could be stored in uninsulated tanks in homes or factories or piped or trucked to where it was needed. It could then be used for water heaters, dishwashers, or clothes driers. The room temperature fluid quickly warms to about 183 degrees when passed over the catalyst, plenty warm enough for heating a home or office. Both the fuel and the catalyst are damaged very little by the reactions, so the process can be recycled many times.

There is much development work needed to optimize shelf life, energy density, good recyclability and other properties before this technology can be commercialized but there are at least 15 groups around the world now studying this intriguing way to get liquid fuel from the sun.

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Scientists transform sunlight into a liquid fuel that can be stored for 18 years

Photo, posted August 17, 2009, courtesy of Hiromichi Torihara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.