Engineers at ETH Zurich, the Swiss research university, have made a rooftop reactor that draws carbon dioxide and water vapor from air, then uses solar energy to turn the ingredients into hydrocarbon fuel. 
The system is made up of three sections. 
The first section sucks in air, extracts water and carbon dioxide from it, then sends those to the second chamber. 
The second chamber is on the business end of a solar concentrator, which gathers, focuses, and intensifies sunlight 3,000-fold to heat the second chamber’s interior to about 1,500°C, or more than 2,700°F. 
Inside the hot reactor, a cerium oxide structure absorbs oxygen from the carbon dioxide and water, producing hydrogen and carbon monoxide, which combine to create synthesis gas, a sort of all-purpose combustible vapor that can be used to make a variety of volatile products.
At that point, the synthesis gas can be siphoned off and used as fuel or the gas can be directed into a third part of the reactor, which condenses the gas into liquid kerosene or methanol.
The system is carbon neutral: although it produces hydrocarbon fuel, the fuel itself is made from carbon already in the air. When the fuel is burned, it doesn’t add new greenhouse gas to the atmosphere.
TRENDPOST: The reactor could be crucial in poor countries where kerosene is a common fuel for cooking, heating, and lighting.
Without kerosene, many rural areas in emerging nations burn wood, deforesting their locales, which can lead to erosion, desertification, and other environmental damage.
Installing the systems could be done following the model of the Solar Electric Light Fund, which establishes revolving loan funds in low-income countries to buy solar power systems, then trains local residents to install and maintain them.
ETH Zurich’s rooftop kerosene refinery.
Photo: ETH Zurich

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