Device uses sunlight to make liquid fuel
Scientists from the US and Switzerland have created a prototype machine that harnesses the sun’s energy to make liquid fuels from water.
“We have a big energy problem and we have to think big,” Prof Sossina Haile, who led the study, told The Guardian.
The solar device uses sunlight and cerium oxide to break down water or carbon dioxide into hydrogen or carbon monoxide.
Cerium oxide, an oxide of the rare earth metal cerium, is almost as abundant as copper and when heated the chemical strips oxygen molecules from water and carbon dioxide.
Using a parabolic mirror to focus sunlight, the device heats up cerium oxide to 1,600 degrees celsius in the presence of water or carbon dioxide, creating either hydrogen or carbon monoxide, which can be converted to liquid fuels.
The cerium oxide is a catalyst and is not itself used up in the reaction, meaning the same cerium oxide can be used multiple times.
Haile, who has been studying fuel cells at the California Institute of Technology, said future versions of the device could be used to create fuels for cars or be utilized in electric plants.
“There has been much national and international attention on hydrogen as the savior to address our energy and climate woes,” Prof Sossina Haile said. “However, those who are honest recognize that hydrogen is merely an energy carrier, not an energy source.”
The current prototype of the machine, which can harness less than one percent of the solar energy taken into the device, is not commercially viable, but Haile and her colleagues believe that efficiency rates of up to 19% could be achieved in future models.
“If we had a perfect reactor, we should easily get 10 percent efficient,” Haile told NPR. “We went through the big numbers and said, ‘Would this make any dent on U.S. energy production?’ And the answer is yes.”