University of Illinois-Chicago and Argonne National Lab scientists have created an “artificial leaf” that can convert carbon dioxide emissions into usable fuel, using solar power.
Researchers have created a patented solar cell takes in carbon dioxide (CO2) and water, and converts it into synthesis gas, or syngas. This syngas can then be turned into methanol, diesel and other fuels. This closed loop could halt additional greenhouse gas emissions from entering the atmosphere while creating a new fuel source from recycled Co2, all powered by the sun.
The research team, funded by the National Science Foundation and Department of Energy, published their findings in a recent issue of Science.
“[Continuously producing] carbon dioxide is not going to be sustainable in the long term–it is a one-way process,” said Amin Salehi-Khojin, assistant professor of mechanical and industrial engineering at UIC and senior author on the study to Chicago Inno. “We wanted to recycle the process, to convert the C02 back to energy again…It can work in a loop, two-way traffic between energy and C02 reduction.”
Salehi-Khojin explained that recycling Co2 has long been an area of sustainability and energy research, but up until now the catalysts used to perform CO2 reduction (the process of converting CO2 into hydrocarbon) has been inefficient and expensive. So researchers engineered an inorganic compound, called tungsten diselenide, to perform the reduction, resulting in a method that is cheap and far more efficient.
“Many catalysts can do this reduction, but they’re not efficient because their reduction rates are not so high and the catalyst is very expensive, like gold, silver, platinum,” he said. “The catalyst we developed has 1,000 times more activity…meanwhile the price is inexpensive.”
The innovation is inspired by another solar-powered process–photosynthesis in plants–which takes in carbon dioxide, breaks it down through organic enzymes and outputs sugar.
“In photosynthesis, trees need energy from light, water and carbon dioxide in order to make their fuel; in our experiment, the ingredients are the same, but the product is different,” said Argonne chemist Larry Curtiss, an author of the study to Science Daily.
Currently they just have a prototype, and Salehi-Khojin said they’re looking for manufacturing and industry expertise to scale their work. He envisions setting up “solar farms” comprised of a field of these artificial solar leaves next to factories with high carbon dioxide output.
The catalyst we developed has 1,000 times more activity…meanwhile the price is inexpensive
The solar leaf project also has implications beyond Earth. Researchers say that this tech could potentially be used as a source for both oxygen and food for astronauts on Mars, where the atmosphere is mostly carbon dioxide.
We’re still a ways from solar farms and oxygen on Mars–Salehi-Khojin estimates it will be at least five years before this tech can scale. However, considering 2015 was the hottest year ever recorded on Earth, solutions tackling global warming take on new urgency. Is it possible, I asked Salehi-Khojin, that with research like this, we can reverse some of the damage we’ve done?
“Definitely,” he said. “And we have to do it.”
“We have to recycle the greenhouse gas and carbon dioxide and use it as a new source of energy,” he said. “This is going to be the most important innovation of the 21st century because we are dealing with energy and dealing with the environmental issue.”