Oct
7
Fuel From The Air a Step Closer
October 7, 2011 | Leave a Comment
University of Illinois chemical and biological engineering professor Paul Kenis and his research group joined with researchers at Dioxide Materials, a startup company, have found a catalyst that improves artificial photosynthesis. Artificial photosynthesis is the process of converting atmospheric carbon dioxide gas into useful carbon freed of the oxygen to make carbon-based chemicals, particularly fuel or other compounds usually derived from petroleum.
For the global warming crowd it’s a promising technology that simultaneously reduces atmospheric carbon dioxide and for everyone else the carbon dioxide can be directed to produce fuel. Whichever suits, humanity would be a much more active player in a complete planetary atmospheric carbon cycle.
The team paper has been published in the journal Science.
Clearly defined, artificial photosynthesis is the process of converting carbon dioxide gas into useful carbon-based chemicals, most notably fuel or other compounds. In plants, photosynthesis uses solar energy to convert carbon dioxide (CO2) and water to sugars and other hydrocarbons. Then mankind steps in and fuels are built from sugars extracted from crops such as sugarcane and corn.
In artificial photosynthesis, an electrochemical cell uses energy from a solar collector or a wind turbine to convert CO2 to simple carbon fuels such as formic acid or methanol, which are further refined to make ethanol and other fuels.
Dioxide Materials founded by retired chemical engineering professor Richard Masel who is the firm’s CEO and a co-principal investigator of the paper explains, “The key advantage is that there is no competition with the food supply and it is a lot cheaper to transmit electricity than it is to ship biomass to a refinery.” There is a lot of power involved, this big hurdle and the technology needed has kept artificial photosynthesis from vaulting into the mainstream.
The first step to making fuel, turning carbon dioxide into carbon monoxide, consumes too much energy. It requires so much electricity to drive the carbon dioxide recovery reaction that more energy is used to produce the fuel than can be stored in the fuel.
The Illinois group’s innovative development is to use a novel approach involving an ionic liquid to catalyze the reaction, greatly reducing the energy required to drive the process. The ionic liquids stabilize the intermediates in the reaction so that less electricity is needed to complete the conversion.
The researchers used an electrochemical cell as a flow reactor, separating the gaseous CO2 input and oxygen output from the liquid electrolyte catalyst with gas-diffusion electrodes. The cell design allowed the researchers to fine-tune the composition of the electrolyte stream to improve reaction kinetics, including adding ionic liquids as a co-catalyst.
Kenis, who is also a professor of mechanical science and engineering and affiliated with the Beckman Institute for Advanced Science and Technology comments on the results said, “It lowers the overpotential for CO2 reduction tremendously. Therefore, a much lower potential has to be applied. Applying a much lower potential corresponds to consuming less energy to drive the process.”
As the headline says, this is a step for an incomplete process. The Illinois team hopes to tackle the problem of throughput. To make their technology useful for commercial applications, they need to speed up the reaction and maximize conversion. “More work is needed, but this research brings us a significant step closer to reducing our dependence on fossil fuels while simultaneously reducing CO2 emissions that are linked to unwanted climate change,” Kenis said.
It would be a dream come true when a solar collector can take CO2 from the air and produce a liquid or gaseous fuel. The technology is not commercial or scalable yet, but the day a collector on the roof can provide an energy dense fuel useful in the home and car isn’t so far off.
Congratulations are in order for the Illinois and Dioxide Materials team. Stay with it.