One-up on plants?

What if we can take carbon dioxide directly from the atmosphere and turn it into useful products like fuels and chemicals without having to go through the process of growing plants and extracting sugars from biomass? That’s exactly what scientists seem to be on way to achieving!

Excess carbon dioxide in Earth's atmosphere created by the widespread burning of fossil fuels is the major driving force of global climate change, and researchers the world over are looking for new ways to generate power that leaves a smaller carbon footprint. Now, researchers at the University of Georgia have found a way to transform the carbon dioxide trapped in the atmosphere into useful industrial products.

This discovery may soon lead to the creation of biofuels made directly from the carbon dioxide in the air. During the process of photosynthesis, plants use sunlight to transform water and carbon dioxide into sugars that the plants use for energy. These sugars can be fermented into fuels like ethanol, but it has proven extraordinarily difficult to efficiently extract the sugars, which are locked away inside the plant's complex cell walls.

Now, the process is made possible by a unique microorganism called Pyrococcus furiosus, or "rushing fireball," which thrives by feeding on carbohydrates in the super-heated ocean waters near geothermal vents. By manipulating the organism's genetic material, the team created a kind of P. furiosus that is capable of feeding at much lower temperatures on carbon dioxide. The research team then used hydrogen gas to create a chemical reaction in the microorganism that incorporates carbon dioxide into 3-hydroxypropionic acid, a common industrial chemical used to make acrylics and many other products.

With other genetic manipulations of this new strain of P. furiosus, they could create a version that generates a host of other useful industrial products, including fuel, from carbon dioxide.

Georgia Institute of Technology and Purdue University researchers meanwhile have developed efficient solar cells using natural substrates derived from plants such as trees. By fabricating them on cellulose nanocrystal (CNC) substrates, the solar cells can be quickly recycled in water at the end of their lifecycle. The technology is published in the journal Scientific Reports.
The researchers report that the organic solar cells reach a power conversion efficiency of 2.7 percent, an unprecedented figure for cells on substrates derived from renewable raw materials.

The CNC substrates on which the solar cells are fabricated are optically transparent, enabling light to pass through them before being absorbed by a very thin layer of an organic semiconductor. During the recycling process, the solar cells are simply immersed in water at room temperature. Within only minutes, the CNC substrate dissolves and the solar cell can be separated easily into its major components. To date, organic solar cells have been typically fabricated on glass or plastic. Neither is easily recyclable, and petroleum-based substrates are not very eco-friendly.