Abby L. Harvey
GHG Monitor
4/24/2015
Researchers at the Department of Energy’s Lawrence Berkeley National Laboratory have created a new system of artificial photosynthesis, which could potentially utilize CO2 captured from flue gas to create useful chemicals. The process requires little energy or feedstock to run, requiring only sunlight, water and CO2 and in turn producing acetate, a biosynthetic intermediate. “The real world application is indeed we are going to sort of produce these chemicals in a totally renewable way,” Peidong Yang, one of the leaders of the study, told GHG Monitor this week. “If you think about the energy inputting here, that’s sunlight, and in terms of the feedstock it’s using water and CO2, that’s it. You use sunlight, water and CO2 and the process, basically through our sort of integrated system, you can get things like acetate.”
The process makes use of nanowires and bacteria to mimic the process of natural photosynthesis. Beyond that the system can be tweaked to produce different chemicals, including fuels and polymers. “In natural photosynthesis, CO2 is first reduced to common biochemical building blocks using solar energy, which are subsequently used for the synthesis of the complex mixture of molecular products that form biomass,’ according the research published in the American Chemical Society’s Nano Letters. “Here we report an artificial photosynthetic scheme that functions via a similar two-step process by developing a biocompatible light-capturing nanowire array that enables a direct interface with microbial systems. As a proof of principle, we demonstrate that a hybrid semiconductor nanowire−bacteria system can reduce CO2 at neutral pH to a wide array of chemical targets, such as fuels, polymers, and complex pharmaceutical precursors, using only solar energy input.”
The process would not likely be used directly on flue gas, but could provide a new utilization opportunity for captured CO2, Yang explained. “We would rely on the existing CO2 capture technology to use the CO2. Captured CO2 would be our sort of feedstock for our system,” he said.
