Microbes could become key allies in global efforts to curb carbon emissions and avoid dangerous climate change. A group of microbes called chemolithoautotrophs consume CO2 through their natural metabolism, spitting out small organic molecules as a byproduct. These microbes could be enlisted to convert industrial CO2 emissions into valuable chemicals, thanks to a new concept developed by Pascal Saikaly and his team at KAUST.
[...] To harness chemolithoautotroph capabilities for recycling CO2 emissions into useful chemicals, researchers supply electrons to the microbes in a process called microbial electrosynthesis (MES). Typically, MES reactors have grown chemolithoautotrophs on a submerged flat-sheet cathode and bubbled CO2 gas into the solution, but this setup has two key limitations, explains Manal Alqahtani, also a Ph.D student in the team. Flat-sheet cathodes are difficult to scale up and CO2 gas has poor solubility.
The team developed an alternative MES reactor using cathodes made from stackable, cylindrical porous nickel fibers that Saikaly's group had previously applied to recover water and energy from wastewater. CO2 is pumped through each cylinder, and electrons flow along it. "Using this architecture, we directly deliver CO2 gas to chemolithoautotrophs through the pores in the hollow fibers," Alqahtani says. "We provided electrons and CO2 simultaneously to chemolithoautotrophs on the cathode surface."
Will the microbes demand minimum wage for remediating our excess carbon dioxide?
Porous Hollow Fiber Nickel Electrodes for Effective Supply and Reduction of Carbon Dioxide to Methane through Microbial Electrosynthesis (DOI: 10.1002/adfm.201804860) (DX)
Porous nickel hollow fiber cathodes coated with CNTs for efficient microbial electrosynthesis of acetate from CO2 using Sporomusa ovata (DOI: 10.1039/C8TA05322G) (DX)
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printed from SoylentNews, Helpful Microbes Inhale Carbon Dioxide via Porous Cylindrical Electrodes and Exude Useful Chemicals on 2024-04-20 01:51:48