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Phoenix666 writes:

KAUST:

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)

Original Submission