Penn State researchers turn CO2 into renewable methane using microbes and renewable electricity

Researchers at Penn State have developed a larger, more efficient reactor that uses microbes to convert carbon dioxide and renewable electricity into methane. The system achieved methane production rates of 6.9 liters per liter of reactor volume per day and coulombic efficiencies above 95%, with energy efficiency around 45-47%. The reactor uses a zero-gap design to reduce internal resistance and relies on hydrogen as an intermediate step for microbial methane production. The technology could help solve long-term energy storage challenges by turning excess solar and wind power into methane that can be stored and transported using existing natural gas infrastructure. Estimated production costs could approach $0.08 per kilowatt-hour under favorable conditions, though challenges remain around catalyst improvements and preventing methane leakage. The research represents a practical approach to treating CO2 as a reusable resource rather than waste.