Combining natural gas recovery and CO2-based geothermal energy extraction for electric power generation

•Dual-purpose utilization of CO2: 1) extracting natural gas and 2) geothermal energy, while storing all CO2 (CCUUS).•Partially depleted natural gas reservoirs are typically suitable for CO2-based geothermal energy extraction.•A CO2 flowrate of 110 kg/s results in a net power of 2 MWe for the highly scalable small system considered.•The technology can extend the useful lifetime of a (previous) natural gas field.