The scientists studied how to make natural gas power plants cleaner by capturing CO2 emissions. They tested a method called selective exhaust gas recirculation, where some CO2 is sent back into the plant to reduce emissions. By using this method, they found that the CO2 concentration in the plant increased, making it more efficient. The recirculation also helped stabilize combustion and reduce the size of the CO2 capture plant. Overall, the study showed that this method can make natural gas power plants more environmentally friendly and efficient.