|There are several ways CO2 can be used to produce more biofuel|
More energy from CO2 from power stations
It is possible to generate a current by adding CO2 to water to form H ions and the bicarbonate ion. There would be a problem in disposing of the weak carbonic acid in an ethical manner.
Even more can be generated in monoethanolamine. Up to 4.5 mW/sq m.
It is theoretically possible to generate electrons from adding CO2 from the stack into the air. However no one has any ideas of how this would work in practice.