What about capturing CO2 during its combustion process?

CCS stands for Carbon capture and storage (or carbon capture and sequestration) that means CO2 capture during combustion. By doing this, it could lower the emission from energy production by 20%.

So how is this process work in reality? First, at mining of fuel locating offshore or near the coal mine, methane gas is produced. All the gases are brought up onshore by pipes that under the sea level or transport by other ways. The oil refinery technique will help us separate different types of gases and also give us CO2 and hydrogen at the same time. The final goal is separate CO2 and then pumps them into an offshore-abandoned oil/gas fields.  By separating CO2 from the mixture we get, a new designed membrane can filter larger CO2 molecular from that. The pipeline, which used for transporting CO2, needs to be resistant with corrosion. The oilfields, which used for storing CO2, are located few kilometers below the sea level. Under most circumstances, the oilfields are arch and have steady landform. The aquifer above the storage points is impermeable that will guarantee the CO2 will not get into the ocean and threat the ocean environment. When inject CO2 into oilfields, it’s a great waste of space if we inject CO2 in its air form. Instead, when inject CO2, reducing the pressure and making CO2 into liquid form can maximize the CO2 storage sites’ usage. 

Reference: http://www.co2storage.org.uk/