The turbine system’s working fluid is a large quantity of very high pressure CO2. High pressure fuel and oxygen streams are injected to the combustion burner within the system at a rate such as to add 3% more to the total CO2 per second. This additional amount is the portion continually tapped off from a lower pressure point (30 bar) in the fluid processing cycle.
The high pressure of 300 Bar is the combustion unit pressure feeding the turbine inlet. The density of CO2 at that point is about half that of liquid water. Due to the density of this working fluid, the CO2 turbine equipment of equal power capacity is of a much smaller scale than the equivalent steam turbine system.
The basic system overview is provided in the first page, and the additional page highlights the additions that will allow coal as the fuel source with about 52% overall efficiency.
https://ngi.stanford.edu/sites/default/files/3_Brown_NET_Power_0.pdf
https://www.globalsyngas.org/uploads/eventLibrary/2014_11.2_8_Rivers_Xijia_Lu.pdf
The CO2 is not consumed in the process and thus must be disposed of. The CO2 is NOT "recycled". Once some small amount is "recycled", the total amount required for combustion is excess that must be disposed of. There is simply no market for all of the CO2 produced in the world to make electricity from liquid petroleum, natural gas, coal, or even unicorn farts. This especially true if electric propulsion becomes mandated for cars, trucks, trains, boats and airplanes.
There is simply no market for all of the CO2 produced in the world to make electricity from liquid petroleum, natural gas, coal, or even unicorn farts. This especially true if electric propulsion becomes mandated for cars, trucks, trains, boats and airplanes.