Thermoeconomic analysis of a CO2 compression system using waste heat into the regenerative organic Rankine cycle

The present paper deals with the thermoeconomic analysis of a CO2 compression system using waste heat into the regenerative organic Rankine cycle. The compressor power required for CO2 compression in the Carbon Capture and Storage has been supplied from a regenerative organic Rankine cycle which is used in thermal power plant. By using the turbine power supplied from the heat drawn and waste flue gas and the intercooler heat exchangers, 8% of the CO2 separated from the waste flue gas compressed in the gas compressor. Thermoeconomic analysis of the system is performed by calculating thermodynamic and economic properties of the system. Energy and exergy efficiencies of cycle have been calculated as 17.2% and 51.6%. The average exergetic cost of waste heat flue gas as a fuel input in the integrated to the system is calculated to be 12.34 $/GJ or 947.5 $/h. The unit exergetic cost of electricity from the ORC system is calculated to be 17.47 $/GJ or 0.063 $/kWh. The unit exergetic cost of compressed CO2 gas is calculated to be 84.9 $/GJ or 184.3 $/h at 310 K and 15,244 kPa. The cost of compressed CO2 in the plant is calculated to be 18.36 $ per tonne of CO2. The total exergy destruction cost rate of the plant and the most destructive component of the flue gas heat exchanger is calculated to be 297.8 $/h and 219.1 $/h, respectively.