Energy, exergy, environmental, and exergoeconomic (4E) analysis of a fossil fuel power plant with carbon capture unit for a sustainable future

Abstract

The contribution of fossil fuels to the detrimental trend of global warming is undeniably real. Given the energy sector's heavy reliance on fossil fuels, it is crucial to take necessary actions to mitigate their adverse environmental impact. This study proposes a fossil fuel (natural gas) power plant integrated with a carbon capture unit (CCU) to minimize the associated environmental impacts. A thorough analysis of the system's energy, exergy, environmental, and exergoeconomic aspects (4E) reveals valuable insights into the proposed design. This CCU system captures CO₂ from the combined cycle power plant (CCPP) exhaust and employs it as a working fluid in the Supercritical CO₂ Power Cycle. The system generates 42.4 MW of power, 25.3 MJ/s of heat energy for hot water production, 49.6 MJ/s of heat energy for water desalination, 192.3 kJ/s for space cooling, and medium-pressure (MP) steam with a heat energy of 24.9 MJ/s. The system achieves 50 % energy efficiency and 54 % exergy efficiency, capturing 190.37 kilo metric tons of CO₂ per year. Additionally, the study examines the impact of variations in inputs, including air-fuel ratio, fuel quantity, ambient temperature, and steam temperature at the Heat Recovery Steam Generator (HRSG) outlet, on system efficiencies. 4E analysis reveals that the proposed system is more beneficial than simple power plants with no carbon capture units.