Analysing the performance, fuel cost and emission parameters of the 50 MW simple and recuperative gas turbine cycles using natural gas and hydrogen as fuel

Abstract

In the present study, firstly, the power production, thermal and exergy efficiencies were calculated for the simple and recuperative gas turbine cycles at constant power production (50 MW) and turbine outlet temperature (450 °C). The system was analysed for the cases of using both natural gas and pure hydrogen as a fuel for simple and recuperative gas turbine systems. After analyses, the efficiencies of the recuperative gas turbine cycle were higher than the simple gas turbine cycle up to 18 bar pressure for both natural gas and H2. At the pressure of 18 bar and above, the efficiency of the simple gas turbine cycle found higher than the recuperative gas turbine cycle since the compressor outlet temperature is higher than the turbine outlet temperature. Despite the higher cost of H2 for unit power production, the H2 used gas turbine cycles has more advantageous than natural gas in terms of performance, environment and CO2 emission. For the cases of using H2 and natural gas as fuel, the minimum fuel cost was calculated as 0.345 $/kWh and 0.075 $/kWh at 20 bar for simple gas turbine cycle, while they were found as 0.322 $/kWh and 0.071 $/kWh at 4 bar for recuperative gas turbine cycle, respectively. The CO2 emission of the 50 MW gas turbine was found between 46.27 tones-CO2/h and 71.15 tones-CO2/h for natural gas using simple and recuperative gas turbine systems, besides zero CO2 emission of using H2.