Advanced Mixed Cycles Based on Steam-Methane Reforming and Air Blown Combustion

In this paper the overall performance of a new advanced mixed cycle (AMC), fed by hydrogen-rich fuel gas, has been evaluated. Obviously, hydrogen must be produced and here we have chosen the steam-methane reforming for its production, quantifying all the thermal and electric requirements. At first, the thermodynamic performance of this cycle has been investigated in comparison with that attainable by combined cycle power plants (CC). Then, the power plants have been integrated with the fuel production system. Including all the material and energetic flows, the overall performance has been evaluated. The main result of the performed investigation is that, while the two power plants attain the same efficiency level without H₂ production requirements (about 56% for AMC and 55.8% for CC), the AMC power plant achieves a net electric efficiency of about 48% when integrated with H₂ production plant: it is about 3 points higher than the efficiency evaluated for the CC equipped with the same H₂ production plant (about 45%). The final carbon dioxide emissions are about 0.0742 and 0.079 kg/kWh for AMC and CC respectively.