Advanced H₂/Air Cycles Based on Coal Gasification

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 coal gasification 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 energy flows, the overall performance has been evaluated. The main result of the performed investigation is that the two power plants attain the same efficiency level with and without H₂ production requirements (over 60% and over 34% without and with hydrogen production respectively). The final carbon dioxide emissions are about 0.123 kg/kWh both for AMC and CC. It is important to underline that the “clean” use of coal in new power plant types must be properly investigated because it is the most abundant and the cheapest fossil fuel available on earth; moreover, hydrogen production, by using coal, is an interesting prospect because hydrogen has the potential to become the main energy carrier in a future sustainable energy economy.