Critical analysis of advanced H2/O2 cycles based on steam-methane reforming

In this paper a critical analysis of H2/O2 cycles is presented. They seem to have great thermodynamic potentialities, but in these analyses it is very important to adopt reasonable assumptions. In fact choosing very high values of the maximum pressure and temperature and neglecting the energy requirements for oxygen and hydrogen compression and production, these cycles can attain very high efficiency: from 65 to 69%, depending on the typology of the thermodynamic cycle. In the present paper the H 2/O2 cycles, one typology proposed by authors and another by other ones [1], have been analysed under realistic assumptions (with respect to the currently available technology) of the cycle parameters - TIT and maximum pressure - and taking into account the overall energetic requirements (H2 and O2 production and compression). The cycles, suitable for these assumptions, have been investigated by means of a parametric analysis as a function of the main cycle parameters. Summarizing, the results of the developed analysis show that the H2/O2 cycles, investigated here, yield very poor performance if all energetic requirements are taken into account