Abstract
Hydrogen, H2, has been well known as one of potential energy storages in utilization of renewable energy with its intermittent characteristic. However, H2, which is in gas phase at standard pressure and temperature, has challenging problem of storage, transportation, and low volumetric energy density. As one of the solution, H2 storage in (C7H8)/methylcyclohexane (MCH, C7H14) cycle is one of the effective and reversible methods. In this study, an integrated power generation cycle is investigated, including the the dehydrogenation process and the combined cycle power generation. Comprehensive analysis on heat circulation was performed through an enhanced process integration to ensure the high energy-efficiency system. Thermal energy required for highly endothermic dehydrogenation reaction was supplied from air-fuel combustion to ensure the effective heat recovery of the system. The performance of proposed system is compared to the Graz cycle-based system, one of the cycle of power generation cycle from H2. The comparison result shows that the proposed integrated system has a significantly higher power-generating efficiency. Additionally, with dehydrogenation included in the system, the proposed system showed a system efficiency of 53.7 %, compared with the Graz cycle based system at 22.7 % under the same operating condition.
