Energy, exergy, economic and exergoenvironmental analyses of gas and air bottoming cycles for production of electricity and hydrogen with gas reformer

The purpose of this study is to investigate an intergration of three cycles consisting of gas, air bottom and steam cycles for electrical power generation and hydrogen production. The configuration of the three cycles is powered by the natural gas that is used by the gas cycle on the top. Then, the exhaust gas of the gas cycle is used by an air cycle at the bottom of the gas cycle and consequently a heat recovery steam generator (HRSG) is driven by the exhaust gas of the air cycle. The purpose of the HRSG cycle is to produce steam to be used in the reformer for the hydrogen production. The energy, exergy, economic and exergoenvironmental analyses of this combined cycle is examined. The results of this study show that addition of air gas cycle to natural gas cycle improves the energy efficiency from 17.2% to 28.% and Payback Period (PP) from 4.72 to 2.92. Whereas, adding HRSG to the whole cycle improves the energy efficiency to 67.6% and Payback Period to 0.41 years. Moreover, this interagation of the cycles improves the Net Present Value (NPV) from 1.13 x 10(9) to 2.07 x 10(9) for gas and air cycle, respectively and to 3.89 x 10(10) $ by the whole cycle. (C) 2020 Elsevier Ltd. All rights reserved.