Energy analysis and economic evaluation of a new developed integrated process configuration to produce power, hydrogen, and heat

Hydrogen has been discussed as a future energy vector owing to its environmentally benign properties. Currently, due to rising fuel prices, environmental crises and energy challenges, simultaneous generation of power, heat, cooling, and hydrogen has been the subject of many investigations. In this study, an integrated process of solid oxide fuel cell (SOFC), solid oxide electrolyzer cell (SOEC), steam Rankine cycle (SRC), and organic Rankine cycle (ORC) is introduced and analyzed to tri-generate power, hydrogen, and hot water. In effect, SOFC is fed by natural gas to generate power. To exploit the waste heat of SOFC outlet, Rankine cycles are used to produce extra power. The system is designed to produce 500kW net power in conjunction with internal required power. The excess power supplies SOEC which carries out steam separation, generating pure hydrogen. To achieve an appropriate design, sensitivity analysis and economic evaluation are carried out for different parts of the integrated system. For design condition of (T-SOEC = 1173 K, i = 0.3375A/cm(2), V-SOEC = 1.1 V, and U-f = 0.825), value of electrical efficiency of the integrated system is found to be 49.43%. Also, SOFC voltage is obtained 0.7910 V. The system cogeneration and tri-generation LHV-efficiencies are 68.18% and 71.55%. Based on the results, H-2 production flow rate in SOEC and heat recovery are 2.8230kmol/h and 34.11 kW respectively. (C) 2019 Elsevier Ltd. All rights reserved.