Evaluation of an optimal integrated design multi-fuel multi-product electrical power plant by energy and exergy analyses

A novel integrated multi-fuel multi-product electrical power plant with a net electrical power output of 5.97 x 10(5) kW is developed and investigated by energy and exergy analyses. The electrical power plant including coal gasification, natural gas solid oxide fuel cell, cryogenic air separation unit, carbon dioxide transcritical and steam cycles, and liquefied natural gas regasification sub-systems. The potential of operating performance improvement by conducted energy and exergy analyses is assessed. Also, the thermal design and heat integration analyses are performed for studying the system sustainability and emphasizing on no requirement for external hot and cold utilities. Effects of the main design parameters such as fuel cell operating parameters, ambient temperature and liquefied natural gas thermodynamic specifications on the system operating performance are examined. The obtained results indicate that the overall energy and exergy efficiencies reach to a maximum value of about 56.4% and 57.9%, respectively; in the case of fuel utilization of solid oxide fuel cell is about 80.0%. Furthermore, increasing the ambient temperature and current density decrease the system operating performance. In contrast, the system performance increases with the liquefied natural gas vapor pressure. (C) 2018 Elsevier Ltd. All rights reserved.