Investigation of an integrated clean energy system using heat recovery from fuel cell and LNG expansion waste heat combined with solar energy

Abstract

This study examines the impact of integrating proton exchange membrane fuel cell (PEMFC) and reverse osmosis (RO) desalination systems into a solar liquid natural gas (SLNG) system. To this end, two configurations are analyzed: the basic SLNG system and the enhanced SLNG-PEMFC/RO system, incorporating PEMFC and RO technologies. Energy, exergy, and exergo-economic assessments are conducted for both setups. The findings reveal that integrating PEMFC and RO into the SLNG system boosts net output power by 26.22%, energy efficiency by 39.28%, and production revenue by 201%. However, the exergy efficiency, LCOE, and payback period of the SLNG-PEMFC/RO system are 31.84%, 82%, and 205.5% lower, respectively, compared to the base SLNG system. Additionally, increasing PEMFC temperature enhances net output power, energy efficiency, and exergy efficiency by 26.5%, 4.64%, and 11.03%, respectively. On the other hand, higher PEMFC temperatures result in increases of 10.56% in LCOE and 21.5% in production revenue. Notably, PEMFC pressure has the least influence on the performance of the SLNG-PEMFC/RO system.