An enhanced exergoenvironmental assessment of an integrated hydrogen generating system

Abstract

This study concerns a novel integrated three-compartment electrochemical reactor, developed in a lab environment. The reactor uses an electrolytic cation exchange method to capture considerable quantities of carbon dioxide from ocean water, in the forms of bicarbonate and carbonate, while concurrently producing hydrogen gas and capturing carbon dioxide for potential hydrocarbon synthesis. This study focuses on the performance and environmental impact of a novel E-CEM (Electrochemical-Continuous Electrodeionization Membrane) system under varying operational conditions such as such as energy and exergy efficiencies, exergy destruction rates, the exergoenvironmental impact factor, exergetic destruction ratio, exergetic sustainability index, entropy generation ratio, entropic environmental impact factor, sustainability index, and relative irreversibility under different temperatures between 10 °C and 90 °C and pressures between 100 kPa and 1000 kPa. Thermodynamic assessments using the Engineering Equation Solver offer quantitative evaluations of system performance, while exergoenvironmental analysis provides an advanced approach that combines exergy analysis with environmental impact assessment to evaluate both the performance and environmental sustainability of energy systems. An exergy destruction ratio value of the reactor is found to be 0.9 at 100 kPa and rises to 1.3 at 1000 kPa, showing increased exergy destruction, particularly at higher pressures. The E-CEM reactor achieves energy and exergy efficiencies of 7 % and 9 %, respectively.