Evaluation of green hydrogen carriers: A multi-criteria decision analysis tool

Abstract

Hydrogen carriers are one of the most promising renewable energy storage technologies, particularly for medium or long-duration applications. However, there are several options with various features, making their selection complex and cumbersome. This study introduces a multi-criteria decision-making (MCDM) model to evaluate several options and identify the most feasible alternative(s) for a given purpose. Eleven different hydrogen carriers are evaluated considering nine criteria: storage energy density, technical readiness, reversibility, material handling, toxicity, safety, environmental impact, and cost. Two hybrid MCDM methods, AHP-TOPSIS and AHP-VIKOR, are applied for three application scenarios of (i) vehicle fuel, (ii) international renewable energy transport, and (iii) energy supply for a steel factory. Results show that the most feasible carrier alternative is highly dependent on the application purpose. For fuel cell vehicles, the best alternatives are methanol, toluene, and dibenzyl toluene, while for international renewable energy transport, toluene, dibenzyl toluene, and N-ethyl carbazole are found as the best carriers. Methane, methanol, and dibenzyl toluene are found as the best carriers for the energy supply of a steel-making factory. It is also noted that the decision criteria have a significant impact on the outcome, and depending on the importance of each criterion (particularly hazard/safety and environmental impact) for a given decision-maker, the outcome will notably vary.