(586a) Environmentally Conscious Design and Planning of Hydrogen Supply Chains for Vehicle Use

The use of hydrogen as an alternative fuel and energy carrier has been the focus of a growing research interest in the last years. This trend has been mainly motivated by the need to reduce the CO₂ emissions and mitigate global warming. Unfortunately, despite the progress made so far, the hydrogen infrastructure that currently exists is unable to cope with the high energy demand of the market. In fact, the current "merchant" hydrogen infrastructure delivers fuel at approximately 1% of the scale needed to serve a major energy market [1]. Thus, there is still a very large gap to achieve the transition from the current fossil-based economy towards a new one based on hydrogen.

The adoption of hydrogen in the current energy system depends to a large extent on the ability to solve the technological challenges posed by the aforementioned transition process. In this regard, one of the key issues that should be addressed is the optimal design of the production/distribution network capable of fulfilling the growing hydrogen demand in the existing markets. This is not a trivial task, since it requires the understanding of the complex temporal and capacity interdependencies arising between the entities of the network. The design task is further complicated by the need to account for different conflictive criteria at the design stage. The strategic decisions made in this area have been traditionally driven by economic criteria [2]. However, in the context of designing hydrogen networks, solely minimizing the total cost may lead to solutions that do not fully exploit the environmental benefits of switching to a more sustainable energy system. To avoid this situation, the design task must be posed as a multi-criteria decision-making problem. This approach allows for the simultaneous assessment of environmental and economic concerns at the early stages of the process development, which may eventually lead to the adoption of more sustainable design alternatives.

The aim of the present work is to provide a quantitative decision-support tool for the optimal design of environmentally conscious hydrogen SCs for vehicle use. The design problem is mathematically formulated as a bi-criteria mixed integer linear programming problem (MILP) that accounts for the minimization of the cost and environmental impact. The latter objective is represented by the contribution to climate change made by the network operation. This metric is calculated by applying the Eco-indicator 99 methodology [3], which follows the Life Cycle Assessment (LCA) principles. To reduce the computational burden of the resulting model, we introduce a bi-level decomposition strategy that exploits its mathematical structure. The capabilities of the proposed approach are illustrated through a case study based on a real scenario, for which the set of Pareto efficient solutions are calculated.

References

[1] Ogden, J.M., 1999. Annual Review of Energy and the Environment, 24: 227?279.

[2] Almansoori, A., Shah, N., 2006. Chemical Engineering Research & Design, 84: 423-438.

[3] The Eco-indicator 99. Technical Report, PRé Consultants, Amersfoort, The Netherlands, 2000.