Techno-economic analysis of a novel clc reactor-based system for energy storage and back-up power in a cruise ship

Abstract

This study investigates the performance of a novel carbon-free CLC fixed-bed reactor system proposed as a sustainable alternative to store and supply the energy demand of a 7-day Mediterranean cruise ship travelling between Spain and Italy. During navigation, propulsive and hotelling energy demand of the MSC Magnifica vessel is supplied by the slow diffusion-controlled oxidation of a batch of reduced fine iron-based solids, which allows to heat up a flow of pressurized air that is used to generate electricity in a downstream gas turbine and high-grade heat. This arrangement imposes very long oxidation times for the reacting solids, thus moderating bed temperatures and avoiding hot spots. An oxygen diffusion-based reactor model is employed to design and model the performance of the multi-reactor system employed, which consists of 22 high energy density reactors of 15 m length and 2.1 m² cross section with a maximum power output of 20 MW_th each. The reactors are integrated in a recuperative gas power cycle that allows fulfilling navigation energy requirements for the 7-day trip with cycle efficiencies up to 45.8 %. During in-port periods, particles are reduced using electrolytic H₂, whereas hoteling energy needs are provided by H₂-fired auxiliary boilers and the gas turbine system powered by a H₂-fired external combustor. An economic analysis shows that the proposed carbon-free system can be competitive against conventional heavy fuel oil combustion options in several scenarios with H₂ cost of 1.5–2.5 €/kg, carbon tax between 90 and 205 €/ton CO₂ and moderate capacity factors (>40 trips per year). Higher H₂ costs and/or lower carbon tax values can be also accommodated with a moderate increase in the passenger ticket below 13 %.