Calcium looping as chemical energy storage in concentrated solar power plants: Carbonator modelling and configuration assessment

摘要

This paper addresses the analysis of different configurations of carbonator for thermochemical energy storage for concentrated solar applications. The design of this equipment is different from the previous experience of calcium looping cycle for carbon capture. The use of fluidized beds and large particles are not feasible for this novel application of calcium looping. New reactors and different arrangements for the carbonation process are necessary. The design of a carbonator reactor for a specific Calcium Looping-Concentrated Solar Power application has not been addressed yet in detail in literature. In this work, a comparison of single stage reactor, two parallel reactors and two reactors in series with intercooling are simulated to calculate conversion rates, gas temperatures and flow rates, and heat transfer rates to the external cooling fluid. The modelling encompasses fluid dynamics, lime conversion kinetics and heat transfer, which are solved using a 1-D discrete mesh. The third arrangement results in the most reasonable sizes, and larger conversion rates, avoiding the occurrence of internal reactor zones in which the reaction is inhibited. Energy balance components are also quantified for each configuration.