Proof of Concept of a Novel Solid–Solid Heat Exchanger Based on a Double L-Valve Concept

Abstract

A proof of concept of a novel parallel-flow solid–solid heat exchanger consisting of two L-Valves with concentric vertical tubes, named as Double L-Valve, is presented for the case of the Carbonate Looping process, as a CO2 capture technology. The operational objective of the solid–solid heat exchanger is to heat up the relatively cold solid stream coming from the carbonator reactor by absorbing heat from the hotter stream coming from the calciner. This novel solid–solid heat exchanger concept has been constructed on a small scale to study the hydrodynamic response of the system experimentally at different designs and airflow rates in its cold state. Based on the experimental data from the small prototype, a scaled-up hydrodynamic model is proposed that provides estimations for the operational requirements at an industrial scale. Apart from the cold flow pilot model, the heat exchanger is being assessed in the current work for an industrial case study in terms of the following: (a) the heat transfer via rigorous one-dimensional thermal modelling, (b) the structural integrity of the design through Finite Element Method (FEM) analysis, and (c) a parametric study for its expected cost. The purpose of this work is to provide a holistic approach of this novel solid–solid heat exchanger concept, the main advantage of which is its simple design and relatively low cost.