Reaction Zone Evolution Governing Thermal Output in a Zeolite 13X Sorption Reactor: An Experimental Study

Sorption thermal energy storage is pivotal for enhancing renewable energy utilization and supporting the transition to carbon neutrality. Its performance hinges on the formation and dynamic evolution of the reaction zone. However, the lack of in situ, spatially resolved measurement tools has hampered a mechanistic understanding and rational design. To address this, this study presents a method for characterizing the reaction zone dynamics through high-resolution intra-reactor temperature profiling. Applying this method to a zeolite 13X packed-bed reactor, we establish, for the first time, quantitative empirical correlations between operating parameters and these intrinsic reaction zone properties. A key finding is that the stable duration and output temperature are governed by the length, propagation velocity, and exothermic area of the reaction zone, coupled with the total sorption heat. Furthermore, the effects of the four critical operational parameters, including inlet air temperature, relative humidity, airflow rate, and packing thickness, on both the reaction zone characteristics and thermal output performances were systematically investigated. By integrating these mechanistic insights, we propose a hierarchical control strategy and actionable application guidelines to tailor the thermal output on demand.