Prospective life cycle assessment for designing mobile thermal energy storage system utilizing zeolite

The decarbonization of industrial heat, especially utilization process heat over 100 °C, is important for the transition to a sustainable society, including climate change mitigation and the transition to a circular economy. This study focused on a mobile thermal energy storage system for industrial use using a zeolite water vapor adsorption and desorption cycle that can utilize waste heat not only in space but also over time, and a prospective life cycle assessment (LCA) to design the system and provide feedback for further development. A numerical model was developed to predict the performance of the system using a moving bed indirect heat exchange system as the heat-discharging system and a moving bed countercurrent contact system as the heat-charging system, coupled with mass, energy, and momentum conservation equations for obtaining the foreground data for the prospective LCA. A prospective LCA was conducted to calculate greenhouse gas emissions (GHG) and resource consumption. The results showed that the m-TES reduces lifecycle GHG, and there are conditions for zeolite flow rates that minimize GHG emissions. It was also found that the resource consumption of m-TES increases as the system size increases, but is less than that of batteries. The hot spots are the fuel-saving effect at the heat-discharging side, auxiliary power at the heat-charging side, and the zeolite manufacturing stage.