On the feasibility of novel reactor configurations for next-generation CH4 storage as an energy carrier using computational, experimental, and statistical approach

Abstract

The present investigation compares the constant pressure charging and controlled flow discharging performance of five different reactor configurations for methane (CH₄) storage as an energy carrier in the adsorbed form. A 3-D transient model, coupling the porous bed and coolant domain, is considered in this study. The study shows how the storage and discharge performance can be improved step-by-step, starting with an adiabatic case and progressing to adding an external cooling jacket, single and multiple rows of cooling pipes with internal longitudinal, annular, and conical fins. The findings also demonstrate the remaining scope for achieving 100 % isothermal efficiency with Maxsorb III (7.8 % and 4 %) and indigenous activated carbon (AC) IndoCarb GC D612 (0.01 % and 4.8 %) for charging and discharging, respectively. A detailed experiment is done to measure the thermophysical properties of the indigenous activated carbon. The reactor with an external cooling jacket and double row of cooling pipes with internal longitudinal fins is identified as the best reactor geometry based on the charge and discharge performance. Using the Taguchi method, a statistical analysis is carried out on the best reactor geometry to check the sensitivity of different design and operating parameters such as gas flow rate, heating fluid temperature, coolant flow velocity, and the reactor aspect ratio. It is found that, for the maximum effective performance ratio (i.e., discharge concentration per unit pumping work), the contribution of coolant fluid velocity (87.2 %) is maximum.