Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
A SIMPLE MODEL FOR THE SLOW STORAGE OF HYDROGEN USING PHYSICAL ADSORPTION
Submission Author:
Ana Lustosa , RJ
Co-Authors:
Ana Lustosa, Leandro Alcoforado Sphaier
Presenter: Ana Lustosa
doi://10.26678/ABCM.COBEM2023.COB2023-1368
Abstract
Hydrogen is an advantageous energy source because it is renewable, and its use can reduce the emission of pollutants. However, the challenge is how to transport and store hydrogen safely and efficiently. There are some methods for hydrogen storage such as compressed hydrogen, liquid hydrogen, metal hybrids and adsorption in packed beds. In relation to constraints regarding mobile applications, the adsorption method has been a potential alternative because they require smaller volumes of gas. Due to a high average surface area, low cost and accessibility at industrial level, microporous activated carbons are good candidates for packed bed hydrogen storage in a commercial level. During the charging process of the reservoir, the exothermal adsorption may lead to high temperature values, reducing the adsorption capacity of the tank. Besides, the discharging process reduces the volume of available gas. This paper aims to investigate the thermal effects during the charging and discharging of a packed bed hydrogen storage tank employing activated carbon. The adsorption dynamics was analyzed using a computational simulation code, developed using the Wolfram MATHEMATICA software. A 1D mathematical model was used to predict the time-variation of the temperature and pressure in the storage tank. An efficiency analysis is performed by comparing with an isothermal process, which serves of reference for evaluating the performance of the system. The main parameters involved in the thermal model are: heat absorption and amount of gas adsorbed, both essential to determine the amount of heat, the thermal capacity of the system determines the temperature variation of the system and the overall heat exchange coefficient. The mass and energy balance equations that govern the system were solved for slow charge and discharge of adsorbed hydrogen gas under ideal conditions of temperature and pressure. Comparisons made between simulations and results of previous experiments were made to seek a better understanding of the thermal performance of adsorption during hydrogen charge and discharge.
Keywords
Hydrogen, adsorptive bed, Heat and mass transfer
