Experimental Study of Thermal Effects in a Hydrogen Cryo-Adsorption Storage System

Abstract

While the main barrier for the development of hydrogen adsorption type storage systems remains the material development, an improved thermal management may offer solutions to minimize the penalties in the amount of stored gas during fast-filling and the residual amount of hydrogen during discharging operations. The emphasis of this work was to experimentally investigate the dynamical thermal behavior of a hydrogen cryoadsorption storage system during fast-filling operations. The experiments were conducted with granulated activated carbon and MOF adsorbents. The influence of the charge pressure and the gas flow rate on the temperature elevations and the amount of filled hydrogen gas was analyzed. The heat generated in the storage vessel originates from the released heat of adsorption, gas compression work and thermal energy transfer that takes place when high pressure gas at the ambient temperature is introduced to the tank. A typical average temperature increase observed during the charging of the test tank, filled with the activated carbon (NORIT R0.8 extra), to 2 MPa was about 21 K. Such temperature elevation leads to a significant decrease in adsorption storage capacity.

Numerical study of thermal effects in cryo-adsorptive hydrogen storage tank

“…The material properties are listed in Table III. Most parameters are referred to Aleksic et al [8][9][10] and Xiao et al [13][14][15] The particle density of MOF is obtained from the mass and the volume of adsorbent. The particle diameters of AC and MOF are estimated according to the principle of equivalent volume.…”

“…The mass flow rates at entrance are fitted from the experimental data of Aleksic et al, 9 and set by using user defined functions (UDFs) in the commercial software FLUENT. The mass flow rates for AC and MOF tanks are fitted as following expressions:…”

“…during the filling process and they suggested using a slender shape tank for hydrogen storage which would enhance heat exchange. Schmitz et al 11 studied the adsorption isotherms and the heat of adsorption for different activated carbons and four metal-organic frameworks, including Norit R0.8 and Cu-BTC which are used in the experiments of Aleksic et al [8][9][10] They claimed that materials with smaller pores would lead to a higher heat of adsorption.…”

“…% on metal-organic frameworks (MOF) at 77 K. 7 The adsorptive hydrogen storage at cryonic condition is of great importance for increasing the hydrogen storage density. Aleksic et al [8][9][10] conducted excellent experimental researches on cryo-adsorption hydrogen storage using activated carbon Norit R0.8 and metal-organic framework Cu-BTC. The studies indicated that the thermal effects would reduce the storage capacity a) Author to whom correspondence should be addressed.…”

“…14,15 The simulation results showed good agreement with the experiments performed in Hydrogen Research Institute, Universit e du Qu ebec a Trois-Rivières (UQTR). In order to validate the models with wide adsorbent materials, the CFD model and the lumped parameter model are used to simulate a 9.853 liter tank packed with Norit R0.8 and Cu-BTC and compared with the experiments of Aleksic et al [8][9][10] This paper will carry out the numerical study of thermal effects in a cryo-adsorptive hydrogen storage tank and compare the experiments performed in Department of Energy and Process Engineering, Norwegian University of Science and Technology (NTNU). The volume of its experimental tank is around 10 liters, which is about four times of that of the experimental tank used in UQTR.…”