Temperature Distribution In Activated Carbon Bed During Adsorption of Nitrogen (model gas for hydrogen); Experiment & Mathematical Model

Temperature distribution in activated carbon bed during adsorption of nitrogen (model gas for hydrogen); experiment & mathematical model

Agnieszka Truszkowska¹, Christopher Loeb¹, Richard Chahine², Bruce Hardy³ and

Goran N. Jovanovic¹

¹Oregon State University, Department of Chemical, Biological, and Environmental Engineering,  Corvallis, OR 97330, USA <>²Hydrogen Research Institute at University du Quebec a Trois-Rivières, PO BOX 500, Trois- Rivières, QC, Canada,  G9A 5H7 

³Savannah River National Laboratory 
Process Modeling and Computational Chemistry Group 
 Building 999-2W, Rm. 122 
Aiken, SC 29808, USA 



Emails: truszkoa@onid.orst.edu, loebc@onid.orst.edu, goran.jovanovic@oregonstate.edu, bruce.hardy@srnl.doe.gov, richard.chahine@uqtr.ca

Providing high volumetric and mass storage density of hydrogen gas is a major challenge in the progress towards hydrogen-fueled automobiles.  Of the various storage media, liquid chemical systems, and metal hydrides, activated carbon adsorbents have substantial advantages in cost, weight, ease of handling and safety.

In this paper we present experimental data (temperature and pressure) obtained during adsorption of nitrogen (model gas for hydrogen) in an activated carbon bed.  We also present the results of a numerical simulation of the same process.

Experimental apparatus used in this study consists of a cylindrical activated carbon bed (2 in diameter x 1.5 in high) placed into a sealed high-pressure cylindrical vessel. The carbon bed, consisting of densely packed activated carbon material and binding agent, is instrumented with six thermocouples placed at suitable locations throughout the bed. In addition, a thermocouple, and three pressure transducers are placed into the high-pressure vessel outside the bed. Dynamic change of temperature and pressure during the charging process are recorded, corresponding to compression and adsorption phenomena.  The charging process starts at 1.0 bar and ends at 50.0 bar pressure.  A parametric study of filling time is performed for time intervals between 10 and 30 seconds, to observe its effect on the charging process.

The mathematical model is developed for the carbon bed – pressure vessel system, which enables numerical simulation of the charging process. Initially, numerical simulations are used to analyze experimental data and to explore characteristic parameters of the carbon bed.  The same numerical tool will be used in the future to design carbon bed with optimal characteristics imposed by requirements for hydrogen storage media in motor vehicles.