(347c) Adsorption Based Hydrogen Storage System; Multiscale Approach and Mathematical Model

Adsorption Based Hydrogen Storage System; Multiscale Approach and
Mathematical Model

Agnieszka Truszkowska¹, Christopher Loeb¹ and Goran Jovanovic¹

¹Oregon State University, Department of Chemical, Biological, and
Environmental Engineering, Corvallis, OR 97330, USA 

Emails: truszkoa@onid.orst.edu, loebc@onid.orst.edu, goran.jovanovic@oregonstate.edu

In an effort to reduce CO₂
emission arising from sources of current forms of transportation energy,
hydrogen is sought as a potential replacement to major fossil fuels.  However, deploying hydrogen into vehicles
faces considerable challenges, one of which is efficient storage solution that
would meet practical performance and cost criteria. Adsorption based storage
systems are one of the promising storage solutions, which are currently under
intensive development.

Adsorption based storage systems
are typically made of materials like activated carbon and MOF-5; hence, they
are considered a porous structure. These materials often meet gravimetric
storage requirements, but their volumetric capacities become sufficient only at
cryogenic conditions. Operation of hydrogen storage system in cryogenic region
creates opportunities for many design solutions.  

In this paper we propose a
numerical tool based on multiscale mathematical modeling,
which supports experimental effort in performance characterization of cryogenic
hydrogen adsorption storage system.

Mathematical model and
corresponding numerical simulation techniques provide a tool capable of numerically
describing hydrogen storage phenomena on an arbitrary number of structural
levels in three dimensions.

Numerical package provides users
with essential properties of porous hydrogen storage media: permeability,
effective diffusivity and effective conductivity of the system. These mixed
properties are based on material, process, and geometric characteristics of the
storage system.

Results of numerical simulation
enable a valid analysis of system performance at each scale and provide means
for further optimization. We also propose the characteristic times analysis
as one of the modeling approaches which informs design development of the
hydrogen storage system.

In addition we provide validation
of the mathematical model and the results of numerical simulation with experimental
data collected on adsorption media (activated carbon and MOF-5) in our
hydrogen storage laboratory.