Triply Periodic Minimal Surface Heat Exchanger as
Metal Hydride Based Hydrogen Storage Reactor
AZIZ Laboratory
Energy and Process Integration Engineering
Institute of Industrial Science, The University of Tokyo
http://epi.iis.u-tokyo.ac.jp
Sustainable energy production growth has become significant in recent years and a well‐developed support technology will bein high demand soon. Energy production from sustainable sources usually has a common problem, which is the excess energythat generated need to be stored to accommodate the limitation of its fluctuation production characteristic. One promising
way is to use the excess energy to generate hydrogen, but current hydrogen storage technology still left unanswered solution
on safe, efficient, and high mobility storage solution.

Metal Hydride with Triply Periodic Minimal Surface (TPMS)
Metal hydride can store hydrogen simultaneously
while releasing heat in the process, and hydrogen isreleased after heat is delivered to the compound
vice versa.
𝑥𝑀𝑒𝐻 ↔ 𝑀𝑒𝐻
2This hydrogen storage solution storage has been
investigated and found attractive with its propertiesof safety aspect as non‐toxic and high energy density
based on volumetric value. It offers ambienttemperature, low pressure, and high volumetrichydrogen density. The biggest concern of Metal
Hydride utilization is due to low gravimetrichydrogen density, Metal Hydride utilization forhydrogen storage on mobility sector is limited.

Attempts on improving storage performance[3] Patil, S. D., & Ram Gopal, M. (2013). Analysis of a metal hydride reactor for hydrogen storage. In International Journal of Hydrogen Energy (Vol. 38, Issue 2, pp. 942–951). https://doi.org/10.1016/j.ijhydene.2012.10.031[4] Ma, J., Wang, Y., Shi, S., Yang, F., Bao, Z., & Zhang, Z. (2014). Optimization of heat transfer device and analysis of heat & mass transfer on the finned multi‐tubular metal hydride tank. In International Journal of Hydrogen Energy (Vol. 39, Issue 25, pp. 13583–13595).
[5] Ardahaie, S. Saedi, M. J. Hosseini, M. Eisapour, A. H. Eisapour, and A. A. Ranjbar. 2021. “A Novel Porous Metal Hydride Tank for Hydrogen Energy Storage and Consumption Assisted by PCM Jackets and Spiral Tubes.” Journal of Cleaner Production 311.

Previous research has discovered that improving
heat transfer ability on the reactor could increase
the metal hydride reaction kinetics rate.

In the other hand, a triply periodic minimal surface(TPMS) is one form of complex geometries in cellular
structure that is created based on mathematically‐
constrained cell shape patterned asymmetrically in
3D space. It has been investigated and found as oneof the better structure to both withstand load andheat transfer if we compared to another lattice
structure.

A scenario of a high strength structure and compacthydrogen storage that could charge and dischargehydrogen at a competitive speed with manageable
pressure and temperature working condition thendeveloped combining the previous mentionedtechnology. The ability to withstand load from TPMS
structure will be utilized to overcome the limitationof low gravimetric density of metal hydride

Expected Results and Future Prospects
Numerical analysis has been conducted with promising result on usability andeven better performance than previous study on common pipe in pipe
approach design. This open the possibility to further explore the application of
TPMS MH reactor on mobility usage like car frame, airplane shell, rocket tankand many other possible application.
Hydrogen fraction

10.8
0.6
500 W/(m^2 K)

0.41000 W/(m^2 K)
0.2

Natural convection

0010002000 3000
Time (s)4000