7th Asia-Pacific Conference on Plasma Physics, 12-17 Nov, 2023 at Port Messe Nagoya

Plasma membrane packed bed reactor for hydrogen production from ammonia
Shinji Kambara1 and Yukio Hayakawa1
1Graduate School of Engineering, Gifu University
e-mail (speaker): kambara@gifu-u.ac.jp

1. Introduction
Ammonia is a promising zero-carbon energy source
because of its easy liquefaction, high energy density, andwell-established transportation and storage systems.
Ammonia production emit CO2, but the generated CO2
can be reduced from 65% to 99%, a process referred toas "blue ammonia." To achieve carbon neutrality by 2050,
Japan has begun using "blue ammonia" as a fuel for
power generation and ship engines. In the industrial field,
there is a need for technology to produce hydrogen fromammonia. However, ammonia cracking catalysts cannot
convert ammonia into pure hydrogen for fuel cells.
The plasma membrane packed bed reactor (PMR) has
been developed to efficiently separate hydrogen and tocompletely decompose any unreacted ammonia in thecatalysis reactor. Details on the research anddevelopment of the PMR will be presented.
2. ExperimentalFigure 1 shows the detailed configuration of theexperimental apparatus for pure hydrogen production1.
The ammonia cracking catalyst was made by 5%Ru andzeolite particles2, which was ammonia decomposition of
99.5% at the temperature of 450ºC. The PMR consists ofa cylindrical hydrogen separation membrane module
coaxially arranged in a quartz tube with an outer
diameter of 42 mm, a thickness of 2 mm, and a length of
400 mm. The hydrogen separation membrane is a
Pd-40%Cu alloy with a thickness of 20 µm, and themembrane is welded onto a cylindrical metal support,
which also serves as a ground electrode. The
high-voltage electrode is made of stainless steel (SUS304), which is 300 mm in length and 0.2 mm inthickness. It is wrapped around the surface of the outer
glass tube.

The gap length is 4 mm. The plasma is generated
between the inner surface of the quartz tube and thesurface of the hydrogen separation membrane. The gap
space is filled with zeolite to generate stable plasma at apressure of 0.3 MPa. A vacuum pump was placed at theoutlet of the hydrogen separation membrane to collectthe separated pure hydrogen and measure the flow rate.
3. Results and discussion
Fig. 2 shows the separated hydrogen flow rate withplasma (plots) and without plasma (dot line) at thevariation of the reactor surface temperature. Clearly, thesystem using the PMR have good performance comparedwith the no plasma system. This is because the PMR
generates much H radicals.

Figure 2 Performance of hydrogen separation with andwithout plasma (Inlet total pressure: 300 kPaG).
4. Conclusion
The greatest advantage of the PMR is the ability tomaximize the performance of the hydrogen separation
membrane (Pd-40%Cu) at low pressure and temperature.
Another advantage is that unreacted ammonia can bealmost all decomposed by the plasma. Maximum H2flow rate was 304.2 L/h at 300 kPaG, which wascorresponded to the maximum flow rate of themembrane.
References[1] Y. Hayakawa, S. Kambara, T. Miura, Int. J. Hydrogen
Energy, 45(56), pp. 32082-32088, 2020.
[2] Mostafa El-Shafie, S. Kambara, Y. Hayakawa,
Catalysis Today, 397–399, pp. 103-112, 2022.

Figure1 Experimental setup for investigating hydrogen
separation performance of the PMR.