(587a) Component Development for Decentralized Sustainable Hydrogen Production

Component Development
for decentralized sustainable hydrogen production

Stephan Nestl, Manfred Wegleiter, Viktor Hacker

Institute of Chemical Engineering and Environmental Technologies, Graz
University of Technology

8010 Graz, Steyrergasse 21/2, Austria

stephan.nest@tugraz.at, manfred.wegleiter@tugraz.at, viktor.hacker@tugraz.at

Fuel cells have
the potential to realise high efficient and emission-free power generation. Fuel
cells have been extensively investigated and various manufacturers start mass production
in the next few years. The resulting cost reduction will make the fuel cell to
a competitive product in various fields of applications, such as electro-mobility,
APUs or residential heat and power generation.

Due to the fact
that hydrogen transport and storage capacities are still inadequate, on site hydrogen
production offers an alternative to the centralised production that is common
today. Besides electrolysis, the reformation of liquid and gaseous energy
sources, as for example methane, or ethanol, in small units located near the
end user, can play an important role as an enabling technology for fuel cells.
Thereby hydrogen production from renewable energy sources also decreases the
carbon dioxide emissions. To achieve these goals small scale reformers have to overcome
the economic hurdle to market entry.

The selection of
an economically advantageous catalyst system with high durability and
satisfying conversion efficiency can be seen as one of the most important steps
for that. Various catalytic active materials can be found in literature. On the
one hand noble metals such as Ruthenium or Platinum show higher stability
against some degradation effects, on the other hand their prices are several orders
of magnitude higher compared to other usable metals like Nickel or Cobalt.

In addition to
the catalytic active materials also the selection of the support structure is
an important aspect. Commonly used catalyst pellets are simple to handle and inexpensive
in production. The pellets can also be exchanged easily which increases
operation time and lowers maintenance costs. But the catalytic active surface
of pellets is limited and a homogeneous gas flow is difficult to achieve. More
complex structures such as ceramic monoliths and metallic foams have the potential
for improved performance. With regard to temperature control and waste heat
utilization also the use of catalytic heat exchanging materials is investigated.

Catalyst
lifetime has a significant impact on economic efficiency and depends strongly
on the reaction conditions. Temperature, steam or oxygen to carbon ratio and
space velocity needs to be optimised for each potential fuel. The operating conditions
and the catalyst material determine the amount of by-products and carbon
monoxide in the product gas, which in turn determines the necessary further
purification steps. Advantages and disadvantages of different system
configurations for decentralized hydrogen production units will be discussed in
the presentation.

Acknowledgment: This work is funded by the Research Studios Austria program of the Austrian Federal Ministry of Economy, Family and Youth.