| TOKYO--A research
team from the Tokyo Institute of Technology has developed a machine that
produces hydrogen from woody biomass more efficiently using less nickel
catalyst.
Because nickel catalyst is expensive,
the machine can produce hydrogen for fuel cells for less cost. The team
envisions a compact version being used by households to generate hydrogen
for fuel cells to provide energy for their homes.
The prototype machine makes hydrogen
from biomass inside a stainless steel reaction chamber that is 3cm in outer
diameter and 30cm tall. The catalyst that drives the reaction is nickel,
and it is affixed to a cylindrical block of multiporous alumina that is
2cm in diameter and 2cm tall.
The nickel adheres to all of the
inner surfaces of the spongelike alumina, so there is a large surface area
where the reaction can take place.
For the reaction, the chamber is
heated to 800 C and subjected to a stream of water vapor from above. When
powdered cellulose derived from woody biomass is inserted into the chamber,
it reacts with the nickel catalyst to yield a mixed gas containing hydrogen.
Virtually all of the hydrogen from the cellulose is retrieved in this mixed
gas, according to the university team.
The procedure is a modification of
the reaction normally used to extract hydrogen from cellulose using a nickel
catalyst. But in that process, air and water vapor are supplied from below
and churn the catalyst. The constant churning breaks the catalyst apart,
necessitating a constant supply of fresh catalyst.

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