Hydrogen still has
potential as a fuel
I read with interest your short article on "Browns Gas" in "Ask
SILICON CHIP" (September 2008 issue,
pages 89-90) and hasten to add that I agree with the majority of your
However, I would like to challenge your comment that the use of
hydrogen as a fuel is never likely to come to anything. There is at least one
quite promising research project being undertaken within Australia which
involves producing hydrogen as a usable and practical fuel, although the
approach is a little unconventional.
There is a reasonably well-known industrial process which uses
waste "high grade" (ie, around 800°C) heat to convert methane (CH4)
to H2 and CO in a catalytic process. The resultant blend of hydrogen
and carbon monoxide is often referred to as Syngas. The principle is that the
otherwise wasted heat energy is stored in the molecular structure of the gas so
that the resultant gas has a higher (up to 30%) calorific content than the
CSIRO have a test plant running at their solar research
facility in Newcastle where they use heat generated in a solar tower rather than
using waste heat. Natural gas is pumped through a catalyst at the top of the
solar tower and H2 & CO comes out the other side (keep in mind
that CO is combustible).
The initial reaction to this concept is that it is cheating.
All they are doing is taking a non-renewable resource and modifying it! Thinking
it through a bit further though, how hard is it to store solar energy and how
much harder to store it in a medium that can be easily transported and used in
The point is that the energy content of the methane is less
than the energy content of the synthesised hydrogen/carbon monoxide mixture. The
difference is the heat that has been added. If that heat is from solar energy,
it is effectively free. If it is from waste heat from industrial processes again
it is effectively free because it would otherwise just be heating up the
atmosphere. Thus, energy has been stored that is otherwise difficult to
My understanding is that CSIRO now have significant Federal and
state government funding for a pilot/research plant to be built in Queensland.
Further details can be found at http://www.det.csiro.au/science/r_h/nsec.htm
While I accept that this is a long way from being developed
into a commercial proposition, it does appear that there is enough happening out
there to stop us writing off hydrogen as a fuel just yet.
Nick Fisher, VK2ZNF,
West Pennant Hills, NSW.