Furthermore, hydrogen can be used to store
energy and thereby address the paradox of
excess renewables in which governments
pay constraint payments to wind and solar
farms to not produce electricity because the
grid has too much electricity on windy and
sunny days. This excess energy can be used
to produce hydrogen which can then be
stored and used on the far more common
overcast, low wind days to power the grid.
So, what’s the problem? Why isn’t the
forecast $24trillon hydrogen economy
already here? It ’s because current
production is either high emission or high
cost. Most (95%) of hydrogen is made via
Steam Methane Reforming
which emits large amounts
of CO 2 (up to 9kg per kg
of Hydrogen). Alternative
green methods are highly
expensive and somewhat
flawed; for example, the
electrolysis of water into
H 2 and O 2 cannot, from
basic conservation of
energy, be the solution as
you start with water and
ultimately finish with water
(and don’t create energy along the way).
The search is on for a new way to produce
hydrogen in an environmentally friendly and
cost-effective way. There are many methods
under investigation but very few have the
potential to produce large volumes of
affordable, emission-free hydrogen soon.
One such method with great potential is the
thermal plasma electrolysis (TPE) of
methane. It is a new process that is under
development by the HiiROC group of
Dutch, Bulgarian and British scientists and
engineers. TPE traps the potent greenhouse
gas, methane, (the main component of
natural gas) and creates hydrogen and
carbon black (a solid, stable carbon rather
than CO 2 ). You can find out all about the
process and its engineering innovations at
Engineering Society but, in the meantime, I
will give you a taster below.
TPE uses world-leading plasma torches
based on ex-soviet technology to
disassemble methane (CH 4 ) into a ultra-high
energy plasma of carbon and hydrogen
ions at over 6000°C. Plasma (the 4 th state of
matter) can be thought of as a sea of high
energy ionised gas and electrons.
The torch needs to have a strong electric
field to rip apart the molecules. The HiiROC
torch is engineered to have ultra-high (over
90%) efficiency which allows it to operate at
high enough currents to allow full
dissociation of the methane and
high pressures to allow commercial
throughput. The power supply is an
incredible bit of kit, capable of
v i r t u a l l y i n s t a n t a n e o u s
(microsecond) self-adjustment,
managing what is ultimately a 200V
and 300A controlled lightning bolt
inside the torch. The plasma of TPE
(which can also be used to propel
rockets in space) is expelled from
the torch at Mach 2-3 where the
gaseous carbon is quenched to produce
solid carbon black, a useful by-product used
in tyres, rubbers, plastics and printer toner.
Their torches’ innovative engineering also
addresses the fundamental challenges
typically experienced with plasma torches,
for example electrode degradation, the
specifics of which remain classified.
In summary, hydrogen could well be the
energy solution our planet needs, providing
a sustainable yet affordable solution for
electricity, transport & heat. Whether TPE
makes the breakthrough or not, there is a lot
of cool engineering that will no doubt
benefit society.