EnergySafe Magazine Spring 2017, issue 48 | Page 11

11
Spring 2017
energysafe issue 48
Gas
News
Hydrogen trial for South
Australia
By Enzo Alfonsetti, Manager Type A Gas
Appliance and Component Safety
In the last edition of EnergySafe,
I reported on the bold plan to reduce
greenhouse gas emissions by converting
the City of Leeds in the United Kingdom
from natural gas to hydrogen, in a project
known as the H21 project.
Essentially, the combustion of hydrogen
does not produce hydrocarbons, but rather water
vapour. Hydrogen gas is produced through the
steam reforming of natural gas, where the carbon
is captured and then stored underground using
carbon capture and storage technologies.
The first Australian trial was recently
announced to inject small quantities of hydrogen
into Adelaide’s grid. If successful, the trial may lay
the foundation for decarbonising the nation’s gas
supply in the long term.
South Australian company, Australian Gas
Networks, is partnering with Wollongong based
company, Aquahydrex, which is developing a
prototype electrolyser to produce hydrogen
from water.
The development of the electrolyser is funded
through a $5 million grant from the Commonwealth
Government’s Australian Renewable Energy
Agency (ARENA).
There are two main differences between
the H21 project in Leeds, and the South
Australian project.
» » The first point of difference is the method by
which the hydrogen gas will be produced.
Rather than ‘steam reforming’ natural gas,
the South Australian project will produce
hydrogen gas through electrolysis, where
electricity will be used to split the water
molecule H2O into hydrogen and oxygen.
» » The second is the focus of the plan. The plan
for the City of Leeds will be to convert sections
of the city, one at a time, to 100% hydrogen.
The South Australian pilot project will focus on
blending hydrogen with natural gas. The level
of hydrogen injected and blended with natural
gas into the gas network during the trial will be
limited by the ability of currently installed gas
appliances to safely burn hydrogen.
Prior to certification, Type A gas appliances
designed for use with natural gas are laboratory
tested using a range of natural gas limit gases.
‘Nb’ gas is one example of limit gases
and contains approximately 13% hydrogen.
Accordingly, this limitation will need to be taken
into account when considering the concentration
of hydrogen to include in the blend.
Hydrogen has a significantly larger (4-75%)
flammability range than natural gas (5-15%),
When simple
things go
badly wrong
Click here to watch Northern Gas
Networks film on the project
Click here to read the report.
of the Gas Safety Act.
How could this have been avoided?
There are four basic steps to ensuring
a job is left safely.
1. When reconnecting gas lines, always
take extra time to check the connection
for gas tightness.
2. Always complete a full recommissioning
after conducting any gas fitting maintenance
or service work.
3. Always test for leaks.
4. Take a few moments to double check
your work on completion.
By Richard Millership, Technical Writer
It’s often said that confidence kills, and in
a case ESV encountered earlier this year,
nothing could be closer to the truth.
A qualified gasfitter with years of experience
was completing repair work to a run-of-the-mill
gas space heater.
The work required him to disconnect one
of the supply feed tubes to two of the heater’s
six burners. After completing the repairs, he
reconnected the feed’s compression nut and
reinstated the burner assembly.
However, during this process the veteran
gasfitter, possibly under pressure to complete
the job, tightened the nut by hand only.
An easy mistake to make.
He then operated the appliance, but only on
the other four burners. Satisfied with his efforts,
the gasfitter left for the next job.
It was only when the owner of the property
turned on the heater to maximum that the
appliance directed gas to the remaining two
and is more prone to leakage given its smaller
molecule, relative to natural gas.
It also has a higher flame speed, which
means it is more likely to ignite back at the injector
of a burner, if the appliance is not designed
correctly or if the appliance is not converted to
suit. Therefore, a project of this nature will aid in
establishing some of the challenges that lie ahead.
The success of a project like the South
Australian project, could pave the way for a
complete conversion of Australia’s gas network
to running at 100% hydrogen, and a carbon-free
gas industry.
The challenge will be to produce sufficient
quantities of hydrogen in the future to meet the
demand of using renewable energy sources
such as solar power, wind power, etc.
For more information refer to the Australia
Gas Networks ‘AGN to play leading role in
Australian renewable energy pilot plant’ and
Arena’s ‘Power gas trial to inject hydrogen
Australia’s gas grid.’ Both articles available
online on their respective pages.
Consequences of a short cut: a gas heater ignites
as an experienced gasfitter fails to carry through.
mandatory steps of installation.
burners, where gas spilled from the loose
connection and ignited.
Had the owner not chosen to watch the
burners turn on and his quick reaction, the
consequences of this incident could have
been fatal.
Consequently, the incident caused severe
stress for the resident, the gasfitter, the company
he worked for and not to mention a substantial
repair bill.
The gasfitter was also issued with an
infringement notice for breaching Section 72
Lucky escape: don’t risk it. Ensure the job
you do is left safely.