by Rose Adams
Further to concerns raised about burning flares at CSG wells, suggestions these may cause bush fires and questions about why CSG companies, in NSW at least, are exempt from total fire bans, I did some research and came across reference to Santos Gas being able to invoke a Total Fire Ban Exemption Under regulation Schedule 15 of the Rural Fires Act 1997, as published in the Government Gazette. There is a particular regulation called ‘SCHEDULE 15 – Exhaust Stacks for Gas Exploration, Collection, Drainage, Refining Facilities, Oil Refineries and Steel Works’ which allows Santos to continue to operate no matter the fire weather conditions.
Pondering on why this should be allowed, I thought back to my long ago physics lessons. The gas flare is burning with non-radiant heat at the point where the gases mix with oxygen in the atmosphere (immediately at the top of the stack). As far as I know, it does not produce embers, ash or burning debris that could be carried into surrounding combustible material i.e. grass. A bush fire by contrast produces radiant heat, which is the destructive force that causes loss of life and property. A visit to Wiki’s pages is always useful, where I read:
“A gas flare
, alternatively known as a flare stack
, is a gas combustion device used in industrial plants such as petroleum refineries, chemical plants, natural gas processing plants as well as at oil or gas production sites having oil wells, gas wells, offshore oil and gas rigs and landfills.
In industrial plants, flare stacks are primarily used for burning off flammable gas released by pressure relief valves during unplanned over-pressuring of plant equipment.
During plant or partial plant startups and shutdowns, flare stacks are also often used for the planned combustion of gases over relatively short periods.”
And “…flaring constitutes a hazard to human health and also significantly contributes to the worldwide anthropogenic emissions of carbon dioxide.”
At this source : I http://siteresources.worldbank.org/EXTGGFR/Resources/578068-1258067586081/FlaringQA.pdf
“What is emitted from flaring, incineration and venting? Complete combustion of pure methane (CH4) produces only carbon dioxide (CO2) and water (H2O). However, combustion in flares and incinerators is seldom 100 per cent complete. Unprocessed natural gas usually contains a mixture of hydrocarbons and other substances, which can form a variety of chemical compounds during combustion. For example, incomplete combustion of hydrocarbons can lead to the formation of carbon monoxide (CO). Nitrogen in the air is also oxidized during combustion to form oxides of nitrogen, known collectively as NOx. As a result, flaring and incineration emit a number of substances that can affect human health, livestock and the environment.
The CH4 in vented natural gas and the CO2 and nitrous oxide (N20) emitted from flares and incinerators are greenhouse gases that contribute to global warming”
I did not come across any reference to flares producing embers (other than anecdotally) or a clear explanation of what constituted a fire hazard from flaring but I would welcome further information. This would also be useful for anti-CSG campaigners so that their messages are based on accurate scientific information. In our fireprone climate, any source that could cause a fire remains of grave concern. ln the meantime, it is quite clear that the CSG industry is highly undesirable because of its contribution to air pollution, the build up of CO2 in our atmosphere, contamination of our aquifers, impacts upon human health and the many, many other hazards that have come to light in the years since fracking commenced.
Readers are encouraged to visit www.lockthegate.org.au
for detailed information on the CSG industry and its impacts.