With climate change in our midst, it seems pretty important to be thinking about energy sources. After reading about all of the potential energy sources for Australia, I was interested in looking at a current source that has recently been making headlines. Coal seam gas is probably not on most people’s radar but it’s been in the news recently for all the wrong reasons. So what is it?
Coal seam gas is just natural gas (methane) that is produced during coal formation. Coal is formed from decayed vegetation over millions of years and is typically found in beds between layers of sedimentary rock (e.g. shale and sandstone). These formations are called coal seams. Methane and water (along with a few other things) are produced during the conversion from peat to coal and they ‘cleat’ to the pores between the coal grains. The gas is extracted as an energy source because the coal is so far down in the earth that it is, as yet, uneconomic to mine it.
In Australia, commercial production of coal seam gas began in 1996 in the Bowen Basin, Queensland. To set up a coal seam for commercial production, the coal seams must first be ‘fracked’. This is the hydraulic fracturing of the rock which allows the gas to flow freely through the seam. Fracking involves the combination of high pressure water and sand with chemical additives to form a gel (the combination is varied depending on the specific well, e.g. if the area has a high clay content then potassium chloride is used). After this process has occurred, extraction can commence using high pressure water. The gas is then collected and sent to be processed. The ultimate uses of coal seam gas are varied, but currently it makes up 30% of gas used to produce electricity in Queensland.
It’s in Queensland that much of the coal seam controversy has erupted. A major environmental concern is that many of the chemical additives used are bleaches and other chemicals which do not readily bio-degrade (like naphthalene). Additionally, some of these chemicals are carcinogenic and toxic to humans. Last October, Queensland changed its laws to prevent the use of chemicals known as BTEX (benzene, toluene, ethylene and xylene) from being used by coal seam gas producers, either in fracking or extraction. However, this week it was reported that traces of benzene, toluene and xylene had been found at a bore owned by mining company CSG in Queensland’s Darling Downs. The concentration was found to be 15-16 parts per billion. This may not seem like much, but it is more than the amount of benzene people are exposed to in rush hour in Los Angeles and more than 5 times what the same study recorded at a fixed outdoor site. There is still an investigation as to whether the chemicals detected in Queensland have come from natural or anthropogenic sources, but it has certainly shone the spotlight on the coal seam gas industry.
Clive Palmer, a billionaire and mining tycoon, has added to the debate by suggesting that Australia is lagging behind in training and expertise in the coal seam gas industry. At the National Party’s Federal Council in Canberra he predicted that the “coal seam gas technology currently used in Australia is lethal and will kill Australians, poison our water table and destroy the land.”
They are pretty big claims to make, but from the information I have looked at it looks like that although the fracking process works well, it could be done with more environmentally friendly (and human friendly) chemicals. Maybe it’s time for bit of Aussie ingenuity; coming up with some alternatives and proving Mr Palmer wrong!