Reports by the ABC this week revealed that a gas storage tank has been leaking methane for nearly 20 years at the Darwin Liquefied Natural Gas (DLNG) plant in the Northern Territory. According to the ABC the leak may release as much as 184kg of gas per hour, and in 2020 the tank’s new owners, Santos, were cleared to use the tank until 2050.
Methane is one of three main greenhouse gasses, along with carbon dioxide and nitrous oxide. It accounts for about 16% of the warming effect of greenhouse gasses, and remains in the atmosphere for about a decade.
“We often call it the ‘low-hanging fruit’ of climate action because it is over 80 times more powerful than carbon dioxide at trapping heat in the atmosphere over 20 years,” Dr Martino Malerba from RMIT University told an AusSMC Expert Reaction.
According to Dr Malerba, a single undetected leak can wipe out the climate gains made elsewhere, and investment in better monitoring systems is urgently needed.
“New technologies, such as the low-cost, solar-powered sensors, are now making continuous, real-time methane measurements possible,” he said.
According to Dr Sean Bay from La Trobe University, we already have the technology, including satellites and sensitive ground-based detectors, to identify leaks early and act quickly.
“Methane is one of the most actionable levers to slow climate warming. Fixing leaks like this should be a top priority,” he said.
So what is the cause of the leak in the Santos tank?
Dr Yujie Yuan from Edith Cowan University told the AusSMC that long-term leakage of liquefied natural gas (LNG) usually arises from a combination of engineering and management factors.
“At the technical level, defects in storage tank or pipeline design, such as welding flaws or sealing failures, can create pathways for gas to escape.”
“The extreme cryogenic conditions of LNG (–162°C) make potential materials brittle, and repeated cooling and heating cycles often lead to fatigue cracks over time,” she said, along with many other factors including the failure of safety valves and extended operation of ageing infrastructure.
According to Associate Professor Fatemeh Salehi at Macquarie University, this leak appears to have been caused by a design flaw in the plant’s LNG storage tank, allowing methane to escape continuously over many years.
“The fact that residents were not informed for decades has been labelled a serious failure of transparency and regulation.”
“With the plant’s environmental licence up for renewal, there is now a critical opportunity for stronger accountability, firm requirements to manage fugitive emissions, and guarantees that such a cover-up will never be repeated,” she told the AusSMC.
“Proper action is needed to protect both the climate and the safety of the Darwin community."
You can read the full AusSMC Expert Reaction here.
This article originally appeared in Science Deadline, a weekly newsletter from the AusSMC. You are free to republish this story, in full, with appropriate credit.
Contact: Steven Mew
Phone: +61 7120 8666
Email: info@smc.org.au