Understanding the Change in Diesel Standards
Australia’s fuel refineries have announced that lowering diesel standards for six months will help increase supply during the current crisis. Energy Minister Chris Bowen stated that the standard for diesel has been adjusted to allow more fuel to flow into the domestic market. But what does this adjustment mean? Is it safe, and how will it help boost supply? Here’s a detailed breakdown of the changes and their implications.
What Has Changed?
The six-month adjustment involves lowering the diesel flashpoint from 61.5 degrees Celsius to 60.5 degrees Celsius. Australia currently has one of the highest diesel flashpoints in the world. For comparison, Europe has a minimum diesel flashpoint of 55°C. The flashpoint is the lowest temperature at which vapours from a fuel could ignite.
Dr Richard Brown, a professor at Queensland University of Technology, explained that if fuel were spilled on the ground and static electricity was present, the flashpoint would be the temperature at which ignition could occur. Petrol typically has a flashpoint around -40°C, classifying it as a flammable liquid. Diesel, with its higher flashpoint, is classified as a combustible liquid.
How Will This Improve Supply?
Dr Brown explained that diesel, like petrol, is a mixture of different compounds. Lowering the flashpoint allows shorter chain carbon molecules, such as decane, to be added to the fuel. These molecules have low boiling points, high volatility, and high flammability.
“By allowing a slightly lower flashpoint, refineries can incorporate more volatile materials into the diesel,” Dr Brown said. “This makes it easier for the refinery to produce a larger amount of fuel because they can be more flexible about what they add to the diesel.”
He also mentioned that other components can be mixed into diesel to increase volume. This flexibility is expected to help refiners meet the rising demand for fuel.
Is Lowering the Flashpoint Safe?
While a lower flashpoint increases the risk of ignition, Dr Brown noted that the one-degree drop is unlikely to significantly affect safety. He pointed out that Australia is entering the cooler season, which reduces the likelihood of ignition. Additionally, Australia’s diesel flashpoint requirements are generally higher than those of other countries.
Dr Alexander Klimenko, a mechanical engineering professor at the University of Queensland, emphasized that as long as diesel is stored safely, the change should not impact safety. “If we can safely store petrol under these conditions and prevent vapour from being ignited, it’s certain diesel would remain safe,” he said.
Refineries and Their Responses
Australia has two operating oil refineries: one in Brisbane and one in Geelong. Ampol operates a refinery in Lytton, an eastern suburb of Brisbane. A spokesperson for Ampol welcomed the decision to lower the diesel flashpoint, stating that it would allow Australian refiners to maximize crude oil yield and broaden diesel import supply options from international markets. They also noted that the temporary change would not affect combustion efficiency, engine performance, or vehicle emissions.
The other refinery is operated by Viva Energy and is located in Corio, a northern suburb of Geelong. A Viva Energy spokesperson said the change provided flexibility. “The change to petroleum and diesel specifications provides us with greater flexibility for importing refined product and production at our refinery. It means we can import refined product from a broader range of diesel manufacturers. It also provides increased production flexibility at our Geelong refinery, allowing slightly more diesel production than normal.”
Conclusion
The adjustment to diesel standards in Australia aims to address the ongoing fuel supply crisis by increasing production flexibility. While the change may raise concerns about safety, experts believe the slight reduction in flashpoint is manageable and unlikely to pose significant risks. As refineries adapt to the new standards, the goal is to ensure a stable and sufficient fuel supply for the nation.
