Sitting across the wharf of Melbourne’s Maribyrnong River, Wilmar Sugar's Yarraville Refinery has been refining sugar since 1873. It is Australia's longest-established sugar refinery and is understandably heritage listed. Building on their strong history in sugar, the site now houses a tank farm where they distil ethanol from molasses for their Wilmar BioEthanol business.
Manufactured on site in the 1940s, the farm’s 11 tanks (one being silver stainless steel) each hold different types of ethanol. They were last cared for around 10 to 20 years ago and the structural integrity of the tanks was becoming a concern as the tank thickness measured at around 6mm. The standard is 8mm and when a tank reaches 4mm it is no longer structurally safe, deemed unusable and made redundant.
Their reports found that deterioration and corrosion was occurring on the outside of the tanks; the inside was protected due to the ethanol. Additionally, a species of black mould that grows specifically in ethanol gas had encroached upon the farm, leaving a thick, black film on the tanks, railings and associated structures making it difficult to identify the tanks.
Project Solution and Outcome
Treating the corrosion and rust would be a challenge. Complexities associated with the task included access, height and proximity of one tank to another with gaps of as little as 300 mm between vats. The distillation process also creates gas vapours and ethanol, being a highly flammable liquid meant even the slightest spark could trigger a catastrophe.
Jason Cassar, maintenance planner at Wilmar Sugar could not stress safety enough and was impressed with the Programmed team who had chemical plant experience and understood the importance of safety. Communication was also crucial but proved tricky as phones weren’t allowed on site or they had to be switched off in case they generated a spark. The rust painting procedure also underwent numerous testing to ensure no potential sparks.
Two coats were applied to the tanks and corrosion points were spot treated before applying the final protective coating. Programmed used Jotun Jotamastic 90 in white as the high build epoxy to get the film thickness. Jotan HardTop Smart Pack was then applied in Australian Standard N14 White as the final coating as the polyurethane for UV protection, preserving the tank from further deterioration.
Works extended from the tanks to the framework that supports the handrails and walkways as well as the pipework. The pipework was also painted to the ISO standards on colour coding for easy and immediate identification. Even the underside of the tanks were not missed and were safely painted and pressure washed despite the tight space.
The repainted tank farm is now aesthetically pleasing and shines, as the structural integrity has been preserved for at least another 10 years. Safety is also reassured to property owners surrounding the area that any leakage of this highly flammable substance is very unlikely to happen due to the restored secure storage system of the tanks.
“The cost of removing unsafe tanks would amount to $20 million. If one of these tanks were to fail an integrity test, let alone 2 or 3 tanks, it can cripple a business. Short term pain for long term gain is something you can live by with this sort of project,” says Jason.
Project completion presented Programmed with an outstanding opportunity being awards the winner at the 2018 Master Painters Awards For Excellence in the EnviroPainter category.