Waste recycling project

The UR-3R household waste recycling project at Eastern Creek on the outskirts of Sydney, which was recently opened, has illustrated the advantage offered by Permastore Australasia with its glass-fused-to-steel product from which both the digesters and all the water storage reservoirs are built.

The plant was commissioned by Waste Services NSW to divert household garbage from landfill to 90% recycled product and is capable of handling around 12% of Sydney's household waste or 256,000 tonnes per year. The plant offers the equivalent of taking 50,000 cars off the road in reduced carbon emissions. The 2 ML digesters generate 17,000 MW hours of green energy from methane generated from the wastewater streamed into them from the recycling process.

The UR-3R Process sorts and recovers pure streams of plastic, glass, paper and metal recyclable materials. All of the organic waste - such as food scraps and garden waste - is then cleaned and deodorised. The liquid portion is then digested in the Permastore glass-fused-to-steel digesters to produce methane gas which is subsequently used to fire electrical generators producing renewable energy. The dry portion is then composted to a high quality compost product for agricultural and horticultural use.

Permastore's glass-fused-to-steel product was chosen for the plant due to its resistance to the acidic gases generated by the process and also the need to have a plant that could be operated by 25 years without being subject to maintenance shutdowns. The tanks and digesters are manufactured from vitreous glass which is fused into high-strength steel at temperatures in excess of 850°C so that the glass and steel are mixed and effectively become a single material from the fusion of the two. This provides the strength and structural flexibility of the steel but the corrosion resistance of a glass bottle.

Uniquely the glass formulation and the Permastore process ensure that the glass can be flexed within the elastic limits of the steel without cracking or crazing, making the product a good choice for applications from potable water to sewage, wastewater and digesters as well as bulk storage of many industrial products including wood by-products and vegetable seed meals.