Start-up of the Subiaco Enersludge (TM) plant

The first commercial-scale plant, to convert sewage sludge to oil, using th e ENERSLUDGE(TM) technology, has recently been constructed at the Subiaco W astewater Treatment Plant (WWTP) in Perth, Western Australia. The plant, de signed to process up to 25 dry tonnes per day (tpd) of mixed raw primary an d thickened excess activated sludge, comprises numerous unit operations whi ch allows the facility to operate in four distinct modes, namely as a chemi cal stabilisation plant, an LPG-fired dryer, an autogenous sludge dryer and ultimately as a sludge conversion plant. As of June 1999, the plant is ope rable in the first three modes of operation. Commissioning of Mode 4, namel y sludge conversion to commence in August 1999 and initial results provide confidence in the technology, with the major problems being mechanical in n ature. Operating results have indicated sludge quality has a major impact o n plant performance. To improve operability, a strainpress has been install ed to remove much of the hair and fibre present in the sludge. The plant ca n now successfully process sludge with between 20 and 50% by weight of thic kened excess activated sludge.