The Western Australian company was placed into voluntary administration in 2004 and forced to sell off its wastewater treatment business to engineering giant Tenix.
Having resumed trading on the ASX last week, ESI reissued its recapitalisation prospectus yesterday in a bid to raise $A20,000 through the issue of 200,000 shares at A10c per share. The offer closes tomorrow.
The company intends to use the funds to continue development of its patented Enersludge technology, which uses a slow pyrolysis process to turn solid sewage waste into energy sources such as synthetic gas (syngas), char or oil.
The technology was originally developed in the mid-1980s by researchers at Germany's Tubingen University, before being sold to the Canadian Government.
ESI purchased the technology, patents, equipment and development rights from Canada in 1989, working with the original inventor Professor Bayer for five years developing processes and applications for the Enersludge technology.
The company has already built two demonstration Enersludge plants: one at a wastewater treatment plant (WWTP) operated by the Water Corporation of Western Australia and another that applied the waste-to-energy technology at a German tannery, which it has since purchased.
The process also offers significant environmental advantages as the slow pyrolysis technique avoids any emissions through combustion, while the majority of pollutants and metals contained in waste can be safely reclaimed, according to ESI.
The Water Corporation decommissioned its Enersludge plant in 2001 for economic reasons, choosing instead to use dewatered waste from the WWTP as a commercial fertiliser product.
EnvironmentalManagementNews.net contacted Margaret Domurad, a supervising engineer at the Water Corporation who was involved with the Enersludge plant. Domurad said that while the waste-to-oil plant was operational, it had performed well.
"It certainly worked in terms of throughput and processing of the commercial amounts of waste at the Subiaco wastewater treatment plant," she told EMN.
"The outcomes were right, in terms of yield, with about 30 to 33 per cent of the waste converted into oil."
Domurad said that while there were economic considerations, potential safety issues arising from the construction of the prototype plant had also been considered in the decision to shut the Enersludge plant down.
Although voluntary administration has restricted ESI's commercial activities, the company claims it has further refined the technology and will aggressively pursue complementary technologies to improve the economics of its waste-to-energy model.
ESI's prospectus includes plans for the development of a commercial stand-alone or portable Enersludge plant.
A portable unit would make it possible for ESI to enter into agreements with wastewater treatment contractors, who would be able to attach an Enersludge unit to a WWTP's output and sell the energy products on to commodity buyers.
ESI said it was already in discussions with one contractor currently operating 26 WWTPs in Australia, with more European contracts in the pipeline.
