CMPS&F - Environment Australia
Appropriate technologies for the treatment of scheduled wastes
Review Report Number 4 - November 1997
The PCB Gone process is no longer offered in Australia because S D Myers has ceased operations here. This treatment process is designed to dechlorinate transformer oils, reducing PCB concentrations to a level which will allow the transformer to remain in service, or allow disposal of the spent transformer oil.
The PCB Gone process is very specific in the scheduled wastes it is able to treat, as it is designed to treat PCB contaminated transformer oils without the need to remove the transformer or take the transformer out of service. The fluid is recirculated through the treatment system until the residual PCB concentrations are below those required (< 2 ppm in the USA). The continued recirculation of the fluid through the transformer largely flushes the PCBs from the transformer windings and other internal components. The treated oil is then suitable for continued use.
In addition to removing PCBs, the PCB Gone treatment system also regenerates the used fluid by filtration through Fullers Earth as with other conventional transformer fluid reclamation systems. This treatment removes acids, sludges and other oxidation by-products by a mechanical filtration process, that in effect reclaims the contaminated transformer fluid. As the treated oil is reused and the transformer decontaminated without the need to remove it from service, significant cost savings could be expected from this treatment approach.
The process uses a proprietary dechlorinating reagent that provides for safe operation and is non-destructive to the transformer oil's dielectric properties.
SD Myers has also recently acquired Fluidex Engineering Pty Ltd of South Africa, a subsidiary of S D Myers. The Fluidex process is offered in Australia by Energy Services International. Fluidex offers a treatment process for regeneration of the Fullers Earth beds contaminated in the reclamation process. This avoids or reduces the need for disposal of the Fullers Earth used as part of the PCB Gone process.
The Fluidex reclamation process was first used in England by the National Grid in 1992/93 and has been approved for use by environmental authorities in the USA, Canada, Mexico, England and Saudi Arabia. There is also a plant in operation in Queensland, at Queensland Power (McDonald, 1997), however Energy Systems International declined to provide further information for inclusion in this review.
SD Myers claims the PCB Gone process has dechlorinated over 70 million litres of PCB contaminated transformer oils to < 2 ppm PCB per individual congener peak (the standard used by all other countries). As SD Myers is no longer operating in Australia, the PCB Gone process is currently not being promoted for use in Australia. However, it is understood that treatment of PCB contaminated transformers oils using the PCB Gone process continues internationally.
SD Myers owns the rights to the PCB Gone process in the US and several other countries. The PCB Gone process has been used by SD Myers commercially for several years in the US and in several other countries including England, Canada, Mexico and Saudi Arabia. Approval was obtained in each of these countries from the appropriate permitting/licensing environmental agencies for operation of the process (Miller, 1995).
The primary waste stream from the process (as operated in the US) is a Fullers Earth material with PCB concentrations that are less than the detection limit (< 2 ppm), making it suitable for disposal to landfill. Air emissions from the PCB Gone system are minimal and filtered through activated carbon to ensure any residual PCBs or other emissions are minimised.
a) Proponents (in Australia)
Nil. SD Myers Pty. Ltd is no longer operating in Australia.
b) Wastes Applicable
PCB contaminated transformer oils.
c) Contaminants Applicable
Commercially available and operational in the US and in a number of other countries such as England, Canada, Mexico and Saudi Arabia.
e) Timing for Commercialisation in Australia
f) Cost (example only)
No information provided. The ability to reuse treated oil and to not take the transformer out of service should provide a significant cost advantage over destruction only technologies.
g) Safety/Environmental Risk
Process is relatively safe and presents a low risk to the environment, as demonstrated by the operational history in the US. The process is a low temperature system that destroys the PCBs, with few emissions. The portability of the system minimises the risks associated with the handling and transport of PCB contaminated materials.
h) Non-technical Impediments
Difficulties in gaining approvals for a portable system, where relatively small volumes of material may be treated at each of a large number of sites.
i) Preferred Mode of Implementation
Portable system, although PCB Gone has also been used as a centralised system in the US.
Only configured to treat PCB contaminated transformer oils (and transformers by recirculating the treated oil). SD Myers had planned to implement the process only for the treatment of PCB contaminated transformer oils in Australia.
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