The name of Endecon has long been associated with unique, environmentally safe systems for the decontamination of oil refinery and petrochemical systems. Today Endecon is part of the Cape DBI, ensuring an even better service built on a team of highly experienced professionals and drawing on the Group’s huge resources to offer cost-effective alternatives to environmentally unfriendly chemicals, prolonged steaming and hazardous man-entry options.

Hydrocarbon Sludge Processing

Ever more stringent Environmental legislation means the demand for hydrocarbon sludge processing is evolving rapidly in the UK Oil Industry. Disposal options for plants that generate oily sludge are now so limited that some facilities are actually stockpiling ‘treated’ solids while they wait hopeflly for a suitable disposal process to become commercially viable.

There are now just FOUR approved Hazardous Waste Landfill sites active in England, with none at all in Scotland or Wales. Whilst two major Incinerators are still taking refinery, their prices are inexorably on the rise. Even the limited number of ‘Mixing Pits’ that are still taking oily sludge that is not suitable for Hazardous Landfill, will close in July 2008 as a result of yet another piece of new legislation.

It seems only a matter of time until all the traditional methods of disposal will be banned.

However there IS a solution. Cape DBI has developed a unique, two-phase approach to oily sludge treatment that takes hazardous sludges or sludges and convert them to a dry, non-hazardous solid suitable for non-hazardous landfill sites. With the closure of the remaining Hazardous Landfill Sites in July 2008 and the fast increasing cost of incineration, Cape DBI’s ability to process oily waste into solids approved for disposal in ordinary ‘local’ landfill sites is major step forward for the industry.

The the first stage in Cape DBI’s unique combination process is a 25-Bar Membrane Press which regularly delivers an impressive 90% reduction in waste volume. The second stage of the process utilises a Thermal Desorption System that ‘cook’ the solids down to a dary, non-hazardous condition. Both stages have now been in successful operation for a matter of months.

Membrane Press Technology
Cape DBI is EXCLUSIVE UK licensee of the unique, patented Membrane Press waste processing technology which was developed to meet the demands of ever more stringent land-farming and hazardous landfill regulations. Now well-proven in the field, the first mobile system was commissioned as far back as December 2005, accumulating many hours of impressive operational performance data.

Membrane Press Technology

• The Membrane Press system is delivered to site in two 40 foot curtain-side trailers. The first houses the Membrane Press itself; complete with feed pumps and integral screw conveyors, plus an auger to lift ‘cake’ solids into Ro-Ro Skips. The second unit is packed with preparation equipment; a 100kvA diesel-driven generator, and a diesel- driven compressor. The system can therefore be fully independent once on site. Future systems will be modular for semi-permanent site installations.
• The process operates in two phases: The first fills and filters simultaneously at up to 7 bar. The second sees the Press isolated from the feed pumps. Internal chambers are the inflated up to 25 bar using moveable membranes. This forces even more filtrate out through the filter cloths. At these pressures even oil adhering to solids is forced to detach itself and pass through the filter cloth.
• Filtration varies depending on the cloths selected, but removes solids down to less than 20 microns in diameter. The filtrate produced, especially in the water phase, is therefore of very high quality. Recovered oil is often clean enough for immediate reuse, whilst water is recycled directly back into the process or the client’s effluent plant.
• Sludge is pre-conditioned with one of a unique range of polymers, in a custom-built, agitated tank mounted on the separate Support Trailer. To accommodate highly contaminated sludges, the Support Trailer also carries an integral Solids Crusher (‘Mono-Muncher’) which removes any stones larger than 2mm. The Cape DBI Membrane Press can process the following sludge and waste:
• Oil Refinery Waste Treatment Sludges (DAF/Separators/Biomass).
• Oil Refinery Tank Bottoms.
• Waste Pond and Lagoon sludges.
• Steel Plant Scale Pit sludges.
• Off-Shore Drilling Muds and Process sludges.

Processing rates depend on the material being pressed; essentially the concntration of solids in the sludge. Whilst each batch of cake produced is around 2m3, it may require 30 or 40m3of feed to produce that cake, meaning daily outputs vary greatly, though they are calculated from Pilot Unit test-work in each case.

Whilst the Cape DBI Membrane Press performance will vary with the type of sludge feed, typically, oily/water sludges (such as Effluent Plant or Pond sludges) can be pressed into ‘cakes’ of more than 70% solid and less than 5% oil content. In some sludge types ‘cakes’ with more than 80% solids content have been produced.

Thermal Desorption Technology

Cape DBI is the EXCLUSIVE UK Oil Industry licensee for this unique, patented thermal waste processing technology. Thermal Desorption Technology (also known as ‘MCS’) was initially developed in the USA by Industry Recovery Systems Inc in 1998, and has been successfully operating since.

The technology has been monitored and tested by the EPA. A copy of a video produced by the EPA in 2005 that features the ‘MCS’ system operating on a soil remediation project was is available upon request.

The first mobile system in the UK is now complete, once proving tests, are completed on actual client material, the system will be mobilised to its first on-site project.

• Waste solids produced by Cape DBI’s Membrane Press are transferred to two 3m trays, that have been specially fabricated to allow heat transfer up through the base into the distributed ‘solids’.
• The loaded trays are placed in the Thermal Processor (essentially an oven), and a vacuum hood is lowered, sealing the trays. Heat is then applied to an array of unique burner tubes under the trays, until infra-red heat is generated. The solids are then ‘cooked’ for a period of around 2 hours, at a temperature, typically 250-350oC, that has been established during the initial trial runs.
• During the ‘cooking’ period, the gases and vapours from the waste material are drawn off through an emissions control unit, where oil, water and particulates are removed, producing a completely clean final stack output.
• At the end of the cooking period, the trays are removed and allowed to cool before being emptied into the collection skip or transfer area. The processed solids are now suitable for disposal at a NON-HAZARDOUSlandfill site. In some cases, the solids may even be classified as ‘inert’ allowing disposal within the client’s own site.
• Depending on the type and condition of solids fed to the trays, the MCS Thermal Desorption System can process 25 to 45m3in a 24 hour period.
• All water and hydrocarbons recovered are recycled back to the client.