Alkali metal reduction (sodium reduction). Status & POPs application Process has been used commercially for approximately 20 years. It has been used extensively.

Alkali metal reduction

(sodium reduction)

Status & POPs application

Process has been used commercially for approximately 20 years. It has been used extensively in particular in North America, France and in Germany where most of the oil above 50 ppm now has been treated

POPs application:PCB-contaminated oils up to 10,000 ppm and for Askarel transformers (>10,000 mg/kg of PCBs)

Canada DCR model

Alternative 1 : Direct operation mode with transformer

P01 : Feeding pump with contaminated oilP04 : Feeding pump of the de-watering devices P16 : Filter press pumpP18 : Dewatered oil discharge pump

TransformerMobile unit

R01 : Nitrogen cylinderS03 : Nitrogen production deviceV : expansion tank

V

P01

P18

P18

R01

P04 S03

P16

Alternative 2 : Indirect operation mode using intermediate oil tank

P01 : Feeding pump with contaminated oilP04 : Feeding pump of the de-watering devices P16 : Filter press pumpP18 : Dewatered oil discharge pumpR01 : Nitrogen cylinderS03 : Nitrogen production device

V : expansion tank

TransformerMobile unit

StorageTank

R01

P18

P01

P16

P04S03

PART I : Adaptation Technology – Country

A. Performance:

1. Minimum pre-treatment:De-watering to avoid explosive reactions with metallic sodium. Drying oil is normally accomplished to achieve a moisture content of approximately 100 ppm

2. Destruction Efficiency: • DE nor DRE has been reported (DE typically 99% - 99.9% in

most applications, it is also possible to go to a much higher DE

• DE values of greater than 99.999 percent reported for chlordane and HCB (Ministry of Environment of Japan, 2004

PART I: Adaptation Technology - Country

A. Performance:

3. Toxic by-products: Salt solution contains some oil and biphenyl polymer. Analysis for to dioxins and furans and have been found to be innocuous. Residue can have a high ph because of the presence of NaOH or KOH. Air at vent routinely analysed for PCB, chlorobenzene + other organic compounds in Canada. PCB at the vent must be < 1 microgram/m3 in Canada.

4. Uncontrolled releases: Steel pan under process equipment collect any leak from piping + vessels. Hoses between units +tanks+ transformers are typically wrapped with sorbent material at connections are underlain by plastic liner

5. Capacity to treat all POPs: PCB-contaminated oils up to 10,000 ppm and for Askarel transformers (>10,000 mg/kg of PCBs)

6. Throughput: quantity [tons/day, l/day] Wide range: Mobile facilities are capable of treating 15,000 litres per

day of transformer oil. For mobile DCR units average flow rate 1000 L/hr.

PART I: Adaptation Technology - Country

A. Performance:

7. Wastes/residuals: Secondary waste stream volumes:

Residues include sodium chloride, sodium hydroxide, polyphenyls and water, sometimes solidified polymer. Separation of by-products: Re-use decontaminated oil (after treatment) and organo-metallic reagent re-used. Rest NaCl + Small amount sludge generated contains NaCl + solidified polymer with some oil and water normally solidified and directed to approved landfill Off gas treatment:

nitrogen and hydrogen gas + organic compounds relatively

minor finally treatment by granular activated carbon

PART I: Adaptation Technology - Country

A. Performance:

Complete elimination:

Certain limits : In case decontaminated oil is circulated in transformer and returned to treatment unit, a certain amount of cleansing of the internals of the PCB transformer takes place, especially if the transformer remains in operation; some of the PCB in the porous constituents gets desorbed in the hot clean oil that returns to the treatment unit; (no reagent is directed to the transformer).

Lot of experience on: % decontamination in transformers after on-line treatment + leach back etc.

PART II: Adaption Country – Technology

A. Resource needs: 100, 200, 300 DCR mobile Unit Canada

Power requirements: 60 Amp at 575 V Water requirements: none Fuel volumes: none Reagents volumes: 200 kg Weather tight buildings: yes Hazardous waste personnel requirement: Sampling requirements/facilities: lab module GC Peer sampling: Laboratory requirements: Communication systems: Number of (un/skilled) personnel required: 2 (1 skilled)

PART II: Adaption Country – Technology

B: Costs for: 0.15 US$/l low PCB, 0.7 /high PCB

Installation + commissioning: --- Site preparation: --- Energy & Telecom installation: --- Compliance:--- Reporting: --- Run without waste:--- Run with waste:--- Decommissioning: --- Landfilling:--- Transport residues:---

PART II: Adaption Country – Technology

C. Impact & D. Risks

Discharges to air: --- Discharges to water:--- Discharges to land:--- Risks reagents applied:

explosion dispersed metallic sodium can react violently with water lot of measures

Risks of technology: fire scenarios

Operational risks: water contact, electricity safety features

PART II: Adaption Country Technology

E. Constructability & F. Output Ease of installation & construction of plant:

standard units Ease of shipping/transit:

container sized units

Ease of operation: environment + safety training + on the job training

Ease of processing: continuing process units for transformer oil

Generated waste (% of input waste):--- Deposited waste at landfill (% of input waste):

Waste quality properties (pH, TCLP)

Experiences France: Mobile system

Exhaust of electrofilter (purification gases)

Italy: mobile treatment transformer

7.5 tons oil from transformer

Treated total 45 tons!!

Storage des bottles CO2 and Nitrogen

Fullers earth treatment of oil

Pre-mixing unitfor the reagents

Storage tank of new oil

Feeder

Waste coming from mobile unit

Drying installation

Inside: Di-electrical oil, during (brown color) and after (yellow color)the operation

Canada: Inside view

Oil fired heater of PCB contaminated oil

Centrifuge separation oil-liquid and sludge

Oil + reagent tanks

Control panel

Canada: Process schedule

Proven long time experience for PCB’s

Fire need for high quality risk management

Flexible treatment at site possible

With continuous treatments limits on total cleaning

Mobile units

Lower and higher quantities possible

Minimum interference for transformers

Strength’s Weaknesses