(QUICK) Overview of PCB disposal technologies

PPG Inception Meeting – Colombo, Sri Lanka 5-10 August 2013

(QUICK)OVERVIEW OF PCB

DISPOSAL TECHNOLOGIES

Carlo Lupi – UNIDO [email protected]

mailto:[email protected]



THANK YOU VERY MUCH FOR YOUR KIND ATTENTION

….sorry – any question?



COMMERCIAL TECHNOLOGIES FOR PCB TREATMENT

Thermal technologi

es

Incineration

Co-Incineration

(Cement kiln)

Plasma

Chemical technologi

es

Sodium based dechlorination

Hydro-dehalogenatio

n

Post -Treatment

Solvent Washing

Retrofilling

Thermal desorption

Vacuum washing

Pre-treatment

Draining

Shredding

Vacuum extraction


TECHNOLOGIES FOR HIGH CONCENTRATED OR PURE PCBS

Oil

Thermal technologies

Transformers


Cleanup of carcasses

Post - treatment

Capacitors

Pre treatment


Post-treatment or

thermal technologies

Other waste

(paper, wood, soil)

Thermal destruction

Thermal desorption followed by

thermal destruction


TECHNOLOGIES FOR LOW-MEDIUM CONCENTRATED PCBS (I.E. UP TO 10000 PPM )

Oil

Chemical dehalogenatio

n

Oil reprocessing

New transformer

s

Pretreatment (draining, flushing)

Chemical dehalogenation (of the oil)

Retrofilling

Old transformer

s

Pretreatment (draining,

dismantling)


n

Post treatment

Recovery of scrap metal

Capacitor (very rare)

Draining or shredding


n or incineration

Thermal treatment of

the waste


DECONTAMINATION TARGETS

•Stockholm Convention: <50 ppm•National regulations: <2ppm to <50 ppmRegulatory level for equipment

and dieletric oil

•Burning oil: (40 CFR 761.20) <2ppm (if greater only incineration is allowed)

•Unused oil: not detectable (IEC 60296 / IEC 61619)

Other uses by sector

•Cleanup level for soils (from 0.1 ppm to 15 ppm)Environmental

standards

•Low POPs content: <50 ppm (cann be landfilled)

•High POPs content: >50 ppm (cannot be landfilled)

POPs waste


REQUISITES FOR DISPOSAL TECHNOLOGIES UNDER THE SC

•“destroyed or irreversibly transformed”

• otherwise disposed of in an environmentally sound manner (low POPs content)

•In compliance with all other national and international rulesArticle 6.1(d)(ii) of the

Stockholm Convention

on POPs requires that Stockpiles of

POPs and waste

contaminated by POPs must be


BAT AND BEP UNDER THE STOCKHOLM CONVENTION

Designed to prevent or to reduce releases of chemicals listed in Part I of Annex C (PCDD/F, HCP and PCB and their impact on the environment as a whole.)

Destruction of PCBs must not result in the release of Dioxins!!


EFFICIENCY MEASUREMENT: DE AND DRE

•((Input mass – Sum of ALL outputs)/Input mass)*100

•>99,99%

DE•((Input mass – mass released

in the atmosphere) / input mass)*100

•>99.9999%

DRE


NEED TO PERFORM TRIAL BURN TESTSID

123456789101112131415161718192021222324252627282930313233343536373839

PCB soil (1-2%)200 kg/h

400 kg/h600 kg/hPCDD/F sampling

12

3Sampling flue gas for other pollutantsSampling waste, bottom ashes, fly ashes, sludge

PCB oil (20%)100 kg/h

140 kg/hPCDD/F sampling

12

3Sampling flue gas for other pollutants

Sampling waste, bottom ashes, fly ashes, sludgePCB Soil and capacitors (10%)

200 kg/h400 kg/h


23

Sampling flue gas for other pollutantsSampling waste, bottom ashes, fly ashes, sludge

200 kg/h400 kg/h


12

3Sampling flue gas for other pollutants

Sampling waste, bottom ashes, fly ashes, sludge

16 18 20 22 0 2 4 6 8 10 12 14 16 18 20 22 0 2 4 6 8 10 12 14 16 18 20 22 0 2 4 6 8 10 12 14 16 18 20 22 0 2 4 6 8 10 12 14 16 18 20 22 0 2 4 6 8Mon 14 Sep Tue 15 Sep Wed 16 Sep Thu 17 Sep Fri 18 Sep Sat 19 Sep

Trial burn with PCB contaminated soil (PCB 1-2%)

Trial burn with PCB oil (PCB 20%)

Trial burn with PCB soil and capacitors (PCB 10%)

DE / TEq test trial burn with PCB soil and capacitors (PCB 10%)


PRE-TREATMENT

Pre-treatment (including meshing, shredding, feeding) may be an important source of release.

It may also represent a risk for workers (exposure to chemicals and other accidents)

Pre-treatment equipment and operations must be properly designed to avoid human exposute and prevent release of toxic wate


PRE-TREATMENT AND FEEDING

No matter how good is the downstream disposal

technology…

If the pre-treatment is poorly managed, it will result in the release of

POPs (low DE)


INHERENTLY AND DEMONSTRABLY SAFE

•A technology that achieves the highest possible level of occupational safety and has a history of safe operation.

Demonstrably safe

•Closed system of the technology as a whole (pre-treatment + destruction process)

Inherently safe


MONITORING AND PERMITTING ISSUES

EIA, IPPC (BAT compliance)

Building permits and land use

Licensing (waste handling, transportation)

Monitoring of releases in atmosphere and water

Environmental monitoring


METALLIC SODIUM DEHALOGENATION OF PCBSMain reactions / Description

Technologies based on the use of metallic sodium to dechlorinate the PCB molecules.

PCB Concentration Generally not suitable for pure PCBProcess temperature 100° - 200°Process pressure AtmosphericReagents Metallic sodium.By products, outflows and waste streams

Sludge,

Applicability OilsNeeds for post or pre treatment

The process requires the dewatering and degassing of the matrix to be treated.

Main advantage Short time. Oil may be reused after treatment.

Main limitations Hazardous substances (Metallc sodium explodes when in contact with water)


COST FACTORS: METALLIC SODIUMSupplier Technology A Technology BArochlor type 1242 1254Amount PCB (tons) 1 1Moles PCB 3883 3063Moles Cl 11649 15318Moles Na 11649 15318Cl (tons) 0.41 0.54Na (tons) 0.27 0.35Na consumption declared

0.41 0.93

Reaction efficency 65.09 37.90Nacl produced 0.68 0.90BiPhenils produced 0.60 0.47Waste (sludge) 1.28 1.37


MOBILE DEHALOGENATION FACILITY


MOBILE DEHALOGENATION PLANT


MOBILE DEHALOGENATION PLANT


STATIONARY DEHALOGENATION PLANT


A-PEG DEHALOGENATION OF PCBSMain reactions / Description

The process consists of mixing and heating the contaminated media with the APEG reagent. During heating, the alkali metal hydroxide reacts with the halogen from the contaminant to form a non-toxic salt; and the PEG takes the location in the PCB molecule formerly occupied by the halogen making it less hazardous. Process can be operated in batch or continuous mode.

PCB Concentration

Reported up to 45,000 ppm. – usually not suitable over 2000 ppm.

Process temperature

70° - 200°

Process pressure

From atmospheric to 3.5 bar (CDP)

Main Reagents Alkali metal hydroxide; polyethilene glycol; (APEG), Hydroxide tetraethilene glycol (ATEG), non alkali metal, polyalkeneglycol and a alkali or alkaline earth metal hydroxide or alcoholate. (SEA Marconi CDP process)

By products, outflows and waste streams

Mainly non toxic salts, and muds; be to when the process is used for the decontamination of transformer, the oil containing de-halogenated aromatics compound is re-used into the transformer; in the case of soil decontamination, de-halogenated aromatic compounds form a non hazardous waste to be further destroyed or incinerated.

Applicability PCBs Oils; transformers containing PCB oils; soil.Needs for post or pre treatment

It may be necessary in the case of treatment of contaminated soil or wastes.

Main limitations

Following EPA (US EPA, 540/S-93/s 506), and regarding the soil treatment, the disadvantages of the conventional APEG processes are that it often takes numerous cycles of the process to achieve the desired results, the process only effects partial dehalogenation, and the formation of dioxin and furans often occurs when the process is implemented”


MOBILE DEHALOGENATION FACILITY


STATIONARY DEHALOGENATION FACILITY FOR SMALL TRANSFORMERS


MOBILE DEHALOGENATION


HYDRODEHALOGENATION OF PCBSMain reactions / Description Under the category of hydrodehalogenation may be included all

the reductive dehalogenation processes involving the breaking of a single bond between a carbon atom and the halogen with the subsequent formation of a single bond between hydrogen and carbon. The process may involve the use of molecular hydrogen, similarly to the hydrogenation of crude oil, or may be based on processes of catalyzed transfer of hydrogen from an hydrogen donor.

PCB Concentration Usually up to around 5000 ppm.Process temperature Pressure and process temperature depend greatly on the type of

process adopted. The use of molecular hydrogen require temperature in the order of 350°C and high pressure. Process based on hydrogen transfer are performed at temperature ranging from 200 to 350 °C atmospheric pressure.

Process pressure

Main Reagents Hydrogen or a hydrogen donor; catalyst; phase transfer agent; Applicability Soil, PCB oils.Needs for post or pre treatment

Pretreatment is needed if soil or contaminated devices are treated;

Main limitations Hydrodehalogenation processes are often operated at high temperature and pressure, requiring complex plants.


INCINERATION

Process DescriptionCombustion in presence of an excess of oxygen

PCB Concentration Usually less than 15% PCB in the waste fed to the plant

Main Reagents Chemicals for the treatment of the exhaust gases;


Ashes; flue gases; secondary reagents after the flue gas treatment

Applicability Any kind of waste may be treatedNeeds for post or pre treatment

Depending on the incinerator type.

Main advantage Highly flexible; capable to deal with any kind of hazardous waste; consolidated technology.

Main limitations High energy requirement. Sophisticated air pollution control system is needed to reduce PCDD/F emissions.


INCINERATION PLANT FOR HAZARDOUS WASTE (INCLUDING PCBS)


INCINERATION PLANT FOR HAZ. WASTE


THE ROTARY KILN OF THE SHENYANG INCINERATOR


NEED FOR AN LCA APPROACH IN PCB MANAGEMENT

Trial burn test 1 (PCB contaminated soil, PCB 1-2%)– PCDD/F 0.104 ngTEq/Nm3

Trial burn test 2 (PCB oil, PCB 20%)– PCDD/F 0.042 ngTEq/Nm3

Trial burn test 3 (PCB soil+capacitors, PCB 10%)– PCDD/F 0.080 ngTEq/Nm3• Minimize release of POPs from the whole

process !!

Site cleanup Transportation and Storage

Final Disposal


PLASMA

Process DescriptionThermal destruction in the absence of oxygenPCB Concentration Up to pure PCBsMain Reagents Inert gasesBy products, outflows and waste streams

Syngas; Chlorinated salts

Applicability Liquid waste (oil)Needs for post or pre treatment

Depending on the plasma type.

Main advantage Reduced volumetric emission; very high process temperature

Main limitations High electric energy requirement. May require a system for the cleaning and storage of syngas


PLASMA (CONT’D)Parameter CSM Mobile Plasma for

solid wastePACTTM System for mixed waste

PLASCON liquid waste unit

Main scope of the plant Mainly pulverized or granulated solids (asbestos); suitable for semisolid waste or liquid waste.

Solids in drums; suitable also for semisolid, pulverized or granulated waste

Only liquids and gases

Capacity (t/hr) 0.3 0.2 (based on the duration of the whole cycle)

0.135 (for pure PCBs)

Maximum power 1MW 150KWMax current and voltage 2000A, 500VType of plasma Transferred arc,

computerized design plasma torches

Multimodal torch (nonTransferred for heating up, transferred for melting waste)

Non transferred arc, in flight destruction of waste.

Type of reactor Cylindrical reaction chamber (1mx1m)

Centrifugal chamber (1m3)

“In flight” tube.

Batch / continuous process

Batch (continuous for liquids)

Continuous Continuous

Operation temperature in the destruction zone

Over 1700°C 1650°C 3100°C

Flue gas flowrate (m3/hr)

500 Nm3/h 0.5 Nm3/hr

Mobile / Transportable / Fixed

Transportable Fixed Mobile


TRANSPORTABLE PLASMA PLANT


RETROFILLINGProcess description Technology based on the physical replacement of

contaminated dielectric oil in transformers with new dielectric oil.

PCB Concentration Not limited by concentration but the cost increases with increasing PCBs concentration.

Process temperature From ambient temperature to around 100°C, depending on the type of technology adopted.

Process pressure May be carried out at ambient pressure or under vacuum.Main Reagents NoneBy products, outflows and waste streams

The main waste stream is the replaced oil that need to be decontaminated or destroyed..

Applicability Transformers and capacitors with high residual value, not at their end of life. Large transformers with low PCB contamination.

Needs for post or pre treatment

None.

Main advantage Simple process very effective for low contaminated transformers .

Main limitations Not a stand alone technology. Requires further process for the subsequent destruction of PCBs.


COST FACTOR FOR RETROFILLING CYCLES

1

10

100

1000

10000

100000

1000000

0 1 2 3 4 5 6 7 8

Number of retrofilling cycles

Decontamination trends with retrofilling, starting from different concentrations. For pure PCBs, at least 6 cycles are required to bring PCBs contamination below 50 ppm


SOLVENT WASHINGProcess description

Technology based on the partition of chemical species between two immiscible phases.

PCB Concentration

Not limited by concentration but the cost increases with increasing PCBs concentration.

Process temperature

May vary with the type of process considered. Critical solvent temperature processes require a variable temperature during the process.

Process pressureMay be conducted at ambient pressure (standard solvent processes); high pressure (near critical temperature solvent process) or under vacuum (solvent extraction in autoclave).

Main Reagents Organic solvents.By products, outflows and waste streams

Different waste streams (contaminated oil, debris, water, sludge, metal scraps) may be generated during the pre-treatment steps. The use of volatile solvent may require a careful control of the atmospheric emissions. The outflow of a solvent extraction system is typically a concentrated extract of PCB, which has to be destroyed.

Applicability Transformers and capacitors at their end of life; contaminated soils and wastes.Needs for post or pre treatment

Pre treatment of contaminated wastes is necessary (opening of the capacitors and transformers carcasses; meshing and fracturing of the soil, etc.) After the extraction, concentrated PCBs must be stored and destroyed.

Main advantage Flexible process capable of treat any kind of media.

Main limitations Not a stand alone technology The use of solvents may require an high level of safety countermeasures to prevent exposure of workers.


SOLVENT WASHING


SOLVENT WASHING


THERMAL DESORPTIONProcess Description Physical desorption of PCB by means of

heating in presence of vacuum or a carrier gas.

PCB Concentration Up to 10000 ppm in soil; Equipment carcasses contaminated with pure PCBs

Main Reagents Carrier gas for the removal of PCB; solvents


Pure PCBs is extracted from the solvent after decontamination; sludge contaminated by PCBs; VOCs

Applicability Contaminated soil and PCBs contaminated carcasses

Needs for post or pre treatment

Treatment of the off gases (scrubbers, fabric filters, condenser);

Main advantage Consolidated technology;Main limitations High energy requirement; high moisture

content may be a limitation to the process


JIANGDE TDU


JIANGDE TDU


THANK YOU VERY MUCH FOR YOUR KIND ATTENTION

….Questions ?

Documents

(QUICK) Overview of PCB disposal technologies