Reference Document on Best Available Techniques in Common Waste Water and Waste

Gas Treatment/Management Systems in the Chemical Sector (CWW BREF)

Aivi SissaTallinn – Estonia

27 – 28 March 2007

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Introduction

• It was finalised late 2001

• Developed to apply to the chemical industry...contains valuable information for other

sectors

• It is a horizontal BREF

Borderline between vertical and horizontal chemical BREFs

Waste water example

Chemicalreaction

Work-up

Productisolation

Recovery

Product

PRODUCTION

CONTROL

Recipient

Waste waterVERTICAL

CHEMICAL BREFs

CWW BREF

Waste water treatment

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Chemical industryThe chemical industry covers a wide range of enterprises:

• One-process-few-products enterprises with one or just a few waste water/waste gas streams

• Multi-production-mix enterprises with many complex waste water/waste gas streams

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Vertical chemical BREFs

• Chlor-alkali (CAK)• Large Volume Inorganic Chemicals –

Ammonia, Acids and Fertilisers (LVIC-AAF)• Large Volume Inorganic Chemicals – Solid

and Others (LVIC-S)• Large Volume Organic Chemicals (LVOC)• Polymers (POL)

• Speciality Inorganic Chemicals (SIC)• Organic Fine Chemicals (OFC)

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Scope• Environmental management techniques

• Generally applicable process-integrated measures (i.e. applicable with an identical purpose in distinct production processes)

• End-of-pipe treatment applied on chemical sites to WW, WG and waste water sludge

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Structure of the document

• CH1: General description

• CH2: Waste water/waste gas management

• CH3: Applied treatment technology

• CH4: Best available techniques

• CH5: Emerging techniques

• CH6: Concluding remarks

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Best available techniques

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BAT – horizontal approach

• The options for emissions prevention/control are assessed independently of the particular production process(es)

• BAT embrace the most effective and suitable measures for achieving a high general level of protection of the environment as a whole against emissions

• BAT are determined more broadly and include more than just technology

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Implementation of BAT• Implementation of BAT in existing

installations:– BAT can be integrated when major alterations

are planned– BAT can be implemented in a step-by-step

construction programme over a period of time

• Implementation of BAT in new plants is not normally a problem

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General BAT

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Waste water/waste gas management

General Environmental Management

• proper and consistent execution of a recognised EMS

• use of management tools

ENVIRONMENTAL MANAGEMENT

SYSTEM

MANAGEMENT TOOLS

Operational management

tools

Inventory management

tools

Strategic management

tools

Safety and emergency

tools

Site inventory

Stream inventory

WG emission qualification

Reduction of water usage and discharge

WEA

EMFA

Monitoring

Internal targets

Choice of treatment options

WW/WG control systems

Choice of collection system

Implementation of control option

Quality control

Risk assessment

Bench marking

LCA

Pollution incident response

Fire fighting

Management techniques

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Process-integrated measures

• General need for prevention/reduction of the amount of WW and WG and/or contamination within a production line

These are generally production- or process-specific and their applicability requires special assessment

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Waste water/waste gas collection

• Ducting and segregating waste water streams to their appropriate treatment system

• Routing waste gases to treatment systems. These are emission source enclosure, vents and pipes

BAT for process-integrated measures

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BAT for waste water treatment

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Waste water – key issues• Emissions to water can arise from, e.g.,

chemical synthesis, WGT (wet scrubbers) and rain water from contaminated areas

• The majority of process water (70 – 90%) has a low pollution load (e.g. cleaning water, vacuum, exhaust air clean-up, pumps)

• The remaining (10 – 30%) contains up to 90% of the pollution load

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WW techniques that fit into the scope

WASTE WATER TECHNIQUES

Process-integrated measures

End-of-pipe treatment

Individual treatment

Central treatment

RECIPIENT

PretreatmentFinal treatment

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BAT for waste water treatment

• Four different strategies:– central final treatment in a biological WWTP on site– central final treatment in a municipal WWTP– central final treatment of inorganic waste water in a

chemical/mechanical WWTP– decentralised treatment(s)

All four strategies are considered as BAT when properly applied to the actual waste water situation

The approach to reaching specific BAT conclusions follows the pathway of pollutants

OrganicInorganic

ABATEMENTTECHNIQUES

(non biodegradable)OxidationReductionHydrolysis

Air oxidationIncineration

RECOVERYTECHNIQUES

NF / ROAdsorption

Extraction/DistillationEvaporation

Stripping/gas treatment

Uncontaminated (e.g. rainwater)

Heavy metals

Free oilHydrocarbons

Salts and/or acids Salts

and/or acids

ABATEMENTTECHNIQUES

(biodegradable)Biological treatment

Pollutants unsuitable

for biological treatment

Waste water sewerage system

Biodegradable substances

Waste water

Refractory or toxic organic

Contaminated

Receiving water

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BAT AELs for the final discharge into receiving water

ParameterPerformance

rates(%)

Emission levels(mg/l)

TSS 10 – 20

COD 76 – 96 30 – 250

Total inorganic N 5 – 25

Total P 0.5 – 1.5

Heavy metals No decision – split view

AOX No decision – split view

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BAT for waste gas treatment

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Waste gas – key issues

• Only rarely can waste gas streams with different characteristics be treated simultaneously

• Waste gas streams can roughly be divided into ducted and non-ducted (diffuse, fugitive) emissions

• The flow rate to be treated is a major parameter in the selection of abatement options

• Recovery techniques are generally used for valuable products

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WG techniques that fit into the scope

WASTE GAS TECHNIQUES

Ducted emissions

Process-integrated measures

End-of-pipe treatment

Fugitive and diffuse emissions

Capture

Individual treatment

Central treatment

Group treatment

STACK

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• low temperature sources

• high temperature sources

BAT for waste gas treatment

The approach to reaching specific BAT conclusions follows the pathway of pollutants

According to treatment, the sources for waste gases are distinguished as:

Decision pathway for WGT: basis for BAT conclusions

Low temperature:production,

handling andwork-up gases

High temperature:Combustion gases

Inorganicvolatiles

Dust DustNOx

SOx HCl, HF

Substancerecovery

Energyrecovery

Recovery techniquesMembrane separation

CondensationAdsorption

Wet scrubbersSeparatorsCyclones

Electrostatic precipitatorsFabric filters

Abatement techniquesBiofiltration

BioscrubbingBiotrickling

Oxidation (thermal and catalytic)Flaring

SeparatorsCyclones

Electrostatic precipitatorsFiltrationSorption

SNCR / SCR

VOC

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BAT AELs for waste gas treatment

Low-temperatures waste gases

There are no BAT AELs for low-temperature waste gases in the CWW BREF. These are reported in the corresponding vertical BREFs

However, the BAT chapter of the CWW BREF reports performance levels related to the application of techniques

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BAT AELs for waste gas treatment

High temperature waste gases

ParameterEmission levels

(mg/Nm3)

Dust <5 – 15

HCl <10

HF <1

SO2 <40 – 150

NOx (gas boilers/heaters) 20 – 150

NOx (liquid boilers/heaters) 55 – 300

NH3 4 <5

Dioxins 0.1 ng/Nm TEQ

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Emerging techniques

• Techniques not yet applied on a commercial basis or outside pilot plant operation. These could be applicable in the future at large scale operation

• Assessment needed during the review of the BREF

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Concluding remarks

• High level of consensus achieved

• There is a lack of information on:– performance data in combination with

operational data (e.g. cross-media and energy issues)

– costs

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Revision of the CWW BREF

• Planned to start late 2007/early 2008

• Currently preparing a comparative analysis of the first series of chemical BREFs:

– to set guidelines/recommendations which will help the Technical Working Group (TWG) with the preparation of the review of the CWW BREF as well as during the review process

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QUESTIONS?