# Commission Implementing Decision of 9 December 2013 establishing the best available techniques (BAT) conclusions, under Directive            2010/75/EU of the European Parliament and of the Council on industrial emissions, for the production of chlor-alkali (notified            under document C(2013) 8589) (Text with EEA relevance) (2013/732/EU)         

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U.K.

# Commission Implementing Decision

# of 9 December 2013

# establishing the best available techniques (BAT) conclusions, under Directive 2010/75/EU of the European Parliament and of                        the Council on industrial emissions, for the production of chlor-alkali                     

# (notified under document C(2013) 8589)

# (Text with EEA relevance)

# (2013/732/EU)

THE EUROPEAN COMMISSION,

Having regard to the Treaty on the Functioning of the European Union,

Having regard to Directive 2010/75/EU of the European Parliament and of the Council of 24 November 2010 on industrial emissions                           (integrated pollution prevention and control)(1), and in particular Article 13(5) thereof,                        

Whereas:

(1)Article 13(1) of Directive 2010/75/EU requires the Commission to organise an exchange of information on industrial emissions                              between it and Member States, the industries concerned and non-governmental organisations promoting environmental protection                              in order to facilitate the drawing up of best available techniques (BAT) reference documents as defined in Article 3(11) of                              that Directive.

(2)In accordance with Article 13(2) of Directive 2010/75/EU, the exchange of information is to address the performance of installations                              and techniques in terms of emissions, expressed as short- and long-term averages, where appropriate, and the associated reference                              conditions, consumption and nature of raw materials, water consumption, use of energy and generation of waste and the techniques                              used, associated monitoring, cross-media effects, economic and technical viability and developments therein and best available                              techniques and emerging techniques identified after considering the issues mentioned in points (a) and (b) of Article 13(2)                              of that Directive.

(3)‘BAT conclusions’ as defined in Article 3(12) of Directive 2010/75/EU are the key element of BAT reference documents and lay                              down the conclusions on best available techniques, their description, information to assess their applicability, the emission                              levels associated with the best available techniques, associated monitoring, associated consumption levels and, where appropriate,                              relevant site remediation measures.

(4)In accordance with Article 14(3) of Directive 2010/75/EU, BAT conclusions are to be the reference for setting permit conditions                              for installations covered by Chapter II of that Directive.

(5)Article 15(3) of Directive 2010/75/EU requires the competent authority to set emission limit values that ensure that, under                              normal operating conditions, emissions do not exceed the emission levels associated with the best available techniques as                              laid down in the decisions on BAT conclusions referred to in Article 13(5) of Directive 2010/75/EU.

(6)Article 15(4) of Directive 2010/75/EU provides for derogations from the requirement laid down in Article 15(3) only where                              the costs associated with the achievement of the emission levels associated with the BAT disproportionately outweigh the environmental                              benefits due to the geographical location, the local environmental conditions or the technical characteristics of the installation                              concerned.

(7)Article 16(1) of Directive 2010/75/EU provides that the monitoring requirements in the permit referred to in point (c) of                              Article 14(1) of the Directive are to be based on the conclusions on monitoring as described in the BAT conclusions.

(8)In accordance with Article 21(3) of Directive 2010/75/EU, within 4 years of publication of decisions on BAT conclusions, the                              competent authority is to reconsider and, if necessary, update all the permit conditions and ensure that the installation                              complies with those permit conditions.

(9)Commission Decision of 16 May 2011 establishes a forum(2) for the exchange of information pursuant to Article 13 of Directive 2010/75/EU on industrial emissions, which is composed                              of representatives of Member States, the industries concerned and non-governmental organisations promoting environmental protection.

(10)In accordance with Article 13(4) of Directive 2010/75/EU, the Commission obtained the opinion of that forum on the proposed                              content of the BAT reference document for the production of chlor-alkali on 6 June 2013 and made it publicly available(3).

(11)The measures provided for in this Decision are in accordance with the opinion of the Committee established by Article 75(1)                              of Directive 2010/75/EU,

HAS ADOPTED THIS DECISION:

# Article 1U.K.

The BAT conclusions for the production of chlor-alkali are set out in the Annex to this Decision.

# Article 2U.K.

This Decision is addressed to the Member States.

Done at Brussels, 9 December 2013.

*For the Commission*                            

Janez Potočnik                            

*Member of the Commission*                            

## ANNEXU.K.**BAT CONCLUSIONS FOR THE PRODUCTION OF CHLOR-ALKALI**

### SCOPEU.K.

These BAT conclusions cover certain industrial activities specified in Sections 4.2(a) and 4.2(c) of Annex I to Directive                     2010/75/EU, namely the production of chlor-alkali chemicals (chlorine, hydrogen, potassium hydroxide and sodium hydroxide)                     by the electrolysis of brine.                  

In particular, these BAT conclusions cover the following processes and activities:
          -  the storage of salt; 
          -  the preparation, purification and resaturation of brine; 
          -  the electrolysis of brine; 
          -  the concentration, purification, storage and handling of sodium/potassium hydroxide; 
          -  the cooling, drying, purification, compression, liquefaction, storage and handling of chlorine; 
          -  the cooling, purification, compression, storage and handling of hydrogen; 
          -  the conversion of mercury cell plants to membrane cell plants; 
          -  the decommissioning of mercury cell plants; 
          -  the remediation of chlor-alkali production sites. 

These BAT conclusions do not address the following activities or processes:
          -  the electrolysis of hydrochloric acid for the production of chlorine; 
          -  the electrolysis of brine for the production of sodium chlorate; this is covered by the BAT reference document on Large Volume                           Inorganic Chemicals – Solids and Others Industry (LVIC-S);                         
          -  the electrolysis of molten salts for the production of alkali or alkaline earth metals and chlorine; this is covered by the                           BAT reference document on Non-ferrous Metals Industries (NFM);                         
          -  the production of specialities such as alcoholates, dithionites and alkali metals by using alkali metal amalgam produced with                           the mercury cell technique;                         
          -  the production of chlorine, hydrogen or sodium/potassium hydroxide by processes other than electrolysis. 

These BAT conclusions do not address the following aspects of chlor-alkali production as they are covered by the BAT reference                     document on Common Waste Water and Waste Gas Treatment/Management Systems in the Chemical Sector (CWW);                  
          -  the treatment of waste water in a downstream treatment plant; 
          -  environmental management systems; 
          -  noise emissions. 

Other reference documents which are of relevance for the activities covered by these BAT conclusions are the following:

### GENERAL CONSIDERATIONSU.K.

The techniques listed and described in these BAT conclusions are neither prescriptive nor exhaustive. Other techniques may                     be used that ensure at least an equivalent level of environmental protection.                  

Unless otherwise stated, the BAT conclusions are generally applicable.

Emission levels associated with the best available techniques (BAT-AELs) for emissions to air given in these BAT conclusions                     refer to:                  
          -  concentration levels expressed as mass of emitted substances per volume of waste gas under standard conditions (273,15 K,                           101,3 kPa), after deduction of the water content but without correction of the oxygen content, with the unit mg/m3;                         

BAT-AELs for emissions to water given in these BAT conclusions refer to:
          -  concentration levels expressed as mass of emitted substances per volume of waste water, with the unit mg/l. 

### DEFINITIONSU.K.

For the purposes of these BAT conclusions, the following definitions apply:

### BAT CONCLUSIONSU.K.

#### 1.**Cell technique**U.K.

*BAT 1: BAT for the production of chlor-alkali is to use one or a combination of the techniques given below. The mercury cell                        technique cannot be considered BAT under any circumstances. The use of asbestos diaphragms is not BAT.*                   

#### 2.**Decommissioning or conversion of mercury cell plants**U.K.

*BAT 2: In order to reduce emissions of mercury and to reduce the generation of waste contaminated with mercury during the                        decommissioning or conversion of mercury cell plants, BAT is to elaborate and implement a decommissioning plan that incorporates                        all of the following features:*                   

inclusion of some of the staff experienced in running the former plant at all stages of elaboration and implementation;

provision of procedures and instructions for all stages of implementation;

provision of a detailed training and supervision programme for personnel with no experience in mercury handling;

determination of the quantity of metallic mercury to be recovered and estimation of the quantity of waste to be disposed of                              and of the mercury contamination contained therein;                           

provision of working areas which are:

covered with a roof;

equipped with a smooth, sloped, impervious floor to direct mercury spills to a collection sump;

well lit;

free of obstructions and debris that may absorb mercury;

equipped with a water supply for washing;

connected to a waste water treatment system.

emptying of the cells and transfer of metallic mercury to containers by:

keeping the system closed, if possible;

washing of mercury;

using gravity transfer, if possible;

removing solid impurities from mercury, if necessary;

filling the containers to ≤ 80 % of their volumetric capacity;

hermetically sealing the containers after filling;

washing of the empty cells, followed by filling with water.

carrying out of all dismantling and demolition operations by:

replacing hot cutting of equipment by cold cutting, if possible;

storing contaminated equipment in suitable areas;

frequent washing of the floor of the working area;

rapid clean-up of mercury spills by using aspiration equipment with activated carbon filters;

accounting of waste streams;

separating mercury-contaminated waste from non-contaminated waste;

decontaminating waste contaminated with mercury by using mechanical and physical treatment techniques (e.g. washing, ultrasonic                                       vibration, vacuum cleaners), chemical treatment techniques (e.g. washing with hypochlorite, chlorinated brine or hydrogen                                       peroxide) and/or thermal treatment techniques (e.g. distillation/retorting);                                    

reusing or recycling decontaminated equipment, if possible;

decontaminating the cell room building by cleaning the walls and the floor, followed by coating or painting to give them an                                       impermeable surface if the building is to be reused;                                    

decontaminating or renewing the waste water collection systems in or around the plant;

confining the working area and treating ventilation air when high concentrations of mercury are expected (e.g. for high-pressure                                       washing); treatment techniques for ventilation air include adsorption on iodised or sulphurised activated carbon, scrubbing                                       with hypochlorite or chlorinated brine or adding chlorine to form solid dimercury dichloride;                                    

treating mercury-containing waste water, including laundry wash water arising from the cleaning of protective equipment;

monitoring of mercury in air, water and waste, including for an appropriate time after the finalisation of the decommissioning                                       or conversion;                                    

if needed, interim storage of metallic mercury on site in storage facilities that are:

well lit and weatherproof;

equipped with a suitable secondary containment capable of retaining 110 % of the liquid volume of any single container;

free of obstructions and debris that may absorb mercury;

equipped with aspiration equipment with activated carbon filters;

periodically inspected, both visually and with mercury-monitoring equipment.

if needed, transport, potential further treatment and disposal of waste.

*BAT 3: In order to reduce emissions of mercury to water during the decommissioning or conversion of mercury cell plants, BAT                        is to use one or a combination of the techniques given below.*                   

The **BAT-associated environmental performance level** (4) for mercury emissions to water, expressed as Hg, at the outlet of the mercury treatment unit during decommissioning or conversion                     is 3 – 15 μg/l in 24-hour flow-proportional composite samples taken daily. The associated monitoring is in BAT 7.                  

#### 3.**Generation of waste water**U.K.

*BAT 4: In order to reduce the generation of waste water, BAT is to use a combination of the techniques given below.*                   

#### 4.**Energy efficiency**U.K.

*BAT 5: In order to use energy efficiently in the electrolysis process, BAT is to use a combination of the techniques given                        below.*                   

*BAT 6: In order to use energy efficiently, BAT is to maximise the use of the co-produced hydrogen from the electrolysis as                        a chemical reagent or fuel.*                   

##### *Description*U.K.

Hydrogen can be used in chemical reactions (e.g. production of ammonia, hydrogen peroxide, hydrochloric acid, and methanol;                     reduction of organic compounds; hydrodesulphurisation of petroleum; hydrogenation of oils and greases; chain termination in                     polyolefin production) or as a fuel in a combustion process to produce steam and/or electricity or to heat a furnace. The                     degree to which hydrogen is used depends on a number of factors (e.g. demand for hydrogen as reagent on the site, demand for                     steam on the site, distance to potential users).                  

#### 5.**Monitoring of emissions**U.K.

*BAT 7: BAT is to monitor emissions to air and water by using monitoring techniques in accordance with EN standards with at                        least the minimum frequency given below. If EN standards are not available, BAT is to use ISO, national or other international                        standards that ensure the provision of data of an equivalent scientific quality.*                   

#### 6.**Emissions to air**U.K.

*BAT 8: In order to reduce channelled emissions of chlorine and chlorine dioxide to air from the processing of chlorine, BAT                        is to design, maintain and operate a chlorine absorption unit that incorporates an appropriate combination of the following                        features:*                   

absorption unit based on packed columns and/or ejectors with an alkaline solution (e.g. sodium hydroxide solution) as scrubbing                              liquid;                           

hydrogen peroxide dosing equipment or a separate wet scrubber with hydrogen peroxide if necessary to reduce chlorine dioxide                              concentrations;                           

size suitable for the worst case scenario (derived from a risk assessment), in terms of produced chlorine quantity and flowrate                              (absorption of the full cell room production for a sufficient duration until the plant is shut down);                           

size of the scrubbing liquid supply and storage capacity suitable to ensure an excess at all times;

in the case of packed columns, their size should be suitable to prevent flooding at all times;

prevention of ingress of liquid chlorine into the absorption unit;

prevention of backflow of scrubbing liquid into the chlorine system;

prevention of solids precipitation in the absorption unit;

use of heat exchangers to limit the temperature in the absorption unit below 55 °C at all times;

supply of dilution air after chlorine absorption to prevent the formation of explosive gas mixtures;

use of construction materials which withstand the extremely corrosive conditions at all times;

use of backup equipment, such as an additional scrubber in series with the one in operation, an emergency tank with scrubbing                              liquid feeding the scrubber by gravity, stand-by and spare fans, stand-by and spare pumps;                           

provision of an independent backup system for critical electrical equipment;

provision of an automatic switch to the backup system in case of emergencies, including periodic tests on this system and                              the switch;                           

provision of a monitoring and alarm system for the following parameters:

chlorine in the outlet of the absorption unit and the surrounding area;

temperature of the scrubbing liquids;

reduction potential and alkalinity of the scrubbing liquids;

suction pressure;

flowrate of scrubbing liquids.

The **BAT-associated emission level** for chlorine and chlorine dioxide, measured together and expressed as Cl2, is 0,2 – 1,0 mg/m3, as an average value of at least three consecutive hourly measurements performed at least once every year at the outlet of                     the chlorine absorption unit. The associated monitoring is in BAT 7.                  

*BAT 9: The use of carbon tetrachloride for the elimination of nitrogen trichloride or the recovery of chlorine from tail gas                        is not BAT.*                   

*BAT 10: The use of refrigerants with a high global warming potential, and in any case higher than 150 (e.g. many hydrofluorocarbons                        (HFCs)), in new chlorine liquefaction units cannot be considered BAT.*                   

##### *Description*U.K.

Suitable refrigerants include, for example:
          -  a combination of carbon dioxide and ammonia in two cooling circuits; 
          -  chlorine; 
          -  water. 

##### *Applicability*U.K.

The refrigerant selection should take into account operational safety and energy efficiency.

#### 7.**Emissions to water**U.K.

*BAT 11: In order to reduce emissions of pollutants to water, BAT is to use an appropriate combination of the techniques given                        below.*                   

*BAT 12: In order to reduce emissions of chloride to water from the chlor-alkali plant, BAT is to use a combination of the                        techniques given in BAT 4.*                   

*BAT 13: In order to reduce emissions of free chlorine to water from the chlor-alkali plant, BAT is to treat waste water streams                        containing free chlorine as close as possible to the source, to prevent stripping of chlorine and/or the formation of halogenated                        organic compounds, by using one or a combination of the techniques given below.*                   

The **BAT-associated emission level** for free chlorine, expressed as Cl2, is 0,05 – 0,2 mg/l in spot samples taken at least once every month at the point where the emission leaves the installation.                     The associated monitoring is in BAT 7.                  

*BAT 14: In order to reduce emissions of chlorate to water from the chlor-alkali plant, BAT is to use one or a combination                        of the techniques given below.*                   

*BAT 15: In order to reduce emissions of halogenated organic compounds to water from the chlor-alkali plant, BAT is to use                        a combination of the techniques given below.*                   

#### 8.**Generation of waste**U.K.

*BAT 16: In order to reduce the quantity of spent sulphuric acid sent for disposal, BAT is to use one or a combination of the                        techniques given below. The neutralisation of spent sulphuric acid from chlorine drying with virgin reagents is not BAT.*                   

The **BAT-associated environmental performance level** for the quantity of spent sulphuric acid sent for disposal, expressed as H2SO4 (96 wt-%), is ≤ 0,1 kg per tonne of chlorine produced.                  

#### 9.**Site remediation**U.K.

*BAT 17: In order to reduce contamination of soil, groundwater and air, as well as to halt pollutant dispersion and transfer                        to biota from contaminated chlor-alkali sites, BAT is to devise and implement, a site remediation plan that incorporates all                        of the following features:*                   

implementation of emergency techniques to cut off the exposure pathways and the expansion of the contamination;

desk study to identify the origin, extent and composition of the contamination (e.g. mercury, PCDDs/PCDFs, polychlorinated                              naphthalenes);                           

characterisation of the contamination, including surveys and the preparation of a report;

risk assessment over time and space as a function of the current and approved future use of the site;

preparation of an engineering project including:

decontamination and/or permanent containment;

timetables;

monitoring plan;

financial planning and investment to achieve the target;

implementation of the engineering project so that the site, taking into account its current and approved future use, no longer                              poses any significant risk to human health or the environment. Depending on other obligations, the engineering project might                              have to be implemented in a more stringent manner;                           

site use restrictions if necessary due to residual contamination and taking into account the current and approved future use                              of the site;                           

associated monitoring at the site and in the surrounding areas to verify that the objectives are achieved and maintained.

##### *Description*U.K.

A site remediation plan is often devised and implemented after taking the decision to decommission the plant, although other                     requirements may dictate a (partial) site remediation plan while the plant is still in operation.                  

Some features of the site remediation plan can overlap, be skipped, or be carried out in another order, depending on other                     requirements.                  

##### *Applicability*U.K.

The applicability of BAT 17(v). to 17(viii) is subject to the results of the risk assessment mentioned under BAT 17(iv).

### GLOSSARYU.K.

Electrode through which electric current flows into a polarised electrical device. The polarity can be positive or negative.                        In electrolytic cells, oxidation occurs at the positively charged anode.                     

Set of six naturally occurring silicate minerals exploited commercially for their desirable physical properties. Chrysotile                        (also called white asbestos) is the only form of asbestos used in diaphragm cell plants.                     

Solution saturated or nearly saturated with sodium chloride or potassium chloride.

Electrode through which electric current flows out of a polarised electrical device. The polarity can be positive or negative.                        In electrolytic cells, reduction occurs at the negatively charged cathode.                     

Electrical conductor used to make contact with a non-metallic part of an electric circuit.

Passage of a direct electric current through an ionic substance, resulting in chemical reactions at the electrodes. The ionic                        substance is either molten or dissolved in a suitable solvent.                     

European Standard adopted by CEN (European Committee for Standardisation).

Hydrofluorocarbon.

International Organisation for Standardisation or standard adopted by this organisation.

Voltage difference between a half-reaction’s thermodynamically determined reduction potential and the potential at which the                        redox event is experimentally observed. In an electrolytic cell the overpotential leads to the consumption of more energy                        than thermodynamically expected to drive a reaction.                     

Polychlorinated dibenzo-*p*-dioxin.                     

Polychlorinated dibenzofuran.

1

OJ L 334, 17.12.2010, p. 17.                           

2

OJ C 146, 17.5.2011, p. 3.                           

3

https://circabc.europa.eu/w/browse/d4fbf23d-0da7-47fd-a954-0ada9ca91560

4

Given that this performance level does not relate to normal operating conditions, it is not an emission level associated with                              the Best Available Techniques in the sense of Article 3(13) of the Industrial Emissions Directive (2010/75/EU).