The BAT reference document entitled ‘Production of Chlor-alkali’ forms part of a series presenting the results of an exchange of information between EU Member States, the industries concerned, non-governmental organisations promoting environmental protection, and the Commission, to draw up, review and, where necessary, update BAT reference documents as required by Article 13(1) of the Directive 2010/75/EU on industrial emissions. This document is published by the European Commission pursuant to Article 13(6) of the Directive. This BREF for the production of chlor-alkali covers 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, this document covers 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.
Important issues for the implementation of Directive 2010/75/EU in the chlor-alkali industry are the conversion and decommissioning of mercury cell plants, the conversion of asbestos diaphragm cell plants and the use of non-asbestos diaphragms, electricity consumption, and emissions of chlorine to air and water. The BREF contains seven chapters. Chapters 1 and 2 provide general information on the chlor-alkali industry and on the industrial processes and techniques used within this sector. Chapter 3 provides data and information concerning the environmental performance of installations in terms of current emissions, consumption of raw materials, water and energy, and generation of waste. Chapter 4 describes the techniques to prevent or reduce the environmental impact of installations in the sector. In Chapter 5 the BAT conclusions, as defined in Article 3(12) of the Directive, are presented for the chlor-alkali industry. Chapters 6 and 7 are dedicated to emerging techniques as well as to concluding remarks and recommendations for future work in the sector, respectively.