Chlorine Dioxide Generation. AkzoNobel Pulp and Performance Chemicals Eka Engineering

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1 Chlorine Dioxide Generation AkzoNobel Pulp and Performance Chemicals Eka Engineering

3 We help make pulp white and bright Eka Engineering is the engineering and contracting division within AkzoNobel Pulp and Performance Chemicals.

2 3 We help make pulp white and bright Eka Engineering is the engineering and contracting division within AkzoNobel Pulp and Performance Chemicals. We specialize in the design and supply of chlorine dioxide plants and equipment to the pulp and chemical industries. Our main assets are our experienced personnel, our technology and project management capabilities. We operate globally and offer our customers quick and personal service backed by the economic strength and stability of AkzoNobel.

3 5 Chlorine dioxide systems The SVP processes Eka Engineering is a world-leading supplier of chlorine dioxide (Cl plants. We have developed a number of different process technologies, for safe and efficient Cl generation. The new standard Cl is an oxidizer commercially used for bleaching pulp since the mid 1940s. Today Cl is a preferred bleaching agent in all modern pulp mills. It is the most cost-effective bleaching agent of pulp, achieving high brightness while maintaining high strength. Modern bleaching sequences involving Cl produce a low level of predominantly non-toxic organo-chlorine (AOX compounds in the bleach plant effluent, making it possible for the pulp mills to adapt to the more stringent AOX discharge regulations in force in most countries in the world. These are the main reasons why Cl in combination with oxygen ( and hydrogen peroxide (H 2 have practically replaced chlorine (Cl 2 as a bleaching agent in most parts of the world. ECF bleaching is the worldwide bleaching standard and considered the Best Available Technique for the production of pulp, paper and board. The basic process Cl is produced on site by reducing sodium chlorate (NaClO 3 in an acidic solution, either under vacuum (SVP processes or atmospheric (Mathieson, HP-A processes conditions. Different by-products are produced by varying the type of reducing agent and acid. The first commercially viable process for producing Cl used sulfur dioxide (S as a reducing agent e.g. the Mathieson process. Since then several new processes have been developed, providing different by-products, improved Cl yield and minimized environmental impact. The SVP (single vessel process chlorine dioxide process family consists of a number of similar processes based on the same equipment configuration. It is relatively easy to switch from one to the other. The different processes are distinguished from each other by use of different reducing agents and acids for converting sodium chlorate (NaClO 3, to chlorine dioxide (Cl. The most common process today is the SVP-LITE process based on the use of methanol (CH 3 OH. SVP-LITE Process The production of Cl in the SVP-LITE process is based on the reaction between NaClO 3, sulfuric acid (H 2, and CH 3 OH. The heart of the process is an all-titanium Cl generator, a large vessel in which the NaClO 3 is reacted to form Cl. The generator is designed to optimize reaction efficiency, promote salt crystal growth, provide efficient liquid-gas separation and provide sufficient volume for easy control of reactant concentrations. A titanium pump circulates the generator solution through the reboiler. Unique to the process is that the components in the circulation loop are carefully designed to minimize the boil-outs. The water evaporation rate matches the rate at which the water enters the generator with the chemical feeds and utilities. The Cl partial pressure is maintained at a safe level by means of a partial vacuum and dilution with water vapor.

7 SVP Process MP Steam Filter Ejector System Ejector Vent Fan Dissolving Tank Saltcake Filter Saltcake Sol. Pump Steam Condensate Tank Generator Cir.

4 7 SVP Process MP Steam Filter Ejector System Ejector Vent Fan Dissolving Tank Saltcake Filter Saltcake Sol. Pump Steam Condensate Tank Generator Cir. Pump Filter Receiver Acid Feed Reboiler Condensate Pump Deluge/Spray Quench Generator Saltcake Filter Pump System Condenser Generator Condenser MeOH Feed NaClO 3 Feed Absorber Absorber Pump Vent Scruber Chilled Water Cl Storage Chilled Water To Bleach Plant Methanol (MeOH (CH 3 OH Hydrogen peroxide (H 2 Sulfuric acid (H 2 Chlorine dioxide (Cl Sodium chlorate (NaClo 3 Gas absorption The chlorine dioxide (Cl gas leaving the generator is cooled in the generator condenser and absorbed in a packed tower, the Cl absorber, by means of chilled water. The resulting product is a strong solution of Cl with negligible levels of chlorine gas (Cl 2. The solution is then pumped to storage tanks for further use in the bleaching process. As the gas from the Cl generator does not contain any diluting gases like air or chlorine, absorption efficiency is high and Cl concentrations in excess of 10g/l can easily be reached. Typically, the vacuum in the Cl generation system is created by means of a steam ejector, but a liquid ring vacuum pump could also be used. After passing the ejector, the tail and vent gases are washed with chilled water in the vent scrubber. The effluent water from the scrubber is transferred to the main absorption tower and thus all the Cl in the vent gases is recovered and added to the produced Cl solution. Sodium sulfate recovery The sodium sesquisulfate crystals (Na 3 H( 2 formed in the generator are pumped to a titanium bottom feed, rotary drum filter for removal as a near dry solid. The filter is equipped with a hot water wash system. The wash water and mother liquor are withdrawn from the filter and returned to the generator, leaving behind a dry, high-quality salt cake. The Na 3 H( 2 is discharged into the dissolving system and pumped to the pulp mill. This filter comes standard with a tantalum filter cloth, providing years of trouble-free service and high reliability. The filter is much less sensitive to crystal size or production rate fluctuations than competing top feed filters.

5 9 HP-A Cl process SVP-SCW Salt Cake Wash System The SCP-SCW process is an add-on option to the SVP-LITE process. The formed salt cake in SVP-LITE is sodium sesquisulfate (Na 3 H(SO4 2, which is an acidic version of sodium sulfate (Na 2, containing about 18wt% of sulfuric acid (H 2. In the SVP-SCW process, the filtered Na 3 H( 2 crystals are transferred to a metathesis tank. Here the Na 3 H( 2 is separated into its Na 2 and H 2 components. The metathesis tank slurry is pumped to a second salt cake filter where the neutral Na 2 crystals are removed and sent to the mill s recovery system. The filtrate from the second filter, containing the H 2 to be recovered, is discharged back to the SVP generator. Other SVP processes SVP-HP The SVP-HP process is based on use of hydrogen peroxide (H 2 for reduction of sodium chlorate (NaClO 3 in an acidic sulfuric acid (H 2 solution to form Cl. By-products are Na 2 or Na 3 H( 2 and oxygen (. SVP Standard NaClO 3 is reacted with sodium chloride (NaCl in an H 2 solution to form Cl and Cl 2. The salt cake by-product consists of neutral Na 2. SVP Partial HCI In this process, NaClO 3 is reacted with hydrochloric acid (HCl in an H 2 solution to form Cl and Cl 2. This will give a substantial reduction in by-product Na 2 compared to SVP Standard. SVP Total HCI NaClO 3 is reacted with HCl, which acts as both a reducing agent and an acid. NaCl is produced as a by-product. Benefits of the SVP-LITE and SVP-SCW processes Very high yield Very low emissions High strength Cl solution produced Easy to operate Fast reaction rate, minimum start-up and stop time (a matter of minutes Low frequency of boil-outs Negligible levels of Cl 2 as by-product The HP-A is one of the newest processes introduced on the market by Eka Engineering. This proprietary technology has several advantages over earlier atmospheric chlorine dioxide (CI processes. HP-A chemistry Sodium chlorate (NaCIO 3 reacts in a two-stage reactor system with a proprietary hydrogen peroxide (H 2 quality in sulfuric acid (H 2 solution to produce CI. The reaction by-products are oxygen ( and spent acid containing sodium bisulfate (NaH. The older atmospheric Cl processes use other reducing agents. Some of the reducing agents contain sodium chloride (NaCl and then form chlorine gas (Cl 2 as a by-product. Sulfur dioxide (S and methanol (CH 3 OH are also used as reducing agents.

11 Benefits of the HP-A process Higher capacity can be achieved when changing chemistry in an existing atmospheric process Easy to operate HP-A Process Sulfuric Acid Fast reaction rate Negligible

6 11 Benefits of the HP-A process Higher capacity can be achieved when changing chemistry in an existing atmospheric process Easy to operate HP-A Process Sulfuric Acid Fast reaction rate Negligible levels of Cl 2 as by-product High yield > 95% Less maintenance on equipment and instruments compared to using S as a reducing agent Additional products and systems H 2 Reducing Agent Sodium Chlorate Cooling Water Primary Reactor Secondary Reactor Chlorine Dioxide Absorber Vent Fan Chilled Water Vent Scruber Anti-chlor You normally need the following systems in association with the chlorine dioxide (CI equipment: Chlorate, acid and reducing agent storage and delivery Cl product storage and delivery Chilled water supply Our extensive experience in this field has enabled us to become experts in the design and installation of customized systems. Stripper Spent Acid to Mill Spent Acid Tank Chlorine Dioxide Storage Chlorine Dioxide to Bleach Plant Methanol (MeOH (CH 3 OH Hydrogen peroxide (H 2 Sulfuric acid (H 2 Chlorine dioxide (Cl Air Compressor Spent Acid Pump Sodium chlorate (NaClo 3

13 World-class service & spare parts Eka Engineering has designed, built, re-built, handled spare parts and operated chlorine dioxide (CI systems for pulp bleaching for over 40 years.

7 13 World-class service & spare parts Eka Engineering has designed, built, re-built, handled spare parts and operated chlorine dioxide (CI systems for pulp bleaching for over 40 years. As the international leader in CI technology, we offer service, support, spare parts and equipment for the large-scale production and application of both vacuum and atmospheric processes. We have long experience in supporting CI systems. Our service and support team can handle all types of support in mechanical and process engineering. Scope of supply Eka Engineering can supply all the Cl processes needed to match your requirements, from the design and procurement of the process equipment to a complete turnkey installation. Our experience and know-how range from rebuilds of existing plants to brand new installations. Process safety Since hazardous chemicals are involved, it is vital that all plant and chemical-handling equipment is designed and built strictly in accordance with local regulations and instructions for the handling of sodium chlorate (NaCIO 3, methanol (CH 3 OH, hydrogen peroxide (H 2, chlorine dioxide (CI and sulfuric acid (H 2. With many years of experience in different Cl processes, we supply a well-designed plant that is service-friendly, reliable to operate and safe. Spare parts for optimal uptime Eka Engineering s spare parts service helps ensure maximum plant availability and minimum downtime. All spare parts are delivered rapidly and reliably using our extensive supply chain and global logistics network. Keeping things running smoothly Eka Engineering maintains an extensive inventory of the spare parts essential to keep your plant and associated processes running with parts available when and where you need them. For quality assurance, we deliver spare parts from the original supplier whenever possible. Some typical spare parts we provide include pump parts, instruments, valves, and filter inserts.

15 Global presence Eka Engineering can offer the following service and support: AkzoNobel Pulp and Performance Chemicals is the leading global supplier of bleaching chemicals and we deliver

8 15 Global presence Eka Engineering can offer the following service and support: AkzoNobel Pulp and Performance Chemicals is the leading global supplier of bleaching chemicals and we deliver customized solutions for bleaching pulp to our customers. Our world-class technology, application know-how, optimized supply chain and global logistic solutions provide customers with a significant advantage for their operations. Optimization Measurement and calculation of the yield on sodium chlorate, reducing agent and acid Capacity tests Process safety Participation in safety audits and risk analysis at the chlorine dioxide plant Training Operator training Safety training Laboratory analysis Storage system Inspection and advice on sodium chlorate, sulfuric acid and chlorine dioxide storage Inspection and advice on methanol and hydrogen peroxide storage Troubleshooting On-site troubleshooting for process disturbances in the chlorine dioxide plant Bottleneck investigations Investigations of process and production limitations in the chlorine dioxide plant Inspection Inspection of all critical equipment at the annual shutdown Emissions Investigations of emissions to both air and sewers Equipment Design, purchase and installation of new equipment Spare parts Order and delivery of spare parts to chlorine dioxide plants Eka Engineering is part of AkzoNobel Pulp and Performance Chemicals that is present in 35 countries all over the world. AkzoNobel as a whole has operations in more than 80 countries with 45,000 people globally committed to delivering leading products, technologies and services to meet the growing demands of our fast-changing world. Headquarters Production sites Offices

9 AkzoNobel creates everyday essentials to make people s lives more liveable and inspiring. As a leading global paints and coatings company and a major producer of specialty chemicals, we supply essential ingredients, essential protection and essential color to industries and consumers worldwide. Backed by a pioneering heritage, our innovative products and sustainable technologies are designed to meet the growing demands of our fastchanging planet, while making life easier. Headquartered in Amsterdam, the Netherlands, we have approximately 45,000 people in around 80 countries, while our portfolio includes well-known brands such as Dulux, Sikkens, International, Interpon and Eka. Consistently ranked as a leader in sustainability, we are dedicated to energizing cities and communities while creating a protected, colorful world where life is improved by what we do Akzo Nobel N.V. All rights reserved. Europe Sweden: Akzo Nobel Pulp and Performance Chemicals AB SE Bohus Sweden T Learn more about Eka South America Brazil: Akzo Nobel Pulp and Performance Quimica Ltda. Rodovia Dom Gabriel Paulino Bueno Couto km 65,2 Jundiaí SP Brazil T North America USA: Akzo Nobel Pulp and Performance Chemicals Inc Parkway Place Suite 1200 Marietta, GA USA T Eka, SVP-LITE, SVP-HP and HP-A are registered trademarks of AkzoNobel in several countries worldwide. AN_202811_061016

CHLOR-ALKALI INDUSTRY

CHLOR-ALKALI INDUSTRY The chlor-alkali industry represents of three major industrial chemicals: Soda ash (sodium carbonate-na 2 CO 3 ) Caustic soda (sodium hydroxide-naoh) Chlorine (Cl 2 ) These chemicals