This document discusses the benefits and achievements of ozone bleaching in the pulp and paper industry over the past 19 years. Ozone bleaching reduces bleaching costs by 20-32% and effluent loads compared to traditional ECF bleaching sequences. It allows high brightness levels above 92% ISO while decreasing brightness reversion and reducing extractives content by 50-75%. Ozone bleaching is now a well-proven technology used in 22 mills worldwide producing both hardwood and softwood pulps.
Ozone enhanced bleaching of softwood kraft pulpsJCHostachy
1) The document discusses using limited amounts of ozone after oxygen delignification in the bleaching process for softwood kraft pulp. Using up to 2 kg/ton of ozone can improve brightness and reduce chemical costs without negatively impacting pulp strength or quality.
2) An experiment evaluated different bleaching sequences with varying ozone dosages on radiata pine pulp. Sequences with 1-3 kg/ton ozone achieved similar or better strength properties compared to a reference sequence without negatively impacting viscosity.
3) Replacing some chlorine dioxide with up to 3 kg/ton ozone could save a mill producing 500,000 tons/year of bleached pulp around $6 million per year with
Achievements In Industrial Ozone Bleaching Germer, Metais & HostachyJCHostachy
Industrial ozone bleaching has proven to be a reliable and economical option for pulp bleaching over the last 30 years. 22 mills worldwide now use ozone bleaching, which provides similar or better pulp quality compared to conventional bleaching while reducing chemical costs. Ozone bleaching also lowers effluent volumes and improves quality. Several case studies show that ozone bleaching improves strength properties and lowers bleaching costs by at least 20% compared to conventional bleaching. Ozone bleaching is now considered a well-proven, flexible, and sustainable bleaching technology.
Altarriba - Chemistry makes. Concentrated Solar Power (CSP) more successfulponenciasexpoquim11
The document discusses the role of chemistry in making concentrated solar power (CSP) more successful. It summarizes BASF's contributions to CSP, including producing high-purity sodium nitrate for heat transfer fluids and thermal energy storage. BASF is working to develop higher performance heat transfer fluids through screening over 1,000 substances and identifying 4 promising candidates. The document promotes collaboration between BASF and CSP developers to provide improved chemical solutions.
1. The document describes research into coating carbon fibers with various ceramic materials to improve their oxidation resistance at high temperatures.
2. Sic coatings were applied using chemical vapor deposition (CVD) and by pyrolyzing a polycarbosilane (PCS) solution. SiO2 and Al2O3 coatings were also investigated using a sol-gel method.
3. Coatings improved the oxidation resistance of carbon fibers, with CVD Sic providing the best protection. A composite or gradient coating combining different materials was found to further enhance oxidation resistance.
The document lists various dyeing and pretreatment auxiliaries used in the textile industry including their functions. Products include wetting agents, detergents, dispersants, defoamers, dye fixing agents, leveling agents, and others. Concentrations range from 40-100%. Functions include improving dye uptake, wash fastness, wettability, penetration of liquors, removal of sizes and impurities, and preventing issues like foaming or backstaining.
Zero ODP Foam Expansion Agent ALternatives for Use in Polyurethane FoamsUNEP OzonAction
This document discusses alternatives to HCFC-141b for use as foam expansion agents in polyurethane foams. It summarizes the properties of various hydrofluorocarbons (HFCs) and hydrocarbons considered as zero ozone depletion potential (ODP) alternatives. One alternative, Formacel® 1100 (HFO-1336mzz), is highlighted for its low global warming potential, non-flammability, suitable boiling point, and potential to provide improved insulation performance compared to other agents. When considering the full life cycle greenhouse gas impact, Formacel® 1100 offers savings over higher global warming potential agents due to energy savings from more efficient insulation.
Azurair B-Twin - Odor pollution control with a sustainable development approachDegrémont
The document describes the AzurairTM B-Twin biological air treatment system. It uses two sequential biofilters - an acid pH tower to eliminate hydrogen sulfide followed by a neutral pH tower to remove mercaptans. This two-stage biological process can remove over 95% of hydrogen sulfide and mercaptans from air streams. The document provides an example of its use to treat odors from a wastewater treatment plant in France, eliminating over 94% of hydrogen sulfide and mercaptans from the air exhaust.
Extraction of Carbon Black from Organic CompoundIRJET Journal
This document discusses carbon black, including its production, properties, and applications. It is produced through the incomplete combustion of organic compounds like petroleum products or coconut shells. There are three main production methods that produce carbon blacks of different sizes and surface properties: channel, furnace, and thermal. Carbon black is used primarily as a reinforcing filler in tires and other rubber products, comprising 70% of its usage. It is also used as a pigment in plastics, paints, inks, and other applications due to its ability to absorb UV light and impart color. Some key properties that make it useful include its high surface area to volume ratio and ability to conduct heat and electricity when compounded with other materials.
Ozone enhanced bleaching of softwood kraft pulpsJCHostachy
1) The document discusses using limited amounts of ozone after oxygen delignification in the bleaching process for softwood kraft pulp. Using up to 2 kg/ton of ozone can improve brightness and reduce chemical costs without negatively impacting pulp strength or quality.
2) An experiment evaluated different bleaching sequences with varying ozone dosages on radiata pine pulp. Sequences with 1-3 kg/ton ozone achieved similar or better strength properties compared to a reference sequence without negatively impacting viscosity.
3) Replacing some chlorine dioxide with up to 3 kg/ton ozone could save a mill producing 500,000 tons/year of bleached pulp around $6 million per year with
Achievements In Industrial Ozone Bleaching Germer, Metais & HostachyJCHostachy
Industrial ozone bleaching has proven to be a reliable and economical option for pulp bleaching over the last 30 years. 22 mills worldwide now use ozone bleaching, which provides similar or better pulp quality compared to conventional bleaching while reducing chemical costs. Ozone bleaching also lowers effluent volumes and improves quality. Several case studies show that ozone bleaching improves strength properties and lowers bleaching costs by at least 20% compared to conventional bleaching. Ozone bleaching is now considered a well-proven, flexible, and sustainable bleaching technology.
Altarriba - Chemistry makes. Concentrated Solar Power (CSP) more successfulponenciasexpoquim11
The document discusses the role of chemistry in making concentrated solar power (CSP) more successful. It summarizes BASF's contributions to CSP, including producing high-purity sodium nitrate for heat transfer fluids and thermal energy storage. BASF is working to develop higher performance heat transfer fluids through screening over 1,000 substances and identifying 4 promising candidates. The document promotes collaboration between BASF and CSP developers to provide improved chemical solutions.
1. The document describes research into coating carbon fibers with various ceramic materials to improve their oxidation resistance at high temperatures.
2. Sic coatings were applied using chemical vapor deposition (CVD) and by pyrolyzing a polycarbosilane (PCS) solution. SiO2 and Al2O3 coatings were also investigated using a sol-gel method.
3. Coatings improved the oxidation resistance of carbon fibers, with CVD Sic providing the best protection. A composite or gradient coating combining different materials was found to further enhance oxidation resistance.
The document lists various dyeing and pretreatment auxiliaries used in the textile industry including their functions. Products include wetting agents, detergents, dispersants, defoamers, dye fixing agents, leveling agents, and others. Concentrations range from 40-100%. Functions include improving dye uptake, wash fastness, wettability, penetration of liquors, removal of sizes and impurities, and preventing issues like foaming or backstaining.
Zero ODP Foam Expansion Agent ALternatives for Use in Polyurethane FoamsUNEP OzonAction
This document discusses alternatives to HCFC-141b for use as foam expansion agents in polyurethane foams. It summarizes the properties of various hydrofluorocarbons (HFCs) and hydrocarbons considered as zero ozone depletion potential (ODP) alternatives. One alternative, Formacel® 1100 (HFO-1336mzz), is highlighted for its low global warming potential, non-flammability, suitable boiling point, and potential to provide improved insulation performance compared to other agents. When considering the full life cycle greenhouse gas impact, Formacel® 1100 offers savings over higher global warming potential agents due to energy savings from more efficient insulation.
Azurair B-Twin - Odor pollution control with a sustainable development approachDegrémont
The document describes the AzurairTM B-Twin biological air treatment system. It uses two sequential biofilters - an acid pH tower to eliminate hydrogen sulfide followed by a neutral pH tower to remove mercaptans. This two-stage biological process can remove over 95% of hydrogen sulfide and mercaptans from air streams. The document provides an example of its use to treat odors from a wastewater treatment plant in France, eliminating over 94% of hydrogen sulfide and mercaptans from the air exhaust.
Extraction of Carbon Black from Organic CompoundIRJET Journal
This document discusses carbon black, including its production, properties, and applications. It is produced through the incomplete combustion of organic compounds like petroleum products or coconut shells. There are three main production methods that produce carbon blacks of different sizes and surface properties: channel, furnace, and thermal. Carbon black is used primarily as a reinforcing filler in tires and other rubber products, comprising 70% of its usage. It is also used as a pigment in plastics, paints, inks, and other applications due to its ability to absorb UV light and impart color. Some key properties that make it useful include its high surface area to volume ratio and ability to conduct heat and electricity when compounded with other materials.
This document summarizes the benefits and performance of Huntsman's Araldite® HCEP Systems, a line of hydrophobic epoxy materials designed for extreme outdoor conditions. The materials offer extended hydrophobic properties, low leakage currents, superior thermal cycle resistance, enhanced flame retardancy, and excellent tracking and erosion resistance. Field tests show the materials exceed requirements for outdoor applications worldwide and maintain hydrophobicity even after years of exposure to harsh weather.
The document describes an IIT Bombay patented soil biotechnology (SBT) system for treating wastewater. SBT uses formulated media, culture, and additives to biologically purify water. It provides primary, secondary, and tertiary treatment in a single facility that is simple to operate and maintain. The technology has been implemented for sewage treatment, effluent treatment from industries like distilleries, and for greywater recycling. An example is presented showing how SBT was used to treat and recycle over 720 cubic meters per day of distillery process condensate.
Maintenance Engineering's Xtrabrite Alpinewite fluorescent lamps are designed and built to last longer and provide brighter light than competitors' lamps. Key features include a proprietary glass composition that is six times stronger, gold end caps, brass end pins for electrical connections, alumina oxide and tin oxide coatings, extended life phosphors, precise fill gases, cathode shields, and rigorous quality control testing to ensure high performance. These design innovations work together to deliver 95% lumen maintenance and longer lifetimes while reducing environmental impact through lower mercury content and energy efficiency.
This document summarizes techniques for reducing the energy requirements of pavement construction and maintenance. It discusses warm asphalt mixtures that can be produced and laid at lower temperatures than traditional hot mixes, reducing costs and emissions. Specific techniques mentioned include using bitumen foaming additives, wax additives, and emulsion-based processes. Foamed asphalt mixtures allow the use of recycled asphalt and can be produced and laid at temperatures as low as 90 degrees Celsius. These low-energy pavement solutions help make transportation infrastructure more sustainable and environmentally friendly.
This is a presentation from ITC Limited, Bhadrachalam, one of the finalists at the 5th CII-GBC National Award for Excellence in Water Management in 2008
The awards are in 2 categories, Within the Fence for work done on minimizing the organisations water footprint, and Beyond the Fence for work done in the community around the industry.
This presentation was in the "Within the Fence" category.
We thank CII and the respective companies for giving us permission to upload these presentations on the India Water Portal website for dissemination to a wider audience.
Extraction of Carbon Black from the Coconut ShellIRJET Journal
This document summarizes the extraction and manufacturing process of carbon black from coconut shells. It discusses that carbon black is produced through the incomplete combustion of hydrocarbon materials. There are three main types - channel, furnace, and thermal - which vary in average particle size and surface chemistry. Carbon black can be extracted from coconut shells through pyrolysis or destructive distillation. The carbon black extracted from coconut shells is a fine carbon powder that has potential applications as an electromagnetic wave absorber or conductive material due to its high surface area.
This document summarizes the work of Prof. H.S. Shankar of the Department of Chemical Engineering at IIT Bombay on soil biotechnology. Some key points:
1) Soil biotechnology uses microorganisms and biochemical processes to purify water, process solid wastes for agriculture, and enhance crop yields in a sustainable manner.
2) Experiments show that multi-stage water purification systems using microbial reactors can effectively treat sewage water.
3) Earthworms and other organisms play an important role in processing organic wastes in the soil and increasing nutrient availability for plant growth.
4) Studies of the carbon cycle, nitrogen fixation, photosynthesis, and other biochemical reactions
Synthesis and Characterization of Various Acid Doped Polyaniline NanofibersIRJET Journal
This document summarizes research on the synthesis and characterization of polyaniline (PANI) nanofibers doped with different acids. PANI nanofibers were synthesized using three different acid dopants - hydrochloric acid, acetic acid, and perchloric acid. The role of acid doping on the structure and morphology of the PANI nanofibers was analyzed using techniques such as Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, dynamic light scattering, and scanning electron microscopy. The results showed that the type of acid dopant affected properties like size, shape, and optical absorption of the PANI nanofibers. Acetic acid doping resulted in fiber-like structures while hydrochlor
This document summarizes research on using osmotic membrane bioreactors (OsMBR) and pressure retarded osmotic membrane bioreactors (ProMBR) for wastewater treatment and renewable energy production. The objectives are to evaluate OsMBR for water reuse and ProMBR for power generation. Various membrane types and solution chemistries are tested in batch and bench-scale systems. Preliminary results show membrane flux characterization and the potential for reverse salt transport in OsMBR systems.
This study evaluated the effect of different curing light sources and chemical catalysts on the degree of conversion of two dual-cured resin luting cements, RelyX ARC and Panavia F. Specimens were light cured using an argon ion laser, LED, or halogen light through a composite disk. The degree of conversion was measured using FTIR. For RelyX ARC, satisfactory curing was achieved with any light source with or without chemical catalyst. For Panavia F, the highest degree of conversion was achieved when used with ED Primer and cured with halogen light. The type of curing light and use of chemical catalyst influenced the degree of conversion of the resin luting cements
This document summarizes chemical EOR progress and challenges in China. It outlines recent advancements in chemicals, laboratory studies, simulation techniques, and field applications of polymer flooding and ASP flooding. Polymer flooding has been applied successfully at large scales in the Daqing and Shengli oilfields in China, stabilizing production and doubling polymer usage over 10 years. ASP flooding also shows potential but faces challenges with emulsions, scaling, and stability. Overall chemical EOR continues to advance but challenges remain around applications at higher temperatures and developing low-cost solutions.
Svaya tech overview for marblar nanoreactors v2marblar
Svaya Nanotechnologies is developing multilayer thin films using layer-by-layer assembly techniques. They can precisely deposit alternating layers of polymers and nanoparticles at an industrial scale to create coatings with a variety of applications. Specifically, Svaya has created silver-loaded antimicrobial films by depositing polyelectrolyte layers and then loading the films with silver ions which are reduced to nanoparticles within the film. Svaya is now seeking new applications for this "nanoreactor" coating technique.
Us approach for recovery of foam in appliancesUNEP OzonAction
1) The US EPA has both a regulatory program and a voluntary program to manage the recovery of foam and refrigerants from appliances at end of life.
2) The voluntary Responsible Appliance Disposal (RAD) Program partners with retailers, utilities, manufacturers and others to ensure proper disposal using best practices.
3) RAD requires the recovery of refrigerants, foam blowing agents, and other materials like PCBs and mercury from old appliances to prevent emissions and properly manage waste.
Araldite S-HCEP epoxy systems provide a cost-effective, semiflexible material for composite insulators with benefits like hydrophobicity, easy processing, and high tracking/erosion resistance. It offers material and processing cost savings compared to other options. The epoxy has intrinsic hydrophobic properties and can recover lost hydrophobicity. It can be processed using standard equipment without extra steps like premixing, vacuum prep, degassing, or postcuring. The epoxy adheres well without primers and provides excellent performance in high voltage insulation applications.
The document discusses steel production, which produces carbon dioxide (CO2) as a byproduct that is difficult to reduce. It outlines the Ultra-Low CO2 Steelmaking (ULCOS) program in the EU that examined various CCS and non-CCS routes to significantly cut CO2 emissions from steelmaking. CCS is present in three of the four ULCOS solutions as it allows continued use of existing blast furnace processes. However, accurately assessing costs of applying CCS to steel production is challenging as the technologies require demonstration at scale with many uncertainties. The document considers some alternative policy approaches beyond
Ozonation of municipal wastewater rev mar 05Tst Thong
This document provides information about using ozone for wastewater disinfection. It discusses that ozone has been successfully used for decades at sewage treatment plants around the world. Recent advances have made ozone generation equipment more effective and economical. The document then addresses 14 questions about ozone disinfection, covering topics like its effectiveness compared to other methods, its treatment benefits, cost competitiveness, suitability for different plant sizes and wastewater sources, and pilot testing requirements.
Concrete based on alkali activated fly ash from one power plant in serbiaeSAT Publishing House
This document summarizes research on alkali-activated fly ash concrete made with fly ash from a power plant in Serbia. Researchers tested different mixtures of alkali activators - sodium silicate and sodium hydroxide solutions - to determine the optimal mixture for strength and workability. The best mixture was used to make concrete specimens with varying water content. All specimens were cured at 80°C for 6 hours. Testing showed that the fly ash from the Serbian power plant can be used to make alkali-activated fly ash concrete with good strength and workability when activated with the optimized mixture of sodium silicate and sodium hydroxide solutions.
Oil and gas pipelines are critical infrastructure that require effective corrosion protection to ensure long-term operational effectiveness. Internally coating pipelines with epoxy provides benefits like increased gas flow capacity, faster drying times, and reduced operational costs from decreased pumping needs. Externally, fusion-bonded epoxy coatings form an electrical barrier against corrosion and have proven effective for onshore and offshore pipelines. Pipeline coating technologies continue to evolve to meet industry needs for transporting oil and gas from more challenging environments.
l The document discusses how applying an epoxy coating to the internal surface of gas pipelines can increase gas flow capacity and reduce operational costs. International oil and gas companies now commonly use internal pipeline coatings.
l Applying internal coatings can increase gas throughput by 10-20% by reducing surface roughness. Studies have shown coated pipelines require fewer compressor stations and use less fuel. Internal coatings also protect against corrosion during storage and make commissioning and inspection easier.
l Specifications for internal coatings aim to ensure coatings can withstand conditions like saltwater submersion and exposure to hydrocarbons. Developments include higher-solids and solvent-free coatings to reduce emissions while still meeting specifications.
This document discusses protective coatings for concrete provided by Sika. It provides an overview of Sika's experience developing coating systems to protect concrete structures around the world for decades. The document discusses Sika's life cycle assessment approach, sustainable concrete protection options, proven long-term durability of Sika coatings based on past projects, key factors in selecting protective coatings, and case studies of award-winning projects.
New uv curing oled encapsulation adhesive with low watertimknight8
The document summarizes the results of a research program to develop an UV-curing epoxy adhesive for sealing OLED displays with low water vapor transmission rates (WVTR). Key findings include:
1) An epoxy adhesive called DELO-KATIOBOND AD690 was formulated and found to have a WVTR of 0.8 g/m2d at 50°C/95% RH, meeting requirements for long OLED lifetimes.
2) Tests on the adhesive showed it maintained high shear strengths even after humidity and temperature cycling stresses.
3) Calcium mirror tests of the adhesive encapsulating an OLED found WVTRs of 0.03 g/
This document summarizes the benefits and performance of Huntsman's Araldite® HCEP Systems, a line of hydrophobic epoxy materials designed for extreme outdoor conditions. The materials offer extended hydrophobic properties, low leakage currents, superior thermal cycle resistance, enhanced flame retardancy, and excellent tracking and erosion resistance. Field tests show the materials exceed requirements for outdoor applications worldwide and maintain hydrophobicity even after years of exposure to harsh weather.
The document describes an IIT Bombay patented soil biotechnology (SBT) system for treating wastewater. SBT uses formulated media, culture, and additives to biologically purify water. It provides primary, secondary, and tertiary treatment in a single facility that is simple to operate and maintain. The technology has been implemented for sewage treatment, effluent treatment from industries like distilleries, and for greywater recycling. An example is presented showing how SBT was used to treat and recycle over 720 cubic meters per day of distillery process condensate.
Maintenance Engineering's Xtrabrite Alpinewite fluorescent lamps are designed and built to last longer and provide brighter light than competitors' lamps. Key features include a proprietary glass composition that is six times stronger, gold end caps, brass end pins for electrical connections, alumina oxide and tin oxide coatings, extended life phosphors, precise fill gases, cathode shields, and rigorous quality control testing to ensure high performance. These design innovations work together to deliver 95% lumen maintenance and longer lifetimes while reducing environmental impact through lower mercury content and energy efficiency.
This document summarizes techniques for reducing the energy requirements of pavement construction and maintenance. It discusses warm asphalt mixtures that can be produced and laid at lower temperatures than traditional hot mixes, reducing costs and emissions. Specific techniques mentioned include using bitumen foaming additives, wax additives, and emulsion-based processes. Foamed asphalt mixtures allow the use of recycled asphalt and can be produced and laid at temperatures as low as 90 degrees Celsius. These low-energy pavement solutions help make transportation infrastructure more sustainable and environmentally friendly.
This is a presentation from ITC Limited, Bhadrachalam, one of the finalists at the 5th CII-GBC National Award for Excellence in Water Management in 2008
The awards are in 2 categories, Within the Fence for work done on minimizing the organisations water footprint, and Beyond the Fence for work done in the community around the industry.
This presentation was in the "Within the Fence" category.
We thank CII and the respective companies for giving us permission to upload these presentations on the India Water Portal website for dissemination to a wider audience.
Extraction of Carbon Black from the Coconut ShellIRJET Journal
This document summarizes the extraction and manufacturing process of carbon black from coconut shells. It discusses that carbon black is produced through the incomplete combustion of hydrocarbon materials. There are three main types - channel, furnace, and thermal - which vary in average particle size and surface chemistry. Carbon black can be extracted from coconut shells through pyrolysis or destructive distillation. The carbon black extracted from coconut shells is a fine carbon powder that has potential applications as an electromagnetic wave absorber or conductive material due to its high surface area.
This document summarizes the work of Prof. H.S. Shankar of the Department of Chemical Engineering at IIT Bombay on soil biotechnology. Some key points:
1) Soil biotechnology uses microorganisms and biochemical processes to purify water, process solid wastes for agriculture, and enhance crop yields in a sustainable manner.
2) Experiments show that multi-stage water purification systems using microbial reactors can effectively treat sewage water.
3) Earthworms and other organisms play an important role in processing organic wastes in the soil and increasing nutrient availability for plant growth.
4) Studies of the carbon cycle, nitrogen fixation, photosynthesis, and other biochemical reactions
Synthesis and Characterization of Various Acid Doped Polyaniline NanofibersIRJET Journal
This document summarizes research on the synthesis and characterization of polyaniline (PANI) nanofibers doped with different acids. PANI nanofibers were synthesized using three different acid dopants - hydrochloric acid, acetic acid, and perchloric acid. The role of acid doping on the structure and morphology of the PANI nanofibers was analyzed using techniques such as Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, dynamic light scattering, and scanning electron microscopy. The results showed that the type of acid dopant affected properties like size, shape, and optical absorption of the PANI nanofibers. Acetic acid doping resulted in fiber-like structures while hydrochlor
This document summarizes research on using osmotic membrane bioreactors (OsMBR) and pressure retarded osmotic membrane bioreactors (ProMBR) for wastewater treatment and renewable energy production. The objectives are to evaluate OsMBR for water reuse and ProMBR for power generation. Various membrane types and solution chemistries are tested in batch and bench-scale systems. Preliminary results show membrane flux characterization and the potential for reverse salt transport in OsMBR systems.
This study evaluated the effect of different curing light sources and chemical catalysts on the degree of conversion of two dual-cured resin luting cements, RelyX ARC and Panavia F. Specimens were light cured using an argon ion laser, LED, or halogen light through a composite disk. The degree of conversion was measured using FTIR. For RelyX ARC, satisfactory curing was achieved with any light source with or without chemical catalyst. For Panavia F, the highest degree of conversion was achieved when used with ED Primer and cured with halogen light. The type of curing light and use of chemical catalyst influenced the degree of conversion of the resin luting cements
This document summarizes chemical EOR progress and challenges in China. It outlines recent advancements in chemicals, laboratory studies, simulation techniques, and field applications of polymer flooding and ASP flooding. Polymer flooding has been applied successfully at large scales in the Daqing and Shengli oilfields in China, stabilizing production and doubling polymer usage over 10 years. ASP flooding also shows potential but faces challenges with emulsions, scaling, and stability. Overall chemical EOR continues to advance but challenges remain around applications at higher temperatures and developing low-cost solutions.
Svaya tech overview for marblar nanoreactors v2marblar
Svaya Nanotechnologies is developing multilayer thin films using layer-by-layer assembly techniques. They can precisely deposit alternating layers of polymers and nanoparticles at an industrial scale to create coatings with a variety of applications. Specifically, Svaya has created silver-loaded antimicrobial films by depositing polyelectrolyte layers and then loading the films with silver ions which are reduced to nanoparticles within the film. Svaya is now seeking new applications for this "nanoreactor" coating technique.
Us approach for recovery of foam in appliancesUNEP OzonAction
1) The US EPA has both a regulatory program and a voluntary program to manage the recovery of foam and refrigerants from appliances at end of life.
2) The voluntary Responsible Appliance Disposal (RAD) Program partners with retailers, utilities, manufacturers and others to ensure proper disposal using best practices.
3) RAD requires the recovery of refrigerants, foam blowing agents, and other materials like PCBs and mercury from old appliances to prevent emissions and properly manage waste.
Araldite S-HCEP epoxy systems provide a cost-effective, semiflexible material for composite insulators with benefits like hydrophobicity, easy processing, and high tracking/erosion resistance. It offers material and processing cost savings compared to other options. The epoxy has intrinsic hydrophobic properties and can recover lost hydrophobicity. It can be processed using standard equipment without extra steps like premixing, vacuum prep, degassing, or postcuring. The epoxy adheres well without primers and provides excellent performance in high voltage insulation applications.
The document discusses steel production, which produces carbon dioxide (CO2) as a byproduct that is difficult to reduce. It outlines the Ultra-Low CO2 Steelmaking (ULCOS) program in the EU that examined various CCS and non-CCS routes to significantly cut CO2 emissions from steelmaking. CCS is present in three of the four ULCOS solutions as it allows continued use of existing blast furnace processes. However, accurately assessing costs of applying CCS to steel production is challenging as the technologies require demonstration at scale with many uncertainties. The document considers some alternative policy approaches beyond
Ozonation of municipal wastewater rev mar 05Tst Thong
This document provides information about using ozone for wastewater disinfection. It discusses that ozone has been successfully used for decades at sewage treatment plants around the world. Recent advances have made ozone generation equipment more effective and economical. The document then addresses 14 questions about ozone disinfection, covering topics like its effectiveness compared to other methods, its treatment benefits, cost competitiveness, suitability for different plant sizes and wastewater sources, and pilot testing requirements.
Concrete based on alkali activated fly ash from one power plant in serbiaeSAT Publishing House
This document summarizes research on alkali-activated fly ash concrete made with fly ash from a power plant in Serbia. Researchers tested different mixtures of alkali activators - sodium silicate and sodium hydroxide solutions - to determine the optimal mixture for strength and workability. The best mixture was used to make concrete specimens with varying water content. All specimens were cured at 80°C for 6 hours. Testing showed that the fly ash from the Serbian power plant can be used to make alkali-activated fly ash concrete with good strength and workability when activated with the optimized mixture of sodium silicate and sodium hydroxide solutions.
Oil and gas pipelines are critical infrastructure that require effective corrosion protection to ensure long-term operational effectiveness. Internally coating pipelines with epoxy provides benefits like increased gas flow capacity, faster drying times, and reduced operational costs from decreased pumping needs. Externally, fusion-bonded epoxy coatings form an electrical barrier against corrosion and have proven effective for onshore and offshore pipelines. Pipeline coating technologies continue to evolve to meet industry needs for transporting oil and gas from more challenging environments.
l The document discusses how applying an epoxy coating to the internal surface of gas pipelines can increase gas flow capacity and reduce operational costs. International oil and gas companies now commonly use internal pipeline coatings.
l Applying internal coatings can increase gas throughput by 10-20% by reducing surface roughness. Studies have shown coated pipelines require fewer compressor stations and use less fuel. Internal coatings also protect against corrosion during storage and make commissioning and inspection easier.
l Specifications for internal coatings aim to ensure coatings can withstand conditions like saltwater submersion and exposure to hydrocarbons. Developments include higher-solids and solvent-free coatings to reduce emissions while still meeting specifications.
This document discusses protective coatings for concrete provided by Sika. It provides an overview of Sika's experience developing coating systems to protect concrete structures around the world for decades. The document discusses Sika's life cycle assessment approach, sustainable concrete protection options, proven long-term durability of Sika coatings based on past projects, key factors in selecting protective coatings, and case studies of award-winning projects.
New uv curing oled encapsulation adhesive with low watertimknight8
The document summarizes the results of a research program to develop an UV-curing epoxy adhesive for sealing OLED displays with low water vapor transmission rates (WVTR). Key findings include:
1) An epoxy adhesive called DELO-KATIOBOND AD690 was formulated and found to have a WVTR of 0.8 g/m2d at 50°C/95% RH, meeting requirements for long OLED lifetimes.
2) Tests on the adhesive showed it maintained high shear strengths even after humidity and temperature cycling stresses.
3) Calcium mirror tests of the adhesive encapsulating an OLED found WVTRs of 0.03 g/
Internal flow efficiency coatings were first applied to gas pipelines in the 1950s to enhance flow and reduce operational costs. Modern high solids and solvent-free internal coatings provide improved environmental benefits over conventional solvent-based coatings by greatly reducing or eliminating volatile organic compound (VOC) emissions. A study found that the volume solids content of internal coatings is highly significant in reducing the surface roughness of coated pipelines, with solvent-free coatings achieving the lowest roughness, even at an equivalent dry film thickness as other coatings. This allows pipeline operators to realize enhanced flow and environmental benefits without increasing coating thickness.
This document discusses the use of pure oxygen in water and wastewater treatment. It outlines several applications of pure oxygen including odor control, replacing traditional aeration, and lake oxygenation. It then describes traditional aeration methods and their limitations. The document discusses how pure oxygen systems like UNOX and OASES work, and the advantages of using pure oxygen over air due to its higher solubility. Several pure oxygen technologies are presented for applications like odor control, wastewater treatment, and groundwater remediation. Product offerings from PCI including the DOCS oxygen generation systems are described along with their lower operating costs compared to other oxygen production methods.
This document summarizes a study that investigated using a blended coarse lightweight aggregate containing both oil palm shell (OPS) and oil-palm-boiler clinker (OPBC) in concrete. When 50% of the OPS was replaced with OPBC in concrete, significant improvements were observed in the compressive, splitting tensile, and flexural strengths of the concrete. Additionally, the initial and final water absorption and drying shrinkage strain of the blended aggregate concrete were significantly less than concrete made with only OPS. The study aimed to develop a sustainable lightweight concrete utilizing wastes from the palm oil industry as coarse aggregates.
B&i2013 donderdag 15.45_zaal_b_low-carbon concretes using novel mineral binde...Bouwmaterialen_Innovatie
The document discusses low carbon concretes that use novel mineral binders as cement substitutes to reduce greenhouse gas emissions from concrete production. It introduces bifam, a zero-carbon cement substitute made from industrial byproducts that can replace cement in concrete at rates from 30-100%. Bifam has binding properties similar to cement and can lower the carbon footprint of concrete products by up to 94% compared to conventional cement. Initial applications in paving blocks and masonry blocks show bifam can increase product quality while reducing production costs. A production plant is planned to begin supplying bifam in 2014.
Study on the Properties of Ultra-High-Performance Concrete-A ReviewIRJET Journal
This document provides an overview of ultra-high-performance concrete (UHPC), including its history, raw materials, mechanical properties, and applications. UHPC has exceptional strength and durability due to its very low water-to-cement ratio and inclusion of silica fume and steel fibers. It was first developed in the 1980s and has steadily advanced, finding increasing use in infrastructure projects. The document discusses the key components of UHPC and their effects on properties such as workability, strength, and bonding. UHPC offers improved sustainability over traditional concrete but remains limited by cost.
Atomization of reduced graphene oxide ultra thin film for transparent electro...Conference Papers
This document summarizes research on using an atomization process to deposit reduced graphene oxide (rGO) thin films for use as transparent conductive electrodes. Key points:
- Graphene oxide was spray coated onto silicon wafers and glass slides using an ultrasonic atomizer. Thermal reduction processes were then used to make the films electrically conductive while maintaining optical transparency.
- Thinner films with 1-2 spray coats had higher transparency (>90%) but higher resistivity, while thicker 3-4 coat films had lower transparency (77.1%) but lower resistivity (5.3 kΩ/sq).
- Rapid thermal processing was more effective than plasma processing at reducing resistivity. Sheet resistance decreased
Atomization of reduced graphene oxide ultra thin film for transparent electro...Conference Papers
This document summarizes research on using an atomization process to deposit reduced graphene oxide (rGO) thin films for use as transparent conductive electrodes. Key points:
- Graphene oxide was spray coated onto silicon wafers and glass slides using an ultrasonic atomizer. Thermal reduction processes were then used to make the films electrically conductive while maintaining optical transparency.
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Achievements In Industrial Ozone Bleaching Ppi
1. bleaching
By EMIL GERMER, ALEXIS MÉTAIS and JEAN-CHRISTOPHE HOSTACHY
The benefits of ozone are now well proven and can include cost
savings and reduced effluent load
ACHIEVEMENTS IN INDUSTRIAL
OZONE BLEACHING
T
he first industrial pulp bleaching line including effluents to 4-6 m3/air dry tonne4. Of course investors
an ozone stage started 19 years ago. Today there always focus on the return on investment (ROI) and it
are 22 mills worldwide using what is commonly has now become clear to all ozone users that bleach-
named light-ECF bleaching. Among those 22 mills, 16 ing costs are reduced by 20-32% when introducing an
produce solely hardwood pulps, four produce both soft- ozone stage in an ECF bleaching line 3,5,6,7 and even
wood and hardwood pulps while SCA in Östrand (Swe- more in the case of TCF bleaching 8. The high bleach-
den) and Rosenthal in Blankenstein (Germany) produce ing efficiency of ozone allows a drastic reduction in
exclusively softwood pulp1. Thirteen mills started ozone the consumption of expensive bleaching chemicals
bleaching in the early years of the 21st century and three - chlorine dioxide in ECF bleaching and hydrogen
mills equipped two of their bleaching lines with ozone: peroxide in TCF bleaching as well as sodium hydrox-
Oji Paper in Tomioka (Japan), Fibria in Jacarei (Brazil) ide in both cases - and the implementation of ozone
and ITC in Bhadrachalam (India). Fibria selected ozone bleaching also results in reduced of steam require-
bleaching in 2002 for Jacarei’s new 2,500-tonne/day line ments during the bleaching process. The ROI in the
C after having operated ozone bleaching as from 1995 replacement of a D0-stage by an ozone Z-stage lies
on its 900-tonne/day line B. This decision clearly shows between two and four years 1,6.
that ozone bleaching has met all requirements and Without affecting the pulp strength properties
expectations on line B for seven years. in comparison with conventional ECF sequences,
In April 2011, four new ozone generation sys- bleaching with an ozone stage additionally gives a
tems have been contracted and will start operating wide range of opportunities by:
in 2012 for: - making very high brightness levels possible (92-
- a 700,000-tonne/yr capacity Chinese greenfield mill 93% ISO)2,9;
owned by Oji Paper (the company already uses - decreasing brightness reversion2,8,10;
ozone in its Japanese mills); - reducing drastically the extractive content10,11 by
- a pulp production capacity increase in Austria at 50-75%8,12;
Lenzing; - reducing energy requirements during refining by at
- two pulp production capacity increases in Brazil least 10%3,13;
(confidential). - precisely controlling the viscosity in viscose pulp
production.
Ozone bleaching is efficiently used on hardwood
and softwood pulps, on kraft and sulphite pulps dedi- Nevertheless, arguing that ECF bleaching has
cated to all kinds of final applications. Pulp produc- already been used in the industry for 30 years, a
ers do not always evaluate the significant ecological number of conservative pulp producers still con-
advantages of ozone-based bleaching sequences over sider the bleaching sequence D0-Eop-D1-D2 and
the traditional ECF bleaching sequence D0-Eop-D1- its variants- as the best alternative today. One should
D2 (or its variants): the quality of wastewater is drasti- however be aware that within the next 20 years,
cally improved 2,3 as it is possible to lower bleaching the pulp and paper industry will have to carry out
34 August 2011 Pulp & Paper International (PPI)
2. bleaching
significant modernisations to retain its competitive- HIGH CONSISTENCY (HC) OZONE
ness and, in turn such a traditional ECF bleaching BLEACHING
will then be over 50 years old. This position could
be understood if no better technique was available. The first commercial HC ozone bleaching started in
But considering the very good results and proven 1992 at the Union Camp mill in Franklin, VA. Accord-
stable operation achieved today by a large number ing to the C-Free® process implemented there, the
of industrial ozone-based light-ECF and TCF bleach pulp was pH adjusted, pressed to high consistency
plants, such a conservative attitude can’t be justified (40%), fluffed and transferred to the ozone paddle
any longer. reactor operating at atmospheric pressure14. The C-
The industrial use of ozone has already under-
gone a long string of improvements and develop-
ments. As with other new technologies, ozone bleach-
ing did not immediately reach its optimal technical
efficiency but faced several issues during its early
years. All the same, achievements of ozone bleaching
have improved year in year out and it is now a well
proven technology. Nevertheless, some pulp produc-
Fig. 1 - OZONE FORMATION IN AN ELECTRICAL FIELD
ers still remember the difficulties faced in the early
years and, unfortunately, this still represents a very
serious drawback towards the modernization of their
pulp mills. By doing a brief survey of ozone applica-
tion in pulp bleaching development over the past 20
years, the present article aims to draw specialists’ and
investors’ attention to practices and technologies that
helped ozone bleaching become the most advanced
and promising technology.
O Z O N E G E N E R AT I O N
Ozone generation is a pure on-site technology requir-
ing only energy and oxygen (usually also produced on
site from a VPSA plant). Ozone (O3) is produced from
oxygen (O2) in an electrical field at a concentration of
12% by weight, Fig. 1.
Modern ozone generators are 50% more efficient
than the ones used in the first ozone pulp bleaching
Fig. 2 - Z-COMPACT SYSTEM IN CELTEJO (PORTUGAL)
applications. Z-Compact-Systems, Fig. 2, were spe-
cially designed for the pulp and paper industry and
they are able to produce up to 250kg O3/h (6 tons/
day) per unit.
Today, ozone production only requires 7 to 8
kWh/kg of ozone and as a result, 1 kg ozone is now
cheaper than 1 kg of chlorine dioxide. Based on a
“plug and play” principle, modern ozone genera-
tion units are easy to operate and can deliver the full
ozone capacity in less than one minute with an avail-
Fig. 3- HC OZONE BLEACHING IN THE 1990S AND TODAY
ability higher than 99%.
Pulp & Paper International (PPI) A u g u s t 2 0 1 1 35
3. bleaching
Free® was provided by Sunds Defibrator until the late MEDIUM CONSISTENCY (MC) OZONE
1990s in the US, Sweden, South Africa and Germany. BLEACHING
Modern HC ozone bleaching uses the ZeTracTM
technology provided by Metso which is a much Improvements in MC ozone bleaching consist in fact
simplified version of the C-Free, Fig. 35. The experi- of alterations to the ozone mixers. This is no wonder
ence gained from the first industrial installations since the ozone mixer is the core of the MC Z-stage
showed that ozone requires very short (around 1 and the quality of the final pulp depends on its ef-
minute) contacting time with the pulp and that a 5-10 ficiency. It is worth remembering that the very few
minute extraction stage after the Z-stage is in most mills which faced quality issues are those where the
cases sufficient. These observations allowed the size first MC ozone bleaching technique was implement-
of reactors to be reduced, which lowered investment ed: this was mainly due to a non homogenous mixing
costs. Then the plug screw feeder, the refiner fluffer and a mixer which mechanically affected the fibers.
and the washing stage prior to the extraction stage Andritz, GL&V and Lenzing Technik are the three
could all be eliminated. These drastic simplifications suppliers of MC ozone mixers and all MC Z-stages are
led to significant reduction of the capital expenditure, designed according to the same principles. Industrial
energy requirements, maintenance costs as well as practice has shown that Andritz technology requires
effluent volume5. two mixers in series for a 3-6 kg/tonne ozone dose to
Figure 3 shows the principle of the modern obtain the optimal bleaching efficiency while Lenzing
ZeTrac system. The pulp is acidified and then pressed Technik considers that one single mixer of its own is
to high consistency (38-42%). Such a high consis- sufficient for a 4-5 kg/tonne ozone charge.
tency is a prerequisite to facilitate the rapid contact Because of the larger amount of filtrate around
between ozone gas and well fluffed pulp and so the fibers at 12% pulp consistency, the reaction must
preserves the reaction efficiency. Once dewatered, take place in a pressurized (7-8 bar) reactor and con-
the pulp is fluffed in a shredder screw on the top of sequently the total gas flow (oxygen and ozone) must
the press and fed by gravity into the reactor. Ozone is be compressed accordingly. A typical MC ozone stage
added to the reactor which is operated at a pressure from Andritz, Fig. 4, features a MC pump that feeds
slightly below atmospheric. After the reactor, the pulp the pulp to the ozone stage, two ozone mixers in
is diluted with alkaline liquor. series, a pressurized reaction tube, a flow discharger
at the reactor top and a blow tube11.
It was noticed that the whole reaction process
takes place in the mixers while the “reactor” has no
effect on the ozone reaction but only guarantees a
stable flow to the blow tube11. It is now possible to
decrease the gas pressure from 12 bar to 9 bar and
thus reduce operating costs.
Andritz improved the original Ahlström mixer
efficiency by reducing the gas bubble size without
making any fundamental change in the design of the
mixer but only increasing turbulence and mitigating
the mechanical action12. It makes the mixing a lot
more homogenous and maintains pulp strength all
along ozonation.
Lenzing started a MC ozone mixing system
from Kvaerner in 1992 and has since investigated all
possible improvements in MC ozone bleaching. It
has been a pioneer in ozone bleaching for almost 20
Fig. 4 - TYPICAL MC OZONE STAGE AND MIXER
years. As a result, LenzingTechnik designed its own
36 August 2011 Pulp & Paper International (PPI)
4. bleaching
ozone MC mixers (called Eccentric Mixers) imple- lower than the ratio of softwood/hardwood bleached
menting the revolutionary idea of an asymmetric pulps produced in those countries.
design to increase both fluidization of the pulp and Numerous studies carried out during the 1990s
retention time16. and in the more recent years have shown that the se-
And this proved to work: Lenzing upgraded its lectivity of ozone against lignin is very high. It is now
two bleaching lines in 2004 with modern Eccentric established that the reaction kinetic of ozone with
Mixers and the use of the new mixing technology typical lignin structures is 10 to 1,000 times higher
resulted in a 2.5 ISO brightness points increase for than with carbohydrates, Fig. 517.
the same ozone dose! Actually, Lenzing reduced its This means that as long as there is some remain-
bleaching chemical costs by 50% on line 1 and 38% ing lignin (even only 0.5-1.5%) a well-operated ozone
on line B16. bleaching process does not impact the cellulose more
than any other bleaching stage (a chlorine dioxide
PULP QUALITY one for example). In fact, according to the best wood
chemistry specialists15,17, the reaction kinetic of ozone
Since the first commercial ozone bleaching instal- with lignin is 1,000 times higher than the kinetic of
lation was started, enhancements to the ozone cellulose oxidation or depolymerisation by ozone.
bleaching process have been conducted jointly by Those scientific results are confirmed by the follow-
laboratories on the chemical side and by both the ing industrial experience of ozone bleaching.
industry and equipment suppliers on the operational In 1998, the Domtar mill in Espanola, ON,
and technical sides. Improvements in ozone bleach- switched from the ECF O-A-D-E-DnD sequence to
ing efficiency were boosted by the development the light-ECF O-A-ZD-E-DnD sequence for bleach-
of automatic control systems, mainly as a result of ing pulp up to 93% ISO brightness. Comparing the
achievements in the accuracy and reliability of elec- two sequences Domtar noticed “ozone has no impact
tronics. It is now possible to adjust very precisely the on viscosity or PFI strength properties and in paper
ozone dosage, pH, retention time and temperature in machine performance”9.
the Z-stage. These improvements now fully guarantee The Mondi mill in Ruzomberok (Slovakia)
the pulp quality after ozone bleaching. produces hardwood and softwood pulps at 89% ISO
When ozone bleaching started to develop in the brightness and switched in 2004 from a D-Eop-D-
early 1990s, the use of such a powerful oxidant in com-
bination with yet non-optimized process parameters
(the most important issue being the mixing homogene-
ity) resulted sometimes in uneven pulp delignification
and affected the pulp mechanical properties. Practices
improved step by step and opportunities soon replaced
difficulties, yet many pulp producers still believe that
the quality of ozone bleached pulp, especially soft-
wood, is lower than traditional ECF bleached pulp.
Since most of the mills using ozone are produc-
ing hardwood pulps, some people even believe that
this evidence sustains the alleged lower strength of
softwood ozone bleached pulps. The true explana-
tion instead is rather simple: ozone bleaching is
mostly implemented in Europe, Brazil, South Africa,
Australia, India and Japan, all countries deficient in
softwood resources. Thus, such an argument does not
Fig. 5 - MAIN OZONE REACTIONS WITH LIGNIN COMPOUNDS
stand considering that 25% of the mills using ozone
AND CARBOHYDRATES
are producing softwood pulps. This proportion is not
Pulp & Paper International (PPI) A u g u s t 2 0 1 1 37
5. bleaching
E-D bleaching to a ZEo-DnD one. It should first be At this stage it is worth remembering that gener-
noticed that there was only one washing stage (after ally, the tensile index is increased by refining while
ZEo) in the new process. Mondi compared hardwood the tear index follows the opposite trend and it is
and softwood pulp strength parameters of the new impossible to increase both of them at the same time.
pulps with the ones of the former pulps set as the Nevertheless the mill reported that the paper machine
reference (100%); only minor differences could be runnability was not affected and the final paper prop-
seen in standard pulp properties, Table 118. erties were even better than expected (stiffness)13.
Hardwood pulp properties were particularly
excellent and the hardwood proportion in the paper
Table 1 - RELATIVE PULP QUALITY FOR ECF-Z COMPARED
WITH ECF AT 27°SR FOR BOTH HW AND SW machine furnish was increased over 90%13. In 2005
Mondi Ruzomberok set up a new world record for
Hardwood Softwood copy paper production at 1,500 m/min13,18. Of course,
PFI rev 89 90 these two achievements would not have been pos-
Burst Index 100 97 sible with a lower pulp quality than before.
Tear Index 92 90 Moreover, the Ruzomberok mill has kept improv-
Breaking Length 104 102 ing the Z-stage operation and its bleaching process
Tensile Index 102 102 by installing a pressurized (PO) stage in place of the
Stiffness 93 94 last D stage in August 2008. Current pulp strength
properties are excellent and would make most pulp
mills envious, Fig. 6.
Concerning hardwood pulp, energy requirements Ozone bleaching process improvements never
for refining dropped by 11%, burst was maintained, stopped. The ITC mill in Bhadrachalam (India)
breaking length and tensile index increased while started ozone bleaching in 2007 after five years of ECF
tear and stiffness decreased. Meanwhile, for softwood bleaching operation. Its results are clear19:
pulp, refining energy was again reduced significantly, • the breaking length increased by 5.5%;
tensile properties increased marginally while burst, • the burst factor increased by 10%;
tear and stiffness showed some reduction. • the tear factor increased by 6%;
Fig. 6 - BLEACHING LINE AT MONDI RUZOMBEROK AND PULP STRENGTH PROPERTIES
38 August 2011 Pulp & Paper International (PPI)
6. bleaching
• the bleaching chemicals cost decreased by about 65 kg/tonne of low-pressure steam only are necessary
450 Rs/tonne ($10/tonne). for the Ze-DD bleaching sequence.
As an example, implementation of the ozone
O P E R AT I N G PA R A M E T E R S stage at Bhadrachalam led to a 50% drop in steam
consumption in comparison to the former D-Eop-D
Pulp temperature is one important operating param- bleaching sequence21.
eter that has been tuned. Ozonation was initially car- Steam savings are the highest in the case of hard-
ried out at 40°C in the 1990s and such a low tempera- wood pulp bleaching where usually a first A-stage
ture was not very convenient as the Z-stage is located (acidic) or DHT-stage (D-stage at hot temperature) is
right after the 85-95°C oxygen delignification and implemented. Such A or DHT stages have 2 targets:
before an alkaline extraction or a chlorine dioxide • removing hexenuronic acids which are responsible
stage (after a few MC ozone stages) generally carried for parasite chlorine dioxide consumption and
out at around 60-80°C. Therefore, it is necessary to brightness reversion;
cool the pulp before reheating it. • cleaning the pulp from transition metals which
It was thought that a higher temperature would are known to decompose H2O2 and responsible
lower the Z-stage efficiency, speed up the ozone for weakening of the cellulose during peroxide
decomposition, increase the negative effect of transi- bleaching.
tion metals and ultimately decrease the pulp quality.
Slowly, throughout industrial trials, it appeared that By removing transition metals the A-stage ef-
such fears were totally unfounded. Several results fectively replaces the use of a chelating agent. Acidic
have demonstrated that for hardwood pulp the Z- stages were built prior to the ozone stage in the
stage temperature could be increased up to 60°C and 1990s at the UPM mill in Pietarsaari (Finland), at the
sometimes even higher without any negative effect Sateri mill in Bahia (Brazil), at Fibria Jacarei and at
on pulp strength and brightness9,13,18. Espanola. But today there is no doubt that the imple-
For example, data from Ruzomberok show that mentation of an A-stage reduces both pulp strength
an increase of the Z-stage temperature from 43°C to properties and pulp yield22.
61°C gives a higher brightness (+1.8% ISO), a lower Of course, there is no such problem of hex-
brightness reversion, a higher stiffness and a better enuronic acids in the case of softwood pulp bleach-
ozone delignification efficiency, with all other proper- ing. But the issue of transition metals remains and
ties (PFI rev, Burst Index, Tear Index, Tensile Index in the 1990s Swedish mills SCA Östrand and Nordic
and Bulk) unaltered, Table 213,20. Paper Säffle as well as the Rosenthal mill in Blan-
Domtar Espanola first operated the Z-stage at kenstein (Germany) chose to start their bleaching
55°C. When it decided to increase the ozone stage sequence with a Q-stage (chelation).
temperature to 60°C, it increased delignification by Such A-stages or Q-stages are costly because they
5-10% and gained 1 point ISO brightness. Today, it is require a tower (with 2-3 hours retention time for
operating the ozone stage at 70°C9. the later) and the use of expensive chemicals. Yet in-
All HW pulp mills which set up an ozone stage in dustrial light-ECF and ozone based TCF experiences
the past 5-6 years are running the Z stage at a 55°C mini-
mum. This also resulted in significant steam savings. For
Table 2 - IMPACT OF TEMPERATURE ON THE KAPPA INDEX, ISO BRIGHTNESS
example, Ruzomberok reduced its steam requirements AND BRIGHTNESS REVERSION AT MONDI RUZOMBEROK
by 75% by running the Z-stage at 58-61°C 13.
Metso has shown industrially that steam require- Temp in Z 43°C 43°C 58°C 61°C
ments for light-ECF bleaching are only 25% of steam Kappa number after Z(EO) 4.1 4.0 4.0 3.8
requirements for conventional ECF bleaching in ClO2 charge, kg/adt (DCS data) 24.5 23.5 24.7 24.4
the case of HW pulp8. While the bleaching sequence Brightness, % ISO 85.9 85.2 86.6 87.7
DHT-Eop-D requires 249 kg/tonne of low-pressure Reverted brightness, % ISO 81.8 82.2 83.9 85.9
steam and 40 kg/tonne of medium-pressure steam,
Pulp & Paper International (PPI) A u g u s t 2 0 1 1 39
7. bleaching
have shown that the installation of those A-stages or In the 1990s it was common to fully bleach the
Q-stages should be avoided. pulp with six or even seven stages as in the following
The hexenuronic acids content is reduced by at sequences:
least 60% in the ozone stage23. This makes the ozone - A-ZD-Eop-ZD-Ep in Pietarsaari (Finland);
stage even more efficient than any A-stage and it - Q-OP-D-Z-PO-P in Blankenstein;
partly explains why ozone bleached pulps have a - A-ZD-Eo-DnD in Espanola.
lower brightness reversion than other pulps.
Actually, removal of transition metals is efficiently Bleaching sequences built in the last decade for
carried out during the ozone stage where the pH both hardwood and softwood pulps usually have only
is acidic (usually 2.5-3). Awareness of this avoids three or four stages and vary little from one another:
investing in any acid or chelating stage when ozone - Z-D-Ep-D at Nippon PaperYufutsu (Japan);
is applied, and results in operating cost savings. As a - ZEop-D-P at Mondi Ruzomberok;
result, only two of the 16 pulp bleaching lines having - ZD-E-D at Nippon Paper Maryvale (Australia);
started ozone since 2000 use an A-stage and none of - Ze-DP at ITC Bhadrachalam, Fig. 7;
them use chelating agents. - Z(EOP)-(PO) at Sniace (Spain, sulphite pulp for
dissolving grades);
BLEACHING SEQUENCES - Ze-D-P at Celtejo (Portugal).
The proven economical, technical and environmen- These bleaching sequences reflect the continuous
tal advantages, the development of oxygen deligni- and impressive developments of ozone application
fication as well as improvements in ozone bleaching in light-ECF bleaching process and clearly show the
and in the whole pulping process over the last 20 worldwide interest of pulp makers in ozone bleaching.
years, have allowed the bleaching sequence to be
shortened by one, two or even three stages, while CONCLUSIONS
simultaneously increasing the brightness ceiling with
2-3 points compared with what was possible. Ozone bleaching has already been industrially imple-
Fig. 7 - LINE 2 AT ITC BHADRACHALAM
40 August 2011 Pulp & Paper International (PPI)
8. bleaching
mented, experienced and improved for 18 years. It 4. CAMPO, R. and MARQUES, P Results Pulp & Paper
.,
is a well proven and safe process, currently used by 3, 32 (2009).
some reference pulp mills among the most modern 5. BOKSTRÖM, M., African Pulp and Paper Week
in the world. Its advantages in terms of bleaching cost 2002, Durban, South Africa.
savings, effluent load reduction and ease of use can 6. HOSTACHY, J.-C., Tappi J., 9(8): 16(2010).
no longer be questioned. It is applicable to all kind of 7. CAMPO, R. and SUNDIN, M., Proceedings of the
pulps and has no negative effect on their mechanical EFPG Days 2004, Grenoble, France.
properties. 8. WENNERSTRÖM, M. et al, International Colloqui-
The Z-stage takes place in just one minute and um on Eucalyptus Pulp 2007, Belo Horizonte, Brazil.
both HC and MC technologies are recognized as fully 9. GARTLEY, B., Ozone Delignification at Domtar
reliable, safe and stable processes. Espanola, paper presented at the PAPTAC Bleaching
High-consistency ozone bleaching is performed Committee, Oct. 21-23 2002.
at atmospheric pressure. Behind the ozone reactor, 10. CHIRAT, C., et al., Proceedings of the ABTCP 2008,
it requires only a 5-10 minutes long extraction stage Sao Paulo, Brazil.
and no intermediate washing is necessary. This solu- 11. VEHMAA, J. and PIKKA, O., Proceedings of Paperex
tion allows the E filtrate to be recycled back to the 2007, New Delhi, India.
brown stock or post-oxygen washing and further to 12. PIKKA, O., Proceedings of the EFPG Days 2004,
the recovery boiler, and so the total bleaching effluent Grenoble, France.
can drop to 4-6 m3/tonne. 13. TOMIS, B. and TUOMI, A., Proceedings of
As a result of continuous improvements of the Zellcheming 2006, Wiesbaden, Germany.
equipment and process automation as well as tuning 14. FERGUSON, K., Pulp & Paper, 66(11): 42 (1992).
of the operating conditions over a period of almost 20 15. CHIRAT, C., Proceedings of the EFPG Days 2007,
years, modern ozone bleaching is now recognised as Grenoble, France.
a state of the art technology for both hardwood and 16. LenzingTechnik, Eccentric Mixer - an innovation
softwood pulps. from LenzingTechnik, commercial presentation.
There are neither technical nor economical 17. LACHENAL, D., Proceedings of the EFPG Days
reasons to stick to a 30-year-old conventional ECF 2005, Grenoble, France.
process. The use of a light-ECF bleaching sequence 18. NORSTEDT, Å. and LINDSTRÖM, L.-Å., ATCP Con-
can by itself decrease bleaching costs by more than ference 2006.
20% and lead to the same pulp strengths with better 19. KUMAR, K.R., Proceedings of Paperex 2009, New
optical properties and refining ability. Ozone bleach- Delhi, India.
ing is by far the most valuable solution not only for 20. BALAZ, P Proceedings of Zellcheming 2006, Wies-
.,
forerunners but for all pulp mills. PPI baden, Germany.
21. PADMANABHAN, A. et al, paper presented at the
Emil Germer, Saint-Petersburg State Forest Technical National Award for Excellence in Energy Management
Academy; Alexis Métais, Jean-Christophe Hostachy, 2007, 22-23 August 2008, Pune, India.
ITT Wedeco 22. KOBAYASHI, T. et al, Japan Tappi, 59 (2005).
23. NORDÉN, S., ZeTrac Forum 2004, Rochehaut,
LITERATURE Belgium.
1. MÉTAIS, A., Proceedings of the TAPPSA National 24. ENGELFELDT A., internal training for ITC.
Conference 2010, Durban, South Africa.
2. CARRÉ, G. and WENNERSTRÖM, M., Proceedings
of the International Pulp Bleaching Conference 2005,
Stockholm, Sweden.
3. NORDÉN, S. et al., Eco-Friendly Bleaching with To read more articles on Chemicals, visit our Chemicals
ZeTracTM, paper presented at the IPPTA Annual Gen- Technology Channel at www.risi.com/
technologychannels/chemicals
eral Meeting & Seminar 2006, Chennai, India.
Pulp & Paper International (PPI) A u g u s t 2 0 1 1 41