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New bio- degradable chelating agent Modern Karton's brand-new board machine Biocides in action at Äänekoski • Focusing on water and energy efficiency • Kemira's flagship retention technology 11 18 26 KEMIRA'S INTERNATIONAL CUSTOMER MAGAZINE FOR THE PULP AND PAPER INDUSTRY. Kemira 2 09

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Page 1: Kemira Solutions 0209 En

New bio- degradable chelating agent

Modern Karton's brand-new board machine

Biocides in action at Äänekoski

•Focusingonwater andenergyefficiency

•Kemira'sflagship retentiontechnology

11 18 26

KeMira's iNterNatioNal custoMer MagaziNe for the pulp aNd paper iNdustry.

SolutionsKem

ira

209

Page 2: Kemira Solutions 0209 En

Editorial

Water efficiency

efficiency is becoming an increasing key issue in all areas of industry. Limited sup-

plies of clean water, ever-stricter official permit levels, and the need to cut costs all mean that more water needs to be recycled. Based on the extensive know-how we have in water treatment chemistry, we want to do everything we can to help our customers face these types of challenges.

The importance of optimizing water and energy usage is growing, and the need to recycle water and treat the raw water used in proc-esses is growing with it. Wastewater treatment costs are rising as well. Water and energy efficiency is an environmental issue, but it is also very much an economic one, as making better use of these resources can bring major cost savings to a production plant.

Water chemistry is an increasingly important factor as recycling levels increase, as Kaj Jansson of Kemira’s R&D explains in this issue of Solutions. The more closed a process is, the better its water chemistry management needs to be. Recycling water within a production plant increases its temperature and the level of contaminants it contains and can lead to corrosion problems and elevated microbial growth.

The amount of water used by paper machines has dropped signifi-cantly over the last decade, and in the future we are likely to see even more water being recycled. Modern Karton, based in Turkey and featured in this issue, is a good example of a producer that has been able to increase its water recycling thanks to efficient wastewater treatment.

By focusing on water and energy efficiency, and on how improvements can be made, we want to highlight some of the expertise that Kemira has to offer in this area – expertise that could help you too.

Kaisa SipiläEditor-in-chief

photo KREETTa JäRvEnpää

Water and energy

Kemira Solutions is published in finnish and english two times a year.

PUBLISHER Kemira oyj, p.o. Box 330, 00101 helsinki, finland, tel. +358 (0) 10 8611, fax +358 (0) 10 862 1694, www.kemira.com.EDITORIAL BOARD Kemira: Kaisa sipilä (editor-in-chief), ari pirneskoski, Nichlas Kavander,Jean-francois caisso, susan flesher, darren swales, tuomo Keskinen, Jan-luiken hemmes, Mats rönnbäck, clayton campbell, susanna ruotsalainen, Johan grön, Johanna Juuti, Kirsti Kalaniemi. lehdentekijät: Jussi-pekka aukia (producer), Jenni sepponen (subeditor), Mervi ahlroth (photo editor), Miikka tikka (ad). PRODUCED BY alma Media lehdentekijät oy, p.o. Box 502, 00101 helsinki, tel. +358 (0) 10 665 102, fax +358 (0) 10 665 2533, www.lehdentekijat.fi. REPRODUCTION aste helsinki PRINTED BY punamusta oy, 2009. Paper lessebo design smooth white 115 g. produced using Kemira products. ADDRESS REGISTER Kemira's customer register.SUBSCRIPTIONS AND CHANGES Of ADDRESS www.kemira.com > Media > publications > Magazines ISSN 1456–5064

“Water and energy efficiency

is an environmental issue, but also very much an economic

one.”

04 Short CutsTen years ago we were talking about water recycling, and we still are today. Marcelo Costa from São paolo gives us his take on R&D in South america in the Q&a column.

08 On TopicThere are still a lot of opportunities left for reducing the energy intensity of the pulp and paper industry, says Research professor Kari Edelmann.

11 To the PointKemira’s patented biodegradable chelating agent, Fennobio S, has been registered under the European REaCH regulation.

12 AnalysisWhen closing water cycles, it is always important to evaluate physical, chemical, and biological factors, according to Kaj Jansson.

18 Modern KartonTurkey's leading board producer is thoroughly committed to quality.

22 R&DKemira's new, special dry strength additive is one of the latest innovations to emerge from the company's R&D pipeline, says Bernd Hauschel.

24 At Your ServiceKemira’s new line of high-temperature, water-based defoamers provideeffective foam and entrained air control at higher temperatures.

26 PartnershipM-real’s äänekoski board mill in Finland has been involved in testing and developing Kemira’s new slime control concept from the start.

28 At Your ServiceKemira's flagship retention technology is now in use at multiple mills around the world producing both printing paper and packaging board.

18 22 26

Try some recycling technology for yourself!there’s a lot of fun things you can do with water, and it’s easy to recycle at home as well.

check out the back cover to see how you can get water to move along a piece of thread from one

container to another, just by capillary action.

Contents

gettyiM

ag

es

2 Kemira Solutions 32 | 2009

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Analyzing biomassNEWS Kemira’s portable LumiKem technology monitors the health of the biomass in a wastewater treatment plant by measuring levels of adenosine triphosphate (aTp), which acts as a direct and interference-free indicator of total living biomass.

LumiKem brings a new generation of process efficiency to biological treatment opera-tions, according to Edouard Papin, Senior application Specialist, Water Quality Manage-ment. LumiKem pORTaL software can monitor treatment processes in their entirety, from early toxicity detection to energy cost optimization.

“It’s a user-friendly program that can make quick correlations between process data and help optimize wastewater treatment operations at a customer’s facility. It can assist in minimizing nutrients, energy costs, and incoming toxic shocks to a process, as well as optimizing the living biomass inventory.”

caSE One of the largest paper machines in Rus-sia was recently modernized, but following the

start-up it was found that extractives from the birch pulp used at the site was having a negative impact on runnability. Following the introduc-tion of Kemira’s pitch control solution, which includes Fennodispo 320 and Fennofix 41 chemicals, the problem has disappeared and the

machine has been breaking all its previous speed and output records.“This is a great example of what Kemira’s local

organization in Russia and our experts in Finland can achieve by working together to solve a customer’s

problem,” says Customer Service Engineer Konstantin Khudozhilov.

Short Cuts

Q&AMarcelo costaSouth American Research and Development Center Manager, São Paulo

What are your main goals regarding the South American marketplace?“Our main goals initially will be to initiate a tech-nical customer service (TCS) for Kemira’s customer industries in South america, with a focus on water-intensive processes. This will mean developing our capabilities for carrying out product development and R&D activities for specific regional needs to open up new markets and new customers, and building a strong network with local customers and research institutes.”

Are you going to develop some new research areas? When will the Center start operations?“We expect eco-friendly processes to grow rapidly in the region, and the R&D Center will cooperate with universities and institutions in this area. We hope to start up the center during Q4/2010. We see future R&D looking at areas like biorefineries linked to the sugar cane industry and pulp mills, and membranes and desalination technologies for the partial closure of industrial water cycles, drinking water supply, and deep water drilling.”

What is your own professional background?“I have over 12 years of experience in the pulp and paper industry. I transferred to Kemira from a Suzano pulp and paper mill, where I was process manager and responsible for process optimization. Before Suzano, I worked for several years at mills operated by veracel and Cenibra pulp. I earned my ph.D. in 2001 and completed an MBa in 2003.”

What is it like living in São Paulo? What about your personal life?“São paulo is a very cosmopolitan city and a great place to live. as traffic congestion is a big problem, it’s very important to live near where you work, so once we’ve decided where the lab will be we’ll be moving close by. I enjoy swimming, fishing, and spending time with my family on the weekend. I like travelling and meeting people from around the world, and I've enjoyed my stay In Finland very much.”

text Jussi-peKKa auKia photos gettyiMages, Jussi-peKKa auKia

Kemira at Expo 2010 in Shanghai

Kemira will take part in the shanghai World’s fair in 2010 as one of the part-ners in finpro’s finland at expo 2010 project. the event – which will focus on the theme of Better cities, Better life – will run from the beginning of May to the end of october and is expected to attract over 70 million visitors. pho-tographs from a competition organized by Kemira and finland at expo 2010 in fall 2009 will be featured at the event to give visitors a view of life in finland and the importance of clean water in today’s world.

See you there!

Kemira is set to showcase its capa-bilities at a number of trade fairs next spring. We will take part in tissue World americas in Miami between March 24 and 26 and in asian paper 2010 in Bangkok between april 21 and 23; and we will be back in the us, at papercon ’10 in atlanta, between May 2 and 5.

Clean technology from Finland

Kemira recently joined the clean-tech finland program to promote its water-related customer solutions. the program brings together top finnish cleantech companies and experts in a new type of network and will provide concrete marketing and communica-tions support for profiling Kemira as a leading cleantech company in the field of water quantity and quality manage-ment.

the cleantech concept covers all products, services, processes, and tech-nologies that prevent or reduce man’s harmful impact on the environment – and is designed to promote better quality, efficiency, progress, effective-ness, and profitability.

text JeNNi seppoNeN photo MiiKa KaiNu

"I've come to like the finnish sauna and I would like to try snowboarding during my two-month stay in finland.”

Focusing on water and energy efficiencyNEWS Optimizing water and energy usage is becoming increasingly important for the pulp and paper industry. as a leader in water chemistry, Kemira is ideally placed to help its customers optimize their processes, water quality, and water consumption (WQQM). Kemira will continue to focus on further developing its unique capabilities in this area and its presence in regions where the pulp and paper industry is growing the most: apaC countries, South america, and Eastern Central Europe.

“We’re committed to improving our long-term profitability and strengthening our competitive position through a regional approach based on understanding the needs of different regions and offering a product portfolio designed for these needs. We want to understand our customers needs even better and adapt our operations rapidly to meet them, and seize new opportunities that emerge in a marketplace where things are chang-ing all the time,” says Petri Helsky, president of Kemira’s paper segment.

Record production in Russia

4 Kemira Solutions 52 | 2009

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Successful start-up for the microbiology lab in Leverkusen

the new laboratory began opera-tions as planned in May, managed by professor dr. olof Norrlöw and his colleagues. Based at the r&d center in leverkusen, germany, the new facility is part of moves to concen-trate Kemira’s r&d functions into five centers operating as a global, company-wide network. the labora-tory handles a very wide range of different types of samples and works particularly closely with the labora-tory in espoo, fnland to compare analysis data and develop strategies.

in addition, the lab routines focus on technical customer service for the microbial process control at Kemira's production site in leverkusen. the target of the new lab is to develop and offer tailor-made solutions for microbial process control to custom-ers of different production segments based on the right product combina-tions and engineering know-how.

ABTCP fair 2009

Kemira took part in the 42nd aBtcp fair organized in saõ paulo by the Brazilian pulp and paper technical association (aBtcp) in conjunction with the finnish paper engineers' association. the four-day event, the largest of its kind in latin america, attracted 163 exhibitors and 8,200 visitors.

“aBtcp 2009 was a very good place to consolidate our relationship with our customers,” according to Luiz Leonardo, paper sales senior Manager – south america. “More than 300 visitors visited our stand, from plant operators to senior execu-tives, which helped make the event a great success for us.”

look at the big picture

The 2/1999 issue of Kemira Solutions fea-tured an article on a biocide project at UpM-Kymmene’s Jämsänkoski mill in Finland. The mill’s process Manager, Matti Taimisto, told readers about his water usage philosophy in a sidebar to the main article. Reducing water consumption was already an important target in the industry.

“Even though water volumes, as such, are not a problem in Finland, attempts are being made here to cut water consumption as well, for environmental and image reasons. When reducing water consumption, care needs to be taken that solids emissions are reduced as well. Water quality can be a problem.

“Reducing total water consumption, and the use of cooling water in particular, is an impor-tant objective − and can be achieved by things such as circulating process water through cooling systems.

“new technologies can help cut water con-sumption, but energy consumption shouldn’t be forgotten either. Great technical solutions can easily increase power consumption, so you always need to look at the big picture when planning water use. In addition to optimizing energy and water flows, attention must be paid to wet-end chemistry as well. The main goal is to improve the operating efficiency of paper machines, in terms of their runnability and efficiency. When managing the totality of a process, everything affects everything else.”

Short Cuts

R&D Center in Atlanta up and running

rESEarch The opening of the latest addition to Kemira’s R&D capabilities was celebrated in Sep-

tember. Located in the centre of atlanta in the Technology Enterprise park alongside the Georgia Tech campus, the atlanta R&D Center has global responsibility for oil, mining, tissue, recycled fiber, defoamers, and polymer research and will be a key part of Kemira’s global R&D network. The Center

consolidates the expertise of four separate north american research locations under one roof and is

intended to promote new levels of synergy between academic research and commercially focused technology

and product development.

10 Years Ago

text Jussi-peKKa auKiaphoto Katri taMMiNeN

Lower demand decreased revenueNumbErS Revenue at Kemira’s paper segment de-creased by 14% in the third quarter of 2009, to €230.2 million (2008: 267.7 million), as a result of a significant slowdown in demand from the segment’s custom-ers. Consumption of newsprint, magazine paper, and printed advertising material was lower in traditional core markets in Europe and north america in particu-lar. Management estimates that demand has fallen by 10–25%, depending on paper grade.

The segment recorded an operating profit, exclud-ing non-recurring items, of €14.8 million (2008: 11.7 million), equivalent to a net operating profit percent-age of 6.4% compared to 4.4% last year. Lower fixed and variable costs compensated for the decline in sales volumes. paper segment revenue for the first three quarters of the year, at €676.8 million, was 11% down on 2008 (756.5 million).

Q3 | 2008

Q3 | 2009

267.7million

230.2million

4.4% 6.4%

Net operating

profit

Net operating

profit

New JV in China gets off to a good startNEWS Kemira and the Chinese company, Tiancheng Ltd., set up a joint venture in January 2009 to produce aKD wax and aKD size for the paper and board industry. Kemira has a 51% holding in the company – known as Kemira-Tiancheng Chemicals (Yanzhou) Co., Ltd – and Tiancheng 49%. Operations have got off to a good start and demand for product has developed well.

6 Kemira Solutions 72 | 2009

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getting more out of your

energy inputsAlthough the pulp and paper industry has already implemented all the easy ways to save energy, there are still a number of opportunities out there for making more savings.

energy it uses is a critical issue for

the pulp and paper industry.“Energy costs are rising all the time and the

price the industry pays for its energy is fluctuat-ing to an increasing extent. new power lines and energy market consolidation are pushing up the cost of electricity in areas where prices have typically been low, such as northern Europe,” says Research professor Kari Edelmann of vTT Technical Research Centre of Finland.

“alongside this trend, we’re seeing a parallel drop in profitability in the industry’s mature markets in Europe and north america, despite the cuts in overcapacity that have been made recently.”

Rising energy and raw material costs are eating away at the industry’s ever-smaller margins and undermining its potential to invest in the future.

“and we shouldn’t forget that energy is still cheap in many places compared to what it’s likely to cost in the future. as a result, cutting energy consumption and greenhouse gas emis-sions is critical.”

Energy-saving strategiesGreenhouse gas emissions can be reduced by making use of new sources of bioenergy, such as harvesting residues and internal waste streams, and by improving process efficiency. The latter will not be easy, however, according to Edelmann, as modern processes are already quite efficient. virtually all the ‘easy’ solutions have already been implemented in Finland, for example.

Making additional savings will become increasingly expensive.

“at some point, we’ll need to start looking at completely new approaches, and this will call for a radical rethink of processes, machine de-sign, chemistry, and the way machines are run. The challenges here include the operation of the wet end at significantly higher consistency and temperature or how to operate the process with smaller amount of water. There will also need to be adjustments in process and additive chemistry.”

automatic control and measurement systems and new types of ‘proactive’ systems can help in

On Topic

reducing how much

text Jussi-peKKa auKia photos MiKKo VÄhÄNiitty

“recycling water and air saves energy.”

Kari Edelmannis a research professor at Vtt technical research center of finland, and responsible for coordinat-ing Vtt’s strategic research on energy usage in papermaking processes. he has over 30 years of experience in r&d in the forest products industry.

8 Kemira Solutions 92 | 2009

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To the Pointtext tiMo hÄMÄlÄiNeN photo gettyiMages

fennobio s chelating agent, based on the aES molecule, has recently

been officially registered as a new substance with the REaCH regulatory system, introduced by the EU to reduce chemicals-related risks and provide better protection for human health and the environment.

The registration process involving the Euro-pean Chemicals agency (ECHa), which is based in Helsinki, was a long and involved one. part of the reason for this was that Kemira did not want to register aES as a formulate but as a pure substance.

Eliminating unwanted metalsChelating agents are used to remove metal ions that undermine bleaching performance from pulp. Kemira began studying and developing biodegradable chelating agents in the mid-1990s with the aim of producing a more eco-friendly al-ternative to existing products for removing trace copper, iron, and manganese from mills’ pulp streams. This work generated some completely new molecules and a number of patent applica-tions. among them were two molecule patents where the aES (aspartic acid Etoxy Succinate) area was included.

Developing products based on one’s own pat-ented molecules is pretty rare in industry. Glo-bally, only some 20-30 molecule patents appear a year. Companies generally patent formulations produced by blending existing raw materials to create a unique combination that can be used in a customer’s process.

Kemira was given special dispensation under previous chemical regulations to develop

Fennobio S, based on the aES molecule. Mill-scale tests showed that Fennobio products were capable of solving the key problems associated with traditional EDTa and DTpa chelating agents.

Multiple benefitsWhile EDTa and DTpa are very efficient in binding metals, they decompose slowly and find their way into rivers and lakes via water treat-ment plants. They are suspected of releasing harmful heavy metals, such as cadmium, mer cury, and lead, from bottom sediment. as a result, the environmental authorities have imposed increas-ingly tough restrictions for their use.

Biodegradable Fennobio products do not have this problem. They also contain only about a third of the nitrogen that EDTa and DTpa do. This means that they also reduce the nitrogen content of the mill effluent.

When using EDTa and DTpa, it is generally recommended that a separate chelating stage should be used to remove iron and manganese from pulp. This is because the metal complexes of EDTa and DTpa act as catalysts for decom-posing bleaching chemicals such as hydrogen peroxide.

Thanks to their completely different chemical composition, Fennobio S products can be dosed directly into a mill’s bleaching process, avoid-ing the need for a separate chelating stage. This makes it easier to simplify the pulping process and introduce closed water cycles. Some trials have also shown that the use of Fennobio im-proves the bleaching performance compared to EDTA and DTPA. •

Kemira’s patented biodegradable chelating agent is the company’s first product to be registered as a new substance under the European REACH chemical regulation system.

An eco-friendly alternativeenhancing process energy efficiency.

“another approach could be to simplify things, by minimizing intermediate stor-age, for example. Eliminating these buff-ers would improve the control you have over a process. at the same time, though, it presents some major new challenges to system capabilities.”

Systematically monitoring energy us-age is critically important to improving energy-related performance.

“process operators today don’t really un-derstand the impact the choices they make have on a line’s energy efficiency or why some mills achieve better performance and how. Better monitoring would teach operators to improve the energy efficiency of the way they run their machines.”

Reducing heat lossEverything that is put into a process will come out of it at some point. The majority of the energy lost by a modern paper mill is channeled through cooling and exhaust air or effluent as it passes through treatment plants on its way to local waterways. The temperatures involved here are relatively low, as all the hotter streams have already been addressed.

vTT’s extensive modeling work on the energy and raw material streams typical of today’s mills has shown that around 80% of the material input of a modern integrated site takes the form of air, which is pumped back into the surrounding atmosphere at some point.

“around 75% of the energy used by a modern mill is expelled from the process via its cooling air. Technologies that are capable of reducing this or that can recover the heat it contains as efficiently as pos-sible will be in great demand in the future.”

Heat pumps are one of the technolo-gies that can address this; the use of heat exchangers will also grow. Employing these units in hot, corrosive areas full of process contaminants will require the use of new materials and efficient deposit manage-ment, however.

Other potential savingsvTT has looked at many other approaches to saving energy as well, including such things as wood fractionation and more energy-efficient mechanical pulping.

“Using process water for cooling would bring some real savings, for example. preheating raw water in different parts of a process by making use of heat that would otherwise be lost makes it possible to get something out of even low-temperature water.”

Installing a wet end hood would enable moist air to be recycled there. Excess mois-ture could be removed by scrubbing units if necessary.

“Turbo fans could be used instead of annular water pumps in vacuum drainage systems in environments with a higher process temperature and could raise the temperature of exhaust air to a level where it could be used for heat recovery purposes. Doing this, though, would call for solving a number of questions, particularly things like how to avoid or manage airborne dirt.”

Raising the moisture content of air inside dryer hoods can reduce steam usage, although condensation risks are involved here.

“There’s some potential for savings in the design and dimensioning of pumps and other equipment. It also makes sense to look at whether we can find passive alter-natives to the components that currently consume a lot of the energy used by today’s fast paper machines.” •

Summary

There are still a lot of opportunities left forreducing the energy intensity of the pulpand paper industry:- Improving the efficiency of unit operations- Developing new types of processes- Improving heat recovery techniques- More advanced control, measurement, and monitoring systems.

"In terms of overall energy efficiency, the best solutions are those that do

not generate waste heat that is difficult

or impossible to recover", says Kari

Edelmann.

10 Kemira Solutions 112 | 2009

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of clean water, environmental

concerns, and ever-rising energy prices are continuing to encourage the forest products industry to improve the efficiency of its energy and water usage. The more efficient a mill is in these areas, the bigger the cost savings it can achieve.

Cutting back on water and energy usage in mill processes goes hand in hand, as a large proportion of the energy a site uses is transferred to its water in the form of heat. The more a mill recycles its water, the greater the amount of energy absorbed by the water can be recovered. any water piped off-site represents a massive loss of energy.

Recycling water is particularly important in areas where clean water is in short sup-ply, such as Central and Southern Europe, and even more so in asia. Mills further north do not face the same problem, but they too are keen to increase the amount of water they recycle and reuse.

Recycling water brings with it a number of problems, however. The more closed a process cycle is in terms of water usage, the higher the concentrations of various

substances in its water will be, and the greater the amount of compounds that will precipitate out.

Water temperature will also tend to rise, corrosion problems will increase, and the size of microbial populations will grow as well, thanks to the warmer conditions.

Managing the water cycleIn principle, the best thing would be to close processes completely in terms of their water cycle, according to Kaj Jansson, vice president of Common Chemistry at Kemira Research and Development. So far, however, only a few mills producing some unbleached board grades have been able to do this. all the others producing both pulp and paper recycle water in varying degrees.

“all mills have the potential to improve their water and energy balance, whether we’re talking about sites producing chemical or mechanical pulp or ones using recycled fiber or deinking waste paper. The challenges involved are big, though, as processes need to be closed in a well-man-aged and cost-effective way.

When a mill begins investigating how it can recycle more of its water, it first needs

saves energy tooPulp and paper mills have improved their water and energy usage significantly by recycling their white water, but recycling has its limits. The less water a process uses, the more well-managed its chemistry needs to be.

“in principle, it would be best if we could close the process completely.”

Analysis

limited sources

text tiMo hÄMÄlÄiNeN photos gettyiMages and KeMira

to look at the areas where fresh water is essential and where suitable recycled water can be sourced from. The right filtrates for the right parts of a process need to be iden-tified and whether they can be used as such or whether they may need to be treated, chemically for example or not.

“Clean water is normally essential in the final stages of a process to ensure the qual-ity of the end-product. ‘Dirtier’ water can be used in the early process stages, though.”

a general rule is that it is most cost-effective and efficient to remove pollutants where they are generated. But not always.

“European mills using recycled fiber and those producing board, as well as deinking units, often recycle their water only after

it has passed through their wastewater treatment plants. Typical volumes vary between 10% and 20%. The reason for this is that they rely on biological treatment to remove the organic matter that builds up in water flows to ensure that this does not promote the growth of microbial colonies, cause production problems, and undermine product quality,” says Jansson.

“Some mills producing unbleached board recycle all their waste water after biological treatment. They often use anaerobic treat-ment to reduce the organic load from the water, and because it produces methane, which can be used as energy. The prob-lem here, however, can be that the entire system can become very anaerobic, which

Saving Water

12 Kemira Solutions 132 | 2009

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the same time, we also look at whether the water would need to be treated in some way,” says Jansson.

“We also carry out lab tests to check how much different filtrates would need to be treated to bring the concentrations of problem substances they contain down to the required level. The results of these tests are fed into the simulation model, which can then tell us whether we will achieve the targeted reduction in water and energy usage with the parameters we’ve selected.”

Making the most of energy recoveryalthough the forest products industry has been able to improve the efficiency of its processes significantly over the years, there are still a lot of opportunities left in this area.

In Finland, the amount of water used per tonne of output has been roughly cut in half since 1992, and the amount of water used by paper machines has fallen by a third in the last 10 years.

producers of chemical pulp typically use around 35 cubic meters of water per tonne of pulp at the moment, while mechanical pulp mills use less than 20, deinking units less than 10, and board mills less than five.

Jansson expects these figures to move down further in the future, thanks to things like new film technologies capable of removing the harmful components that build up in recycled water.

“We’ll also probably see more biologi-cal treatment being used in the recycling chain. The popularity of anaerobic treat-ment is set to increase, because of the methane benefit. Some mills are already generating 5–10% or more of the energy they need from this methane.”

Jansson also believes that evaporation technology has more to offer. The draw-backs here are its high energy requirement and problems keeping equipment clean with certain types of water. Evapora-tion plants are simple and hard-wearing, however, and can handle large amounts of water easily. The sludge they produce can be burned directly as fuel as well.

“In the future, we’ll also see solutions in which water that’s passed through biologi-cal treatment is then sent through local marshland for further polishing. I wouldn’t be surprised to see green methods like this increasing over the next couple of decades.”

Enhancing the efficiency of energy recov-ery is also important. One option is to send treated waste water to other facilities, such as market gardens and fish farms, which can recover the heat it contains.

“Heat can also be recovered using heat pumps or heat exchangers. The right chemi-cals can help keep their surfaces clean to maximize their overall efficiency.” •

usually results in an increase in corrosion problems and a drop-off in the dewatering performance of board machines caused by anaerobes.”

You’ve got to know your chemistryKemira has been involved in numerous development projects aimed at closing mill water cycles, often in partnership with an equipment manufacturer.

“It’s good to have a manufacturer on board from the start, as this enables us to develop a maximally stable, reliable, and cost-efficient system from the very start.”

Jansson emphasizes that when closing water cycles it is always important to evaluate physical, chemical, and biological factors.

“You need to identify the substances that have a tendency to cause deposits and in doing so upset a process. These sub-stances – typically extractives and calcium carbonate – need to be removed from the filtrate using chemicals. The process can be enhanced using flotation, evaporation, and filtering. These ‘kidneys’, as they’re known, can be installed at suitable locations around a mill.”

a similar approach is used when look-ing for chemical techniques to prevent problems developing on the biological side, such as build-ups on machine and pipe surfaces. Chemicals can be used to improve the efficiency of a biological treatment plant by eliminating the substances that impact its operation, such as reduced sulfur compounds and extractives.

You need to know your white water chemistry in detail to avoid selecting chem-icals that will only make problems worse.

“Chlorine-based products can easily lead to increased corrosion, as their concen-trations in process water will rise, while sulfates can cause odor issues in anaerobic treatment units if water is recycled too much. Some substances can easily cause deposit problems when they react with each other, while others can encourage the growth of microbial populations.”

When looking at a major project, Kemira’s specialists always evaluate the entire process before doing anything.

“We can use a mill simulation model to see which parts of a process it would be best to take water from for recycling and where it would be best to return it to. at

Analysis

Summary

industry is recycling an increasingly large pro-portion of its process water today. this is not without its problems, however. as processes become more closed in terms of their water cycle, concentrations of contaminants tend to rise, as do water temperatures.

Many sites have the potential to further improve their water and energy performance, and that includes mills producing chemical and mechanical pulp, those using recycled fiber, and deinking units. the challenges are significant, however, as water cycles need to be closed in a controlled way that is also cost-effective.

Kaj JanssonM.sc. (eng), has been responsible for numerous water research-related projects at Kemira since the mid-1990s. he is currently Vice president of common chemistry at Kemira research and development.

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The amount of raw waterused by the pulp and paper industry today has dropped to a fraction of what it was 50 or 60 years ago. as much as 60 to 70 tonnes of water were needed to produce a tonne of paper in the 1950s, for example, while the best technology today can produce a tonne of paper with only 6-8 tonnes of water, and as little as 2 tonnes of water are needed in the case of fine paper.

“the first flocculent-based clarification basins were introduced in the 1960s. they were followed by systems designed to separate cooling and white water from each other in the 1970s, when biocides were introduced. the 1970s–1980s also saw the launch of biological wastewater treatment, the recycling of filtrates, material recovery, and the use of fixatives to bind problem substances into the paper web,” explains research professor Kari edelmann.

“a little later, we saw the introduction of washing presses in paper mills, and the reuse of cooling water. the counter-current principle was introduced for managing white water streams soon after. and by the 1990s systems were be-ing introduced that were capable of managing process fluctuations, as well as internal treatment systems within mill processes. the new millennium has seen engineers begin developing balanced water networks based on sophisticated control and expert systems.”

Theme Spread

the ankkapurha rapids in the river Kymijoki around 1900.

text Jussi-peKKa auKia photo M.l.carsteNs (ca 1900), the collectioN of the NatioNal Board of aNtiQuities

16 Kemira Solutions 172 | 2009

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committed to

QualityTurkey’s largest packaging board producer is committed to quality, in its products, its technology, and its choice of partners.

Case

packaging board plant is located in Çorlu, roughly 100 kilometers from Istanbul. part of

the Eren Holding Group, the plant is Turkey’s largest and most modern papermaking facility and also a significant player on the European market.

Mill production Manager Sirzat Açikgöz explains that the growth in the plant’s capacity in recent years has been driven by the rapid expan-sion of demand in the marketplace.

“We started up our first board machine, pM1 in 1981 and this was joined by a similar-sized unit, pM2, 10 years later. Both are 100,000 t/a units. With the coming of the new millennium, we invested in a new 200,000 t/a machine, pM3, and last year we started up our biggest machine yet, pM4, with 400,000 t/a of capacity.”

Modern Karton produces over half of Turkey’s 1.4 million t/a requirement for unbleached packaging board.

The Çorlu mill occupies a 530,000 m² site, of which 130,000 m² are under cover. The location is excellent, as the majority of the mill’s test liner, corrugating medium, and white top liner goes mainly to custom-ers in the Marmara region, which also supplies the bulk of the mill’s recycled input.

Being large is not all plain sailingÇorlu’s pM4 is Turkey’s largest paper machine, and its pM3 the country’s second-largest. pM4 virtually doubled the mill’s capacity at a single stroke, and its speed has been steadily increased, and it is now running at some 85% of its baseplate capacity. Capacity levels have been partly affected by the ongoing global economic crisis.

Modern Karton has always believed in making use of the best avail-able technology and pM4 is no exception, but its size has called for a number of changes in mill operations to make the best use of its capabilities.

“We understood early on that standard solutions were not going to be sufficient to boost capacity and develop the quality of our output with this new fast and efficient machine,” says açikgöz.

Modern Karton’s

text Jussi-peKKa auKia photos arif Mustafa zade

“We want to achieve the best European standards when it comes to both efficiency and quality, and we believe we will. Our approach is to concentrate on problems and bottlenecks one at a time, resolve them, and then move on,” says Mill Production Manager Sirzat Açikgöz (on the

left). Mill Maintenance Manager Bülent Binat (on the right) stresses the importance

of efficient maintenance as part of good mill management.

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Working together helps improve raw material quality the average per capita consumption of paper in turkey is very low. in the country’s large cities, however, such as istanbul, which has a population of 14 million, consumption runs at european levels. Modern Karton depends on a partner supplier to source its recycled raw material.

“the recycled paper we get from turkey is of a better quality than the material we can buy from the european spot market, which we do buy sometimes. one of the reasons for this is the good partnership relationship we have with our local supplier and the fact that their personnel is well-trained,” according to Çorlu’s Mill production Manager Sirzat Açikgöz.

“in the future, the government wants to regulate paper collection more closely to ensure that the original source of the material can be tracked easily and help prevent chemical residues from ending up in the wrong products, for example. But it won’t bring any improvements for us, as we already operate to these higher standards.”

Case

•ModernKartonproducesoverhalfofTurkey’srequirementforunbleachedpackagingboard.•KemiraisresponsiblefortheretentionanddewateringchemistryofbothPM3andPM4,which areTurkey'stwolargestpapermachines.

Summary

“So we set about looking for partners in paper machine clothing, felts, and chemi-cals that could offer us a high standard of product support and expertise, and would be able to tailor their products to our needs where needed.”

One of the partners Modern Karton selected was Kemira, which is responsible for retention and dewatering, the key aspects of wet-end chemistry, for both pM3 and pM4.

“Getting the most out of pM4 is a key issue for us. We’re keen to keep on im-proving its productivity, runnability, and the quality of its end-product by working together with our partners. Kemira has a wide range of products that enable us to adapt to even small changes in running conditions, such as the charge level of our process.”

açikgöz has been very satisfied with Kemira as a partner in this respect.

“Kemira provides us with regular technical support, and their local support personnel can call on Kemira’s exten-sive international expert network when needed. Kemira regularly takes samples from our process to analyze and passes on all the data to us as well.

“We’re papermakers, so we only know the main parameters when it comes to

chemicals. That’s why it’s very useful to be able to sit down together and go through test results with Kemira and identify pos-sible problems and decide how we should proceed.

pM3 was the first machine at Çorlu to switch to using Kemira’s retention system, but pM4 followed soon after. Handling the switch-over in this order made the testing process a lot cheaper and safer, says açikgöz.

“Larger-capacity machines mean faster and faster running speeds. Retention and drainability quickly become key factors. The strength and homogeneity of our products are already very good, and we want to see our efficiency and quality rank among the best in Europe.”

Recycling saves resourcesTurkey follows the EU lead in envi-ronmental legislation, which means that operating permit limits are getting tougher all the time, and this is one of the reasons why a producer like Modern Karton is keen to invest in the latest pro-duction technology that offers the best in resource usage.

This has seen Modern Karton become a pioneer in the environmental field in Turkey.

“alongside the pM4 project, we also invested in an advanced wastewater treat-ment facility. We recycle the water treated here in our process. In the case of pM4, over 60% of the water treated is returned to the machine, which means that we only use less than four tonnes of water for every tonne of board we produce,” says açikgöz.

“The treatment plant is the first in Tur-key to use anaerobic digestion to process sludge. The biogas produced is used as fuel in our natural gas-fired power plant to generate electricity and steam. We use specialty Kemira chemicals to dewater the plant’s sludge.”

The mill uses groundwater for its water needs. Quality water is a limited natural resource, as it is in many other countries, and the Turkish government is monitor-ing and restricting usage to an increasing extent.

“Our permit sets a maximum of 870 mg/l COD for the effluent leaving the mill, but thanks to the new treatment plant the ef-fluent leaving pM4 has a COD content of only around 200 mg/l now.”

Reducing water usage brings its own limitations, however, as too high a COD content in white water will eventually

impact runnability. The effluent running from pM4 to the treatment plant has a COD content of 5,000 – 10,000 mg/l.

“You can begin to experience runnabil-ity problems if white water COD content exceeds 7,000 mg/l, and by 10,000 mg/l you can encounter serious problems on the production line. COD is one of our most important parameters for making the most of our potential to treat and recycle water.”

Efficient and integratedThe most important reason for ensuring that the mill has a modern production infrastructure, according to açikgöz, is to keep everything running smoothly.

“Runnability is the main parameter when it comes to getting the most out of the efficiency offered by pM4, which means that effective maintenance man-agement is very important,” continues Mill Maintenance Manager Bülent Binat.

“That’s why we’ve introduced a proac-tive system at the mill, and why mainte-nance issues are discussed with operations people at our weekly meetings. This helps ensure that we have a good produc-tion program for the week ahead and that maintenance and operations work

together as smoothly as possible.”problems in any part of the integrated

process at Çurlu, from raw material sourcing to sales, are likely to become expensive. at the same time, the inte-grated nature of the mill’s operations is one of Modern Karton’s strengths. Some of the board it produces is converted into corrugated board-based packaging in an adjacent plant, for example.

“Modern ambalaj, one of our Group companies, buys around a quarter of our output,” explains açikgöz. “The remain-ing three-quarters goes to other Turkish producers, and some volumes even go for export.”

açikgöz says that end-product quality is often a more important factor than price in Turkey, as it is elsewhere. The extended width of pM4 makes it possible to supply even large roll sizes both flexibly and cost-effectively. Many customers have various other special requirements as well. Which is why Modern Karton focuses on quality as one of its main selling points.

“We tried producing poorer-quality product for the low-price category, but had problems, as we ended up with run-nability issues, so that wasn’t for us,” laughs Açikgöz. •

getting the most out of pM4 is a key issue for us.

The extended width of PM4 makes it possible to supply even large roll sizes both flexibly and

cost-effectively.

Sirzat Açikgöz, in the middle, with the proud team running PM4.

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increased dry strength with

Fennobond 4000Kemira’s new, special dry strength additive is more efficient and stable, has a higher solids content, and works better in packaging than the conventional alternatives. The product launch is expected next year.

Bernd Hauschel says that the existing

technologies do not work efficiently in board production and recycled furnishes. This was the need driving the develop-ment of Kemira’s new strength additive, Fennobond 4000.

The project dates back to the beginning of this decade. Hauschel led the devel-opment work in those days, as he does today.

“We picked it up again in 2007 with people from R&D and from the product line, and came to the conclusion that we should take a closer look at it. We did the upscaling very quickly in two months, and it worked very well. Since then, we have been working on the product’s fur-ther development,” says Hauschel.

The laboratory development work was done by Kemira's R&D in Leverkusen in Germany and the upscaling in vaasa in Finland.

Stable and effectiveTwo primary goals were set for the project: the first was to create a stable product with a high solids content.

“The competing products currently available have a low solids content and remain stable only for weeks. Fennobond 4000, on the other hand, has a shelf life of up to six months and has a much higher solids content than its competitors. Fen-nobond’s greater stability and higher solids content make the distance to the customer a much less critical factor.”

The second goal was that the product should be efficient in recycled furnishes, where the existing chemistry is not effec-tive. Strength improvement in packaging materials offers huge potential.

“It took eighteen months to two years to really develop the recipes, including about nine months of intensive laboratory development work. now we're looking at the stability of the formulation and improved versions of the product.”

A completely new technologyThe main innovation of the new technol-ogy is the combination of two types of polymers.

“The product is a chemical combination of a natural polymer and a synthetic poly-mer. It’s not just a question of mixing the two – the chemical process is such that we benefit from both. The resulting product has a higher solids content, is more stable and efficient, and works better in packag-ing.”

Hauschel points out that the product is still in the development phase. Different versions for board and paper could be developed later, for example.

“The strength enhancement depends on the paper grade, furnish quality and the particular property in question. Currently, it is between 5 and 50%. Clean systems and rather strong fibers benefit the most. It’s more difficult to add strength in dirty systems with high conductivity.”

The new technology also brings indirect cost savings.

“Savings might come through increased filler loading or the replacement of expen-sive kraft pulp fibers. In packaging, they might also be derived from surface starch replacement. This reduces the need for energy in the post-drying section and also the number of breaks. Using less wet-end starch gives better drainage, and that ena-bles faster-running paper machines.”

at the moment Fennobond 4000 is be-ing produced in Europe, which is the pilot market for the application’s development. Later, it may be transferred to north america and asia.

“We have not yet launched this of-ficially within the company or on the market. We're currently building up expe-rience from trials for further development of the appli cation. The product launch is expected in 2010.”

Bernd Hauschel is also a team leader for wet end chemicals, which combine not only strength and retention but also drainage and sizing. He predicts that Fennobond will be an important part of Kemira’s wet end portfolio.

“I think it’s very important that we develop a good product line for dry strength enhancement. Filler loading and fiber substitution using lower quality fiber will be a general and ever-growing trend in the industry.

“The paper industry is always looking for ways of cutting its costs. Suppliers can help them in this process. Strength enhancement has the potential to play an important role here.” •

R&D

team leader

text Jussi-peKKa auKia photo MiiKa KaiNu

Synthetic dry strength chemicals

havebeenavailablesincethe1970s,andtherearecurrently a handful of options for enhancing the strength of various paper grades and reducing raw material costs.

In printing and writing, dry strength chemicals are mainly used to increase the filler content. In the packagingandboardsegment,theyareusedtogivemore strength to products made of recycled and otherlesserqualityfibers.Theycanalsobeusedtomanufacturelighterweightproductsormakeitpos-sibletouselowerqualityandcheaperrawmaterial.

22 Kemira Solutions 231 | 2009

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v

and paper industry has striven for years to clean up its internal systems and effluent

streams. Tighter municipal, regional, and national regula-tions have forced the industry to adopt practices designed to reduce the environmental impact of mill operations.

Kemira’s Research Scientist John Martin says that these improvements have not come without their costs, however.

“Closing process cycles, which has led to the increased use of recycled water, has left pulp and especially paper mills to deal with a myriad of issues, such as higher operating temperatures and increased dirt and pitch.”

Defoamers that can take the heatHigher operating temperatures on paper machines are a growing trend in the industry, and can lead to foam and entrained air control issues when using traditional water-based defoamers.

“Historically, water-based defoamers were the product of choice for paper machines that ran at temperatures below 50 °C. However, due to the melting point of the waxes and fatty alcohols used in water-based defoamers, which is around 40–50 °C, these products are not as effective at higher operating temperatures.”

To address this issue, Kemira has recently developed a new series of water-based defoamers to alleviate the problem.

“The new technology offers effective foam and entrained air control at temperatures up to and even exceeding 70 °C.

This innovation also provides customers with an alternative to using oil-based and water-extended defoamers in their processes at elevated temperatures.”

An oil-free alternativeThe use of traditional oil-based defoamers has never been problem-free. Oil and EBS are routinely found in pitch deposits, both in machinery and in paper, and residual defoamer in pulp can lead to downstream quality issues.

“These typically come from over usage or poor product placement in the system, or both. Because of these issues, water-based defoamers are the preferred product.”

The use of the appropriate product at the appropriate place and time is crucial in preventing runnability and quality issues.

“By offering a line of water-based defoamers that provide effective foam and entrained air control at higher tempera-tures, and providing the application and operational knowl-edge to use the products, we are providing a cleaner option to traditional chemistries,” says Kemira’s Defoamer product Manager Ricky Dixon.

“By removing EBS and oil from the paper machine, the new Kemira defoamers are helping to provide higher-quality products, improved runnability, lower pitch deposits, lower dirt counts, and lower volatile organic compounds, while maintaining foam and entrained air control at the higher operational temperatures seen on today’s paper machines.” •

text Jussi-peKKa auKia photo gettyiMages

cleaner

systemsCleaner pulp and paper processes are now possible thanks to Kemira’s new high-temperature water-based defoamers.

At Your Service

Comparing the technologies

traditional water-based defoamers are typically formulated with fatty alcohols or waxes, or both, which have a relatively low melting point range (40 – 55 °c). the defoamer in figure 1 is formu-lated with a fatty alcohol that has a melting point range of 50 – 57 °c, and demonstrates that once the melting point of the wax is reached, the efficacy of the defoamer decreases dramati-cally, resulting in lower initial knockdown and quicker foam recovery.

Kemira’s new high-temperature defoamers provide better initial knockdown and better longevity at higher temperatures when compared to traditiownal water-based defoamers. figure 2 demonstrates the efficacy of one of Kemira’s new high-temperature defoamers at various tem-peratures. Note that while the knockdown and longevity is affected by the increase in tempera-ture, the performance drop observed between 40 °c and 70 °c is relatively low when compared to traditional water-based defoamers.

When tested head to head at equal solids dosage, the performance advantage of the new Kemira defoamers at higher temperature becomes apparent. figure 3 demonstrates the knock-down and longevity advantage of Kemira’s new water-based technology at 70 °c.

Kemira’s new line of high-temperature, water-based defoamers enables the customer to remove eBs and oil from their system by eliminating the need to use these substances for foam and entrained air control. figure 4 shows the performance one of Kemira’s new defoam-ers compared to a traditional oil-based paper machine defoamer containing silica and eBs. the results show an increase in longevity – control of foam build over time – with the use of the new derefoamer and over an oil-based defoamer containing eBs and silica at 60 °c.

the pulp

figure 1: Performance of a traditional water-based defo-amer at varying temperatures. Shorter run time and higher foam height means lower performance, longer run time and lower foam height means best performance.

figure 2: Performance of a Kemira high-temperature water-based defoamer at varying temperatures.

figure 3: Traditional water-based product compared to one of Kemira's new high-temperature water-based products at 70 °C.

figure 4: Kemira’s new product compared to a paper machine defoamer containing oil, EBS, and silica.

-10 10 30 50 70 90 110 130 150

70°C 60°C 50°C

40°C

Foam

Hei

ght

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Foam

Hei

ght

Time (sec)

0 20 40 60 80 100 120 140

70°C 60°C 50°C

40°C

Traditional @ 70°C High Temp @ 70°C

Foam

Hei

ght

Time (sec)

0 20 40 60 80 100 120

Foam

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0 20 40 60 80 100 120 140 160 180

Oil Based Defoamer

Kemira’s new product

figure 1

figure 3

figure 2

figure 4

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Water is the

Best BiocideM-real’s Äänekoski board mill in Finland has been involved in testing and developing Kemira’s new slime control concept from the start. The concept has been commercialized – and successfully – as Fennoclean L.

Partnership

Kalle Viljanen remembers

the ‘father’ of biofilm research at Kemira, Marko Kolari, visiting the mill to take samples back when he was working on his ph.D. thesis. Kolari’s find-ings made their way into a product in 2005, when Fennosurf 300 was selected for short circulations.

“It was around this time that we started taking a harder look at how clean things were in our machine, drawing people’s attention to the need to keep splash areas clean, and started carrying out more systematic washing routines. We also switched to washing surfaces with hotter water. all in all, we learnt that even the best biocide cannot keep a mill clean on its own, you also need thorough and regular washing routines as well.”

Operations Manager Mikko Hietanen stresses that there is a limit to how much you can increase your usage of biocides in any case, because of the costs involved and the residues that build up in end-products.

“Following the introduction of Fennosurf 300 and thanks to various other measures, we’ve been able to extend our wash interval from a couple of weeks to four to five weeks today.”

Mill Manager Petri Vakkilainen brought the concept of using run-time washing units and large quantities of washing water to the board machine from paper production, where odor and taste issues are not generally a big issue, but

where runnability is a major priority.“Increasing the number of washing units was

an excellent fit with the new biocide philosophy focused on combating biofilm formation. Together, these two changes were what it took to put an end to the conventional boardmaker’s ‘wisdom’ that washing cycles have always been run every two weeks and always will be.”

Combating microbe colonization using biocides is always a question of getting the balance between the problems caused by the microbes and those caused by the residues from the active ingredients in the biocides right, continues vakkilainen.

“Water is the best biocide, if only you can spray it where the microbial colonies are growing. That’s the reason why we’ve installed new spray nozzles throughout the process and why we’ve also been one of the pioneers of continuous ‘kidney’ technol-ogy. When you can stop surfaces getting contamin-ated in the first place, your biocide system will keep them clean between your maintenance outages.”

Increasing the amount of run-time washing does not increase a machine’s overall water usage per tonne of output either.

“Extending our washing intervals has improved our productivity significantly,” says Mikko Hietanen. “We’re now able to coordinate our washing outages with our normal maintenance outages, rather than the other way around.”

development engineer

Kalle Viljanendevelopment engineer, Äänekoski board mill, M-real

Mikko hietanenoperation Manager,Äänekoski board mill,M-real

petri VakkilainenMill Manager, Äänekoski board mill,M-real

text Jussi-peKKa auKia photos haNNe NyKÄNeN

Joni Välimäkiarea Manager,Kemira

KALLE VILJANEN:“We have been moving towards a greener approach to combating microbial coloni-zation for some time. And it’s a move that has saved us money as well.”

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A pioneer always takes a riskKemira’s Joni Välimäki admits that shift-ing from simply eliminating microbes where and when you can to a new anti-slime philosophy based on dealing with the select few bacteria that actually cause biofilm to form in the first place was something of a risk for the company.

“We couldn’t be completely sure in advance that the scientific data would actually translate into results in mill conditions.”

Kalle viljanen says that the choice to go with the new concept was taken with everybody’s eyes open and jointly.

“We decided to go out on a limb and put the theories that had been developed in the lab at the University of Helsinki to work for us at the mill. The proposal to do this came from Kemira, and by being part of the trial we were able to be in on something that no one else knew any-thing about. We were very up front with Kemira, as they were with us.

“The efficacy of anti-slime measures had previously been measured simply by measuring the numbers of colonies of bacteria swimming in white water,” he continues. “We took the bold step of turning this at least partly on its head. We didn’t say no to monitoring micro-

bial levels, but we emphasized that what was most important was to keep surfaces clean.

“and it proved the right way to go, as it has improved our efficiency and the quality of our end-product.

all our products today, whatever they’re intended for, are now suitable for packing foods containing fats,” confirms vakkilainen.

“Chocolate products are a real yardstick here in terms of quality, as even the small-est taste issue with packaging can result in major financial repercussions for our customers. Our approach is that nothing we do on our board machine or with the chemicals and systems we use in conjunc-

...withadevelopmentprojectaimedatenhancingthequalityofthemill’scoatedfoldingboxboardbyimprovingitsbrightnessandweight.Thesuccessoftheprojecthasreinforcedthemill’sreputationforhigh-quality,food-gradefoldingboxboardamongcustomersinthetobacco,alcohol, pharmaceutical, and chocolate industries.Productionmachineryandthemill’soverallprocesshavebeenupgradedonaphasedbasis.

Theboardmachine,withtheexceptionofitswetend,wasmodernizedin2002,anditsrawmaterialinputswitchedtoBCTMP.Theprocesswasswitchedfromanacidonetoaneutralonesometimebeforetoimprovequalityandrunnability.KemirahadsuppliedÄänekoskiwithbiocidesformanyyearspriortothestartoftheproject,

andonceitwasunderwaycooperationbetweenthetwocompaniestookonanewdimension.

Everything began around the beginning of the new millennium...

Partnership

tion with it can be allowed to cause those kinds of problems.”

The tough demands associated with these types of board products also impact the mill’s chemical supplier.

“What it means for Kemira is that we have a much smaller palette to work with in microbial control here than we do in other areas of paper and board produc-tion,” says välimäki.

An ongoing partnershipThe partnership between Kemira and the mill has every potential to be an ongoing one, believes petri vakkilainen.

“Kemira is helping us supply our cus-tomers with products that are problem-

free and offer consistent quality, and they can optimize their own processes as part of this. They make things easier for us, and that’s something we want to pass on to our customers.”

To ensure process continuity and eliminate unexpected problems develop-ing, Kemira carries out checks on agreed parts of äänekoski’s process at regular intervals to see that everything is working as it should.

Kalle viljanen describes this monitoring process as a joint one.

“In addition to normal customer service routines, we also hold more extensive follow-up meetings every couple of months even when there aren’t any prob-lems. We’re all committed to continually optimizing the process and our costs and getting everything running even better than it is today.”

“as part of this, we also do more with our analyses than we used to,” continues välimäki. “We pay a lot of attention to making sure we measure the right things in terms of process and end-product per-formance.”

Mikko Hietanen has been very satisfied with the improved reliability and predict-ability of operations that has resulted from the mill and Kemira working together.

It has made it easier to plan maintenance outages and things like switching felts and wires more efficiently.

“When we no longer have to ‘budget’ for emergency shutdowns and things are better planned overall, our maintenance people have more time to concentrate on what they’re doing. We can now plan our fall outages well in advance. Everyone realizes the benefit of not having to shut down the machine because of microbial issues.”

“We both share common goals: to extend our wash intervals, improve how we monitor the state of our surfaces, and ensure that our process stays aerobic,” says viljanen.

Real progressFollowing its last modernization, the output of the board machine at äänekoski has increased from 160,000 t/a to 210,000 t/a, although average grammages have dropped.

“We haven’t needed any major invest-ments to achieve this, we’ve just consist-ently focused on developing our opera-tions,” says Mikko Hietanen.

“Efficient slime control has been one of the factors that’s made this possible, among other things. When you eliminate

one problem, you’ve got more time to deal with the other ones.”

petri vakkilainen says that the pressure to succeed has been pretty heavy, as M-real has invested a lot of money in the mill.

“perhaps that’s also one reason why we’ve been a little more receptive to new solutions and technologies than the average. In a situation like this, it’s very important for a supplier to understand where things stand and where they can help, and not just try and get us to buy more of what they’re selling. Kemira understood where we wanted to go and what was important for us and leveraged all their expertise to help us get there.”

Joni välimäki believes that the partner-ship between the two companies has been very successful from Kemira’s standpoint.

"We’ve moved forward together very systematically. Recently we’ve started focusing on logistics, procedures, environ-mental issues, and occupational safety."

“The world’s changing and new things are coming up all the time,” says petri vakkilainen. “But when you come down to it, it’s not really about the technical side of things. When a supplier under-stands what’s important for a customer like us, then we understand what’s impor-tant for them as well." •

PETRI VAKKILAINEN:“Our cooperation with Kemira has gone so well, in fact, that although their people have been making regular visits to the mill for a long time now, I’ve never had much cause to note down their names or keep their cell phone numbers handy.”

JONI VÄLIMÄKI:“The work we’ve done here has opened up opportunities for fennoclean applications on other M-real machi-nes, and this has been to both our advantages, I believe.”

MIKKO HIETANEN:“It took us some time to sell all the additional capacity of the modernized machine, and this gave us the time we needed to put all our productivity-related matters in order. When the machine was running at full output, no one really had a problem about extending our washing intervals.”

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retention system is an all-in-one solution for enhancing dewatering ef-

ficiency, cutting energy costs, and optimizing the furnish mix. product Line Manager Kimmo Strengell says that demand for Kemform technology, which was patented three years ago, has grown strongly, and it is now in use at multiple mills around the world producing both printing paper and packag-ing board.

In fact, Kemform has become the undisputed flagship of Kemira’s retention product offering.

“Thanks to Kemform, mills can achieve up to a 10–15% sav-ings in energy usage as a result of improved dewatering. Stud-ies have also confirmed that filler content can be increased by 2% in fine paper products,” says Strengell.

“Kemform works equally well with both new and old machines. In the case of new machines, the benefits tend to be seen in better overall productivity, while lower energy usage will be the biggest benefit in older setups with limited dewatering capacity.”

a Kemform system is typically made up of two or three components: inorganic microparticles, either bentonite or col-loidal silica, and micropolymers, which are normally anionic in fine paper applications and cationic in packaging ones. The third component is Fennopol retention polymer.

Strengell says that applications based on colloidal silica seem to be growing in all segments, particularly in the fine paper area.

“Our ‘three-dimensional’ Fennosil micropolymer, dosed in weak solution, plays a central part in Kemform solutions, as it results in significantly better dewatering performance than conventional ‘two-dimensional’ polymers,” he explains.

“Fennosil polymers also contain hydrophobic end groups that bind to hydrophobic substances in process water, such as pitch, stickies, and fine particles coated in pitch. In the application, this results in less foaming in the process."

Greater product strengthKemform was initially developed for use in machines produc-ing fine paper, and its first trial runs were done on these. Following its commercialization, it was tested on some cus-tomers’ packaging board machines. The good results achieved with these encouraged Kemira to continue development work to extend Kemform’s scope to board production.

The key benefits Kemform offers in board production are reduced energy usage, as a result of improved dewatering, and an increased level of dry content in the web after the wet press section and further downstream.

“a high level of dry solids after the wet press improves board strength, and makes it possible to keep the elastic modulus as high as possible,” explains Strengell.

“Elastic modulus is an important metaparameter for board manufacturers, as it tells you a lot more about a product’s stiffness and other strength-related characteristics than peo-ple generally realize.”

Kemform helps keep elastic modulus as high as the strength potential inherent in the fiber being used will allow, in fact.

Each fiber has strength potential as it is. a sheet matrix is formed from the fiber raw material. The final elastic modulus of the matrix is dependent on formation, wet pressing, draws, and drying.

“Board mills typically run headbox consistency very low. Typically half of that used when running fine paper for ex-

text and photo Jussi-peKKa auKia 3d-illustration Metso

adding strength and

saving energyKemira’s Kemform retention system was originally developed for use in fine paper production. It also has a lot to offer for board producers.

Kemform has become the undisputed flagship of Kemira’s retention product offering,” says Kimmo Strengell.

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the Kemform

ample. Floc size remains small when using Kemform, and this makes it possible to maintain or improve formation even when operating at a higher consistency in the HB than normally. This translates into better energy efficiency and strength.”

Using Kemform also makes it possible to reduce draw when the paper web travels through the dryer process. The reeler at the end of the dryer runs faster than the wire by a factor of few per cent and reducing this difference, by 50% for example, will improve the strength properties of board significantly.

“Thanks to Kemform, the dry solids of the web leaving the wet press will be higher and the web itself will be stronger. This makes it possible to keep tension between the wire and the wet press and the wet press and the first drying section as small as possible.

“The smaller the total draw, the smaller the loss of elastic modulus will be,” says Strengell.

In terms of dewatering efficiency when producing board, it is important that a mill

can achieve as high a dry solids content as possible from the suction roll stage onwards. Kemform typically increases dry solids by 1%, from 17% to 18% for example. This reduces the amount of water trans-ferred to the press and ensures that the press will operate more smoothly.

“If a wet press is operating near the upper limit of its hydraulic capacity, this represents a clear production bottleneck and Kemform offers the perfect solution. Let’s not forget that the wet press is a key component of many paper machines when it comes to the strength of the products they produce.

“If there’s too much water in the nip, it will be squeezed out along the length of the web (x-y direction), reducing the elastic modulus of the board. Ideally, it should travel along the z-direction in the wet press. Efficient wet pressing is the cornerstone of good operations and good end-product quality when producing board. Kemform offers an excellent solution here."board. Kemform offers an excellent solution here.” •

The Kemform retention system gives the web good wet press strength, which is valuable in delivering an optimum level of board perfor-mance. A modern press section designed for board machines, a Metso ValPress, can be seen here.

30 Kemira Solutions 312 | 2009

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Let’s do it!

Try some recycling technology for yourselfIf you want to see how water will absorb itself into a piece of thread and start moving around, put a couple of containers of water on a table and dye the water different colors using food color. Then place a piece of cotton thread between the containers as shown in the illustration, ensuring that the thread is slightly submerged below the surface of the water. It will only take a minute or two before you will see the water getting on the move!

photo gettyiMages illustration tuuli raNta