A brand new greenfield mill has put the Baltic state back on the world pulping map
June 2007
By Justin Toland, Editor
My grandfather was a pulpmaker. It was because of I him I studied pulping," explains production manager, Estonian Cell, Lauri Raid. "For me it is an honor to work here. We are bringing Estonia back to the pulp Globus -- back among the pulp nations."
The return of large-scale market pulp production to Estonia was not an overnight process. Norway's Larvik Cell had the notion to build a pulp mill in the country back in 1999, recounts chief financial officer, Estonian Cell, Riia Ratnik. In 2000, possible locations in the towns of Türi, Kehra and Kunda were scouted out. The following year detail planning started. However, following an environmental impact assessment in 2002 and demands from the authorities for a sulfur-free process technology, Larvik Cell decided that rather than transferring a second-hand 40,000-tonne/yr neutral sulfite semi-chemical (NSSC) pulp line from a site in Denmark, it would build a greenfield mill using best available technology.
This new direction entailed bringing additional shareholders on board -- Austria's Heinzel Group and the European Bank for Reconstruction and Development (EBRD), each owning one-third of Estonian Cell.
In 2004, a long-term lease was signed for an 80 ha plot in Kunda, a town 110 km east of the capital, Tallinn, on Estonia's north coast (the mill occupies 35 ha -- the rest of the site is protected forest). Contracts with suppliers were signed and work began on the site in September of that year. The mill started up on April 24, 2006.
Construction was carried out on a turnkey engineering, procurement and construction (EPC) basis by KSH, the Canadian subsidiary of Germany's RWE. "The cooperation was good," says Ratnik. "The contractor reached all the milestones on time. The whole project came in on time and on budget."
High-yield hardwood
Estonian Cell is designed to produce 140,000 tonnes/yr of high-yield bleached chemi-thermomechanical pulp (BCTMP) from 100% aspen. The mill uses Andritz's PRC-APMP process (the letters stand for Preconditioning Refiner Chemical-Alkaline Peroxide Mechanical Pulping). The supplier delivered the process technology, basic engineering and DCS for the complete line, from the woodyard to baling.
According to Ratnik, there is growing interested globally in the use of hardwood mechanical pulp for paper and board production. Aspen gives good bulk, opacity and high-brightness. Estonian Cell's products can be used to manufacture tissue, board, coated (LWC/HWC) and other printing/writing papers, and newsprint.
Estonian Cell sources the majority of its aspen from Estonia, also taking some from neighboring Latvia and Russia. Annual consumption is 380,000 m3, or around 2.6 m3 per tonne of product. The mill has long-term supply agreements with Estonia's state forest organization, RMK (at a fixed price), and with the private firm, Nor-Est Wood.
Estonia is a heavily forested nation (close to 50% of the territory). Aspen accounts for 7% of the volume and 6% of the forest area. "You don't go to the forest [just] to cut aspen, you go to cut birch or something else more valuable," explains Ratnik. However, the main reason for the new mill was the availability of aspen. Rather than seeing the wood exported to the Nordic countries, the Estonian government wanted to see value being added in Estonia.
The mill is using logs of 3-6 m long, with a diameter of 10-60 cm. The technology that Estonian Cell is using means that it, "Can consume adjusted quality wood, even with rot inside. We are cleaning our forests," the CFO points out.
Wood to pulp
The woodyard has a capacity of 70,000 m3. On each shift one person is responsible for loading the logs onto the line; a second monitors the process from the woodyard control room. "That's the optimum," says Raid. A third party company, VMF Qbera, evaluates wood quality, re-measuring every 100th log.
The Andritz woodyard technology begins with a RotaDebarker (1,400 m3/day). "We want a bark content of below 0.5%", explains Raid. Between debarker and chipper there is a metal detector (the line stops if there is metal in with the wood). The chipper has a capacity of 150 m3/hr. Knives are changed every day. The mill has its own knife-grinding workshop.
Bark goes to the bark shredder then to the bark stack. Excess is sold to biomass plants; sawdust from the chipping process is sold to make chipboard.
"It took at least half a year to get harmony between the debarker, chipper and bark shredder," recalls Raid. Once achieved, "The line has been working quite satisfactorily for a long time," he says.
After chip screening (oversized chips are fed to a rechipper), a chip silo acts as a buffer between the woodyard and the main process line. The silo's capacity of 10,000 m3 equates to two days' production.
The operator of the main process line also controls the reclaim system in the chip silo. Chips are transported to the pre-steaming bin in the fiber line where they are washed with warm water to remove impurities such as bark, sand and stones. After dewatering and a second pre-steaming bin, the chips are fed into a two-stage impregnation system. This comprises a chip press followed by a vertical twin screw impregnator (with retention bins at each stage). The chip press has a high compression rate to reduce COD and extractives levels and ensure efficient distribution of the chemicals into the core of the chips. Complex agent is applied in the first impregnation stage to deactivate heavy metal ions; alkaline peroxide is applied in the second stage.
Refining is by means of two high-consistency (HC) refiners. Each has a 17 MW capacity. There is inter-stage bleaching between the two refiners.
The refined pulp drops to a latency chest where it is diluted and fed into a two-stage pressure screening plant. There are two screens in the primary stage and one in the secondary stage.
The well-impregnated nature of the shives from the P-RC process allows reject to be refined in a low-consistency (LC) refiner. Accepts are dewatered on a disc filter and then a screw press. The dewatered pulp (25% consistency) is mixed with peroxide in an HC mixer, before entering the HC-Peroxide bleaching tower, where the final brightness is achieved (up to 85 ISO, depending on grade - reaction time is 90 minutes).
Bleached pulp is stored in an MC storage tower with a capacity of 1,500 m3 (eight hours of production), from where it is fed to a twin wire press that dewaters the pulp to 47% dryness. A two-stage gas powered flash dryer increases dryness levels up to 88%.
The mill's slab press is the first of its kind. Typically, the capacity of this kind of press is no more than 330 tonnes/day. Estonian Cell wanted to produce 450 tonnes/day. To achieve this aim, Andritz designed a press with a pre-compaction unit on the floor above.
The Unityer baling line also has a capacity of 450 tonnes/day. Pulp bales weighing 200-230 kg are wrapped and put in units ready for storage. The line capacity is 13 units/hr (there are eight bales per unit).
From warehouse to customer
The mill's 7,000 m2 warehouse is able to store up to 10,000 tonnes of pulp.
All of Estonian Cell's output goes for export. "Vessel is getting more and more attractive as a delivery method," says Ratnik. Kunda has its own port; for container deliveries, the mill uses the harbor at Tallinn.
Sales and marketing is done through Heinzel's international sales network. Some 37% of all production is currently exported to France. As well as the rest of Europe, Estonian Cell's pulp has also found a home in China, India and Malaysia, among other countries. "Our market will be fine tuned this year," notes Ratnik. However, she is keen to point out that, "Logistically, as most of the market BCTMP is produced in Canada, we have a clear advantage in flexibility when it comes to deliveries to European customers."
Branding also remains to be defined. "We are still looking for the optimum mix of our product range. Brand names for out high-quality products have to be found then," explains the CFO.
Estonian Cell is designed to produce everything from low freeness grades (125 ml CSF) to 450-500 ml CSF board and tissue grades. The firm's EPC contract with KSH specified that pulps of four different freeness levels must be successfully produced before mill acceptance (500, 450, 250 and 125 ml CSF). "It was good for the mill to go through these qualities in tests," believes Raid.
"One of our goals is to supply European high quality paper producers," explains Ratnik. "FSC is very important to them and is becoming more so."
Taking care of the environmental side extends to the mill's waste products. YIT Engineering built the process water and effluent treatment plant, which is controlled by a Siemens DCS. The mill takes on average 6,600 m3/day of raw water from the Kunda River. Fresh water consumption of 14 m3/tonne of pulp is one of the lowest in the industry.
Treated effluent is transported by an underground pipeline to the Baltic Sea (the mill is 1 km inland) and discharged 2.4 km from the coast at a depth of 12 m.
The effluent treatment plant also includes two DEWA sludge presses, with a combined capacity of 120 tonnes/day. The sludge can be used as biofuel after drying or as soil after composting.
As part of its commitment to international standards, Estonian Cell is in the process of securing ISO 9001 and 14001 certificates.
The role of successive Estonian governments in creating the conditions for the investment should not be forgotten, believes Ratnik. "This project has been supported by the Estonian state mentally," she says. Perhaps this is unsurprising given that, at a cost of Euro 153 million ($208 million), the mill is the second largest foreign direct investment in Estonian industry ever. Since Estonian Cell is also the country's second largest industrial consumer of energy, being able to secure long-term fixed price contracts with Estonian energy and gas companies was a key achievement. A transformer at the Kunda site links Estonian Cell to the grid. To supply the extra steam needed for startups and in winter, the mill has two 6 MW gas boilers.
Managing the process
Estonian Cell provisionally accepted the mill on September 1, 2006.'Schedule B' tests (main process, woodhandling, effluent treatment) were carried out from October 2006 until January 2007. "Andritz is still working with us on process optimization, but now we are really running independently," says Raid.
Before acceptance, the mill's operators ran the process under the supervision of Andritz and RWE. "This'learning by doing' was quite useful," believes Ratnik. "There was no large basis pulp industry in Estonia and no pulp training," she continues, so almost all employees had to be trained from scratch (production manager Raid had eight years' experience with Horizon Pulp and Paper, an integrated mill producing unbleached sulfate pulp, sack kraft and extensible sack kraft paper, located in Kehra, Estonia. "But I was new to mechanical pulping," he says.) From six months before startup, "The boys went to our'school' everyday," recalls Ratnik. Part of the training involved an Andritz IDEAS DCS simulator, while "KSH developed very useful safety routines for our plant that are not usual for small mills," observes Raid.
The mill is also responsible for its own maintenance. "Since the volume of work was unknown, we wanted to have the knowhow in-house," explains Raid.
Although the facility only has 88 employees, "The whole recruitment process was really hard work," remembers Ratnik. "There is no unemployment in Estonia -- in fact the opposite. The Estonian economy grew 11% last year."
Despite the recruitment difficulties, now the mill is up and running, the crew is really warming to its task. "People really like [managing] the process," says Raid. "This is really nice to see."
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