Environment & Sustainability
Eliminating the bad days Is the key to success for Donohue Saint-Felicien
By Pulp & Paper Canada
By Pulp & Paper Canada
The mill recently installed the first Tubel concentrator in CanadaDonohue’s Saint-Felicien, QC, kraft pulp mill has enjoyed a number of firsts since it opened in 1978, but the secret to its success, a…
The mill recently installed the first Tubel concentrator in Canada
Donohue’s Saint-Felicien, QC, kraft pulp mill has enjoyed a number of firsts since it opened in 1978, but the secret to its success, according to mill manager Lucien Desmarais, is not the all-time high production days, but eliminating the bad days. “We don’t care about the thousand-tonne days, but we care about the 300- or 400-tonne days.”
Designed for 700 tonnes per day (t/d) when built, capacity is now 950 t/d. The mill was able to boost production to 950 t/d, not all by capital equipment installations, but by eliminating the “bad days.” For two months in 1998, the mill averaged 1000 t/d, but this was done under optimum conditions, Desmarais added, “We started the month with full tanks and the wrappers done.” In the last couple of years, the mill averaged 942 and 956 t/d.
The mill has a reputation for producing high-quality bleached softwood kraft pulp. Desmarais said the mill has “run like a clock” since Day One. There are various reasons for this. First was a good “basic design” by British Columbia Forest Products which was a partner with Donohue when the mill opened. (Donohue purchased BCFP’s shares during the recession of the early 1990s.) Or, as Desmarais described it, “an improved Mackenzie mill” (the kraft pulp mill in Mackenzie, BC, now owned by Fletcher Challenege Canada).
High-quality fibre — 80% black spruce, 20% balsam/jackpine — is important. Proven equipment was selected. Of course, at the time, this meant pneumatic equipment, so the mill is in the midst on an ongoing, multi-million dollar automation project. Finally, there are the people. Although the plans were to hire experienced people, Desmarais said that 60% of the employees had never seen a mill prior to being hired. An intensive training program helped overcome the lack of experience. The mill was one of the first to institute this type of program in which manuals were developed with the help of a consultant. Now, a new program is being developed (see sidebar).
Good housekeeping also plays a part. For a 20-year-old mill, it is in pristine condition and many Canadian mills could take a lesson from it.
This all has led to a consistency, from fibre to equipment to operation which leads to high-quality pulp and an enviable reputation. Desmarais credited BCFP again. “It knew kraft; Donohue was a newsprint company.” He added that once the mill was built, BCFP took a “hands-off” attitude, letting the “locals” operate it.
Desmarais has been with Saint-Felicien since 1980 and mill manager since 1984. For an industry that seems to change mill managers more often than losing hockey teams change coaches, this is another remarkable accomplishment. He spoke of the pride of the 320 employees and their desire to succeed. At the beginning, there were many skeptics, he said, who claimed kraft couldn’t be made in the Lac St-Jean region. Now, 20 years and five million tonnes later, the mill is still pushing the envelope. And, to top it off, a Price Waterhouse benchmark study in 1997 showed Saint-Felicien to be the lowest cost producer among 29 softwood kraft pulp mills in Canada. This is despite the mill’s relatively high chip costs. Desmarais points with pride to a long list of firsts. Among them:
First metric mill in Canada.
First ISO 9003 mill in Quebec (9002 was granted in 1994).
First mill in Quebec to generate 80% of its energy needs from biomass; it is now at 100%.
One of the first mills in Canada to use lagoons for effluent treatment (from start-up).
First Eka Chemicals saltcake washer (SCW) in North America. All sulphuric acid is now recovered from the process. The Eka Chemicals equipment complements the mill’s SVP-LITE chlorine dioxide plant.
First Quebec mill to integrate pulp making operations with woodlands and sawmills. The mill uses 100% chips, 90% of which come from six Donohue sawmills. The mill receives up to 200 truckloads of chips per day.
First Tubel (Tampella Power, now Kvaerner) concentrator in Canada.
Since start-up, Donohue has not hesitated to put money back into the mill. “We’re always updating and looking to improve,” Desmarais said. The Tubel installation is one example. The primary goal was to increase the solids content going to recovery while upgrading the liquor cycle. The recovery boiler was a bottleneck. Also, the existing concentrator was creating mechanical problems, specifically, cracks in the dimple plates, which were causing production losses. In June 1995, following another plate failure, the mill chose the Tubel system with conversion to be done on a fast-track basis. Steam and recovery superintendent Jean Belzile said the unit adds the equivalent of an extra effect to the five-effect evaporation process the mill uses. The Tubel falling film-type concentrator brings black liquor concentration to 70% from 50% and the mill can go as high as 72%. The Tubel increases capacity in the evaporators by 800 L/min.
Steam consumption is lower because with no cracks in the evaporator, no steam escapes. With an increased solids content, the recovery boiler needs less air; the fans were at maximum before, Desmarais noted.
As technology advances, dated equipment can cause process bottlenecks. Saint-Felicien has invested to remove these as they happen. The addition of the Tubel removed one bottleneck in the evaporator. Improvements to the pulp machine such as the installation of a booster dryer (done “on the run”) raised dryer capacity by 16%, thus removing another. Now, Desmarais said the digester can “hold things up.”
The digester has held up remarkably well for 20 years. It was stress-relieved during construction. The mill uses a high-pressure water wash, never an acid wash. It is inspected after each wash and has never needed an inch of welding. “It is still in perfect condition,” Desmarais said with pride.
The digester has just been updated as part of an ongoing mill-wide automation project. Donohue will spend more than $30 million over the next eight years to replace all its pneumatic systems with a Foxboro I/A distributed control system (DCS). Desmarais noted that despite the lack of automation, pulp production was still less than two man-hours per tonne.) He added that the increased automation will not affect the level of employment. The improved efficiency and chemical savings will pay for the project. Foxboro also supplied field instrumentation which is integrated into the I/A system digitally. Remote maintenance work can be done from a console.
The burner management systems for the recovery and power boilers as well as the chip handling system, digester and diffuser washer were the first parts of the process to be automated. In the future, the following will be updated: in order, boiler operations, evaporators, bleaching, liquor cycle, causticizing and, finally, the pulp machine. Foxboro’s Roger Evans noted that the mill took a systematic approach to system control, developed a plan and went through with it.
Walsh Automation was responsible for all aspects of the engineering and construction of the automation project that have been completed. This included transferring controls to the new system — I/A and Allen-Bradley programmable logic controller, advanced controls — as well as design engineering (cabling, junction boxes, PLC cabinets) and the configuration of the DCS and PLCs. As supervising contractor, Walsh Automation was responsible for specifying the equipment but the mill chose the supplier.
Walsh Automation Inc. project manager Marco Gerbeau said the preliminary engineering was done in 1994-95. This covered the entire mill. For the first part of the automation project — burner management system — Walsh was also responsible for the training. The training effort for the digester automation was designed in-house but Walsh participated. A simulation software package that simulates all the I/Os was used. Since the digester started up with the new controls, Desmarais said, “It has worked like a charm.”
One feature of the digester’s advanced supervisory controls is cooking modelling that can h
elp optimize digester performance. Not surprisingly, the operators are eager for the change and this will be a major part of the new training program.
Composite tubes were installed in the recovery boiler in 1985. The mill runs a fairly closed process and there had been serious corrosion problems. The mill has spent “millions” according to Desmarais replacing panels of tubes. However, it did not use composite tubes on the floor of the boiler which, in hindsight, considering cracking problems other mills have had, is a blessing. There are about 40 ft of composite tubes in the recovery boiler which, Desmarais added, is in “good shape”. The Combustion-Engineering (now ABB) boiler has three air levels and four fixed nozzles. It produces 243 000 kg/h of steam but can go up to 263 000 kg/h.
Environmentally, the mill has also been a pacesetter. “While everybody was building lagoons and installing precipitators on their recovery boilers, we were making pulp because we already had these things,” Desmarais said. “Our money went to improve our mill.”
Recently, an electrostatic precipitator was installed on the bark boiler, low-odor equipment was installed on the recovery boiler, more aerators were put into the lagoon and $629 000 was spent on a turpentine recovery project. The mill has the option of burning (in the lime kiln) the pure turpentine it recovers or selling it. The decision depends on the price of oil or the price the mill can get for turpentine.
The mill’s environmental numbers are good. Total reduced sulphur (TRS) levels have gone from 0.16 kg/t in 1994 to 0.05 in 1998. Solid waste went from 45 kg/t to 28 kg/t from 1994 to 1997. Total suspended solids (TSS) levels went from 7.9 kg/t in 1991 to 3.2 kg/t in 1997, while BOD levels have dropped from 8.3 kg/t to 3.7 kg/t in the same period.
The mill started making elemental chlorine free (ECF) pulp in 1991 when it boosted chlorine dioxide production to 37 t/d. This allowed it to shut the chlorine plant and it did not have to eliminate chlorine use by stages. Its pulp did not suffer any brightness loss in the change; it is now at 89+ ISO.
What’s next? The mill is looking at oxygen delignification but, as Desmarais said, AOX levels are already low (0.3 kg/t) so would O2 delig really help?
“I had to go to New York two years ago,” Desmarais recounted, “to make a presentation to Time Magazine in response to environmental pressures. We have to please our customers’ customers. I had to show all our programs: silviculutre, harvesting, mill operations and energy consumption.”
Another project the mill is now looking at is Lo-Solids cooking. Studies are underway with Ahlstrom and close to a million dollars will be spent. One of the reasons is strength. Although Desmarais said the mill’s pulp is already strong, if it wants to increase that strength, it may use Lo-Solids cooking. “We do not want to be seen as a commodity. We don’t want people to be able to replace our pulp with something cheaper.”
He said that the mill is in a “good trend” because its pulp is stronger than it used to be thanks to recent projects. The pulp is also cleaner thanks to the addition of five banks of Celleco Cleanpac 350 cleaners and an RCC (rejects concentrator). This was done to attract new customers.
End products for Saint-Felicien’s pulp include fine papers, LWC, news and hygienic products. The mill’s biggest customer is the Champion Papers’ mill in Bucksport, TN. Kruger’s Trois-Rivires, QC, mill is another large client. About 33% of production is shipped to Europe via the nearby port of La Baie on Lac-St-Jean. The rest is shipped by rail or truck to customers in eastern Canada and the northeast US.
Due to its distance not only from its customers, but also from its suppliers, the mill must keep an extensive inventory of parts on hand, some $5 million worth, according to Desmarais. “We must be careful,” he added, as for most equipment, there is only “one of everything.” Therefore, a failure of a simple part such as a small pump could cause a total mill shutdown. Partnerships with some suppliers that have operations in the Lac-St-Jean region have helped reduce inventory.
Maintenance crews work eight-hr shifts, production 12 hours. This is the way it has been since start-up. At night, there is one shift millwright and one electrician. There are no full maintenance shifts on weekends. Desmarais said the mill is “reliable” as is the equipment because the crews “work on it.” It is a point of pride for them.
Since 1978, two millwrights have been dedicated to vibration analysis. The mill has changed its analysis equipment three times in that span. “We believe in prevention,” Desmarais explained. As for flexibility, the mill uses the principle: “What can you do at home?” The mill moved into this controversial issue slowly. “We don’t need or want a pipefitter to be a welder when the mill is up,” Desmarais said.