Research & Innovation
Keep It Simple… and Smart
By Pulp & Paper Canada
The challenge of designing and building the new TMP line at Stora Enso Port Hawkesbury (SEPH) in Nova Scotia was to provide a high quality furnish for the newsprint machine PM1 with a budget that refl...
By Pulp & Paper Canada
The challenge of designing and building the new TMP line at Stora Enso Port Hawkesbury (SEPH) in Nova Scotia was to provide a high quality furnish for the newsprint machine PM1 with a budget that reflected the reality of the severe economic climate. In the end, not only was the challenge met, but the resulting project introduced a new design of TMP and proved to be the fastest start-up for a TMP line.
How did Port Hawkesbury do it?
It was a question of attitude and careful preparation. Throughout it all, potential problems were circumvented through design solutions created by the project team. For example, during commissioning meetings, the motto for overcoming any difficult situation was: “But, of course!” and it was this attitude towards solving problems that created the right dynamics for the success of the project.
A mill modernization study was started in January 2001 and was finished by the end of August that year. Under the direction of Tor Suther, the mill president and general manager, an overall study was conducted, involving the potential direction of the entire mill, from infrastructure, supply chain, customer base as well as marketing the end product in the U.S.
“The purpose was to decide the future structure of the mill,” explained Seldon MacKenzie, manager of Development Projects. He said a large part of the focus was on the furnish and product of PM1.
One of the recommendations of the study suggested that the best option for the PM1 line was to supply all the machine’s furnish through the installation of a new TMP line. This would rationalize and streamline the mill’s pulp production. An option for de-inking was rejected and it was decided to have virgin fibre-based TMP because of the abundant supply of spruce and balsam in the area. This meant that Port Hawkesbury was to become a totally TMP-based mill (with the exception of continued purchased kraft and clay for the PM2 SC machine).
However, the economic environment dictated that a different approach was needed than with the first thermomechanical pulp plant. That TMP plant, a two-line state of the art installation by Andritz for producing pulp for top quality supercalendered magazine paper, had been built under different conditions. It was part of a large new production line producing SCA+ and a key driver was to accept only proven solutions with minimal technical risks.
“No one will likely ever build one like it again,” smiled Seldon ruefully. “It had all the bells and whistles and now no one could afford it. This time around, we needed to follow a very simple plan.” This meant, he explained, that each piece of equipment and process had to be looked at carefully and analyzed for its function and importance in the total design. For example, high consistency reject refining was not included. Instead Port Hawkesbury opted for 3-stage mainline refining with low capacity, low consistency rejects treatment. Pulp cleaners were also deleted from the flowsheet.
Jan Lauritzen, manager, TMP, Clay and Kraft, agreed, “The whole industry has to make it simpler — it’s the only way to go.”
So the challenge was to be as capital efficient as possible with a simplified TMP that required a limited amount of equipment.
The 2001 study had been done with consultants from Jaakko Pyry.
“In the fall and winter of 2001 and in the spring of 2002, we made inquiries for new TMP quotes,” said MacKenzie. A decision was made to enter into co-operation with KSH in 2002, should the project be approved. This included the definition study and also the start of an “open-book” study for engineering, procurement and construction (EPC).
By late summer, a portion of the study was used to present the potential project to the corporate investment group of Stora Enso for approval in London, England. The plan was well-received but the decision was deferred until 2003 until certain hurdles were overcome, notably reductions in wood, power and personnel costs. This resulted in a six month delay in final project approval until agreements on these issues had been resolved.
“We used that six month opportunity to ‘refine’ (excuse the pun) the TMP concept and perform more detailed pre-engineering,” said MacKenzie. “Thus we were ready to stick the spade in the ground as soon as we got the OK. This way, we didn’t lose those months and it proved very advantageous since we took the time to work on this very unique concept.”
The project was approved on January 30, 2003. The bidding for the main equipment had started already in 2002. The main layouts and building design were well advanced upon project approval. Therefore, early civil works and main equipment purchasing started in February 2003, and, as MacKenzie said, “the construction was jumped right into” during March 2003.
The new single line TMP consists of three stages of Metso CD 82 mainline refiners and a simple low consistency refining treatment of screening rejects (low rate of 5% reject by mass). The cost was approximately CAD 90 million. “This concept provided the lowest capital cost/tonne for any plant built in North America in the last 15 years.” said Fred Hussey, vice president Engineering/Services.
The reasoning behind the selection of Metso was the high availability with the proven capacity. The highly-successful example of the modernization of Papier Masson, QC, was studied and MacKenzie admitted that it was a big influence in the decision-making.
“We had the best solution to offer,” Jean Pierre Bousquet, Metso process engineer for the mechanical pulping line, who was in charge of the commissioning for Metso at Port Hawkesbury. “The objective of the project was to satisfy the customer who wanted the lowest dollar per tonne. We had the performance package.”
And it was a ‘first’. “No one has ever loaded the secondary or tertiary refiner like we have,” said Bousquet.
A bagless disc filter from Voith, made in Poland, meant never having to change the bags; this enhances the availability of the plant.
Although there were delays in the final stages of construction, which created a larger overlap in commissioning and construction than desired, MacKenzie said “we made it up with an exceptional start-up.”
The first chips for refiner commissioning runs were on August 18, 2004 and the plant produced the first pulp to PM1 newsprint machine on September 27th .
Although this was three weeks later than planned, the start-up was a jumpstart. “We turned the key and we ran,” said MacKenzie proudly, since the project is proving itself very quickly on capacity, availability and quality. The new plant is already producing 750 ADMT/day through the mainline refiners and the mill expects to exceed the 780 ADMT/day design capacity.
“We attained our target efficiency in early November of 95%,” MacKenzie continued, “just six weeks after first pulp to PM1.”
“Six weeks from the first production of pulp – it’s never happened before,” said Lauritzen. “People said it couldn’t be done since the one closest took 30% more time. We brought different people together and we did it!”
“We’re capable of making design capacity and we expect to surpass that rather easily in the new year,” MacKenzie said. “The line was designed for 780 ADMT/day and Metso expects that we can reach 900. We see potential for higher and are challenging Metso to work towards 1000 ADMT/day on a single line TMP.”
“Because of the simplifications,” explained MacKenzie, “we didn’t lose anything. We gained capacity, reliability and integration with the existing system.”
Power is always an important consideration for a thermomechanical mill because of the tremendous quantity needed. It is a constant challenge to keep energy prices down and avoid times of higher prices.
“We can also do corrective action but we never have to stop PM1 for
lack of pulp,” said Bousquet. “Any shut-downs are mostly power-related. We can adjust our power consumption level by 30 megawatts because of the contract with the power company and we can help them maximize their power consumption while minimizing their cost.”
Port Hawkesbury uses software that enables real-time energy decisions. The added advantage to the current higher capacity is the possibility of load shifting. The control room is manned 24/7 to monitor prices and enable temporary adjustments in production depending on confirmed energy prices. Power interruptions are still a factor but the power can be bought at optimal price taking this into account.
Everyone at the mill was very proud of the TMP project safety record which spanned 555 days with no lost time accident. This was recognized by the government of Nova Scotia Labour Department and the project was given a place by the Minster of Labour and Environment. [ed. note; see Safety Matters, on page 62].
Continuing with the vision
“The TMP project was only part of the modernization study, the rest was a whole development plan for the mill, a strategic plan for 2002-7,” said MacKenzie. “We’re sticking to that plan, pretty well.” There were more upgrades to the existing TMP, a new rewinder for PM1, a new raw water treatment (provided by John Meunier), a new demineralizer plant, a new stores warehouse, as well as new debarking drums for the wood room, among other miscellaneous projects. Ongoing installations include a new chipper from Metso and a de-icing deck for the woodroom from Andritz. Studies continue on a fossil fuel-free vision for the Port Hawkesbury mill, using only biofuel.
The new stores warehouse facility is modelled after the airline industry and is probably the most sophisticated you’ll see in the pulp and paper industry. “We now deal with 25,000 parts, down from 35,000. Efficiency is up,” says Lauritzen. “Every part has a special place, easy to find through the computerized system.”
Asked how everyone worked together, Lauritzen answered, “Certainly the performance has surpassed expectation.” He had a very positive view of the human element of the project that was supported by the evident outcome of the project. “If you enjoy work and you are given the right conditions, you are productive,” he said. “People should be supported and then they are happy and productive.”
“It’s a very open mill,” said MacKenzie. The door swings both ways. You have to let people out to learn something from others and you have to reciprocate and let others in for them to learn something….It’s give and take.”
When asked if he would do it again, Jean Pierre Bousquet replied, “But of course!” He compared starting a new installation to having a baby. “It is painful,” he explained, “but once you have it, you are so happy and proud!”
Brent Gillis, superintendent, TMP, clay and kraft, was very positive about the entire experience. “One of the biggest things I noticed was the commitment of everyone to improve the design, layout, ease of maintenance,” he said. “Everyone strove to come up with the best TMP-line in the world.”
“I’m glad that the soon-to-be the highest-producing and most efficient TMP plant in the world is in Cape Breton,” added the native Cape Bretoner.
As Seldon MacKenzie summarized, “It’s rewarding when the project goes well from the get-go.”
Stora Enso Oyj is an integrated forest products company producing magazine papers, newsprint, fine papers, packaging boards and wood products, based in Finland. It employs some 42,000 people in more than 40 countries on five continents.
Stora Enso North America is North America’s leading producer of coated and supercalendered papers for the printing and publishing industries. In addition, Stora Enso North America produces specialty papers used for consumer product packaging and labelling, and manufactures cores and coreboard products. The division produces elemental chlorine-free kraft pulp, totally chlorine-free mechanical pulp and recycled pulp from printed pre-consumer and post-consumer scrap papers.
Port Hawkesbury mill, located in Nova Scotia, has been in operation since 1962. Today its capacity is 185,000 tonnes of newsprint on PM1 and 360,000 tonnes of supercalendered (SC-A+ and SC-A) paper on PM2. Since the start-up of PM2 in 1998, the SC paper machine had reached several world daily speed records at 1600, 1700 and 1800 meters a minute. Approximately 85% of the paper production goes to the U.S. and the remainder within Canada.
SEPH is on the Strait of Canso, one of the deepest, ice-free ports in eastern North America, provides easy access, by land or sea, to North American publication paper markets. Stora Enso North America’s sales and marketing organization has had great success introducing high-quality supercalendered paper to these markets.
The Woodlands Unit achieved a milestone when it became the first forestry operation in North America to get approval for both Canadian and American environmental certification for its Sustainable Forest Management.