Plaster Rock Fires Up

A brand new biomass powered energy system is helping a long-standing sawmill in western New Brunswick secure its future. Employees at the Plaster Rock dimension lumber mill, which is owned by Fraser Papers and located in the small town of Plaster Rock, fired up the new equipment in mid-November of 2009.

The KMW combustor at Plaster Rock is an improved Scandinavian design with moveable step grates.
Paul McKinley is general manager of lumbermill operations for Fraser Papers.
A new fuel bin at the Plaster Rock mill can hold up to 350 green tonnes of bark. The new biomass energy system consumes about half of the bark produced by the sawmill.
Biomass project co-ordinator Ron Beaulieu checks system functions in the biomass control room.
Two new M-E-C dry kilns at the Plaster Rock sawmill are powered by the new biomass energy system.

At a cost of about $10.5 million, the energy system accounted for the biggest portion of an almost $18-million investment Fraser Papers made in the facility. But it hasn’t been an easy ride for the company. The upgrade project had been approved in the fall of 2008; the last log was processed on February 13, 2009, prior to the upgrade work starting. But everything came to a screeching halt four months later in June 2009, when Fraser Papers went into creditor protection. It would be an additional five months before the mill would produce another stick of lumber.

“When we went into creditor protection, we had already gutted most of the sawmill, we had started work on the energy project, and really nothing was operational except for the planer mill,” explains Paul McKinley, general manager of lumbermill operations for Fraser Papers. “At that point, there was no turning back if we wanted to run again. We had to finish the work in progress.”

The mill site and the project sat idle for approximately two months while Fraser Papers negotiated a repayable loan from the Province of New Brunswick. Securing the government financing was enough to get things rolling again; however, the markets were not so kind. Lumber prices and demand were still low, meaning that even if they could start up earlier, producing lumber would probably be a money-losing proposition.

“With the lumber markets the way they were, it worked in our favour to take our time with the project,” explains McKinley. “The good news is, that allowed us to complete this project carefully and safely, employ many of our own previously laid-off employees to do the installation labour, finish the project without incurring overtime costs, and re-open when we thought the timing was right.”

Back to Work
Once the work resumed, a team of 25 to 30 people, including the mill’s entire maintenance team, some operators, and a few helpers, started erecting the boiler and other components in the energy system and began work on other parts of the project, which included two new dry kilns that are heated by the energy system, and upgrades in the sawmill production process. On November 16, 2009 the sawmill officially started up again. By the time the planer mill was re-started in early December, about 140 people were back at work. Two shifts are now running, employing about 175 people.

“These have been very tenuous times for us,” McKinley adds. “With the support of our employees, the New Brunswick government, our owners, and our suppliers, we have been able to put some of our difficulties behind us and move on.”

Now that they are up and running again, the cost savings alone from the new biomass powered energy system, when compared to the facility’s old oil burning energy plant, will help the mill be more competitive. Prior to the 2009 shutdown, the Plaster Rock mill consumed 5.5 million litres of oil annually when running at full capacity, most of that going to run a pair of approximately 10-year-old oil-fired package boilers that biomass project co-ordinator Ron Beaulieu explains came preassembled on a skid and required only a hook-up for steam and water, and of course, oil.

“We were using the oil-fired boilers for two-thirds of our energy, and we also used four old Dutch oven biomass boilers that date back 60 to 80 years for the balance of our heat,” adds Beaulieu, who is the manager of energy projects for Fraser Papers and splits his time between sawmill and pulp and paper operations across the company. “We were using bunker C oil, which is one of the lowest priced oils on the market, but when prices peaked at around $150 a barrel, our oil costs would have been about $3.5 million when calculated on an annual basis at full capacity.”

Fuel Costs Plummet
Beaulieu estimates that with the annual fuel costs of running the new energy system at just $500,000 per year based on today’s cost of biomass, the mill will see a payback on the $10.5-million investment in about three years. “The financial benefits were of course one of the main driving factors behind the project, but the environmental benefits were also important to us,” he says. “Our emissions were controlled in the past, but with the new energy system in place, our greenhouse gas emissions have been substantially reduced and we are carbon neutral.”

Biomass power isn’t new to Fraser Papers. As Beaulieu explains, the Plaster Rock mill has been somewhat dependent on biomass boilers for years, and at the Edmundston pulp mill, the company installed a cogeneration plant in 1996 that includes a 600,000-pound/hour biomass boiler and a 46-MW steam turbine. “Here at Plaster Rock, we didn’t install a turbine at this time, but we have left the space and designed the boiler such that we can install a 7.5-MW turbine at a later date,” Beaulieu says. “The timing just wasn’t right for us right now, but we are looking at it for down the road. If it goes ahead, we could sell excess power to the grid.”

Making it Happen
After a careful vendor selection process that included proposals and bids from five companies, Fraser Papers went with London, Ontario-based KMW as the main supplier for the Plaster Rock project. “Our timing was good,” Beaulieu says. “We started the submission process right at the beginning of the recession, and companies were starting to feel the pressure, so there were some good deals out there.”

Initially, Beaulieu says they thought about trying to fit all of the new equipment into the mill’s existing boiler building, but they ended up using that space for a fuel bin and leaving enough floor space in the building for the turbine to be added later. A new building was erected to house the KMW-specified Cleaver Brooks 80,000-pound/hour steam generator (boiler). The energy system runs on mill waste, which is primarily bark from the sawmill’s Cambio and Nicholson debarkers. “Our sawmill will process 18,000 to 19,000 logs/day, and 10 to 12% of each log is bark,” Beaulieu explains. “That gives us about twice as much bark as we actually need for the energy system, so we will send our excess to the Edmundston mill. We don’t need to buy any biomass on the open market or use any biomass from logging operations, so we are essentially self-sufficient in this area.”

The energy process starts in the fuel bin, which can hold up to 350 green tonnes of bark. From the fuel bin, the bark feeds into the KMW combustor, which is an improved Scandinavian design with moveable step grates. The combustor step grates feature three zones, with the first zone designed to condition or dry the fuel, the second to gasify the fuel, and the third to burn leftover carbons. Very limited undergrate air is used, with the bulk of combustion air introduced directly above the gasification zone. Glycol is used to cool down the grates. This heated glycol is then circulated through floor-embedded tubing in the fuel bins to preheat the biomass before combustion, making the entire process more efficient.

The flue gases from the combustion process, which enter the Cleaver Brooks boiler at 1600°F, heat the water to generate steam before exiting the boiler at 500°F. An economizer that was specified by KMW and supplied by Eco Inc from Tulsa, Oklahoma, preheats the boiler feedwater and further reduces the flue gas temperatures to 250°F. The flue gas then goes through a multi-clone dust collector to remove particulate matter before exiting through the stack to the atmosphere.

The steam generated by the process is sent to a pressure reducing station that takes the steam from 100 pounds per square inch (PSI) to 40 PSI, and this is used to heat the mill’s two new MEC kilns, the older existing kilns, and the log conditioning ponds, and also provides heat for the mill buildings. The pressure reducing station and 1,200 feet of steam line that runs from the energy system to the kilns were designed and installed by Design Build Mechanical from Bathurst, New Brunswick.

Safety Measures
KMW specified and supplied several safety measures in the energy system, including temperature sensing equipment and a water spray system at the point where fuel is pushed into the combustor. This is to prevent a fire from burning back into the fuel supply equipment. They also supplied a flue gas recirculation fan to ensure that the maximum temperature of the combustor is not exceeded.

“This is a highly efficient system, and there are some fairly significant environmental benefits,” Beaulieu adds. “Because of our gasification system, we don’t need an electrostatic precipitator to control environmental emissions, which reduces our costs and means the system only produces about 1.5% ash from the biomass combustion.”

Although the new energy system won’t solve all of the mill’s financial woes, it is certainly a big part of the plan aimed at putting this facility back on track to being profitable. It’s also seen as a long-term investment that is helping the employees, suppliers, customers, and supporters of this historical sawmill look forward to the future with a new sense of optimism.

For more on the sawmill upgrade at Plaster Rock, see the Jan/Feb 2010 issue of Canadian Wood Products or visit www.canadianwoodproducts.ca.