Environmental benefits of innovative EPA program at Georgia fluff pulp mill include improved water quality parameters and energy conservation

Weyerhaeuser’s Oglethorpe Pulp Mill Benefits from Project XL Involvement

A thorough investigation of the program led Weyerhaeuser to choose its Flint River operations in Oglethorpe, Ga., to be one of the first participants in the program in January 1997. The mill produces 320,000 mtons of bleached softwood kraft fluff market pulp annually.

As of May 2000, there were 21 XL projects in the implementation phase and many more under development. A review of Project XL strategies and Weyerhaeuser’s environmental goals for its Flint River operations was summarized in the August 1998 issue of Pulp & Paper. This article reviews specific environmental progress made to date at the Oglethorpe mill and the challenges that the mill still faces through 2006.

Weyerhaeuser's Oglethorpe, Ga., mill produces 320,000 mton of bleached softwood kraft market fluff pulp annually.

Environmental performance update. One of the primary objectives of the final project agreement (FPA) for Weyerhaeuser’s Project XL participation was to delineate the level of superior environmental performance that the Flint River mill would achieve under its MIM evolution strategy. Under Phase IV of the MIM strategy (Table 1), Weyerhaeuser implemented several process technology improvements, including Isothermal cooking as part of its brownside optimization, an odor control system upgrade and energy steam reductions. All of these improvements were completed before 1999.

Commenting on the biggest Project XL program successes to date, Anna M. Skrobecki, Vice President and Mill Manager says, “Early in the agreement we completed the Isothermal cooking and odor control system upgrade projects. These gave us very measurable results in the reduction of BOD, AOX, and effluent color. The amount of solid waste going to our landfill was also reduced with the added ability to recycle knots and undercooked wood chips and put them back into the process. Although the mill generally has few complaints, odor was reduced because of improvements to the total reduced sulfur (TRS) and low-volume high-concentration (LVHC) systems. These improvements also positioned the plant well for the Cluster Rule, which was not fully defined at that time.”

Skrobecki adds, “The Timberlands Resource Strategies project (a Phase V goal implemented in 1997) provided a documented environmental management system to effectively manage more than 340,000 acres of forestland, providing streamside buffers, habitat for threatened and endangered species, reduced soil erosion, and many more benefits. More recently, the hazardous air pollutant (HAP) emission reduction project has led the Flint River Plant to purposefully make a change to the process in order to increase foul condensate collection and destroy 83% more methanol than guidelines set by the Cluster Rule.”

The only Phase IV project not yet completed is its implementation of an ISO 14001 environmental management system (EMS). The project requires a great deal of effort for environmental resources to document the significant environmental aspects and the supporting management structure to conform to the international standard. The EPA is evaluating options that will lead to development of an agency policy on EMSs. The Weyerhaeuser XL project will provide data on the compliance and environmental benefits of an EMS approach.

Only moderate progress was made towards this goal in 1999. Several significant environmental aspects were documented with about 25 others remaining to be completed. Most of the supporting documentation and structure for ISO 14001 already exists or needs only minor updating with the plant’s ISO 9002 quality system. This project is expected to be completed by the end of 2000.

FIGURE 1: Continued emphasis on energy conservation has resulted in significant reductions in steam usage.

Phase V progress. During 1999, feasibility studies for a number of Phase V objectives were continued, including solid waste reductions, HAP emission reductions, water use reduction, bleach plant effluent reductions, and energy conservation. Tables 2 and 3 present selected environmental performance data for water, air and solid waste emissions.

Solid waste generation was up slightly in 1999 due to continuing calciner operating and mechanical issues and in increase in wastewater primary clarifier sludge. However, improvements were made with a reduction of 126 tons of screening room knots and 630 tons of power boiler flyash. In addition, woodyard “sticks” from the debarking drum are now being recovered back to the fiberline via the log flume.

Efforts are being focused on reducing lime mud by continuing the calciner throughput and reliability study, reducing fiber losses from the pulping process and reducing power boiler flyash by performing a thermal efficiency study and installing advanced process controls on the boiler. A review of data confirmed that the Flint River mill is collecting and destroying more HAPs through its current noncondensable gases (NCG) collection systems than is required by the Cluster Rule. The collection system includes most of the vents required by the Cluster Rule and several additional vents that are not required. As a result of the superior performance of the Flint River system, the few vents specified under the maximum achievable control technology (MACT) rule not collected would not be required to be added to the NCG system.

TABLE 1:Current and recent goals of Weyerhaeuser's Project XL program at Oglethorpe.

As a result of piping changes made following extensive testing, the condensate collection system is treating 83% more methanol than what is required by the Cluster Rule in biological treatment alone. This does not take into account the recycle of condensate back to the process or the destruction of HAPs in the NCG gases in the boilers. It is not clear if Weyerhaeuser may receive any additional flexibility in this area where it has achieved outstanding environmental performance.

TABLE 2: Flint River key environmental data parameters.

Reductions in total water use have not met performance targets, as shown in Table 3. The first goal in the XL agreement was to lower the surface water permit monthly average daily usage by 1 million gpd. The new permit levels would then be 11.5 million gpd.

During the first six months of 1999, the mill had an unusually high number of operating problems. During such periods, the mill uses more water. In addition, some quality issues drove the operation to increase water use while making a high brightness product for a specific customer. However, during the second half of 1999, plant water use was below the 11.5 million gpd limit.

Typically, short-term operational problems are not expected to have a major impact on environmental performance goals. Gary Strandburg, plant risk manager, notes, “For the most part, our progress toward achieving Project XL goals are measured in a six-month or a yearly snapshot. Therefore, operational problems of a short duration do not significantly change our results. However, if operational problems continue over a longer period of time, our results could be affected.”

Biological oxygen demand (BOD), total suspended solids (TSS), and adsorbable organic halides (AOX) have remained below the new tighter permit levels that were established in 1997 (Table 2). Solid waste generation was a little higher in 1999 compared with 1998, but the mill has achieved nearly half of the Phase V goal of 310 lb/mton. Hazardous waste generation remains at a very low level, maintaining the plant status as a conditionally exempt small quantity generator.

Bleach plant effluent flow has remained constant at 20 m³/mton. However, the Phase V goal is to reduce this in half to 10 m³/mton. The feasibility study as outlined in the FPA was done to determine the equipment required, effects on product quality and effluent, and estimated capital costs. Based on that study, the current path forward is not technically and economically feasible. Weyerhaeuser has technical resources searching for research and development work from within the industry that may uncover new opportunities to reduce bleach plant effluent.

Skrobecki comments, “The biggest challenge to date is the project that will deliver a 50% reduction in bleach plant effluent flow. We remain committed to continue to look for creative paths to achieve this challenging goal. New technology may be required to reduce this flow.”

TABLE 3: Flint River baseline performance and Phase IV goals to be included in enforceable permits.

Looking ahead. Weyerhaeuser does not anticipate that new technology will be required to meet other goals within the Project XL agreement.

According to Skrobecki, “For example, energy consumption has been reduced by a series of non-capital projects that lowered the steaming rate of the power boiler. Additionally, water usage is trending downward, due to increased employee awareness of the goal and a continuing search for opportunities to make process changes, with both capital and non-capital funding.”

“Future challenges include determining the path to take in reducing solid waste to the landfill by 50% and maintaining employee awareness and attention to recognize conservation of water.,” she adds. “Composting trials have proven that a desirable product can be made from several solid waste streams in the plant. A joint venture to compost plant materials is being investigated. To fully achieve one of the XL goals, the calciner must improve in reliability or a lime kiln must replace the calciner.”.

One key to continued progress and success in the XL program is maintaining enthusiasm and commitment to the improved environmental performance of the Oglethorpe operations and subsequent benefits to the community.

“Weyerhaeuser people at the senior management level and the mill operations continue to be enthusiastic about Project XL,” Skrobecki says. Local residents are interested in our progress, attend the annual public meeting and are proud that one of their local industries is involved in the national program. We continue to make progress, learning our way through the challenges that were not apparent in early 1997. Goals have been met, many of them early in the project. The few exceptions are on track for completion but may take more time to achieve, since we want to ensure they are solidly integrated projects that meet the intent of Project XL.

For other mills that may consider participating in Project XL, Skrobecki advises, “Start early in discussing your ideas with the potential participants—the stakeholders and regulators—in a project. It takes time to build the mutual understanding that a project will need to be successful. Also, have a clear business plan linked with the project goals. The resulting focus on objectives allows new opportunities to be incorporated in the most effective way. Finally, since XL’s implementation phase is long term and personnel involved with the project may transition into new roles, it is also important for the mill to stay calibrated with project participants to ensure continuity of the project.”

To learn more about Project XL, visit www.epa.gov/ProjectXL/