Federal Paper Board Company, Inc Augusta Operations Highway 56 South P. 0. Box 1425 Augusta, GA

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1 ps 6- GEORGA TECH RESEARCH NSTTUTE ENVRONMENTAL SCENCE AND TECHNOLOGY LABORATORY POLLUTON PREVENTON PROJECT m / Company: Contact: Primary Products: Federal Paper Board Company, nc Augusta Operations Highway 56 South P. 0. Box 1425 Augusta, GA Mr. Jeremy J. Pearson, P.E. Senior Enviromental Engineer Heavy Stock Paper Process Description The Federal Paper Board Company at Augusta produces a nominal tons per day (TPD) of bleached coated paperboard converted from kraft process wood pulp. The mill was purchased by Federal in 1985 (from Continental Forest ndustries) and various plant renovations and additions have been made since that time to improve plant efficiency, reduce environmental impacts, and increase production capacity. All pulp is produced in three Kamyr continuous digesters, the oldest of which is presently on stand-by status. Bleaching is accomplished with two older 4-stage [(CD) Eo H D] plants and a new 3-stage [(CD)(Eo)(D)] plant. One of the older bleach plants has been put on standby and the other will be converted into a [(CD) (E,) D N D] sequence. The elimination of hypochlorite and high C10, substitution should significantly reduce chloroform and dioxin formation during the bleaching process. / Other plant changes planned for completion by 1994 include the addition of a fourth paperboard mill and a new lime kiln which will bring mill capacity to about TPD. At that time, employment at the mill is expected to reach over 1000 persons. The wastewater generated from this process and from the Augusta Newsprint Company goes to three parallel primary wastewater clarifiers. The clarified water is then sent to two fiber traps which are 7.5 acres each. After which the wastewater is directed to a series of six treatment FOB&, the first three of which are aerated and the last three are nonaerated. The water is then routed to the Savannah River. Sludge from the three clarifiers is pumped to three parallel screw presses. The dewatered sludge is then landfilled onsite. 0-1

2 Federal Paper Board Company, nc. Project Scope Federal Paper Board generates approximately 150 dry tons/day of sludge from their water treatment plant clarifier. The sludge is dewatered in three parallel screw presses which i increase the solids content to 30%. They are currently di3posing the dewatered sludge in an onsite landfill. The Federal Paper Board landfill is now near capacity. Plant personnel have expressed an interest in burning the clarifier sludge in its power boilers for energy i recovery. A major factor in burning this sludge for energ3 as it comes out of the sludge. press is its moisture content. The higher the moisture content, the lower the BTU-value of the material. GTR has examined the kinetics of outdoor sludge moisture loss and i evaluated the alternative methods to increase solids content. Analyses Results and Discussion A study was performed by Simons-Eastern Consultants, nc. to investigate the feasibility of burning sludge at moisture levels of 55% or less. Simons has recommended expanding th e existing dewatering capabilities to decrease the moisture level to 55% and conveying the dewatered sludge to a metering bin and then to a boiler feed. Federal Paper Board is planning to perform a trial burn of their sludge at 45% solids with a mix of 20% sludge (80% bark) and 28% sludge (72% bark). The study will be performed using two of their three boilers. A comprehensive plan has been developed to monitor the feed fuel, operating parameters of the boilers, and input sludge parameters (including moisture, BTU-value, carbon, nitrogen, sodium, hydrogen, oxygen, sulfur, and chloride). The 1 resulting ash will also be analyzed for several hazardous and TCLP constituents. The trial bum will prove to be very informative in terms of boiler performance and generation of ses at the two sludge feed rates. P $ 1 // nt that the trial bum proves inefficient at 45% solids content, a study was performed to investigate the drying kinetics of Federal Paper Board s water treatment sludge and to support possible implementation of drying systems. A large sample of sludge was obtained from Federal Paper Board. Transportation by conveyor was simulated by distributing the sludge on a cardboard pad at approximately 2.5 to 3 inches thick. Samples were taken at 0, and after air-drying for 2,4, 6, and 25 hours and were analyzed for BTUvalue, moisture content and ash content. BTU-values were also determined on three 100% solids samples. The weather condition at the time was 80 to 85 deg C, 75% humidity and clear skies. See Table 1 for data and Figure 1 for a plot of BTU-value versus Moisture content. 0-2

3 Federal Paper Board Company, nc. Table 0-1 Moisture, Ash, BTU-value Data b Sample Number Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Dry Drying Time 0 hours 2 hours (a.m.) 4 hours (a.m.,p.n) 6 hours (a.m.,p.m.) 25 hours n/a Number of Moisture Ash Analvseq Content Content n/a , n/a 3 0 n/a BTU-value 2,685 3,817 4,574 6,173 7,057 8,662 Figure 0-1 Solids Content vs. BTU-value Linear Plot BTUAb io io b Solids Content (% Dry Solids) Linear Curve Fit Rx) = E+l*x R squared =

4 Federal Paper Board Company, nc. f the sludge is spread to a depth of 2.5 to AO inches, soligs content of 40% can be achieved at approximately four hours, whereas at 6 hours the solids content jumps to approximately b 70% solids. Four to six hours of drying time, under ideal outdoor conditions, would result in moisture content and BTU-values which are adequate for burning in Federal Paper Board s boiler. Ambient drying times are probably too long for practical application considering the transport time of the sludge from the press to the boiler and less than ideal weather conditions. Therefore support drying systems to aid the drying of the sludge have been identified and are presented below. Recommendations The following are some system alternatives to drying sludge beyond the 45% dry solids content level. Sludge Drvers There are several alternatives which will bring moisture content down to less than 45% dry solids. Thermal drying is a process which can raise solids content up to 85% to 90%. Drying can be accomplished using both thermal and mechanical systems. n some drying Drocesses the thermal gases transfer the heat by direct contact to the sludge. Several of hese direct dryer systems are listed below: Belt Dryers Multiple Hearth Dryers Drum Dryers Fluidized Bed Dryers Flow Dryers Grinding Dryers n indirect drying technology, thermal energy is transferred to the sludge using a heating surface and an intermediate heat transfer medium (such as steam, hot water, or thermal oil). Several indirect dryers are listed below: Screw Dryers Disk Dryers Thin Film Dryers Kneading Dryers Thermal drying systems are expensive in terms of capital and operational costs and would probably exceed Federal Paper Board s drying needs. However, if the trial run proves that 0-4

5 Federal Paper Board Company, nc. greater sludge solids content is necessary, thermal dryers or other alternative drying systems would probably be Federal Paper Board's only alternative. P See the Appendix for companies which supply drying systems. Solar Panels n most cases solids content at 85% to 90% is not necessary, however solids content above 45% is necessary for adequate boiler operation efficiency. Solar panels directed at the sludge along the conveyor (from the sludge press to the boiler) would assist in drying the sludge to the 60% to 70% solids content level by providing additional thermal energy to the sludge and increase moisture loss. Solar panels require little operating and maintenance cost and can provide the additional drying required by the boilers. t! Alternatively, solar energy can also be used as a power source in conjunction with a thermal heating device to aid in sludge drying. See the Appendix and Bibliography for companies and facilities which provide and utilize these systems. nfra-red nfra-red elements. which are run on local power, can be used along a portion of the conveying system to further dry dewatered sludge. This type of system uses infrared energy directed at the material for drying purposes. The capital costs of such a system would be moderate, however the power, operational, and maintenance costs may be prohibiting. Although solar energy as a power source can also be used for this system. See the Appendix for a company which supplies this type of system. Outdoor Storage By storing sludge in the open air for 24 to 48 hours, the sludge canpaturally dry to 60% to 70% solids content. An auger could be used to aid in drying the sludge thoroughly. Following 24 to 48 hours, the sludge can be transferred to the boiler using a front-end loader. See the bibliography for facilities involved with this type of application. 0-5

6 ', Federal Paper Board Company, nc. Project Appendix The following are companies which supply sludge dryers or potential sludge drying equipment. Sludge Dryers b, ),', MEC Company The Dupps Company P. 0. Box 330 Department M 1 1 Neodesha, Kansas Germantown, Ohio : Richard Chaney (513) (316) Envirex Corporation Stord, nc. Milwuakee, Wisconsin 309 Regional Road South Jim Methurst Greensboro, North Carolina (414) Bruce Low (919) c nfra-red Application Casso-Solar Corporation P.O. BOX 163-A US Route 202 Pomona, New York (914) ! Solar Applications ndustrial Solar Technology Siemens Solar ndustries 1 Denver, Colorado 4650 Adohr Lane Randy Gee Camarillo, California (303) (805)

7 1' Federal Paper Board Company, nc. 1 i".b Bibliography "A State Demonstration Program in Wood Energy", Georgia nstitute of Technology, Engineering Experiment Station, Volume V1 Project A "Paper Mill Sludge as a Valuable Fuel", TapDi Journal, December 1989, pp "Drying of Sewage Sludge - An mportant Step in Waste Disposal", Water Science and Technolom, December 1990, pp "Dewatering of Sludge by Natural Methods", w, 1! March/April 1990, pp "mproved Efficiency of Sewage Sludge ncineration by Preceding Sludge Drying", Water Science and Technoloiq, December, 1990, pp "Solar Energy For Sludge Drying in Alexandria Metropolitan Area: Case Study in Egypt", Water Science and Technolow, December, 1990, pp

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