Increasing Process and Energy Efficiency at a Plywood Plant
A plywood plant in
Approximately 1,500 feet (547 m) of steam lines carry steam from the boilers at the plywood plant to dryers, which are used the glued wood shavings which make up plywood panels. Heat loses in the steam lines increase the amount of time it takes for plywood panel to be properly dried. Based on the recommendations of the project team, nearly 970 feet (296 m) of steam lines were insulated with 2-inch (5-cm) mineral fiber. In addition, 70 steam traps were replaced with new traps, which in itself resulted in a 10% increase in condensate return. These two steps increased the dryers' operating temperature by 15 °F (8.3 °C).
Insulating the plant's steam lines and replacing old steam traps with new ones reduced steam usage by about 6,000 lbs (2,721 kg) per hour. In addition, the new steam traps increased condensate return by 10%. In total, about 17,000 tons of fuel are saved annually. Total annual energy savings is about 63,000 MMBtus.
The increased efficiency of the steam lines has increased productivity at the plant and has reduced the amount of fule consumed by about 17,000 tons. Based on a fuel cost of $8 (USD) a ton, total savings run about $139,000 (USD) annually. Because of the decreased fuel needs, Georgia Pacific no longer has to buy outside fuel, and in fact now often has a surplus it can sell itself. Total project cost was about $70,000 (USD), resulting in a simple payback of six months.
The reduction in fuel use at the facility resulted in the annual prevention of 34,600,000 lbs (15,694,000 kg) of CO2, 318 lbs (144 kg) of SOx, 293 lbs (133 kg) of NOx, and 23 lbs (10.5 kg) of CO. Emission reductions would have been greater, but more than half of the electricity saved at the facility was generated by hydroelectric plants.
North American Insulation Manufacturers Assoc.
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Rock Wool Manufacturing Inc.