University of Minnesota
Minnesota Technical Assistance Program
http://www.mntap.umn.edu
612.624.1300

Energy Efficiency in Pulp & Paper Mills

While only a little more than 20% of the total energy demand of pulp and paper facilities is electricity, there are still changes and upgrades that can be made to save electrical energy. Conducting assessments of motors and pumps, fans, and compressed air systems can help you identify areas where efficiency can be increased. For example, replacing pneumatic conveyors with belt conveyors can be successful in reducing electrical use by almost 1%. Additionally, identifying and replacing pumps that are oversized, have worn impellers, or operate while upstream valves are closed or only partially open can save energy and money. Lastly, motors that have been rewound more than once also hamper the return of electricity in phase.

A longer term strategy for generating electricity on-site is to install combined heat and power (CHP) systems at your facility. These CHP systems can potentially use available steam at high pressure to generate electricity. Integrated systems can also use paper sludge and other biomass as the natural gas material to feed the boiler, heating the dewatered extract from the paper waste, and depressurizing the steam through a turbine. Pulp and paper mills are typically ideal for a CHP system, since the facility is generally equipped with the infrastructure and the thermal demand is a daily constant.

Lighting and HVAC changes also serve as potential for electrical energy savings.

Resources

  • MnTAP Intern Summary: Boise Cascade (2007). The facility worked with a MnTAP intern to increase energy efficiency and reduce water by improving the compressed air system, insulating steam lines, and replacing spray nozzles.
  • MnTAP Intern Summary: Rock-Tenn Company (2004). The paper mill insulated steam and condensate lines and saved over $170,000 annually by reducing energy use.
  • Case Study: Blue Heron Paper Company (2004). This mill in Oregon uses model-based energy assessment to identify energy and cost savings opportunities. [PDF 393KB]
  • Case Study: Appleton Papers (2002). A plant-wide energy survey resulted in twenty-one recommendations for projects to reduce energy consumption and waste production and improve process efficiency. [PDF 220KB]
  • Case Study: Daishowa America (2002). By installing adjustable speed drives on just two effluent pumps allowed the company to save $42,000 annually. [PDF 207KB]
  • Case Study: Boise Cascade Mill Energy Assessment (2000). An integrated effluent heat reduction and water conservation study was performed at the plant in International Falls, Minnesota. The implementation of four projects and two process modifications are projected to remove 45.6 MM Btu/hr from the effluent. [PDF 324KB]

 

Like our content and want to share it with others? Please see our reprint policy.