Using Simulation to Identify and Evaluate Operating Cost Savings by Recovering Waste Heat, 2000 Engineering Conference Proceedings

Devin Cole, Dan Farmin, Loren Euhus--Heat recovery opportunities exist in nearly all pulp and paper mills. Recovering this heat back into the process holds the potential to save money by reducing the overall energy demand. Projects to accomplish this generally consist of installing heat exchangers to recover energy from process effluent or other high temperature streams where heat is lost.

Computer simulation provides a means to identify and quantify savings opportunities available in a process. A detailed, first principles simulation of the Ponderay Newsprint Company in Usk, Washington, along with interviews with mill personnel, showed the energy savings opportunities in that mill. Once identified, potential projects were implemented in the simulation. Each proposed heat saving project could be enabled or disabled to show the interactions of different projects.

Finally, additional mill realities were considered, including seasonal variation, equipment layout, and vendor heat exchanger design data. After final feedback from operations, these results were integrated and the analysis re-run. A detailed capital proposal was created for the project combination with the most energy recovery and best payback period.