Benchmarking and Modeling of a Closed-Loop Pilot System, 2002 Fall Technical Conference

Computer modeling and tracer studies are useful tools for benchmarking and characterizing closed-loop paper recycling systems. Mills can benefit from these tools by using them to investigate and solve problems related to contaminant removal/cycle-up of contaminants, yield loss, brightness reversion, and holding times. Forest Products Laboratory (FPL) is using these tools specifically to examine contaminant cycle-up time and arrival to steady state concentration in their closed-loop recycling pilot plant.

Closed-loop recycling system has been modeled using a general mass balance modeling program. Following model development, pilot plant trials were conducted using a tracer species to test the model. The goal of these trials is to monitor the tracer concentration in clarified process water and compare trial results with model predictions. This paper will introduce the methods employed, present data and results, and provide specific examples of how mills can use these tools for their benefit.