Energy Use Characterization for TCF and Closed-Cycle Processes at Louisiana-Pacific, Samoa, CA, 2000 Pulping / Process & Product Quality Conference Proceedings

T. Jaegel, N. Keeley, P. Gleadow, D. Bruce--The Samoa operation is unique in North America as it is the only kraft pulp mill to produce bleached pulp without the use of chlorine chemicals on a permanent basis. Samoa is also working to eliminate bleaching effluent through filtrate recycle. An Energy Use Characterization and Conservation study described the energy implications of moving towards closed-cycle totally chlorine free ("TCF") operation. This was conducted with support from the U.S. Department of Energy’s NICE 3 program (National Industrial Competitiveness through Energy, Environment and Economics).

The degree of electrical energy self-sufficiency increased from 90.5% with chlorine based bleaching to 94.7% with TCF operation and is projected to be 93.3% with Full Bleach Recycle (FBR). The degree of thermal energy self-sufficiency decreased from 90.8% with chlorine based bleaching to 86.5% with TCF and is projected to be 86.8% with FBR. The specific steam energy consumption increased from 18.0 GJ/ADt to 21.8 GJ/ADt with TCF and is projected to be 22.0 GJ/ADt with FBR. The specific electrical energy consumption increased from 861 kWh/ADt to 909 kWh/ADt with TCF and is projected to be 919 kWh/ADt with FBR. On a production weighted basis, thermal and electrical energy use at Samoa is higher than new mills, but is comparable with mills of a similar age. The lowest energy consumption per tonne of product for both electrical and steam was for fully chlorine bleached product.