FPInnovations has completed another successful Near-Neutral Brightening (NNB) technology application at a kraft mill in Pennsylvania. This latest implementation marks the sixth application of FPInnovations' patented bleaching process in pulp and paper mills across North America.
FPInnovations scientists recently returned from a Domtar mill in Johnsonburg, Pennsylvania, where the NNB technology was newly implemented, and is continuing to improve bleach-plant operations using the FPInnovations control process. The NNB trial results demonstrated that the historical brightness loss has been eliminated in the HD tower and savings of chlorine dioxide was realized, while maintaining the target final pulp brightness. "We are very pleased with the technology and it has resulted in substantial savings in bleach chemical costs in addition to reducing the use of caustic at our mill," said Bill Hoh, Fiberline Superintendent at Domtar.
The proprietary technology maximizes the efficiency of chlorine dioxide bleaching by reducing its use, decreasing the variability of final brightness, eliminating the need for antichlor, and requires low capital investment to implement. The proprietary treatment of brightening pulp was developed by FPInnovations scientists. They demonstrated that generating sodium bicarbonate in situ by adding carbon dioxide to alkaline pulp, or sodium carbonate to acidic pulp, to maintain a pH close to neutral throughout the final chlorine dioxide brightening stage, is the ideal strategy for economically obtaining high brightness.
"NNB technology improves substantially the bleach-plant efficiency and stability," said FPInnovations Lead Scientist, Theodore Radiotis. "That makes the mills more competitive in a global market." NNB technology can be used on hardwood, softwood, and sawdust kraft pulp and is applicable to 3-, 4-, and 5- stage bleaching. With this technology, the demand for chlorine dioxide can be reduced up to 10lb/ST (5 kg/MT).
Michael Subilia, Process Engineer and Continuous Improvement Lead at Domtar, will present the successful implementation case at the upcoming Pulping, Engineering, Environmental, Recycling, and Sustainability (PEERS) Conference in Portland, Oregon, from October 28 to 31, 2018. Co-authors of the Domtar NNB research paper, Radiotis and FPInnovations Researcher, Chung-li Lee, will also attend.