Determination of kappa number reduction in pulp and COD in bleach plant effluents using multiwavelength spectrometry and multivariate calibration.Application: Pulp mills A pulp mill is a manufacturing facility that converts wood chips or other plant fiber source into a thick fiber board which can be shipped to a paper mill for further processing. could adapt this method to on-line monitoring of kappa number The Kappa number is an indication of the lignin content or bleachability of pulp. It measures the amount of bleach required during digestion of a wood pulp (part of the process of paper making) in order to obtain a pulp with agiven degree of whiteness. reduction. We propose a method for the simultaneous determination of kappa number reduction ([DELTA][kappa Kappa Used in regression analysis, Kappa represents the ratio of the dollar price change in the price of an option to a 1% change in the expected price volatility. Notes: Remember, the price of the option increases simultaneously with the volatility. ]) in pulp over a bleaching stage and chemical oxygen demand (COD) in bleach plant effluents, by measuring the organic content in the effluent using multiwavelength spectrometry spectrometry /spec·trom·e·try/ (spek-trom´e-tre) determination of the wavelengths or frequencies of the lines in a spectrum. spec·trom·e·try n. in combination with multivariate The use of multiple variables in a forecasting model. calibration. For studies in the ultraviolate (UV) region, we used a flow system for on-line filtration and sample transport. We used a manual system to obtain measurements in the visible/near infrared (Vis/NIR) region. The agreement between values predicted with the multivariate model and corresponding values using the standard reference method, oil bleached pulp samples was good, with a mean prediction error of 0.24 [kappa] units. Based on the same UV measurements, COD could be readily predicted (relative error = 2.8% to 3.7%). The models based on the Vis/NIR region showed slightly less ability to predict COD, compared to those for the UV region (relative prediction error = 6% to 8%). The proposed method is rapid, easy-to-use, and has good repeatability. Sparen and Danielsson are with AstraZeneca, Tablet Production Sweden, SE-151 85 Sodertalje, Sweden; Renberg is with Eka Chemicals, Bohus, Sweden; Furusjo is with IVL IVL Independent VLAN Learning IVL Individual Validated License IVL Institute for Vibrant Living (Camp Verde, Arizona) IVL Image & Video Library (American Society for Cell Biology; Bethesda, Maryland, USA) Swedish Environmental Research Institute, Stockholm, Sweden; and Hillforth is with Cellchem AB, Stockholm, Sweden; email Danielsson at lars-goran.danielsson@astrazeneca.com. |
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